[Hammarlund] HQ-100C Alignment

[Roy Morgan]

On Oct 19, 2009, at 8:55 PM, Bill Stewart wrote:
> Thanks Rodger and Glen for your ideas on the alignment situation.  
> I'll mull them over and go back to work on it tomorrow.

Bill,

There is a test for "wrong side" local oscillator operation:  Usually  
the LO is above the received frequency (as Mac has confirmed for this  
radio).  With this true, if  you tune the signal generator to the  
frequency twice the IF frequency *above* where the radio is set (for  
455 kc IF's, 910 kc above),  and turn the generator output up  
(sometimes quite a bit) you should hear the "image" signal.

If you have to tune the generator below the radio frequency to hear  
the image, the LO is below the received frequency.

A second way to find out if your LO is on the wrong side, is to use  
another receiver. Put a bit of wire feeding the other receiver near  
the LO tube, or the LO part of the tuning cap and see what the LO  
frequency is.

Any moderately good general coverage receiver is good for such bench  
testing.  The R-388 is very nice.  The R-390A is kind of a pain to  
tune around quickly. A ham band only receiver will be frustrating to  
use.

Roy

Roy Morgan
k1lky at earthlink.net
529 Cobb St.
Groton NY, 13073
Home: 607-898-3607
Cell: 301-928-7794