[Collins] Hammarlund and Collins Radio

[Dr.Gerald Johnson]

I don't think Art would have cooperated with anyone unless they had a 
gun to his head (or some bank insisted on cooperation to make a loan).

The mechanical filters were sold to other radio makers as a Collins 
product, like the toroidal coils, and complete radios. Using those 
component products doesn't even hint at a cooperative relationship, 
other than as vendor and buyer which could have been through a 
distributor.

Many radios have RCA phono jacks on the back, for sure Heathkit (and 
the SB line was designed by an Ex Collins engineer who had worked on 
the S-line) and Tentec, to say nothing of virtually every AM/FM stereo 
tuner. Some would criticize the use off RCA phono jacks on 
communications equipment, though Collins did use a better quality jack 
from Switchcraft than the ordinary home entertainment product. 
Motorola did use RCA phono jacks for RF connections internally to two 
way radios for a long time, again, not the cheapest parts and they 
were adequately reliable. When making patch cables, the use of 
Switchcraft plugs can result in a more reliable set of cables than using 
phono plugs from the Pacific rim.

With the 32S1 control outputs being relay contacts, it could be 
considered compatible with any receiver that had its own antenna 
input and that was muted by opening a circuit. And that muting was 
common in most receivers from the 30's on. Either by opening the B- or 
the RF-gain control line. Neither would have been so effective 
necessarily in a transistorized radio, but a suitable control circuit would 
only take another transistor or two. Mating the VFO and crystal circuits 
would have required the frequency conversion scheme be the same 
and that wasn't typical of Hammarlund equipment before that time. I 
don't know what frequencies the HQ-215 used.

For many years, my S-line was connected together through a patch 
panel and under stormy conditions on 75m I used a Q-5er with converter 
that handled static immensely better than the ringy mechanical filter in 
the 75S-3B connected to the 32S-1 and they worked together just fine, 
just wouldn't transceive with single knob frequency control.

73, Jerry, K0CQ, Technical Advisor to the CRA

-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.