Picked up a nice, working Hammarlund HQ-100A receiver. At the very least, it is a cool looking radio.
Anyone tell me anything about this radio?
www.mods.dk has schematic and manual. Had one in 1958 not a bad receiver ... not real great above 20M however.
Also, like most Hammarlund receivers, it is pretty "drifty" above around 15 MHz.
Unless it has the optional true BFO, the HQ-100A just puts one of the i.f. stages into regeneration for CW/SSB.
Nice radios. I like them. I like most of the early HQ series for general listening. I own a 100, 100A, 110, and a mint HQ-110AC with 6m & 2m which I use everyday.
Here's a link to an image of the Hammarlund in one of the iterations of my workshop station:
The SSB reception is a little tough to get used to. You usually have to turn down the RF gain or the reception sounds distorted.
Also while they have pretty good audio output quality, there are some mods to improve the audio performance, around the web. One thing is there are some Centralab Couplates in the audio section. These are a limiting factor in the performance of the audio characteristics and were added by Hammarlund as a assembly time & cost saver for them. In my personal Hammarlunds I swap these out for discrete circuits I build up on lug terminal strips, changing some values and removing some filter circuits completely in some cases. These mods are on the web as well, as well as schematics for the couplate circuits themselves.
Also the way the radio works, the audio amplifier goes from Class A to Class B as you change the volume control from low to high. So it sounds nicely warm & smooth at low volume and gets decided swirly and nasty at high volumes.
Also you can mod it to add receive muting, which basically involves adding a wire to the audio cathode circuit shunting it to ground when you need the receiver to mute. You can find this in the schematic for a HQ-110 and add it to your HQ-100 if you need it. Very simple.
That being said, in its stock setup its still a nice GC radio once you learn it quirks.
Last edited by W2WDX; 07-02-2012 at 02:10 AM.
Originally Posted by K9STH
IIRC, it's the A that has the BFO. Dad bought me a new HQ100 when we were transferred to NC, and some time later the converson to A model with VFO. That let me use the Q multiplier on CW, the only HF mode Novices had then. But my first DX was F9TV calling me on 15 AM. Heh!
I found the manual on the HQ-100A. It does have a separate BFO. The HQ-100 had to have the optional BFO, Hammarlund model PL-38657-G5 installed.
The HQ-100A manual is available at the following URL: