[Hammarlund] Bob Young:HQ-180 audio

[Roy Morgan]

At 10:13 PM 5/1/2005, you wrote:
>Bob, Your post exactly decribes how the circuit works. But you didn't
>mention if you think it's a good idea,

Mike,

Did I email you on this before (memory is a bit weak hi..):

(This is all someone else's opinion, not mine based on experience.  My 
HQ-170 has an oscillation in the IF strip that I need to solve before I 
make any changes.)

In the 170 and 180 the change to the audio circuits may not be worth while, 
since audio bandwidth is limited by the low IF strip selectivity.

SOoo.. If you stagger tune the 60 kc if strip to broaden and flatten it 
(sweep alignment recommended) then you may have enough improvement to 
warrant the audio network changes.

See The AM Window web site for more on this topic.

>  There has to be some way to improve the
>audio permance of this very wonderful radio.

These two methods may be joined by others as we get more opinions:

1) Stagger tune the low IF strip (and the 455 one, while you are at 
it.)  Use a sweep alignment method if you can.  Then do the suggested mod 
to the audio setup.

2) Pick off the audio signal from the diode load and feed it to an outboard 
amplifier.

Roy




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