[R-390] SDR

[William A Kulze]

The way I'm doing it with a winradio isn't something I'd say go out and get one of these for this purpose, but already having it, hey... the idea is the same. 

The radio has a bandwidth of 20kHz, but the R-390 won't do more than 16kHz, works out OK. You just need the right amount of attenuation between the IF out and the Rx input. At this bandwidth it's a limited panadapter, but I get AM, AMS, USB, LSB, DSB, ISB, FM, and CW. Plus, I can run 3rd party demodulator software, including DReaM, Power SDR, HD-SDR or SDR-Radio, which is one that Simon Brown is developing.

A couple of issues back in QST there was the article regarding the DVB-t dongle, which tunes from around 64MHz up to about 1.7 GHz. The go for $25 or $30. The author built his own up-converter with a 125MHz osc chip and a 555 timer, or you can buy one online for about $50. Software is free, or the adventurous can write their own. Basically DC to 2GHz, all mode, for under $100.

One nice thing about this approach is that it's not a dedicated setup, you still get the full functionality  of the SDR hardware, demodulating a boatanchor's IF out is just one of the things you can do with it.

Bill W2NVD

-----Original Message-----
Subject: Re: [R-390] SDR

THe only real problem is how much bandwidth do you "see" in the IF out.  
A Softrock set-up right after the first mixer, before any IF filtering lets and you see 100Khz or more of the band at once.

It sure is nice tho...even to see what is a few Khz up or down from your set.

I use a SR on my Drake A and B line as a panadapter--works well and Is really useful.  Comes out right after the first mixer.  THe technology is amazing.  There are guys using those 100 dollar Fun Cube Dongles for 
2M EME!!   It doesn't get much more demanding on a receiver than 
that--at least noise and sensitivity-wise.

FWIW

Curt
KU8L