Hammarlund HQ-180 and digital readout

[wc4r]

I'd like to add the ebay/Chinese digital readout to my HQ-180. But I'm not certain as to the best point to pick up the tuning frequency. My thought is to use C155/C28 just before the second converter stage.

What is the best point? (I bow to those vintage experts.)

Here is the display unit:
https://1drv.ms/f/s!AlUa4HQk6C10gd1ZnuOBHmrSrjhuUQ

[Pete, WA2CWA]

The HQ-180 is a triple conversion receiver. On the lower bands, double conversion is used; on the higher bands triple conversion is used. You need the proper interface circuitry between the receiver and the display to interpolate the various oscillator and mixer frequencies to have the digital display read correctly. That's why this fellow is in business: http://www.electronicspecialtyproducts.com/dd101hu.html

[wc4r]

I noticed that info in the manual's circuit description Pete. Not an easy interface. May have to work up a compromise.

[N3GTE]

Have used that counter on my pre war HRO and it works great but it's a single conversion set. On your triple conversion set every time the conversion scheme changes from single, double, or triple the IF offset needs to change too. I don't know that you can set this counter to do more than one offset.

[MikeKE0ZUinkcmo]

Since those counters are so cheap, you might consider just using two of them, and picking some point to move power from one to the other when the receiver switches from double to triple conversion.

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Terrell, nice transmitter.

[N3GTE]

Hi Mike,
Looks like are H-W's close in serial#as they both have the flat silk screened logo on the panel. That would indicate that it's an early run of the B,C,or D models. Somewhere around 3000 to 4000. The earlier TBS-50's and later B-D model used the cast chrome logo.
The one in the pic is a B or Jr. No modulator just cw no mic jack either just a hole for one. Don't think many of these were sold. Have only seen two over about the 30yrs I've been fooling with them. Probably geared for the "new" Novice class op's minted in the fall of '51.

Terry

[N3GTE]

To get back on topic you might be able to resize some of the spacers on the bandswitch to accommodate a switch wafer at the back end to do the counter switching. Did this on a TBS-50 to add in the extra loading cap for 40 and 80mtrs.
GL
Terry N3GTE

[MikeKE0ZUinkcmo]

It looks like you could tap "switched" power off the back side of S2G.   That's where the B+ is switched between pins 6 of both  the "455kc Gate" V18, and V3 the "first converter", ie double and triple conversion.   These things don't use much power so a 1 or  2 Watt dropping resistor for each counter would probably do the trick.



YMMV, Good Luck.


Mike