[Hammarlund] HQ-150 question

[D C _Mac_ Macdonald]

Your calibration is probably about 30 kHz off at 15 MHz.  With a 455 kHz I.F. your image will be at 910 kHz above or below the actual frequency.  15,000 plus 910 kHz puts the image at 15.910 vice 15.880, ergo 30 kHz calibration error. 
 
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* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* Oklahoma City, OK * 
* USAF, Ret (61-81) * 
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> Date: Fri, 4 Apr 2014 12:45:03 -0700
> From: markdinsmore at gmail.com
> To: Hammarlund at mailman.qth.net
> Subject: [Hammarlund] HQ-150 question
> 
> Hello colleagues,
> 
> I have a Hammarlund HQ-150 I acquired a couple years ago. For the most part
> it plays fairly well.  In a past life it had the 5U4 replaced with silicon.
> It also has been modified with a 'hang-agc' unit as described in the old
> QST articles like the Dec 1965 QST articles like "Some thoughts on Hang AGC
> Systems," Chet Opal, K3CUW.
> 
> Anyway I recently noticed that on one of the bands, 10-18 Mcs, that I
> receive WWV on  15.00 at S+10 where I expect it, but also receive it at
> 15.88 at about S7 as well. Other strong stations in the middle of this band
> exhibit similar images at about the same 880kcs. Note that the WWV  at the
> low end of the band (10.00) does not have an image, the phenomena seems to
> be primarily in the center of the band.
> 
> Any thoughts on how I should begin diagnosing this?
> 
> Mark NZ7X