[Hammarlund] HQ-129-X Question

[Richard Knoppow]

     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