[Hammarlund] HQ-180A alignment

[Bob Young]

OK I think I have finally found the correct way to align the IF's, I used the Feb 1970 manual and it is correct EXCEPT that it neglects to tell you to change to the BCB for the 455 KHZ alignment and then change back to the 7.85 - 15 MHz band for the final 3035 alignment.
I did it the way the Feb 1970 manual has it, first 60 KHZ, then 455 KHz and then 3035 MHz which is only two tweaks. I just did the lower BCB and two passes and it came out good, the frequency shift I got from changing the selectivity is also gone as far as I can tell, will update later today hopefully after I go through all the bands.


Bob
KB1OKL


This I got from Roger WQ9E in the Antique Radio forums:

I think this is one of the better copies of the manual: http://www.atwaterkent.info/Images/Manu ... HQ-180.pdf<http://www.atwaterkent.info/Images/Manual_Hammarlund_HQ-180.pdf> but the alignment instructions from any of the series should work fine.

The most critical part is making sure that your signal generator is accurately set at 60 Khz. and note that some of the lower cost frequency counters aren't very accurate in this range so double check. Once you get the 60 Khz. IF strip properly aligned you have the hardest part done. Some of the procedures have you align the 455 Khz. first with a 455 Khz. signal while others have you go directly to alignment of the 3035 Khz. IF and either process is fine BUT make sure you are on a higher RF range where the 3035 Khz. IF is in play if you align 3035 first (range starting from 7.85 Mhz. upward if you start with the 3035 Khz. alignment and/or to do the 3035 Khz. alignment). The alignment of the 3035 IF isn't critical since its bandwidth is measured in 10s of Khz. and the 455 Khz. IF strip is not much more selective than a typical broadcast receiver but do align it and particularly the 455 Khz. slot filter carefully for best performance.

In general the procedure is align the 60 khz. carefully then apply a 3035 Khz. signal and set the third conversion oscillator (L4) so that the 455 Khz. IF signal is converted to 60 Khz. T1 is a dual frequency transformer and only the top slug is adjusted for 455 Khz., this adjustment should be made on the broadcast band. T3, T4, and T5 are the regular 455 Khz. IF transformers and can be adjusted on any band. The bottom slug of T1 along with T2 are the only 3035 Khz. IF transformers and these must be aligned on a higher frequency band (7.85 Mhz. or higher) where the HQ-180 is operating in triple conversion mode.

On the ranges from .54 to 7.85 Mhz. the HQ-180 operates in dual conversion modes with IF frequencies of 455 and 60 Khz. and the HFO operates 455 Khz. above the signal frequency. For the ranges from 7.85 Mhz. and up the HQ-180 is a triple conversion receiver with a first IF of 3.035 Mhz. and the HFO operating 3.035 mhz. above the signal frequency; this is what provides excellent image rejection in the higher bands.

The HQ-180 is effectively a HQ-160 coupled with the Hammarlund HC-10 SSB converter while the sister HQ-170 is effectively a HQ-110 with the HC-10. The HQ-170 and HQ-180 share much of their circuitry in common but of course there are differences in the front end due to the general coverage vs ham band only nature of the two sets. The circuitry between the first and second mixers of these two sets is very different but from the first 455 Khz. IF on they are very similar.

Rodger WQ9E