[DSP-10] 1296 RSU Rx Works!

[Courtney Duncan]

I'm talking to myself on FM!  Frequency is within a KHz, audio sounds  
good.  Signal level about right for not using an antenna on the HT, ~  
-83 dBm.

In configuring the DSP-10, it wanted to know "transverter gain,"  
presumably so the received power readings will be about right.

For the front end the schematic says INA-10386.  The data sheet for  
that says 26 dB gain typical.  The parts sheet just calls this MMIC  
"SGA" and the part itself says 35Z.  Google isn't finding much for  
"SGA 35Z," at least not much that's close enough.  But, I can imagine  
26 dB is about what it does.  Does someone know of a cross reference,  
or what the shipped part actually is/does?

The mixer datasheet says 6.6 dB typical conversion loss.  Let's say 7

 From Figure 3. of the paper, the 1296 hairpin filter insertion loss  
looks like 7 dB.

So that makes about 26 - 7 - 7 = 12 dB transverter gain, right?   
(Making the signal level ~ -95 dBm.)

Next:  finish populating the transmitter and see if I can hear myself  
on the FM HT.  (Whenever I open one type of part I install them all so  
I don't lose these little pepper flake sized things.  This means  
installing only A3 and a little hookup stuff at this point.)

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
144.200, 7.040.
n5bf at amsat dot org