[Hammarlund] Unstable Oscillator adjustments in the HQ-180

[djed1 at aol.com]

I suspect what you're seeing is normal.  Remember, when you're tuning an IF of 455 KHz, an adjustment of say 1 KHz is 1/455.  If you're adjusting the oscillator to the same tolerance, the ratio is (at 20 MHz) 1/20,000.  So it is a lot harder to adjust the HF oscillator.  I definitely avoid using an output meter to adjust the HF oscillator.  I either use the BFO, aiming for zero beat with the generator, or I couple a frequency counter to the oscillator and set it that way. And any of my Hammarlunds will shift the oscillator frequency a bit when you put a metallic screwdriver on the trimmer.
Aslong as it is stable when you're done, you probably don't have a problem.

Ed  Hammarlund SP-200, SP-400, SP-600

 

 

 

-----Original Message-----
From: K3PID <Ron.K3PID at sbcglobal.net>
To: hammarlund <hammarlund at mailman.qth.net>
Sent: Sun, Jan 31, 2016 7:45 pm
Subject: Re: [Hammarlund] Unstable Oscillator adjustments in the HQ-180

It's not a drift problem! The VFO is rock stable after a short warm-up. Imade the addition of the separate filament supply for V2 & V18. The problem( or perceived problem ) is touchy transformer adjustments! I watched Pete,K7PP adjust the transformers on his YouTube video and they did not appeartouchy at all.-----Original Message----- From: manualman at juno.comSent: Saturday, January 30, 2016 4:27 PMTo: hammarlund at mailman.qth.netSubject: Re: [Hammarlund] Unstable Oscillator adjustments in the HQ-180Try a different 6C4. 6C4's can be very flaky at times.Pete, wa2cwaOn Sat, 30 Jan 2016 15:19:30 -0700 RAY FRIESS <rayfrijr at msn.com> writes:> The old tube rigs, while great radios, were susceptible to drift and> stability problems, mostly for a while after first being turned on.> That's why we would often turn them on (or in the case of the> Hammarlund rigs, set the clock timer to turn on the rig) for about> 30 to 60 minutes before we were ready to do some serious operating.> This would allow them to become as stable as they could, and would> cut down the amount of drift substantially.   I would recommend> doing the same thing before you make adjustments and> aligning.   It might help.>>> > From: Ron.K3PID at sbcglobal.net> > To: Hammarlund at mailman.qth.net;> Hammarlund_moderated at yahoogroups.com> > Date: Sat, 30 Jan 2016 16:12:21 -0600> > Subject: [Hammarlund] Unstable Oscillator adjustments in the> HQ-180> >> > I’ve been working on my HQ-180 and have had some success but I> have discovered that while all  the adjustments in the ANT and RF> section are nice and stable easily adjusted for peak, the> transformer adjustments in the HF OSC section ( T23 thru T27 ) are> very touchy and might even be called unstable.  Has anyone else ever> encountered this? Any speculation on possible causes?> >> > Regards> > Ron K3PID> >> >> >> > ______________________________________________________________> > Hammarlund mailing list> > Home: http://mailman.qth.net/mailman/listinfo/hammarlund> > Help: http://mailman.qth.net/mmfaq.htm> > Post: mailto:Hammarlund at mailman.qth.net> >> > List Administrator: Duane Fischer, W8DBF> > ** For Assistance: dfischer at usol.com **> >> >> > This list hosted by: http://www.qsl.net> > Please help support this email list:> http://www.qsl.net/donate.html>> ______________________________________________________________> Hammarlund mailing list> Home: http://mailman.qth.net/mailman/listinfo/hammarlund> Help: http://mailman.qth.net/mmfaq.htm> Post: mailto:Hammarlund at mailman.qth.net>> List Administrator: Duane Fischer, W8DBF> ** For Assistance: dfischer at usol.com **>>> This list hosted by: http://www.qsl.net> Please help support this email list: http://www.qsl.net/donate.html>______________________________________________________________Hammarlund mailing listHome: http://mailman.qth.net/mailman/listinfo/hammarlundHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Hammarlund at mailman.qth.netList Administrator: Duane Fischer, W8DBF** For Assistance: dfischer at usol.com **This list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.html ______________________________________________________________Hammarlund mailing listHome: http://mailman.qth.net/mailman/listinfo/hammarlundHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Hammarlund at mailman.qth.netList Administrator: Duane Fischer, W8DBF** For Assistance: dfischer at usol.com **This list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.html