[R-390] [off topic] HQ-180A alignment craziness

[mlmccauley at att.net]

Thanks a lot for the quick reply, Cecil!

I got the manual from a guy who sells them "buy it now" on the standard 
online auction place. And I've noticed a few subtle differences between 
my set and the schematic in that manual.

I'm going by the alignment procedure in that manual, so that may be part 
of my problem, maybe all of it. Your procedure corrections will probably 
set me straight.

Again, thanks!

Mike



> Depends on which manual you are using.  There is a mistake in the 
> majority of manuals as to the settings of the front panel controls for 
> alignment of the 60Khz IF.  I'll see if I can find the info...I went 
> through this same issue with the HQ-170. It does make you crazy...
>
> Cecil
> ----- Original Message ----- From: <mlmccauley at att.net>
> To: <R-390 at mailman.qth.net>
> Sent: Sunday, February 17, 2013 4:35 PM
> Subject: [R-390] [off topic] HQ-180A alignment craziness
>
>
>>
>> I'm having big trouble doing an alignment on this set, and to my 
>> thinking what I see just doesn't make any sense. Any help anyone 
>> could give me would be greatly appreciated.
>>
>> As I tell this tale, bear in mind that, as is, the set will receive 
>> stations and properly demodulate AM, SSB and CW. Sensitivity is poor, 
>> but the radio does basically work. Selectivity is super tight, 
>> standard HQ-180A behavior.
>>
>> The very first step in the procedure is an initial rough alignment of 
>> the 60KHz 3rd IF. You connect a voltmeter to the AM detector and a 
>> 60KHz CW source to the coupling cap going to the grid of the 2nd 
>> mixer (presumably, leakage though the self-oscillating mixer gets the 
>> 60KHz out the back of this stage (?)). You are instructed to tweak 
>> the 60KHz IF transformers for maximum negative voltage at the test 
>> point.
>>
>> The directions say to keep reducing the signal level as you tweak so 
>> as to keep the test point from going no more negative than -5VDC. 
>> Problem is, I see -.35VDC, which never changes, 60KHz injection or 
>> no, low or high injection level.
>>
>> I've verified the generator freq at 60KHz with a counter that tests 
>> one Hertz off at 10MHz against a Cesium standard. I even swapped 
>> voltmeters.
>>
>> I've verified the injection and test point about 47 times.
>>
>> Any ideas?
>>
>> A guess - could it be that the 2nd oscillator (395KHz), mixer, and IF 
>> transformers have been jacked with *so badly* that the IF strip is 
>> tuned to a totally different frequency than 60KHz? These sets are 
>> notoriously super-selective, maybe my "real" 60KHz is being chopped 
>> off, totally outside the bandpass of the IF strip.
>>
>> I'm stumped. I've aligned entire radios and had them working great in 
>> the time that I've been messing with step #1 on this set.
>>
>> Again, thanks in advance for your help.
>>
>> Mike, WB5MYY
>>
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>