[Boatanchors] 2,000 Volt Power Supply for Hammarlund SP-600 ;-)

[Philip Atchley]

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 noticable 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".

ANYWAY, that is a digression from the subject at hand.

The subject of this post is "A 2,000 Volt power supply for the SP-600" ;-) 
After reinserting two groups of the coil modules and their little clips (I 
DON'T try to pull the RF deck without removing some coils) I started to put 
the bottom cover back on.  When I had the set apart before I'd noticed a 
penciled in schematic on the INSIDE of the Bottom RF deck cover.  I didn't pay 
any attention as I figured somebody had drawn the schematic of the RF deck.

WRONG!  It didn't look right and closer examination shows that it is the 
schematic of a 2KV power supply with 3B28 tubes and metering.  I guess 
somebody planned to "Soup Up" their SP-600. Anyway,  I'm taking it outside and 
am going to clean it off  with a brillo pad.

73 de Phil,  KO6BB
991 Different NDB's heard to date.
SWL QSL GALLERY: http://photobucket.com/albums/y123/KO6BB/
THE BEACONEER'S LAIR:    http://www.geocities.com/ko6bb/
Merced, Central California, 37.3N  120.48W  CM97sh