[Hammarlund] Re: 2,000 volt SP-600 - digression

[Al Parker]

Hi Phil,
    Maybe the cover was gonna be for his new miniature HV p.s.?
    Anyhow, I'm more interested in the digressed subject - did the
stability increase any from all your efforts.  If so, which did it, the
re-touched solder joints or the EGD's (Epoxied Green Drops?  Maybe that's
a new term we need, like BBOD's, GLOD's, OD's, etc.  I can just hear
somebody in abt 50 more yrs saying, "why did they have to epoxy these EGD
things to the chassis, it makes them so hard to replace, and what shade of
black should I use to stick my new chartreuse drops in with?"  Then a big
discussion on the lists.
    Really tho', did it get better?  I've had some of the same thing
happen, once did find that it was a flakey mica in the osc. secn in the
turret.  Recently, for another digression, I've found my latest
SP-600-JX-5, sn 5911, (R-274B sn 13) with a K9EUI prod. det. mod, to be
very stable on 20m.  After abt 10 min. warmup, I can listen to the MM net
on 14.300 for 2-3 hrs and only have to touch the tuning a few times.  I
had noticed some drifting on 40m, a single conv. band, but haven't done
anything further on that.
    This prod. det. ckt puts a 6BE6 in place of the 6BA6 AVC amp tube, and
so far I'm very happy with it.  I got the rcvr from Bob, K9EUI, he had
done the mod. some yrs ago.
73,
Al, W8UT
New Bern, NC
BoatAnchors appreciated here
http://www.thecompendium.net/radio/
http://www.hammarlund.info

----- Original Message ----- 
From: "Philip Atchley" <beaconeer at sbcglobal.net>
To: <hammarlund at mailman.qth.net>
Sent: Thursday, June 09, 2005 12:04 PM
Subject: [Hammarlund] 2,000 Volt Power Supply for Hammarlund SP-600 ;-)


> Hi,
>
> After doing a preliminary of this SP-600JX14 for several days to
determine any
> "problem areas", I had to pull the RF Front End deck (again).  On the
lower 3
> bands the set had just a touch of frequency instability when anything
was
> thumped, especially the LO and mixer tubes(yes I tried replacing them).
They
> weren't huge jumps but was noticeable when copying CW (not noticeable on
AM).
>
> Since the LO and Mixer circuit uses two gangs of the tuning capacitor on
those
> lower bands I suspected something down in the "innards around the
contact
> fingers etc was either not making good contact or was vibrating.  I used
a lot
> of those .01uF Radial lead "green drops" because they fit nicely up next
to
> the walls etc.  Not nearly as clumsy as Orange drops.  Anyway, while I
had it
> apart, I resoldered a lot of connection (old and new).  Then I took a
tip from
> the Satellite work I did for TRW.  ALL components (except SMT) are
"bonded".
> That is, held in place by a black Epoxy substance (mixes and looks
identical
> to J.B. Weld).  So, I mixed up some J.B. and secured each and every
> "greendrop" to the adjacent wall just to "be sure".
>