[R-390] R-390a question

[Jon Schlegel]

Tony,

Following Bob's lead, I guess you might try backing the IF gain down 
some.  I think this should cause the receiver to go less into gain 
reduction and I'd expect the front end to pick up some noise figure 
improvement.  AGC voltage would become less negative and the receiver 
should behave more like when in MGC.  Another thought is the 
possibility of a soft tube somewhere in the lineup.  That could upset 
the sought after AGC delaying characteristics.

Regards,
Jon


At 07:33 PM 2/11/2008 -0500, you wrote:
>Hi
>
>The IF gain setting will make the radio behave any way you wish it to
>going from AGC to MGC.
>
>Bob
>
>
>On Feb 11, 2008, at 7:21 PM, Tony Casorso wrote:
>
>>Hi everyone,
>>
>>I have a question about MGC vs AGC mode. On my R-390a there is a
>>substantial jump in gain when switching from AGC to MGC while I am
>>tuned to nothing but atmospheric noise. I measured it with the line
>>meter and the jump is about 12db. I also measured the AGC terminal
>>on the back of the set and the AGC sits at -1.8 volts in the AGC
>>position with the same signal. In MGC the AGC voltage goes to zero.
>>
>>Does this sound right? The reason I ask is that I have noticed that
>>weak stations are easier to copy in the MGC mode. I thought the AGC
>>delay was supposed to prevent this. Maybe the Lankford SSB mod (2
>>diodes) affects this?
>>
>>Thanks,
>>
>>Tony
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