[Hammarlund] HQ-129-X Question

[D C *Mac* Macdonald]

Local oscillattor running on the wrong side of the incoming
signal? If so, I'd bet that could REALLY screw up calibration.

* * * * * * * * * * *
* 73 - Mac, K2GKK/5 *
* (Since 30 Nov 53) *
* Oklahoma City, OK *
* USAF, Ret (61-81) *
* * * * * * * * * * *




> From: 1oldlens1 at ix.netcom.com
> To: hammarlund at mailman.qth.net
> Date: Thu, 25 Nov 2010 11:19:13 -0800
> Subject: [Hammarlund] HQ-129-X Question
> 
> I've finished tuning up my HQ-129-X. I find the 
> calibration of the band spread is just awful especially for 
> 80 and 40 meters. The error becomes progressively larger as 
> I tune from the "set" point downward. I wonder if this is 
> normal for these RX or not. The capacitor sections look OK, 
> no bending and the rotor blades appear to be centered in the 
> stator OK. I am tuning as directed, that is the set point is 
> at the high end of the band with the Band Spread set at the 
> highest frequency using a marker.
> Main tuning calibration is fairly good although there 
> is some error at the high end. Again, the tuning cap 
> sections appear to be mechanically normal. The main dial 
> errors are acceptable, perhaps that way originaly or from 
> drift in the fixed padding caps in the oscillator circuit. I 
> would be surprized if the band spread error was normal.
> I also get some hum on the carrier, noticable on CW on 
> the highest bands only. Perhaps a weak bypass cap in the 
> oscillator or a little heater to cathode leak in the 6K8. 
> The latter tests good but I will probaby get a couple of new 
> ones and see if they make any difference. The hum does not 
> appear to be coming from the power supply.
> Another minor problem: the crystal filter phasing 
> adjustment wants to center at about 4 on its dial rather 
> than at the pointer. I moved the "gimmick" capacitor around 
> to minimise this but it still doesn't quite center. Perhaps 
> the crystal has drifted. Otherwise the filter seems to work 
> perfectly.
> The RX is surprizingly stable after a reasonable 
> warm-up and does quite well for 20 meter SSB.
> BTW, I bought a speaker some time ago at an antique 
> radio sale which appears to be the matching speaker for this 
> receiver. 10" Jensen in a rounded corner case, finish is 
> close although not quite identical, and grill is similar to 
> the illustrations of the original. I understand that there 
> were variations on the cane metal used for the grills. Also, 
> in illustrations there seems to be more contrast between the 
> panel and cabinet and trim gray than in my RX, again there 
> were probably variations. My RX has "Hammarlund" and the 
> type number in white, which I understand indicates a fairly 
> late model. I wonder if anyone has any serial number records 
> for the HQ-129-X.
> 
> 
> --
> Richard Knoppow
> Los Angeles
> WB6KBL
> dickburk at ix.netcom.com 
> 
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