[Hammarlund] HQ-180 AVC and Audio Issues

[Roy Morgan]

On Dec 18, 2014, at 4:29 PM, Byron Tatum <bjtatum1 at att.net> wrote:

> Hello-
>    Just a note to all following this- the Hollow State Newsletter (80's era newsletter) has a fair amount of info on the HQ-180.
...
> Most of the info is provided by Dr. Dallas Lankford; he published his original treatise of the HQ-180 AVC in the Hollow State Newsletter.

I have looked for an index to the Hollow State News but can’t find one.  The issues through number 37 compiled into three big files are at:
http://mikea.ath.cx/
I have a copy of an index developed by Reid Wheeler, the editor, through issue 45.

> ..., there are some other mods I did to my HQ-180's:
>      1. I rebuilt the power supply...Achieved desired result of dropping the B+ voltage some, ... Had to reduce value of VR tube dropping resistor.

It would be interesting to hear what the B+ wound up at, and what the VR tube dropping resistor was.  There have been reports lately of radios working BETTER at B+ voltages lower than the design value.

>      2. I added a 6BH6 osc tube and removed the crystal (around 2.5 MC if I recall correctly) from the 6BE6 second converter ... I obtained the idea from this when I read a lab evaluation of an HQ-180A by Jay Rusgrove W1VD, on his website.

His website is:
http://www.w1vd.com/
Today I can only find an article there about th HQ-170A:
http://www.w1vd.com/HammarlundHQ-170A.html

Roy

Roy Morgan
RoyMorgan at alum.mit.edu
K1LKY Since 1958