[Hammarlund] From Hammarlund HQ-180 service manual.

[ROBERT YOUNG]

AUDIO The HQ-180 features the exclusive Hammarlund Auto-response which 
automatically adjusts the audio passband to best meet the receiving 
conditions. A (6AQ5) provides 1.0 watt for maximum undistorted output. The 
auto-response circuit employs controlled feedback which is decreased as the 
gain control is turned up, thus narrowing the audio passband. As the gain is 
decreased, the feedback increases, thus permitting a greater frequency 
response to the audio output. the result is crisper, easier to read sound on 
weaker signals, and broader, more realistic reproduction on stronger 
signals.


I experience a cut in both bass and treble when the volume is set on a high 
level in mine so the human voice cuts through better on weak stations, but 
the bass cut is more pronounced to me. I believe the audio response is 
flatter at high levels to enhance the human voice at the expense of good 
music reproduction which means both less high and low end.

Bob Young

----- Original Message ----- 
From: "Mike Taylor" <reel2reel at hotmail.com>
To: <hammarlund at mailman.qth.net>
Sent: Tuesday, April 26, 2005 9:10 PM
Subject: [Hammarlund] Roy Morgan-HQ-180


> Roy, Haven't had a chance to look at the mail lately. Anyway, I believe 
> you
> have it backwards. Turning the volume up cuts the high end response.
> Hammarlund called this the "Auto response feature" and played it up in 
> their
> advertising. The idea was that stronger stations needing less audio gain
> could be heard with better fidelity. Advancing the volume control 
> increases
> selectivity for weaker signals. (More or less a combination volume/tone
> control.) A feature I don't care for as the HQ-180 can provide more
> selectivity than I know what to do with using the selectivity switch and
> slot controls. Ever heard  a bunch of eleven meter CB stations squeal with
> each other (like on channel 19)? The HQ-180 can separate them...a feat 
> I've
> never seen any CB radio able to do. If you're going to do away with or
> modify the "auto response" feature on your HQ-170, let us know what you 
> did
> and what results you got.  By the way, how are you comming with your 
> HQ-170?
> Enjoying your posts on the list, Roy. 73's, Mike
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