[Hammarlund] HQ140X questions

[Dan Martin]

Yep, this is a mod. A means to enter the path between the output of the mixer, pin 5, and the first IF can, Z1, which has as an internal component, T1. Pin 5 has 200-plus VDC on it, by the way.

Hammarlund serial numbers are a mystery, at least to me. I have both an HQ-140 and HQ-150, both identical but for the Q-multiplier in the 150. My 140 has a X-XXXX stamped on the back where all characters are numbers. The 150 also has X-XXXX stamped on the back but the first character is a letter. Go figure! Both were made in the same mid-late 50’s era and may have even been made concurrently for a short time, at least.

Both are fine single conversion receivers and among my favorites.

Dan
WB4GRA

Sent from my iPhone

> On Dec 13, 2023, at 12:45 PM, Ray G3XLG via Hammarlund <hammarlund at mailman.qth.net> wrote:
> 
> Just had a look Richard, the centre pin of the strange chassis connector
> goes via a 56K resistor to pin 5 the anode of V3 the mixer.
> 
> A blue wire also on pin 5 goes up through the chassis to T1 between the
> mixer and the first 1st IF.
> 
> I think you are right it's a Ham mod, perhaps to feed a signal generator?
> 
> 73
> 
> Ray G3XLG
> 
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