[Hammarlund] HQ-180A alignment questions

[jthorusen at centcoast.com]

Greetings to Bob and the List:

   Are you sure you have the correct schematic for the 180A?   According to 
the one at BAMA, C28 connects to the high end of the T5 secondary.   The 
value of the inductance of this secondary winding is not specified, but it 
is resonated by a 330 pF capacitor internally.   C168 also appears to be 
connected to this same point.  Also, I presume that your specification of 60 
Hz is a typographic error; the needed frequency to be injected here is 60 
KHz (kilocycles).

   You can use a modern DMM to look at the AVC bus (junction of L8 and C44) 
for alignment purposes.   This is a fairly low impedance point, compared to 
most AVC circuits.   However, trying to do an alignment with a digital meter 
can be an exercise in frustration.   Trying to interpret rapidly changing 
numbers while peaking IF transformers is very difficult.   A VTVM would be 
much better for this purpose.

Good Luck,
Jim T.
KB6GM
Palus delenda est.


----- Original Message ----- 
From: "Bob Young" <bobyoung53 at hotmail.com>
To: <hammarlund at mailman.qth.net>
Sent: Tuesday, December 05, 2023 16:28
Subject: [Hammarlund] HQ-180A alignment questions


I bought one several years ago and I'm finally getting around to aligning 
it, for the 60 Kc alignment it says to send a 60 Hz unmodulated signal to 
the junction of C28 and T5 and ground. By the junction I assume it means 
between C28 and the 330 mH choke? Also can I use a modern digital multimeter 
to keep it around -4V DC at the junction of L8 and C44 and the chassis as my 
VTVM got stolen in a move?

Bob
kb1okl
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