On Tue, 24 Jan 2006 17:43:07 -0500, "xpyttl"
wrote:
"Tim Shoppa" wrote in message
roups.com...
wrote:
How about a simple one to three transistor regenative reciever.
In principle that's a great idea, but the gotcha is that very near
WWV's 10MHz frequency there are a lot of powerhouse SW broadcasters.
Well, I suppose it depends on where OP is. Here in the middle, 10 MHz isn't
much of a problem but 15 is.
*HOWEVER*, 10 has one huge advantage -- there are very low cost uP crystals
for 10 MHz, so building even a simple reciever with a brick wall front end
isn't such a big deal, if the only frequency you care about is 10 MHz.
Personally, I'd go with a DC rather than a regen - a lot simpler and these
days, a simple SA612 will give you way more sensitivity than you can
possibly use on 10 MHz for a couple bucks. Well, with a crystal filter in
front maybe you will need a little amp, not so sure. But still quite a bit
simpler than a regen. Heck, if the local QRM isn't too strong, I bet a 10
MHz uP crystal, a 612 and an audio amp (like a 386 or so) is all you would
need.
A friend of mine did an article on a simple WWV reciever for QRP Homebrewer
recently, issue #5 I think. He was more interested in the frequency
standard than hearing the sounds, so his contribution was recognizing the
zero beat, but still an interesting article if you can find a copy.
For wwv I consider DC the least useful. One approach I've also tried
is 9.6mhz crystal LO and use 455khz if can retuned to 400khz. that
works and uses fairly easy to get parts. That allows a diode
detector for zero beat against external sources and copy of the audio
without beats.
Allison