[DSP-10] Gain in receive chain question for W7PUA

[Courtney Duncan]

Bob, (and all)

I've been studying the DSP-10 receive chain to understand how it works with respect to gain and noise figure.

It doesn't look like there's enough gain on the boards I built, just 32 dB at RF, some filter and mixer losses, then 50 dB at 15 KHz.

Then I looked at the AD1847 data sheet http://alsa.cybermirror.org/manuals/ad/ad1847.pdf and noticed that there is an ADC Programmable Gain Amplifier that runs 21-24 dB gain.  With that additional gain, I can see that it should work.  And it does work because I've been using it for six years....

Do you use the gain in the AD1847 ADC and if so what do you have it set to?

Courtney, n5bf/6


"It's science. They don't know anything; they just make a lot of educated guesses."  -- Viannah Duncan

Courtney Duncan, n5bf/6
cbduncan at earthlink dot net
1296.100, 1.810.
n5bf at amsat dot org