I continue to work on this old beast. I picked it up in the Dominican Republic around 1994. One of the IF transformers had gone open. I fixed that. Had to replace the AF output transformer too. And the variable cap that tunes the antenna. Check out the flywheels! And the rope and pulley thing. You don't find those kinds of things in any of those fancy modern rigs. Earlier I had removed "the exclusive Auto-Response audio output circuit." See: http://soldersmoke.blogspot.com/2016/02/snowed-in-audio-mods-on-hammarlund-hq.html Today I installed a simple feedback network in the AF amplifiers (as prescribed here: http://www.amwindow.org/tech/htm/hqaudiomods.htm It sounds nice now.The rest of the bands have been ravaged by some sort of solar event, but 160 seems to be benefiting -- signals last night and this morning were quite strong. I was being heard by WA1HLR way up in Maine.
UPDATE 20 Feb 2016: After installing the feedback network mentioned above, I noticed a big increase in AC hum. It was not the electrolytics. I reversed the feedback mod and the hum went away. But the receiver continues to sound a lot better with the removal of the Auto-Response output circuit.
In response to popular demand, "SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
For the print version:
For shipping from a printer in the U.S. (probably better for N. American buyers) Click here: SolderSmoke USA Version
For shipping from a printer in the UK, Spain, or the USA (probably better for UK and other European buyers)
Click here: SolderSmoke EU Version
The two versions are identical, except for a minor difference in the paper used. That's why the prices are a bit different.
Bill's OTHER Book (Warning: Not About Radio)
Click on the image to learn more
W4HBK's QRSS Grabber: The Amazing Pensacola Snapper (Live!)