WB4GBI

Exciting news for 146.73!!

2009-11-07T08:06:00.001-08:00

EXCITING NEWS FOR 146.73!

I’m sure many of you know that I have been struggling with 146.73. I purchased the repeater from Sam (WB4HAP)’s widow, Debbie, and after rebuilding it around a GE Mastr II unit, I took it back to its long-time home on English Mountain. However, its performance has not been great. The antenna was installed just above the 10 or 15 foot level on the tower, as that was the only space available. However, I have been working with the tower owner (I rent space on the tower) and he has graciously allowed me to relocate the repeater antenna to the 130 foot level on the tower! I am purchasing a new Decibel Products DB-222 antenna for .73, and I will be installing 7/8 inch heliax to connect it back to the repeater. This should significantly improve .73’s footprint over East Tennessee. I will let everyone know when work is completed. THANK YOU for your interest and support!

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

146.94 is 42 years young!

2009-10-29T21:23:00.001-07:00

146.94 is 42 YEARS YOUNG!!

Hello, everyone! It’s been a while since my last “blog.” I hope everyone is enjoying the new 146.94 antenna. Speaking of .94, I have been on a bit of a mission lately to find out exactly when .94 went on the air. For those of you who are recent additions to our great hobby, you might not know that the 146.94 repeater was the very first two meter repeater in East Tennessee. Its history is that of great and continuous service. I am VERY proud to be carrying on the tradition started by George, K4HXD, who was the creator and founder of this repeater. We lost George in 1992. He was of my mentors. Please read the article about K4HXD on my website if you haven’t already.

Lately, I have been attempting to learn more about .94’s history, which started before I received my license in 1973. Thanks to conversations with great hams like Gene (W4UVR), Charles aka “Digger” (WA4QGX), Jerry (N4SH), Lee (WA4QXC), Bill (WB4YPO), Jim (WA4HQP), Bob (W4ZTV), and others, I am starting to piece together some of the history of this great repeater that I am now proud to own and operate. As of today, I have been able to determine with some accuracy that 146.94 is 42 years young this year. The repeater started out in George’s basement in Maryville, Tennessee, before it went to its long-time home atop Chilhowee Mountain near Walland. I am told that in 1967, Ed (ex WA4GKN, now WF4H), moved to Knoxville from Nashville, and was one of the first users of .94 from his RCA tube-type dynamotor mobile as he came into the area. Note that this commercial radio, state-of-the-art in its day, was capable of only ONE channel. Look how far we have come in just a few short years!!

I hope to be finding out more about .94’s storied history, and I will be adding a few details to its service record before 1985, when I was able to take over for George as .94’s owner and caretaker. I can readily share about the post 1985 years, including a story about how my then-girlfriend, who knew very little about what she was getting into, helped me pay for the repeater. I guess that’s why I might have married her…J

If you or anyone you know can share anything about .94’s early years, PLEASE contact me. I would love to include your information about .94’s history as I share it with everyone.

What’s going on elsewhere? I’m sure you have noticed some of the problems that I have been having with 146.73. Something has been “mixing” with the repeater transmitter’s signal and appearing as a signal in the receiver input. The result is a nasty “squealing” sound similar to what happened on 145.47 when I was experiencing the problem with the high-powered UHF TV station. I hope to travel to English Mountain next week to at least install a 118.8 Hz tone board on the repeater receiver, again similar to that of 145.47. I chose 118.8 as it is an SERA- recommended tone for East Tennessee. Please note that this is NOT a permanent solution. I will be attempting to find the source of the problem and removing its capability to “mix.” This could be as easy as finding a transmitter on the mountain that has gone astray, or it could be as expensive as adding a $600 isolator to .73’s transmitter. It’s almost a two-hour trip to English Mountain, as I am a renter on a site and I must go to the office of my “landlord” and get the keys before I can access the site. I am VERY fortunate to have .73 on the site that it calls home, and these are the rules I must abide by. I am also working toward improving the antenna situation on .73, as it is low to the ground at this time. Stay tuned and please be patient as I attempt to get .73 back to the service it provided when Sam (WB4HAP, SK) and Matt (WB4IOB) placed it on the air around 1973. And if you know anything about .73’s history, I would love to hear from you as well! I do remember the great .73 picnics!

THANK YOU for reading. If you like what you see, please tell others. If you have a comment or even a complaint, please tell me. I can be reached via the email link on the website…www.wb4gbi.com.

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

2009-09-18T13:47:00.000-07:00

Sent from my iPod

ITS ON THE AIR!

2009-08-27T20:16:00.001-07:00

IT’S ON THE AIR!!

This afternoon, shortly after 12 noon, the new 146.94 repeater antenna was installed! Initial reports show a MAJOR improvement in .94’s signal strength and receiving capability! From a mobile in Cleveland to a mobile in Church Hill, all reports indicate that 146.94 is back at full strength. It’s about time, huh? J

THANK YOU to all who helped…especially to those who contributed to the WB4GBI repeater fund. Thanks also to those who helped check the coverage this afternoon, and to Kevin, W4KEV, who helped me with checking and retuning the duplexer earlier this summer and helping me find the problem with the antenna.

If you get a chance, check the website (www.wb4gbi.com) and look at the pictures of the antenna installation. It’s not easy getting a 20 foot antenna up to its 250 foot above-ground home on the tower! Kerry Klimecki of Tower Services did his usual great job. I have used Kerry’s company for over 15 years for my tower needs.

So, for all of the nets… SKYWARN, METERS, SCRES, Blount County ARES, the Breakfast club, the Sunday Evening APRS net, and for the hams who just enjoy using the 146.94 repeater…it’s back!!

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

IT'S HERE!!!

2009-08-21T17:35:00.001-07:00

IT’S HERE!!!

After almost eight weeks of waiting, the NEW 146.94 antenna is finally here! It arrived at my place of work yesterday. Today, Kevin (W4KEV), Todd (KA4OAK), and I unpacked and inspected it. There are a couple of things that I will do to it to help weatherproof it, but I will be contacting the tower climber that I use for my employer’s work, post haste, and arranging its installation! Hang on…the long wait is almost over!

A couple of other things: You may have noticed the 146.73 repeater has been off the air more than it has been on. Unfortunately, it has been plagued with some kind of interference that is causing it to lock up and pass noise. My immediate plan is to install a tone board on the receiver. The tone will be 118.8 Hz, the same as used on my other repeaters when needed. I will then be attempting to locate the cause of the “mix” that is plaguing the repeater. I have some great plans for .73, but I can’t discuss them just yet. Stay tuned, as I try to get .73 back to its high standard of performance that was enjoyed by all when Sam (WB4HAP, now SK) had this heritage repeater on the air in recent years.

Also, I am THRILLED to announce that 145.47 has been selected to be the primary SKYWARN repeater for the district 6 area as defined by the National Weather Service. If you are using .47 and someone breaks in and advises you that the repeater is needed for SKYWARN, please allow them to start their nets as it means sever weather is eminent. SKYWARN is a prime example of how we as amateurs can use our hobby to provide vital communications to agencies that need our services. If you are not trained to be a SKYWARN weather observer, check out the upcoming training classes so you can help out with this important service.

THANK YOU all for reading my blog, and I look forward to hearing each of you on the air on one of my repeaters soon!

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

Antenna UPDATE!

2009-07-30T10:54:00.001-07:00

ANTENNA UPDATE!

As I am sure you already know, I have been (impatiently) waiting for the new .94 antenna to arrive. I made a phone call this morning to the manufacturer and found out it should ship by the end of this week. Now, I am not “holding my breath,” as I have already heard this once before. The antenna has been tested on an actual test range, similar to the way radio and TV broadcast antennas are tested. I do appreciate that, as most land mobile antennas are built en masse, and probably don’t get tested individually. I just wish the process would speed up!

Now, on a separate note, I need to pass along a request to those of you who read the blog, and hopefully it will get out to others as well. I am very aware that someone has been interfering with one or more of my repeaters. It tends to happen when people are on the air and enjoying a normal QSO. I want to ask those of you who may be involved in a QSO when this deliberate QRM’ing starts to do a couple of things:

1) DO NOT MENTION IT ON THE AIR. DON’T acknowledge that the person is causing interference. If you can still hear the person whom you are in QSO with, then PLEASE carry on the conversation as though nothing is happening. I know that it is likely that you will not be able to hear the person you are chatting with, depending on how successful the jammer is in his efforts. In that case, either sign off, or move to another repeater…and make it one that you may have previously agreed to…because if you mention which machine you plan on switching to, the jammers will simply follow you.

2) LISTEN ON THE REPEATER INPUT to see if you hear the interfering signal at your location. Let me or someone else know if you do hear the signal and how strong it is at your location. If you have the means to determine which direction it is coming from, that would be especially helpful.

Once we determine where the offending signal is coming from, I can ASSURE you that the offending person or persons will be prosecuted to the fullest extent of the law. If they are a licensed amateur, they will be banned from ALL of my repeaters. And yes, that is enforceable. However, in the meantime, the more we acknowledge them, directly or indirectly, the more we feed their “jollies,” and they will continue to cause interference. I know its hard not to do so, but PLEASE do not engage them in any way. If you have to, sign off, or move to another frequency. It’s better to do this than to engage in a “whizzing contest” with them on the air.

I’m sorry to have to devote a blog entry to this, but the problem is growing, and it is only going to get worse if we don’t stop letting these people know that they are getting to us.

As soon as I have more information on the .94 antenna, I will post it here. I am also working on some other good things for 146.73 and 53.15. Stay tuned!!

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1 WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

ITS ON ITS WAY!

2009-06-24T21:35:00.001-07:00

The new 146.94 repeater antenna is on its way!!

I am thrilled to report that I have ordered the new repeater antenna for the 146.940 repeater. I’m not sure as to exact arrival date just yet, as they are made to order. How cool is that? I can tell you it will be a four element open dipole design, very similar to the antenna that is up there now. I will keep everyone posted here as progress is made toward its installation.

I want to say a HUGE “THANK YOU” to the METERS group (of which I am proud to be a member) for their recent contributions to the “repeater fund.” I didn’t have any idea that they were even considering this action until I received the email in which they had already voted to do so. To say I am overwhelmed at the outpouring of support would be an understatement. Thanks to them, the antenna installation at the 146.94 site is paid.

Have you noticed how quiet the 145.47 repeater is lately? No, I don’t mean activity…it has plenty of that! I mean the lack of the howling interference that was the result of the interference “mix” from the adjacent TV station. I am planning a trip to re-install the receiver preamp now that it’s possible to have it online again!

Lastly, I’m sure that most of you are already aware of the situation involving the WA4BVW repeaters in North Carolina. I have met Ken several years ago and admire what he has done for VHF repeater users in his area. His 145.190 repeater has to be the widest area coverage repeater in service in the Eastern US. I am very pleased that the powers-that-be have agreed to allow him to keep this valuable resource to Amateur radio at its present site for at least another year. I am VERY fortunate that my employer humors my hobby and allows me to keep my repeaters at their tower sites. I also know that from the sites I don’t own or control that I am just one bad impression away from losing site location privileges at those sites. Let us all remember to be mindful of who is listening when we are on the air. Leave the scanner listener or non-ham with a good and favorable impression of our hobby and its vast capabilities. The next repeater site to be lost could hit much closer to home.

I hope everyone plans to participate in Field Day at some point this weekend! And please keep the SCERS (Sevier County Emergency Radio Service) group in your thoughts…they had to abruptly cancel their field day due to some bad circumstances beyond their control.

I’ll see you on the air! And on an improved 146.94 repeater soon!

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1 WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

It's official.. (repost)

2009-05-27T19:12:00.000-07:00

Let’s try this again with a smaller font that doesn’t run together. Sorry! 73 de Tim WB4GBI

It’s official…

The 146.94 repeater needs a new antenna. Kevin, W4KEV, and I visited the 146.94 site on Memorial Day Monday. Kevin fine-tuned the duplexer to near perfection. It will duplex perfectly on a 50 Ohm load, but still would not do so on the repeater antenna. Upon closer inspection with binoculars, you can see that one of the dipole elements on the DB-224 antenna is obviously damaged. The other elements may be damaged as well, but if so they are not visible from the ground. However, with this type of antenna, one damaged element is all it takes. I’m sure this is the reason for the noisy signals and “desense” that has plagued .94 for the past several weeks.

So now what? It is possible to replace the one obvious defective element. However, please bear in mind that any trip up the tower by a bonded tower climber is going to be expensive. What if the repeater antenna has more damage, and we don’t find it out until after he has made one trip up the tower, only to have to make another? This would make it even more expensive, and .94 would still not perform as it has in the past. In addition, the repeater antenna is over 10 years old. I’m not sure of its exact age, as I brought it from another site when I installed .94 at the WIVK site in 1998. That’s at least 10 years exposure to some very nasty weather atop a 3000 ft mountain. Remember when the weather guys say things like…”more snow and ice in the higher elevations…?” Well, .94 lives at a higher elevation. I want to do something for .94 that will last a long time and justify the total expense that will be necessary.

So, it’s time to replace the antenna. Too many nets and emergency communications groups depend on .94. I will be saving sheckels and attempting to purchase an antenna in the very near future. I will have to shelve some of the other repeater’s needs that I had planned on for a while. But I consider this a high priority. I hope to have .94 restored to its original high performance standard soon.

On a related note, I also spent Sunday afternoon at the 145.17 site. I have determined that its’ interference issue is NOT the paging transmitters on site, but rather something external to the site. I hate to say this, but it acts a lot like the TV station interference I am receiving on .47 and that Todd has been plagued with on his 147.36 and 145.13. I do know that 145.17 works great on a dummy load, so that rules out a problem internal to the repeater. There are several of us repeater owners that can’t wait to see what happens on June 13^th!! That’s the day after the DTV transition, and the problematic 5 MW UHF transmitter will be in retirement. It’s also the day of the Knoxville Hamfest!! I hope to see you there!

I spent some time Saturday at the 147.075 site. It was just a checkup. I sure know how to have a holiday weekend, don’t I? J

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1 WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1 WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

It's official...

2009-05-27T07:00:00.001-07:00

It’s official…

I spent some time Saturday at the 147.075 site. It was just a checkup. I sure know how to have a holiday weekend, don’t I? J

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1 WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

2009-05-18T09:08:00.000-07:00

HEY! Why is 146.94 so noisy!

I’m re-posting this one, with a little easier to read font, hopefully…

Happy Monday, everyone! If you are a regular 146.94 user, or of you catch one of the many nets called on my 146.94 repeater, you may have noticed it is a little “noisy, “ or that portables and some mobile have trouble getting in to the repeater. It’s not the fault of the noisy stations. Here’s what’s happening:

The basic function of a repeater is to be able to receive and transmit signals at the same time without degradation. One of the performance functions that repeater operators check is that of receiver desensitization, or “desense” as we call it. “Desense” happens when the repeater transmitter masks the input sensitivity of the repeater receiver. This can be caused either directly or indirecty, but it is usually a direct effect. Most repeaters employ a duplexer to allow the repeater to function properly, i.e., to transmit and receive at the same time and filter the transmit and receive frequencies from interfering with each other. A duplexer usually consists of either four or six tuned cavities, tuned to “pass” the desired frequency, and “notch” (filter out) the frequency(s) that are undesired. It is possible to operate a repeater without a duplexer, but it is very difficult on two meters to keep two signals that are only 600 Khz apart from affecting each other in a duplex situation.

The 146.94 repeater has a six-cavity “pass-reject” duplexer, built by Phelps-Dodge in the 1980’s. At the time of its manufacture, it was most likely the best duplexer made. I have owned four of them, three are still in service (146.94, 147.075, and 145.47). I also have a similar Phelps-Dodge duplexer on 444.3. Recently, I had noticed .94 being a little more “noisy” than usual. On a recent repeater maintenance trip, I decided to check the .94 duplexer. While attempting to “touch up” the duplexer tuning, I discovered that one of the transmit filters had “locked up” and would not tune! I called Kevin, W4KEV, who has the preferred test equipment and knowledge to see if he could help. I took the duplexer to his home, taking .94 off the air for the first time in YEARS. Kevin tried to “free up” the tuning shaft of the affected cavity to no avail. However, he did loan me a Wacom pass/notch cavity to substitute for the bad one, and I returned .94 to service the same night (at 3 AM to be exact). Still, while .94 is on the air, the substitute cavity is not matched to the others, and .94 still has a considerable amount of “desense.” In addition, Kevin found another cavity that did not want to tune.

In the meantime, Kevin has been working on the defective cavity with success! He has replaced the tuning rod after getting the old one removed. He also has the parts necessary to repair the one still in service with the rest of the duplexer, but in order for this to happen, 146.94 will need to go OFF THE AIR. I will be working with the METERS group and other net controls to make sure that this scheduled “downtime” affects as little of .94’s activities as possible. If you or your net is affected by this temporary “off-air” situation, you are more than welcome to use one of my other repeaters until .94 is back on the air. The repair/retuning process may take a couple of days. I hope this works and restores .94 to its original great performance standard! If the duplexer continues to struggle, Kevin and I have agreed that the next step will be to replace it. That is not a cheap proposition. I have been shopping for duplexers that would be suitable for .94’s needs. A suitable replacement would need to be a six-cavity duplexer, due to the fact that .94 is in a very high RF environment. After all, it lives in the same room as WIVK’s 40 kilowatt transmitter! Plus, there are many other two-way and broadcast transmitters at this site. I want to make sure that .94 is not affected by their normal operation. Even with discounts, I am still looking at over $1600 for a new duplexer. Operating repeaters is not cheap, and I recently spent $1700 for a duplexer for 146.73. So, say a prayer that Kevin’s efforts will succeed and 146.94 will return to its pervious high standard of service. I’ll keep everyone apprised of our progress. Thank you for reading, and PLEASE thank Kevin when you talk to him for his efforts!

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1 WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

Hey! Why is 146.94 so noisy?

2009-05-18T08:19:00.001-07:00

HEY! Why is 146.94 so noisy?

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1 WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

What have you done for me lately? V II

2009-04-21T11:06:00.001-07:00

What have you done for me lately?

(Chapter 2)

Last year, I wrote a blog entry called “what have you done for me lately?” that detailed a few things going on with the repeaters. So as to keep everyone up with some “new” information, here is another installment, with info for each of my repeaters. Questions are welcome (that means someone is actually reading this!).

53.15: The WB4GBI six meter repeater is tuned and ready to go at my home QTH. I have two side mounted antennae that I acquired at the same time I got the repeater from WB4HAP’s estate. My present plan is to mount the antenna array at the 146.625 site (I think the owner will let me J ) and place the repeater on the air from there. However, the tower work will be an expen$e to be budgeted. However, I may have a SUPER location for 53.15 that will take precedence over the .625 site!! Stay tuned and I will let everyone know as soon as I can.

145.17: repeater is in good shape. Last maintenance issue was the intermittent audio problem back last summer. More recently, I have signed a three-year agreement to keep 145.17 at its View Park home for another three years. I am very grateful that the current tower owner has honored the agreement that I have had with previous owners so that .17 can stay there. I have had a repeater at this site since 145.47 was there in 1981.

145.47: repeater is sporting a borrowed PA to get it back on the air from a failure a couple of weeks ago. The old PA and another VHF Mastr II PA are in the process of being repaired so I will have some spares. Eventually, I would like to install a commercial grade aftermarket PA on this repeater to increase its reliability even more than it is now. The receiver tone is OFF. The offending TV station will be going off in June, and I will re-activate the receiver preamp when that happens. If the TV station interference starts up again, please remember that the tone is 118.8 Hz.

146.625: On my last maintenance trip to fix the audio problem on .625, the kit-built ID’er died. I ordered another one from the same supplier that I bought 146.73’s ID. Unfortunately, when they sent it to me, it had “DE WB4GDI/R” programmed into it! So, I called the company and asked for a correct ID chip. That chip actually arrived yesterday. I will try to get it to the .625 site before the “redneck net” meets on Thursday. For its coverage, I still think 146.625 is one of my best kept secrets. Also, a remotely-selectable decode tone of 118.8 will be added in case we have another interference problem on the next trip.

146.73: Last week, I had a meeting with my landlord (I am renting tower space for .73) and he has offered me an antenna that, if it works out, will allow me to raise the height of the .73 antenna on his tower. I’m not sure whether the antenna will work yet; I will need to go to his place and test it. I also don’t know about its co$t yet. Meanwhile, I am working on a surprise for 146.73 that I can’t discuss just yet. Stay tuned.

146.94: Last week, I repaired the time-out timer on the .94 repeater. It needed new capacitors. The timer is a resistance/capacitance circuit that won’t function when the capacitors are “dried up.” The timers now work properly. Not only is it an FCC requirement, but the time-out timers will help remind everyone to keep their transmissions short. I have had some reports about intermittent noise problems with .94. I’m not quite sure what’s going on with this problem, but I’ll be watching it over the next little while. Also, a new remote control system is here and will be added in the next few days.

147.075: This repeater is doing well with its Motorola “micor” PA that was (re)installed last fall after the Quintron commercial-grade transmitter failed for the third time. In its original life, the Quintron was a VHF paging transmitter. They are normally very reliable under continuous duty conditions, but this one had failed three times. I had spent more money on it than it was worth, so I returned 147.075 to its original compliment of micor exciter and PA. I also replaced the older remote control receiver with a newer Motorola “spectra-tac” receiver. It is basically a “micor” series receiver as well, with its original use as a satellite receiver in a voted receiver system. If you happen to “kerchunk” the repeater late at night, don’t be surprised if my controller asks… “Why are you up?” The smart aleck repeater controller programmer strikes! J The autopatch is up and ready for use…PLEASE ID ON AND OFF WHEN YOU USE THE AUTOPATCH. Your call will be terminated if you do not.

224.34: This repeater is doing well at its new home on Sharp’s ridge. I removed it from the 146.625 site after something kept keying it up. When I brought it home for repairs, I discovered that the errant signal wasn’t bothering it at my home. A trip back to the mountain confirmed that the problem was indeed still there. Kevin, W4KEV, generously allowed me to locate the repeater at his site, which had an existing 220 MHz antenna. You can hear the result…the repeater did not suffer the problem that it had at the .625 site. I do think the transmit deviation is a little high, so I will be checking it soon.

444.300: This repeater also got a “re-capping” in the timer circuits. In the not-to-distant future, I hope to add a receiver preselector/preamp to the repeater receiver. Other repeater expenses have taken precedence over this addition for the moment. The soon-to-be added remote control system for 146.94 will also control this repeater, as they are located beside each other at the repeater site.

A general note for all of the repeaters: As I can afford to do so, I am adding tone decoders to the repeaters, particularly the GE units. ALL of my repeaters will be set to decode 118.8 Hz when this project is completed.

Lastly, I would like to say a very special “THANK YOU” to those who have recently contributed to the “WB4GBI repeater fund.” Thanks to you, I have been able to get spare PA’s repaired for the GE repeaters, replace and upgrade my necessary remote controls, and pay the recurring bills! THANK YOU!

73 de Tim WB4GBI

It's Baaaacccckkkk!!!!

2009-04-08T15:38:00.001-07:00

It’s baaaaaccccckkkkk!!!!

As I’m sure many of you already know, the 145.47 repeater is back on the air. I went to the site and repaired the repeater Sunday evening. What happened to the repeater? It had a power amplifier (PA) problem as I suspected. Fortunately, thru the generosity of another ham, I had a loaner spare PA assembly to swap out. I also did some tuning of the duplexer, which appeared to be out of tune on the transmit side causing a higher-than-normal reflected power reading back to the transmitter. That problem may have contributed to the PA failure, or it may have been its long hours of transmitting. 145.47 stays busy almost all hours of the day!

For those two reasons, I have decided to purchase an aftermarket commercial-grade continuous duty PA that will have VSWR protection. This will not be an inexpensive undertaking. The discounted price of the PA that I am looking at is $1000. However, I replaced the 444.300 PA with one of these same model amplifiers 10 years ago and have never had any problems with it since then. I want 145.47 to be as reliable as I possibly can, and I believe this is the next step.

Several of you have mailed in contributions to the “repeater fund” since .47 went off the air. For those who did so, I am very grateful. You will be receiving personalized thank-you letters soon. I will NEVER require contributions of any kind to be necessary in order to use my repeaters. But for those who have chosen to support them, I wish to express my sincere thanks. Your contributions will go toward this purchase. Operating repeaters is not cheap. I’m not quite halfway there, but I’m “saving my shekels” every chance I get!

OH, NO! 145.47 is OFF THE AIR!

2009-04-04T09:25:00.001-07:00

OH, NO!! 145.47 is OFF THE AIR!

I’m afraid it’s true. The repeater gave out around 2 AM on Tuesday morning. I will be going to the mountain this weekend to try to determine what is wrong. I suspect the power amplifier (PA) has failed, but I won’t know for sure until I have inspected it personally. As always, I’m sorry that the repeater’s off. Along with 146.94, .47 is my most popular and busy repeater. Please bear with me while I restore it to service. I have a fairly good stock of spare parts, but I may have to purcha$e $omething. Not a good thing to have happen when ball season is over! J

On a related note, a recent trip to the 146.625 repeater to fix the repeat audio problem also brought forth an ID failure. I’m not really sure why, but the ID is well over 20 years old, and I guess it was time for it to show its age. I *did* fix the audio problem, and I think you will find .625 has a nice footprint of coverage of the area. It doesn’t go north nearly as well as .47, but it is very good in town and to the west. I worked .625 fully quiet from Greeneville last week, as well. I have purchased another ID’er ($75 or so) and will install it as soon as I can. In the meantime, please ID the repeater when using .625. For example, “This is Wx4xxx on the WB4GBI repeater (I hope wx4xxx is not reading this blog if he has that call!).”

Lastly, an incident happened on .47 on Monday morning about which I am concerned. In the midst of an ongoing QSO, someone broke in with an emergency. He used the proper procedure of saying “Break” three times. A car and a tractor-trailer had collided in Wears Valley, where there is NO cellphone service in that area. He found .47 because it was active at the time. However, he was not acknowledged immediately when he ID’ed and declared his emergency. Folks, in the nicest way I know how to say it, THIS IS NOT ACCEPTABLE. The conversations on the repeater MUST COME TO A STOP if someone comes on the air and identifies in a proper manner (saying “Break” or says “emergency traffic”). We must stay with them and assist until there is a conclusion, even if they are noisy or not well understandable. Under no circumstances should they be ignored or told to go somewhere else. This gentlemen’s ONLY link to the outside world was Amateur radio, specifically my repeater, and he found it because there was activity on it. Please, let’s all remember that emergencies take priority over EVERYTHING. While I absolutely do not condone the use of the word “Break” just to get into a conversation, the use of that word—especially when it is repeated three times—is tantamount to stopping everything and stating an emergency. Please use it properly, and recognize it when it is used. Our amateur radio licenses are a privilege, and we justify that privilege when we provide emergency communications when there is no alternative.

I will post a status report on .47 as soon as I can. Thank you all for your concern; it’s nice to know it’s missed!

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1 WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

"Do you really want to know what's wrong...or do you just want me to fix it?

Two important things from WB4GBI

2009-03-11T19:51:00.001-07:00

TWO IMPORTANT THINGS FROM WB4GBI

Hello, everyone! I apologize for not writing a blog entry in a looooonnnnnggggg time. This thing called work keeps getting in the way. However, basketball season is almost over, you’ll probably grow tired of hearing me on the radio so much! J

There are a couple of important things I would like to pass along.

First, Please attend a garage sale to benefit Matthew Kirby, WB4IOB, Sam (WB4HAP)'s brother and the long time co-owner of the 146.73 repeater. Matthew has had to leave his home and move into an apartment due to his health issues. He has a large collection of radio equipment, test equipment, and parts. He also has a large collection of tubes! The garage sale will be held THIS SATURDAY at his home at 103 Woodrush Avenue in North Knoxville. Sam's widow, Debbie, and her daughter, Jan (who used to be a ham!) are conducting the sale. They are not setting fixed prices for Matt's equipment, instead they are asking for donations which will be solely for Matt's expenses. Please go by on Saturday and help support Matt.

Secondly, the audio problem on 146.625 has been fixed. The audio on .625 is working great now. However, while working on the repeater, the ID'er developed problems and had to be removed. So, when you use 146.625, please identify by saying..."This is (your callsign) on the WB4GBI repeater." I will be repairing or replacing the ID'er as soon as I can. Thank you for helping the repeater legal!

73 de Tim WB4GBI

O say, can you see...

2009-01-28T22:50:00.001-08:00

Oh, say can you see….

Warning….this blog entry has NOTHING to do with ham radio or my repeaters. It’s a shameless promotion of a VERY proud Dad. When you visit my website (and if you haven’t been for a while…it’s got some new stuff!), please check out the “bio” page. Down toward the bottom, you will see a couple of pictures of my daughter, Paige, at a recent UT basketball game where she was singing the National Anthem. She has been blessed with a beautiful singing voice, and that night she got a chance to showcase her God-given talent in front of a 20,000 plus crowd and 50 plus radio stations on the Vol Radio Network. Thanks to the efforts of Dave KE4YBZ, and Teri KJ4IPR (Teri’s a co-worker who just got her ham license!), the audio from that night is posted on the page below her pictures. Have a listen…and Paige…if you stumble across this article…know that I am SO proud of you!!

73 de Tim WB4GBI

The 146.73 duplexer is on the air!

2008-12-06T08:40:00.001-08:00

The 146.73 duplexer is on the air!!

This past Wednesday, December 3^rd, Josh McDaniel (KI4WWY) and I went to English Mountain and installed the newly acquired 146.730 duplexer on English Mountain. The power that I am able to deliver to the repeater antenna has doubled, and instead of 13 db of duplexer loss, I now have less than 2 db. What does this mean to you? It means the coverage of 146.73 has dramatically improved with this investment. This duplexer, if purchased at new list price , is over $ 3,000. Obviously, I couldn’t and didn’t pay that, but I was able to purchase a brand new duplexer for about half that price. I would like to say a very special THANK YOU to those who have recently contributed to the WB4GBI “repeater fund.” Those contributions, along with some funds from Debbie Kirby, Sam’s widow, helped to allow this purchase to happen. I hope you will check out 146.73 if you haven’t done so already. I am also working on more improvements to 146.73’s coverage, but I can’t discuss all the details right now. But I can assure you that you’ll be pleased.

The tone is still OFF on 145.47. For whatever reason, the TV interference has abated for the moment. I’m not sure why, but let’s enjoy! Remember it should be completely gone when the DTV transition happens on February 17^th.

I hope to be turning my attention to the 53.15 repeater very soon. I acquired it at the same time I acquired 146.73. It is ready to go on the air, located at my home. I am probably NOT going to be able to return it to English Mountain at this time. Remember, I am paying rent for 146.73, and also the six meter antennae take up a LOT of tower space. But I have a surprise in the works that should give 53.15 as good as if not better coverage than it had before. I may also be able to get it on the air from one of my other sites in the interim if necessary.

Here’s hoping that you and your family are enjoying the Christmas season! But let us all remember the real reason for the season.

73 de Tim WB4GBI

Tim Berry WB4GBI (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM WNOX-FM WNML AM/FM WNRX-FM WOKI-FM

"Do you really want to know what's wrong...or do you just want me to fix it?

O WB4GBI, where art thou?

2008-11-29T09:33:00.001-08:00

O WB4GBI, Where art thou?

Well, its been a while since I have done a “blog” entry. Heck, its been a while since I have been on the radio much. So, let you think I have fallen off the face of the earth, let me offer you a glimpse of why you don’t hear from me much during the month of November.

In my “other” life, I am Chief Engineer for the Vol Radio Network. If you listen to Bob Kesling on the radio calling UT football or basketball, or Mickey Dearstone calling lady Vols home basketball games, you are hearing my handiwork. Incidentally, Dave, KE4YBZ, is almost always on the other end of our audio feed, producing the game back at our studios. As for me, I am at the stadiun or arena setting up the equipment and sending it back to Dave for distribution to our stations (WIVK and The Sports Animal) as welll as 80+ other radio statins throughout the Southeast. And this is my “second” job…I still take care of WIVK and its sister stations as their Chief Engineer.

If you are a UT fan, you already know this, but if not (GO VOLS!), then I’ll try to explain our November schedule. Football is still in full swing, and Men’s and Women’s basketball is starting up. Add to that a Monday Night coache’s show on location, a Thursday Night show (which Josh, KI4WWY produces), and a Sunday Evening show that is produced by another engineer but supervised by yours truly, you start to have an eveny almost every night of the week. Throw in a couple of press conferences about football coaches…and… well, you get the picture. A wise farmer once said , “You gotta make hay while the sun shines.” I have to make sure these broadcasts get on the air while we are in the season.

So, While you may not har from me as much, I’m around…I listen a whole lot more than I talk. You learn more that way J.

Now, what’s happening with the repeaters? Well, I have the new duplexer for 146.73 here at my house and ready to go. I was going to try to go to English Mountain this past Friday, but my daughter’s 4-runner (actually, its MY 4-runner…I’m making the payments!) needed tires and brake work, so I postphoned the repeater trip. I will try to make it up there sometime this coming week. Its about a two hour trip by the time I get the keys and head to the site. But I am sure that the time and effort is going to be worth it! If you like 146.73 now, imagine what it will be like when the receiver can “hear” what its supposed to!

I am also hoping to put a pre-selector and preamp on 444.300 real soon. This should help its receiver sensitivity.

The tone is presently OFF on 145.47. If the TV noise comes back, I will have to turn the tone decoder back on. Please remember to set your tone encoders to 118.8 Hz. And, as a side note, if the repeater tone happens to be off, it doesn’t hurt anything to leave your rig’s tone encoder on. It just makes you ready for the times when I have to turn the one decoder back on.

The rest of the repeaters seem to be doing well. I am hearing a few more autopatches on 147.075 that I used to. That’s great! Please just remember to ID ON and OFF of the autopatch. I hope to have some new 147.075 pictures on the web site soon. I had to retire the Quintron transmitter that you see on the main picture…it just wasn’t stable. I went back to the old Micor exciter and used a new 100 watt PA that I acquired from WB4HAP’s estate. I put two cooling fans on it to keep the PA cooled down. ALL of the repeaters have fans on them…heat is not a friend of transmitters.

THANK YOU once again for reading the blog. I’m sorry I haven’t been able to post on it much lately. And a special THANK YOU to those who recently contributed to the “WB4GBI repeater fund.” Although never solicited, these contributions helped buy the duplexer for 146.73 recently, and they help defray the regular and monthly expenses that all of the repeaters incur.

73 de Tim WB4GBI

IMPORTANT NEWS ABOUT 145.47!

2008-10-20T23:09:00.001-07:00

IMPORTANT NEWS ABOUT 145.47!!

Due to a request from the 145.47 repeater group in Atlanta, I am changing the tone on 145.47 from 100.0 Hz to 118.8 Hz. The Atlanta group had already started using 100.0 Hz, and some of my users are now keying up their 145.47 repeater since it has the same tone. I want to be a good neighbor to my co-channel repeaters, especially since the N4CLA repeater is already using 100.0 Hz. I will make this announcement on the net on Tuesday evening. After the net is completed, I will most likely change the tone on Wednesday. If you attempt to use the WB4GBI 145.47 repeater and you cannot access it, please change your tone encode programming from 100.0 to 118.8. Remember, as soon as the TV interference issue is resolved, I will turn the decode tone off and make 145.47 an open squelch repeater again. Please pass this information on to other .47 users. Thank You!

73 de Tim WB4GBI

Why can't I key up 145.47?

2008-10-19T12:33:00.001-07:00

WHY CAN’T I KEY UP 145.47?

Have you tried to key up or talk on 145.47 and cannot? Well, unfortunately, I have had to add a tone board to the repeater receiver. What does that mean? It means that when you transmit, you must also transmit a 100 Hz sub audible tone with your signal in order for the repeater receiver to “open up.” Many of you understand this practice. But for those who may not be familiar with it, I’ll give a brief tutorial.

While not as common on amateur radio repeaters, tone squelch has been a staple of the land mobile radio world for years. It was developed in the late fifties or early sixties. Your local police department or public safety agency’s radios have tone squelch. They use it to insure that only their users access the repeater, and NOT other users that happen to be on the same frequency. Like our amateur frequencies, they are shared, but unlike our amateur frequencies there are FCC sanctioned coordinating bodies to (hopefully) insure that the users of the same frequency are separated by some distance. Land-mobile frequency coordination, unlike our volunteer coordinators (SERA), is mandatory before a license to operate is issued. Even with this frequency coordination, it is still necessary to keep users separated in these “closed” systems. The term Tone squelch goes by several names in the commercial radio world: Motorola calls it “private line,” GE called it “channel guard,” and RCA called it “QC (quiet channel).” In later years, Motorola developed a digital counterpart for tone squelch that the called “digital private line” or “DPL”. Even today’s trunked radio systems use a version of tone squelch or digital tone squelch.

In early years of amateur repeaters, a repeater that utilized a tone squelch was considered a “closed” repeater. Only the authorized users were given the tone frequency to access the repeater. I’m not sure what kind of honor system they were using, as the purpose of the closed repeater could be easily sidestepped if someone decided to share the tone frequency with a friend. More recently, repeater owners have used tone squelch to mitigate co-channel users of other repeaters from accessing their repeater. Amateur repeater frequencies are also shared, meaning that a repeater in the Knoxville area can be sharing the same frequency in another area. There are 145.47 repeaters in Nashville, Winston-Salem, and Atlanta. Tone squelch is sometimes used to keep the users of the “distant” repeater from accessing the “local” repeater, and vice versa. It doesn’t mean that either repeater is “closed.”

Another use of tone squelch is interference mitigation. That’s what I am doing with 145.47 right now. I am using the tone to keep the interference from the TV station from keeping the repeater keyed up with the loud squealing noise that I’m sure you have heard by now. I have also had to place a tone decoder on the 146.625 earlier this year when it experienced a similar kind of continuous interference. However, I’m happy to report that the 146.625 problem is gone now.

Now, here’s the caveat: Just because you can’t hear the “other” repeater’s user(s), or the interference, it doesn’t mean the interference is gone. It is merely masked, or muted. What does that mean? It means that if your signal is not strong enough to overcome the offending signal, it still won’t bring up the repeater, even if the desired signal (yours) has the right tone. This means that if you are using a hand-held portable or your signal is weaker than the TV interference, your signal won’t make it thru the repeater.

It is my belief that the 145.47 repeater will not need to have the tone squelch on it for the long term. As soon as the TV interference is mitigated, I will remove the tone from the receiver and return .47 to its normal “open squelch” state. Certainly, it makes it easier for travelers and those who don’t have tone units on their radios to enjoy 145.47. I have remote control of the repeater’s tone board, and have turned it off occasionally to check the repeater receiver status. In the meantime, please understand that even if you have your tone encoder on and selected to the right frequency (100.0 Hz), you still may not be able to access the repeater as easily as you did before this TV interference problem started. I promise you this will not be a permanent problem. The staff at the TV station and I have discussed several options to (hopefully) reduce or eliminate the offending signal that is causing the “mix.” If you are unfamiliar with what is happening to cause the problem with 145.47, please read the prior blog entry and it will bring you up to date.

What else is happening in the WB4GBI repeater world? As you read this, the NEW duplexer for 146.73 is being tuned. As soon as it arrives in Knoxville, I will take it to English Mountain and install it! I am convinced that 146.73 will see a drastic improvement in its coverage when the new duplexer is installed. I will post in the blog as soon as the duplexer installed.

Thanks again for reading!

73 de Tim WB4GBI

Get your tone encoders ready!

2008-10-07T17:17:00.001-07:00

GET YOUR TONE ENCODER READY!!

Well, folks, as bad as I hate to do so, it appears I am going to have to place a 100 Hz tone decoder on 145.47 in order to get it back on the air. As I am sure most of you know, I had to turn 145.47 off a week ago due to a LOUD squealing noise that was keeping the repeater keyed up. I suspected a 5 megawatt TV transmitter that is located at the same site, since the noise heard thru the repeater was TV video, also known as “ sync buzz.” Last Thursday, I was able to confirm that suspicion when the TV stations transmitter was turned off at 5 AM for a test. 145.47 was crystal clear, and I worked a station in Lexington, North Carolina without any noise whatsoever. As soon as they turned the TV transmitter back on, back came the noise. Several of you were up at that wee hour to help me, and I want to say thanks. But the problem came back with the return of the TV transmitter to the air…so I had to turn it back off.

How is this happening? Well, here’s a little unplanned blog entry on intermodulation interference, sometimes called “intermod.” Not all interference that is generated is “intermod,” but I will explain why this case is. When two RF signals are combined, they produce a sum (added together) and a difference (one subtracted from the other) of the two individual frequencies. This combining, or “mix,” can happen in numerous places, from one of the two transmitter amplifiers or a rusty joint that is ripe for RF rectification. The interference that we are receiving on 145.47 is a result of a RF carrier (coming from the TV transmitter) on 290 Mhz. The 290 MHz signal is “mixing” (combining) with the output of my repeater on 145.47. There is probably a “sum” frequency that is around 435 MHz, but the problem is the “difference” frequency, which falls right on 144.87 MHz, which is, of course, the input to my repeater. When two signals combine, you will hear modulation components of BOTH signals. That’s why you hear the video noise AND the squeal. The squeal is from my repeater feeding back into itself. Think of it as the same thing as when a PA system is too loud and the output from the speakers gets back into the microphone(s) and squeals.

There are other ways to have intermodulation interference. Mixes can occur on a transmitters harmonic frequency. For those of you who have been around a while, you may remember when 146.625 would come up randomly and play the weather station. After thinking it was a QRM’er at first, I decided that no QRM’er was dedicated enough to do this 24 hours per day at various intervals. So the search began. What I found was that a paging transmitter that was being used by our local fire department had a nice second harmonic, and that harmonic was mixing with the weather service transmitter and showing up on my repeater input. Here’s the math: 154.250 X2= 308.500. 308.500 – 162.475 equals 146.025, which is dead on the 146.625 input. This is referred to as a “third order” intermodulation problem or 2 times freq A minus freq B equals freq C. There are also fifth order intermodulation products, but I have never had to deal with them.

So, now we know what the problem is, what can you do to fix it? The easiest thing to do is eliminate the mix. I am working with the TV station to eliminate the 290 MHz frequency that is causing this problem. Bear in mind that this is a FIVE MILLION WATT TV transmitter. The offending frequency doesn’t have to be very strong and the TV station still be considered legal. The TV station engineer has traveled to the transmitter site twice so far to try to find where this signal is coming from. Today, he went with a spectrum analyzer, which is an absolute MUST when troubleshooting this kind of problem. However, he can’t “see” this signal on his analyzer. However, we know the signal exists, because several of you have confirmed it for me by listening on your receivers wherever you may be located. So, I am planning a trip to the transmitter site with *my* spectrum analyzer and a receiver capable of receiving 290 Mhz. I fully expect to receive the signal on my receiver, and point it out to the engineering staff of the TV station. However, until they locate the signal and reduce or eliminate it, 145.47 will still have the lovely noise that you have heard until I take another course of action. That action, unfortunately, is a CTCSS (or “PL” or tone board) installed on the repeater receiver. I had to do this recently on 146.625 until another stray video carrier finally went away. I wish I had thought to check the same source as this problem…they might have been the same thing.

Now, here’s another lesson to be learned from this type of problem: When I install the tone board, the problem will not be heard anymore. Notice that I did NOT say that the problem would go away. It will merely be “muted” until a signal with the proper tone is received at the repeater. Then, if the signal (from you, the repeater user) happens to be weak enough, then you will STILL hear the video noise as it “scrubs” with the legitimate repeater user. It will affect the weaker signals the most. Some of you that were used to getting into 145.47 with low power from a distant location may find that you can’t get into the repeater, or that your signal isn’t as good as it once was. This is because the tone decoder only hides the problem of the signal that it is still on the input frequency of the repeater. This is also one of the reasons that I do NOT like tone squelch amateur repeaters, along with other reasons. A repeater with a tone squelch is not friendly to a traveling user, unless the user happens to know the tone frequency and has the tone encode enabled on his or her radio. Most modern radios have tone encode (and decode) capability, but you have to KNOW what the tone frequency is first.

Lastly, what happens if the TV station can’t or won’t eliminate the interference? There are two options. I can attempt to eliminate the “mix, “ IF (that’s a big IF) the mix is happening in the 145.47 transmitter. Unfortunately, its not always easy to determine where the mix is happening. Another problem…the device used to eliminate this problem is called an isolator. You probably don’t have one of these laying around in your ham shack. They are around $1000 each and they are finely tuned fro the exact “pass” frequency (in my case, 145.47). If you *do* have one, I would like to talk to you J !!

Have you been hearing about the “Digital TV conversion?” Well, if you have, there is some good news for this problem that relates to the changeover to digital television. In February, ALL analog TV stations are mandated to shut down in favor of their digital signal. All of the local stations (this one included) already have their digital signals on the air. When February rolls around, guess what…this transmitter will be off the air. HOORAY!!

It is my sincere hope that I can restore 145.47 to useable service long before February. I don’t like having one of my busiest and most active repeaters crippled, especially if its something that is not the fault of the equipment I have on the aire or a situation that I have control over. Please bear with me and I will do my very best to correct the 145.47 problem…the best way I can, as soon as I can.

NOW, FOR SOME GOOD NEWS!

I have saved enough shekels for a new duplexer for 146.73! I will be making the final payment on a six-cavity repeater duplexer that I have had in “lay away” for several weeks. I hope to have it here and tuned up within a couple of more weeks. If you think .73 is doing good now…wait until it can actually hear better!!!

73 de Tim WB4GBI

Why is 145.47 off the air?

2008-09-24T21:47:00.000-07:00

HELP!! Why is 145.47 off the air?

Well, this certainly wasn’t what I was *planning* for my next blog enrty, but I’m going to have to write it anyway.

As you may have noticed, I have had to turn the 145.47 repeater off the air. Tuesday afternoon, it started passing this horrible squealing noise. I suspect the noise to be an “intermod hit” that involves a 5 megawatt (that’s 5,000,000 watts) TV transmitter immediately adjacent to the building that .47 is housed in. You can hear the video “sync buzz” when the repeater is enabled. We have had this noise on the repeater before, but never quite this bad. In fact, the last time we had this noise, I simply bypassed the receiver preamp and all was well again. I’m afraid that solution won’t work this time.

What am I going to do about this problem? As soon as I return from a little football trip this weekend, I will pay a visit to the repeater site. I will do some troubleshooting to try to determine where the “mixing” of signals is taking place. If it is in the repeater transmitter, I will try lowering the power, checking the transmitter with a spectrum analyzer, and trying to determine where the “mix” is occurring. I can install an isolator on the repeater transmitter to keep RF from getting back into the transmitter PA from the outside world. I hope this isn’t the case, as a good isolator is around $1000. If the mix is NOT occurring in the repeater transmitter itself, I’m afraid short of getting the offending station to cooperate, I will have to install a tone decoder on the repeater receiver. This means that you will need to encode a 100 Hz tone to access the repeater. I’m not a fan of tone squelch amateur repeaters, but it will keep the repeater on the air until the mix disappears.

The good news is that the transmitter that I suspect to be causing the problem will be off the air after the February 29, 2009 DTV conversion. That means that the transmitter in which the “mix” is occurring will be going away. Wouldn’t *that* be nice?

On another note, I visited the 146.625 site today and tightened the noisy squelch on the repeater receiver. .625 had a similar interference problem last year. I had to tone it up but its fine now. I tightened up the squelch adjustment, so the repeater didn’t stay on the air passing squelch noise after the user has unkeyed his transmitter.

Why not give .625 a try?

I will keep you posted as to the 145.47 repeater’s status. Thanks again for reading this!

P.S. I will be unable to attend the Ten-Tec hamfest this Saturday. There’s a little football game going on down in Auburn this weekend that necessitates my presence.

73 de Tim WB4GBI

This and That...

2008-08-18T14:34:00.000-07:00

This and that…ramblings from WB4GBI

Here’s hoping everyone had a great weekend. I know several went to the Huntsville hamfest. I had planned on going, but this weekend was “move-in” weekend for on-campus UT students, which included my daughter. I doubt she reads this, but just in case: Paige, I am SO proud of you. You excel at anything you do. Study hard and go with God. Love, Daddy.

And besides, I wanted to save my shekels for a new duplexer for 146.73 instead of going to the hamfest and spending them. So, speaking of duplexers, I have made a down payment on a set of six-cavity TX-RX duplexers. These are new in the box, but were bought for a project that was never completed. I hope to finish paying for them in the next two or three weeks, and then have them shipped here. From that point, I will see if Kevin (W4KEV) will be kind enough to tune them up using his sweep generator. I know for a fact that you will notice a marked improvement in 146.73’s receive capability. I have heard a lot of people trying out .73, and I hope that those who are having a little difficulty accessing the repeater will remember that it is practically “deaf” at this point in time due to duplexer loss. I didn’t intend to put it on the air this way, but these things happen, and I’ve had to work these kinds of “bugs” out before when I have placed a new repeater on the air. 145.47 had some technical issues, believe it or not, before it became the wide-area coverage repeater that it is now.

So, what’s going on with the other repeaters? Well, at this point in time, there are no major needs on any of the other machines. I hope to add a receive preamp on 444.3 sometime soon, but its not nearly as “deaf” as 146.73 is right now. It seems that my quietest repeater is 146.625, for the range it has. If you find one of my other repeaters too crowded and too busy for your liking, why not try .625? It has a nice footprint and has been on the air at this location for about four years. I have had 146.625 on the air since 1988.

Some of you may have noticed that I had to turn off 145.47 last night. It was not meant as an indictment of those who were using it, but there was someone who thought it was his playtime and proceeded to key up and make miscellaneous unidentified transmissions. I know that conventional wisdom tells us to ignore jammers and QRM-ers, and I usually try to do just that. This, however, had gone on long enough, so I turned it off for a while. The result was that when I turned it back on, the problem had disappeared, probably due to him knowing that his “playtime” was now ineffective. It’s hard to jam a repeater that has been turned off on you, isn’t it? Turning a repeater off is my last resort, but please remember…it is my license that is in use as well as the repeater user's, as defined by the FCC. It is the same as if I had invited hams to my house to use my equipment.

For my next blog entry, I think I will start a series on repeater basics. I hope you will want to read it. If you like what you see, tell others. If you don’t, please tell me.

73 de Tim WB4GBI

ITS ON THE AIR!!

2008-08-07T21:07:00.001-07:00

IT’S ON THE AIR!!!!

After almost a year of planning, purchasing, installing, connecting, tuning, configuring, spending, crying, praying, site renting, grunting, more spending, and just plain old hoping everything worked out, IT’S ON THE AIR!!!

Please look at the 146.73 web page when you get a chance. Josh McDaniel, KI4WWY, one of my co-workers, took the pictures that you see on the 146.73 web page. He and Dave, KE4YBZ, assisted me on Wednesday, August 6^th, in transporting the repeater on the mountain. After 11 months, the dream has come true!

Now, here’s the caveat…it has a duplexer problem. Despite the valiant efforts of Kevin, W4KEV, the duplexer is still struggling. It has 11 db of loss on the receive side. What does this mean? A 3 db loss is considered to be half of the signal in question. So you can imagine what an 11 db loss is now. It’s only running 24 watts on the transmit side as well. The coverage ain’t too bad for 24 watts, huh?

I am actively looking for another duplexer. I hope to have one tuned up and installed as soon as time (and finances) allow. I am right now over the $3,000 mark in my investment on 146.73. But to see the repeater return to the mountain after all that Sam, WB4HAP, went through, it’s worth it. I am glad to see it through to completion. It’s only going to get better!

Sam, this is for you. I hope I’m doing OK so far. J

73 de Tim WB4GBI

Thank You, Kevin!

2008-08-03T15:57:00.001-07:00

From “The Radio Amateur’s code,” written by Paul Segal, W9EEA, in 1928…

The Radio Amateur is:

FRIENDLY...slow and patient operating when requested; friendly advice and counsel to the beginner; kindly assistance, cooperation and consideration for the interests of others. These are the hallmarks of the amateur spirit.

As many of you know, I did not take the 146.73 repeater to English Mountain a couple of weeks ago when I installed the antenna. At the last minute, I discovered that the duplexer was not performing up to par. Since I could take the repeater to the mountain a lot easier than I could take the antenna, I went ahead and installed the antenna and line so as to be ready for the repeater to return home. My access to the repeater site is very limited, and I wanted to make sure everything was ready when I actually put the repeater on the air.

Meanwhile, I asked Kevin, W4KEV, if he would help me with the duplexer. I already knew that Kevin was very talented at tuning duplexers, as he re-tuned a duplexer that I bought for 146.625 that arrived out-of-tune. Note to self: beware of promises made on ebay!

I called Kevin and asked him if he would be willing to help, and he readily agreed. I took the duplexer to his home. Kevin researched the origin of the duplexer, which we both knew was home built but never knew by what guidelines it was built. We found it on the “repeater builders’ webpage, which is a great resource for repeater owners and trustees. Kevin also ascertained that the inter-cavity cables were the wrong length, and the output harness was wrong as well. Thankfully, Kevin had more time than I did to test various cable lengths with his sweep generator. If you don’t know what a sweep generator is…well…lets say I was drooling when I saw his. It generates a “sweep” of RF on a given range of frequencies at a given level. This allows you to tune filter cavities, duplexers, and any other frequency-sensitive devices with ease and accuracy. It is very difficult to tune a pass-reject device such as a duplexer without one of these pieces of test equipment.

After several attempts to get back together with Kevin and test the cables that Josh (KI4WWY) and I had built, we finally met at his home again on Thursday. Kevin had already connected the inter-cavity cables and was awaiting the output harness cables that I needed to cut to length to finish the tune-up. Kevin took several hours out of his evening time and tuned the duplexer and a filter cavity I am placing on the receive side to allow me to operate the repeater with a receive preamp. While the duplexer is not perfect, it is a far cry better than it was before. I left Kevin’s late that evening and took the duplexer back to my shop and restored 146.73 to its temporary service. It is performing much better, and is ready for its English Mountain trip. It’s on the air again at my shop if you want to try it out.

Kevin owns the 145.23, 145.37, and 442.500 repeaters. He willingly gave his time to help another Amateur repeater owner. I am very grateful for his time and talents. I have obviously dealt with duplexers since my repeaters went on the air, but I have never been able to tune them locally. So, that’s the reason for the quote from the Radio Amateurs code listed above. If you talk to him on the air, tell him “Thank You.” This is what all ham radio operators should be willing to do.

I hope to make it to English Mountain this coming week. Stay tuned!