[R-390] R-390A IF gain setting and S/N measurement

[Tisha Hayes]

It is definitely bad to set the IF gain too high to chase after the mostly
irrelevant super-high sensitivity. We are talking about the HF band here,
not chasing jansky's (Jy) for a radio-telescope. You will get much more
bang for the buck with reducing system noise due to using too much stage
gain, tube (and thermal) noises and gain balance. Put a R-390A in a Faraday
cage and find out how much internal noise the radio makes all by itself.

I chased low noise in the R-390A for several years with all sorts of things
like component and tube swaps, shielding and filtering. I picked up about 2
dB of S/N improvement but it was not consistent from radio to radio (I have
a couple of them). For "that" type of monitoring I ended up with completely
different receivers that are not nearly as much fun as an R-390A.

Now I just listen to them.



*Ms. Tisha Hayes, AA4HA*
*"*There are many who live in the mountains and behave as if they were in **the
town; they are wasting their time.*
* It is possible to be a solitary in one's mind while living in a crowd;
and it is possible for those who are **solitary to live in the crowd of
their own thoughts.*"*
**-Amma Syncletica of Alexandria**