[Hammarlund] Modifications to a HQ-180A

[Edward Kusalik]

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