EMRFD Message Archive 1211

Message Date From Subject
1211 2007-12-05 17:17:54 George LaBelle New to group - current activity
I got the "homebrew a receiver" bug again recently. I ran across the
SoftRock SDR and built one. WOW! The best sounding audio I'd ever
heard, bar none. Brick wall filters - as many different bandwidths as
you want - all modes, all for free! Geez, I thought this made the
I.F. section through to speaker rather obsolete. (at least at home,
not mountain topping, maybe ;-) So, I built a tunable 80M front end
for one at 5.52 Mhz. The other thing I wanted in a receiver was a BIG
linear slide rule dial (ala SX-101). I always liked those. So I made
one out of PC board and an ARC-5 transmitter variable and a junked
dial pulley. I found out, however, I rarely look at the dial anymore,
I'm always looking at the spectrum display on the PC. So a digital
readout will be in the future.

Then I discovered a potential limitation, at least in this
configuration. Another local station came on and wiped out the band.
Therefore I'll be redesigning the receiver to include
crystal "roofing" filters when this happens. I also want to add Wes'
new cascode IF amp. so that alternatively I can have a self contained
receiver without having to boot a PC all the time. I think I will
switch in the SDR before the XTAL filter for a spectrum display, and
afterwards for better IMD performance. It will be interesting to see
how much distortion is caused by the XTAL filter.

Aloha, Oregon