[R-390] RF gain

[Flowertime01 at wmconnect.com]

Chuck Bolland,

You can adjust the IF GAIN ADJUST resistor on the top of the IF deck to move 
the receiver gain up or down.

There are as you imagine for military receivers many exact detailed 
procedures to do calibrated settings.

Just twist that pot around to get a response you like.

Not knowing how many hours the receiver has operated since its last go around 
with tube testing and good alignment and inspection with a signal generator 
and voltmeter hung on the audio output with a 600 ohm load, It may be time to 
test all the tubes in a tube tester and do what you can to check the alignment 
and signal to noise.

All you really need is a RF signal generator. It need not be calibrated. An 
AC volt meter, any one will work. A DC volt meter, Again any one will work. A 
600 ohm resistor. a couple 1200 ohm 1/4 or 1/2 watt work fine.

Then of course better signal generators, meters, power meters just make the 
job more detailed. They will not get you one signal better, the stuff just 
makes the process proceed with a warmer better fuzzy feeling.

Fear not you can do this your self. The US Army fellows taught other US Army 
fellows to do it and passed it down from one to another for years and years.

The US Army TM 11-5820-358-35 is on line as PDF.

But look up the Y2K manual on the R390 web site and down load it.

It is so much more readable than the original TM.

All R390 and R390/A parts are available.

If you need something ask here first for leads on the exact parts you need. 
Different parts come from different places.

When you get into doing an alignment with the Y2K manual in hand and have a 
problem, post some mail here on the R390 reflector and detail your problem as 
best you can, Someone or several some one's will post you some mail back.

Good luck with the receiver and hope you enjoy many hours listening.

Roger AI4NI
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