[R-390] R-390 Digest, Vol 102, Issue 7

[William A Kulze]

One approach that I'm using, and I've seen someone else mention it, is connecting the IF out to an SDR. You have to run it through some attenuation, but it will give you whatever modes are built into the sdr. I've been playing around with this for a while and I think I've got it pretty close to where I want it. I found that I can use the sdr panadapter to find good sweet spots for both IF and RF gains. You can see when you start introducing noise with the gain too high. The 'S' meter on my SDR (winradio g303) can be selected for microvolts, and I've got it to where the meter pretty well matches (close enough, anyway) to what my generator is putting out. I've found it to work best with the R-390a in MGC, utilizing the agc in the sdr. The two AGC's together wasn't as pleasant to listen to.

I can use other dsp programs with the winradio, and the one Simon Brown (HamRadioDeluxe) is working on (SDR-Radio.Com) has, among others, SAM, ECSS (upper, lower or both sidebands), and also has a pseudo stereo audio mode that is interesting and seems to improve legibility in some instances.

The audio quality depends on what you want to run it through, but it easily overcomes the one weakness of the R-390a. With this I can enjoy all the signal grabbing of the old rig and fully enjoy whatever I'm picking up with it.

Of course, this completely kills the 'vintage' equipment setup. :-) 

Bill Kulze W2NVD

-----Original Message-----

Rather, it would be a downconverter, from the receiver's 500kHz output to the SE-3's 455 input.

It's intriguing that he would choose that approach.  I imagine he tried bending the VCO; I wonder what went wrong?
Or maybe just prefers an extra board to hacking the main one.

Dave

>-----Original Message-----
>
>Rob Sherwood at Sherwood Engineering can make an up converter from 455 
>to
>500 KHz if needed.
>
>Les
>
>-----Original Message-----
>
>Will it work with a 500kHz IF? Does it require a cap replacement to 
>bring the VCO into range?  Has anyone done it?
>
>Dave Wise
>
>>-----Original Message-----
>>
>>I can also add that I have used it with many other receivers, a Ten 
>>Tec RX-340, Yaesu FRG-8800 and presently a highly modified Icom 
>>IC-746, superb audio especially with the proper speaker.
>>
>>Les
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