[Hammarlund] HQ-100C Alignment

[Glen Zook]

Sounds like the r.f. and mixer stages are tuned on the "image" which will be 910 kHz away from the desired signal.  Unfortunately, a single conversion receiver like the HQ-100 doesn't have that good of an image rejection especially on the highest frequency band.

As for the "stuck" slug:  There is a very good chance that the slug is cracked and will have to be removed and then a replacement slug inserted.  Removing a cracked slug requires patience and being very careful to remove the slug a piece at a time.

As for images:  Back around 1960 there was a "brand new" ARRL "Official Observer" who started sending out hundreds of cards to amateur radio operators who were operating "outside" of the 40 meter band.  This went on for a couple of months and letters to the OO as well as letters to the ARRL had no effect.  Finally, several amateur radio operators telephoned ARRL headquarters and got their attention.  What was happening was that the OO had a single conversion receiver with a 455 kHz i.f. and was receiving on the image which was 910 kHz away from the actual frequency.  I never heard exactly what happened.  However, the OO cards ceased to be received for operation outside of the 40 meter band.  I suspect that the OO appointment was rescinded.

Glen, K9STH

Website:  http://k9sth.com


--- On Mon, 10/19/09, Bill Stewart <cwopr at embarqmail.com> wrote:

Now comes a problem. On the 10-30mc band, the rcvr is dead from about 11.5mc down to 10mc...no sig. gen. heard in this area. Above 11.5 or so, I can hear the gen., and with the antenna connected, sigs. come thru quite well. Also on the 10-30 band, the dial calib. is way off...over a mc., ie: 12mc dial = 13.516 sig. gen.; 11.5mc dial = 12.968mc sig. gen. This goes on up to 30mc dial = 33.268mc sig. gen. 
 
On a whim, I tried to adj. out some of the dial calib. error with the 30mc HF Osc. cylindrical trimmer cap (Fig. 8). The trimmer screw was out about 3/8 inch or so, but with it now all the way in, the dial error decreased slightly and is per the above para. 

And another woe is that the 10mc RF coil slug (bottom) is stuck. Is there anything safe to spray in the can or is a heat gun about the only 'safe' method to loosen it. Sure hate to have to remove it.