[Hammarlund] HQ-170A drift

[Bob Camp]

Hi

Standard drill on Field Day back when the HQ-170 was brand new was to get them fired up ahead of everything else to give them time to warm up and stabilize.

The voltage regulator tubes in them look *really* pretty when the generator accidentally gets set a bit to high in voltage ….

Bob

On May 17, 2014, at 5:19 PM, Al Parker <anchor at ec.rr.com> wrote:

> Hi JOhn,
> 	The 6C4 advice is good, could be most of your trouble.  But, you have a 170A.  Does much of the drift go away after 30-45 min. of being turned on?  Do you have it plugged into a "power strip"?  Many folks do that to preserve the life of the on-off switch, but the -A models do keep the filaments on at all times for the 6C4 osc. and the mixer tubes.  That keeps the tubes warm all the time and the extra heat helps keep the rest of the ckts a bit above room temp.
> 	I had an HQ-180A which developed drift, and I realized that I had recently plugged it into the power strip that I used to turn off the desk light and soldering iron.
> 73,
> 
> Al, W8UT
> www.boatanchors.org
> www.hammarlund.info
> 
> "There is nothing -- absolutely nothing -- half so much
> worth doing as simply messing about in boats"
> Ratty, to Mole
> 
> On 5/16/2014 6:28 PM, John Boyle wrote:
>> I recently bought an HQ-170A at a hamfest.  It’s in good condition but has the well-known frequency drift in spades.  I’ve read comments about the instability of both the capacitors and inductors in the oscillator section.  Would some new high-quality capacitors help and if so, which ones?  Any thoughts on this matter would be appreciated.
>> 
>> John  VE3PMA
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