/Soeren

Yes i got an engineer degree, though it was never one of the hot topics when i was in school.

vy 73 de OZ2DAK, Soeren

FB on your WSPR reports..

Have you tried WSPR 2way inside of WSJT? It takes a little while, but its fun.

Make sure there is zero ALC swing. hi

Good luck, N6SPP Benicia,CA– back to jt65a on 7.076

I’d love to see a machine like that working.

Yes I meant diode ROM decoders, rectifier being an attempt at a generic term for any particular implementation technology. I realise solid state rectifiers have been available for a very long time and wouldn’t penalise any implementation that used them along with vacuum tubes.

I am indeed familiar with WireWorld. I’ve built some trivial stuff in it, and always marveled at what others have managed to build with it.

Core rope ROM is probably way too slow for the kind of computer you are talking about. Braiding core rope ROM would be a PITA compared to a diode matrix. Of course diodes have speed limits too.

I’d still start with whatever 7400 series logic family you can get in the quantities required at a reasonable price. First make it work, then make it fast.

Alternative technologies you have hinted at using RF lines and non-linear elements as switches would be interesting, but I suspect extremely frustrating to build and debug. At least something like that would be vaguely similar to optical computers and could test the general concepts.

Given that we are under no such “gun”, radio is a hobby and many of us work on a PC all day and look forward to a break from it when we come home at night.

I don’t think it non-visionary to call a spade a spade. I think that root canals have served mankind well but I don’t want to celebrate them!

Other than the Softrock kits, I wasn’t aware that any of the others you mentioned included transceivers — I thought they were receive only.

I think the best place for the computer and software is embedded deeply inside the rig where I don’t have to deal with it. I like my computer for computer things and my radio for radio things and see no reason why the two should be shared.

But I do understand that desire makes me a curmudgeon and out of the mainstream of current thought. No matter, I also believe that those who believe in techno-triumphalism will eventually come around to my way of thinking.

73, Jeff

In software defined radios, software is responsible for additional functionality such as mixing or modulation. You could choose to ignore that of course. If the functionality that you got is equivalent to a radio you already use and like, and presents the same interface, maybe that’s cool. But to me, software represents an upgradeable component that is inexpensive to modify (no hardware changes) and even better, can be redistributed cheaply (bits are cheap to mail).

As a practical example, consider making a phasing SSB exciter. Traditionally, what you would do is take your audio input, and pass it through some carefully constructed all pass phasing networks. These would then be mixed with the carrier frequency in quadrature and then either added or subtracted to generate the appropriate upper or lower sideband. Depending on the accuracy of the phasing network, you get good or not so good sideband cancellation.

But, let’s imagine something different: instead of using an all pass network, let’s compute the phase shift using a Hilbert transform. A simple dsPIC costs a few dollars, and has no difficulty whatsoever computing a Hilbert transform at audio signal rates in real time, and takes just a few ma of current. In addition, you can fold in all sorts of other functionality (filtering, compression, whatever) at no additional cost beyond just writing the software.

Once you begin integrating microprocessors into radios, then you can begin to do all sorts of fun stuff. Integrate SWR and power meters. Good battery indicators. Frequency counters. Time synchronization via GPS. Satellite tracking and Doppler tuning. Even provide streaming audio from the radio via Ethernet. The addition of each of these features is very cheap, because compute power is just about free inside of radios.

Having compute power also means that we can make better displays. Why does the average HT have such a crappy display compared to even the cheapest of cell-phones? If you surf over to sparkfun you can find nice graphic lcds for about $20. Instead of wiring in a bunch of 7 segment LEDS, why not create a generic interface that can display all kinds of information (I am always baffled why HT’s don’t include a time display that shows both local and UTC time).

Flex-Radio isn’t the only game in town either. At the low end, we see things like the Softrock kits. Moving up the ladder we see things like Genesis Radio. GNU radio. HPSDR from TAPR. RFSpace’s SDR-IQ, SDR-14 and SDR-IP.

Let’s not be so curmudgeonly that we draw a line between radios and computing. One enhances the other. I’m teaching myself RF design, I wonder why so few statesmen for ham radio work on teaching themself DSP and software design.

I don’t look at my toaster, for instance, and think to myself, I need to hack the software in that to make it a better toaster. I simply plug it in and use it to make toast.

The same goes for my DvD player, my television, the list goes on.

It is simply someone’s opinion that a ham transceiver is made better by connecting it to a personal computer and applying a lot more software. The person who believes this rarely takes into consideration the diminishing returns of having to use a specific hardware platform with a specific operating system to achieve optimal results.

Some day, when this is truly an ‘open’ field of endeavor, things might get a little more interesting. Until then, SDR in the world of amateur radio is a one-trick pony named Flex-Radio.

Not saying that’s bad, I’m just saying…

This wasn’t meant to be as negative as it sounds, now that I read over it. I just feel that a few small changes in different areas could help out ham radio quite a bit.

Software defined radio is the future. I think our phones are already using this technology.

The thing I think we should fear is that the age of home brew may come to an end when the only components are surface mount and too small for us to work with.

Nice post.

Just curious, does you Signallink have a low frequency rumble on receive?

73

Eric

So unless my gauges are consistently reading high, I think you’re underestimating the burst pressure at 120PSI.

After all, nobody would shoot themselves in the foot that badly.

Would they?