[Hammarlund] Question about warm-up vs. signal strength

[Carl]

Crystals lose activity over time and the oscillator tube may be weak. 
Any tube in the basic RF path will act the same way.

Does the cal signal drop on all bands?

What about using your rice box as a sig gen (NOT into the front end!) ?

Carl


----- Original Message ----- 
From: "Mike & Coreen Smith" <ve9aa at nbnet.nb.ca>
To: <hammarlund at mailman.qth.net>
Sent: Friday, January 30, 2009 1:31 PM
Subject: [Hammarlund] Question about warm-up vs. signal strength


> Hi Gang,
>
> I've got my new-to-me HQ-170a running pretty fair now .  Really a very 
> nice
> RX.  Thanks of course are due in part to the help I have rec'd from 
> the FB
> folks on this list.
>
> Cleaned lots of contacts, replaced a couple tubes,. etc.  Works very 
> well.
> (some of the tubes in it are marked "Hammarlund", so presumed 
> original) The
> inside underneath looks nearly new and there is almost no rust or 
> other
> damage on the face/case whatsoever) Still a few tiny bugs to work out,
>
> One thing I have noticed is that when I first turn it on, the signal 
> from
> the Xtal calibrator is (for example) s9 on 20m, but after the radio is
> warmed up (15-30 minutes later we'll say) the signal has dropped to 
> perhaps
> S6 or S7)
>
> I notice it fairly consistently right across the spectrum.. Ie: on 6m, 
> it's
> S3 when first turned on, holding steady back to s1 after warm up. (it 
> will
> be rock steady @ S1 for days, so I don't think it's the onboard Xtal 
> cal,
> but the RX itself.)
>
> Is this pretty much indicative of a RX ~45 years old, or are there
> components that I should be looking at swapping out?
> (ie: caps, IF tubes, etc.)  I'm quite happy with its performance the 
> way it
> is now, but I suppose if I could make it better. . . .
>
> I have not yet done an alignment on it.  I am working a little on my 
> old
> PACO signal gen to see if it will be accurate enough to use for an
> alignment, otherwise I may not actually do one until I have a better 
> signal
> source.
>
> BTW, last weekend we had an opening on 6m and I had some W9's in here 
> well
> over the s9 mark, so I was quite pleased about that. I am sure my 
> 2x8el yagi
> antennas on the end of the coax cable didn't hurt however ;-)
>
> Cheers,
>
> Mike VE9AA
>


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