[Hammarlund] Modifications to a HQ-180A

[Bonddaleena at aol.com]

In a message dated 3/28/2006 8:53:19 PM Eastern  Standard Time, 
ekusalik at telusplanet.net writes:
A recent acquisition,  a  modified HQ-180-A , has some interesting 
modifications which I have not been  able to find any information on.The 
owner is deceased and further attempts  to find any files has met a dead 
end.  The person was a Ham , who also  was a ( I believe) Electronics 
Teacher at a local College. I'm wondering if  these modifications where 
his own design and something he developed on his  own. I still  hoping 
somebody can help me where one can get info on  these modifications.

They are:

1)Where the clock was the following  controls have been added:
a)Separate Tone Control
This is a separate 10K  Pot
b)Separate  R.F. Control
separate 1500 ohm Pot from the original  one that was part  with the 
on/off switch
c)ON/ OFF Toggle  Switch

Now the interesting modification:

a)The R.F control now has  been identified as a  I.F. Pot Control ( with 
the on/off switch   that was the back, now a separate toggle switch)  
This is R15, part of  the 455 IF Amplifier on the schematic diagram.
Any one what the idea behind  this?

b) The 6BV8 AVC - AM Detector  now  is replaced with a  12AU7 with a 
Vactor in the tube socket.
What's the idea behind  this?


And finally in the AC Line a EMI/RFI  filter ( Radio  Shack) has been 
installed.

Would appreciate if any body out there can  enlighten me
on where one can get information on this or answer my  inquiries.

Edward  Kusalik
VE6EFK





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Interesting. My only thought concerning the IF control would be that he was  
attempting to control the gain of the IF strip independent of the RF gain. I  
know my HQ-17A has tremendous RF/IF gain, really too much.......
 
ron
 
N4UE