[Boatanchors] HQ-180 bandwidth

[Singley, Rodger]

Carl is absolutely correct and this same thought applies to the
Hallicrafters SX-96 family of receivers and the Heathkit RX-1 "Mohawk".
Easiest setup on all of these is to zero beat the AM signal in the SSB
position and then switch to AM and choose the sideband that offers the
least QRM.  The selectable sideband, slot or notch filter, and variable
selectivity can do wonders under bad conditions.

I read a magazine article from the 50's where Heathkit sent out a note
to RX-1 owners explaining how to properly set up the receiver on AM
since so many were complaining about difficulty tuning AM signals since
they were trying to center the carrier in the passband which doesn't
provide enough bandwidth.

My one real disappointment with my Hallicrafters SX-88 is that it
doesn't offer the easy sideband switching on AM as the later members of
the 50 Khz. IF family of receivers.  You can get the same effect by
re-tuning to favor either sideband but it isn't as convenient.

The HQ-170/180 receivers are some of the best out there under "battle
conditions" AM and I use a Hammarlund HC-10 with my TMC GPR-90; the
HC-10 is basically the last IF, detector, and audio stage out of a
HQ-170 packaged as an external SSB adapter.  This turns the GPR-90 into
an excellent receiver for both good and bad conditions and I found an
HC-10 but I never had any luck getting the matching TMC adapter for the
receiver.

The HQ-170/180 are designed to automatically reduce the audio bandpass
at higher volume settings.  You might look into bypassing this; I
haven't bothered but my casual observation is that it does little to
help copy and probably detracts a bit from the audio passband.  Another
good receiving aid for vintage receivers is an Autek QF-1 or similar;
these help a bit on AM and a lot on CW.

Rodger WQ9E


> -----Original Message-----
> From: boatanchors-bounces at mailman.qth.net [mailto:boatanchors-
> bounces at mailman.qth.net] On Behalf Of Carl
> Sent: Friday, September 25, 2009 8:23 AM
> To: Joe Roth-WC4R; boatanchors at mailman.qth.net
> Subject: Re: [Boatanchors] HQ-180 bandwidth
> 
> If you want improved AM bandwidth simply select U or L sideband. Then
> shift
> the carrier to the edge of the passband using the vernier tuning. You
> now
> have 1 sideband taking up the full bandwidth which is well over 3 kc
on
> even
> a moderately strong signal.
> 
> Many do not realize that all those controls work on any mode.
> 
> Carl
> KM1H
> 
> 
> ----- Original Message -----
> From: "Joe Roth-WC4R" <wc4r at live.com>
> To: <boatanchors at mailman.qth.net>
> Sent: Friday, September 25, 2009 9:12 AM
> Subject: [Boatanchors] HQ-180 bandwidth
> 
> 
> >I have a Hammarlund HQ-180C, all stock. Is there a reasonable way to
> change
> > the 3 KC receive bandwidth to 5 or 6 KC? I don't want a butcher job.
> > Something clean & reversible.
> > Joe, WC4R
> >
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