[Hammarlund] update HQ-180 issues

Wed Dec 17 09:42:04 EST 2014

I love the HQ line.  I always wanted one when I first got licensed back in the 60s, but, as was often the case with young
new hams, they were out of the price range for availability.   Now, years later, I am getting and playing with the old tube
rigs that I could not afford back then.  While I have a couple of more modern solid state rigs and hybrids like the Kenwood TS
line, I still enjoy the old rigs more.  I firmly believe in the old maxim that REAL radios glow in the dark HI HI>

I have an HQ 180, HQ 145 and HQ 170.   My 170 was sent off to a guy who is a real expert at them.  He went through it
top to bottom and put it back to almost original shape as far as sensitivity, tuning, etc.  Unfortunately, it has now developed what
I understand to be a common problem, the little ceramic capacitors across the canned coils are getting flaky, causing 
oscillation, sensitivity to touching the panel, and microphonics.  Often though, if I turn it on and leave it to get really warmed up
it will be okay for most of the time.  When it has trouble, it also has static crashes and static even in the standby position of
the mode switch.  Almost like a bad tube in the audio section, but it's not a tube issue.

Anyhow, my thought is this.  The Hammarlund line was, and still is, a great line of receivers.  Especially the 180 which still holds
its value and costs a fair amount even today.  However, we need to remember that it was sold and used during a ham radio
time when operating conditions were not what they are now, so of course they may not compare to todays fancy solid state
rigs with all their doohickies and newfangled things on them.  They were sold back when AM and CW were king, and still did
quite well when SSB first started coming into vogue.  

Overall though, I still love mine with the big dials, lit up tubes in a semidarkened shack, and coupled with a good old tube
transmitter, whether its SSB or CW.   Especially the rare AM signal.   A real joy to operate.

> Date: Wed, 17 Dec 2014 08:27:19 -0600
> From: WQ9E at btsnetworks.net
> To: rsauvan at beyondbb.com; hammarlund at mailman.qth.net
> Subject: Re: [Hammarlund] update HQ-180 issues
> 
> Bob,
> 
> The RF gain control has two sections, one controls cathode bias for the RF amp and the other controls cathode bias for the second IF stage.  I believe this pot is probably a reverse log taper and will likely be somewhat difficult to find now.  It is quite possible someone replaced this in the past with a wrong taper pot.  Other possibilities are a tube issue in one of these controlled stages or someone substituted a different tube type.  In practice I am not sure you are ever going to need fine control of the RF gain control and normally it can be set at maximum gain.  I have several of these family member receivers, a HQ-180 along with HQ-170, HQ-170A, and HQ-170A VHF ham band versions of the HQ-180 and I don't recall needing to reduce RF gain on any of these.  They all have good all mode AGC systems.
> 
> Can you better describe how the audio sounds bad?  One fault I found in a HQ-180 I restored was a bad audio "couplate" Z2 that had a leaky internal capacitor and was allowing positive bias on the output tube audio grid.  With volume set to minimum check for DC voltage on the output tube audio grid.
> 
> Another reason for poor audio with the HQ-170/180 series is misalignment of the low IF.  This alignment is critical and given the selectivity at 60Khz. poor alignment will result in very poor operation.  Make sure that your signal generator is accurately placed on 60 Khz. for the alignment.
> 
> The HQ-170/180 receivers were never meant to be high fidelity receivers and although these are some of the best "battle conditions" vintage receivers when interference is tough even in the widest mode AM fidelity is quite restricted.  I used a HQ-170 with my Ranger/Desk KW for quite awhile and it did a very nice job with AM under rough conditions.  I now use a Hallicrafters SX-88 with that station but I sometimes miss the easy sideband selection on AM provided by the HQ 170/180 receivers, the SX-88 requires a slight retuning to choose AM sideband to avoid interference. One of the most versatile Hammarlund setups is a HQ-160 coupled with a HC-10 sideband adapter.  The HQ-160 is the predecessor of the HQ-180 and has a final IF of 455 Khz., the HC-10 is effectively the final converter, 60Khz. IF, AGC, detector, and audio section from a HQ-170/180 receiver and the combination allows better fidelity when conditions permit by using the HQ-160 audio output while using the interferen
>  ce fighting capabilities of the later models, albeit with lesser fidelity, when conditions are bad.  
> 
> I have a slight preference for the Hallicrafters approach to selectable sideband receivers (used in the SX-96, 100, 101, 115, 117 family) since only the bandwidth and not the passband position is changed in the selective IF.  Hallicrafters uses either low or high side injection in the final converter to choose sidebands while Hammarlund changes both width and passband offset direction in the low IF which is a bit more complex and in practice doesn't allow perfectly identical response for the sideband chosen. The choices in the Halli system allow a little more fidelity with the widest choice of 5 Khz. which is the equivalent of 10 Khz. with conventional dual sideband detection.  But both approaches provide good performance under trying conditions.  If my SX-88 had the later selectable sideband approach of the later family members it would be the near perfect vintage receiver :)  Heathkit borrowed the Hallicrafters approach when designing the RX-1 Mohawk.
> 
> Rodger WQ9E
> 
> -------- Original Message --------
> > From: Robert Sauvan <rsauvan at beyondbb.com>
> > Sent: Wednesday, December 17, 2014 7:40 AM
> > To: "jdteske at verizon.net" <jdteske at verizon.net>,  hammarlund at mailman.qth.net
> > Subject: Re: [Hammarlund] update HQ-180 issues
> > 
> > Thats interesting. Before I replaced the Hayseed cap, the RF gain acted 
> > as I described in the previous email but now it is worse. I am going to 
> > put a meter on the pot to see what it might be doing. If I need one, not 
> > sure where a replacement can be found but may have to start looking. 
> > Just one of my couple of issues Im trying to work out for now.
> > 
> > Thanks-Bob-W0YBS
> > 
> 
> 
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