[R-390] HSR-2 vs 390a

[Dan Merz]

Bryce,  if you use the Chuck Rippel check on i.f. gain what does your line
meter read?

for info,  the check
disconnect antenna
set recvr to 15.2 Mhz
function switch to MGC
4 kc bandwidth
rf gain at maximum
peak ant. trimmer for max on line level meter
line meter switch to  -10 db scale
line gain control full clockwise
what is the reading on the line level meter?  Rippel recommends  -4 to -7
db by adjusting the i.f. gain control,  assuming the rest of the radio is
operating right.

I did this check on my receiver and it was reading lower than this so I'm
guessing that my rf stage may need attention since if I adjust the i.f to
bring it up to his recommended level,  I think the noise is just going to
get higher without really helping the radio receive better.  As best I can
recall,  I used a 150 microvolt 455 khz signal to adjust the i.f. per the
handbook, which according to  Rippel  is already too high.   I also noticed
that the antenna trim doesn't really peak the  internal noise with the
antenna disconnected so this would indicate that the rf section isn't doing
its job (I think,  according to Rippel).  It does work in peaking a signal
or band background noise.

I think this excursion into the archives answered one question that I had
regarding "hiss" or noise that is there when the rf gain is turned all the
way up.  I think the line level meter indication is a direct measure of
this level,  so the -4 to -7 db is at least an indicator of what that level
would be in one guy's opinion of a well-adjusted set.


Bryce Ringwood wrote:

> Hi,
>
> Also run with RF Gain full and AGC on. IF Gain set way way way lower
> than when I purchased the set. Noise I get is almost all aerial noise -
> a combination of power lines, electric fences ,TVs , hair dryers, .....
> :(
>
> - Bryce
>
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