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Old April 23rd 08, 02:06 PM posted to rec.radio.amateur.homebrew
Tim Shoppa Tim Shoppa is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 263
Default May QST... winner of $50 homebrew SSB transceiver challenge

The May 2008 QST has WA2EUJ's winning entry for the ARRL Homebrew
challenge - the TAK-40 is a homebrew SSB transceiver made out of
$49.50 in parts.

I am truly fascinated by this gadget. I ordered the parts (alas,
inflation from entry time until now has driven the total bill up to
closer to $60 these days... but some stuff from the junkbox brings it
down again for me. And that's still cheaper than a new copy of the
ARRL handbook!) and hope to build it in the next few weeks.

Even though it won in the "PC-supported" category, it does not require
a PC to use it at all, just to program during construction the PIC
microcontroller which does all the T/R switching as well as VFO and
BFO and frequency counting magic. Get someone to program the PIC for
you and you won't have to use a PC at all.

Some (including me) had previously postulated that the PC-supported
entries would be closer to a software-defined radio, with a low IF and
a lot of digital processing done via a PC's sound card and software. I
am actually reassured a bit that this is not what the winner did...
but wonder what software-defined entries were submitted. Maybe there
were some, but in terms of performance WA2EUJ's seems to have beat
them.

The WA2EUJ entry uses a PIC for T/R switching and even drives DAC's
for VFO and BFO tuning (it's necessary to shift these for modes, T/R
on CW, etc.) with frequency counting via the PIC and display on a LCD,
but the only use for a PC is to program the PIC.

I think KD1JV's entry, in the non-PC-supported category, will be
interesting as well. I think it gets published this month, but on
KD1JV's website he already has construction details. His PTO looks
pretty nifty!

Tim.