[Hallicrafters] SX-62 & SX-42 mica values

[Chuck Kembring]

Al.....
	I have just finished rebuilding all the cans on my SX-42 (Early Version,
SN# HA59397) and it was worth the time. The second IF uses 47Pf on the
primary and secondary of the 10.7 winding and 82 Pf on the primary of the
455 Khz winding and 330 Pf (To Pin 7) and 390 Pf (To pin 8).
	I disassembled and replaced one cap at a time. I found the color codes to
agree with the schematic in all cases. I do have a pretty good schematic for
the SX-42 thanks to Chuck McGregor N7RHU.
	I had many shorted micas as measured on my Heath IT-11 capacitor tester
step voltage test. I check values on my Boonton capacitance  74C-S8 bridge.
In most cases the leakage was identified on the very lowest range of the
hi-pot.
	I replaced my caps with dipped micas and bedded them in the holders with
silicone sealer. It seemed to work well.
	I hope this helps and let me know if I can help you with any other info.
	By the way, I finally repainted the homebrew transmitter (Viking II clone)
we talked about a couple of years ago and it turned out well.....
Take care,
73,
Chuck Kembring	WB3LGG
Cochranville, Pa.

-----Original Message-----
From: hallicrafters-admin at mailman.qth.net
[mailto:hallicrafters-admin at mailman.qth.net]On Behalf Of Al Parker
Sent: Friday, June 20, 2003 3:02 PM
To: Phil Atchley; hallicrafters at mailman.qth.net
Cc: Chuck McGregor
Subject: [Hallicrafters] SX-62 & SX-42 mica values


Hi Phil et al,
    I know Phil's found bad micas, so have I & others.  I'm suspecting some
in my SX-42 IF transformers.  I presently have 2 of them open, suspect T-2,
the 2nd IF as possibly flakey.  But, what are the proper values?  I have 2
paper schematics, one Halli, one Sam's.  Can't read them well.  Also got the
2 different -62 manuals from BAMA, same problem.
    Does anyone have a good manual of the SX-42 or -62 & can take a look for
me?  I'm particularly intersted in the 2nd IF, sometimes called that,
sometimes T-2, it's between the 6SK7 & 6SG7 in  either rcvr.  Note that the
signal runs from right to left.
    From the skems, I "guess" values of 52, 62 and 82 for the cap in the
455kc primary, and 320, 330, 390 in the secondary.
    I"ve pulled the primary cap, colors aren't much help.  I have an
accurate Ballantine capacitance meter that reads it as 82 +-5%.  I know that
values can show high if there's some leakage, but putting it on the Freed
megger, at 300 vdc it reads 50k megs, plenty good.
    Any help out there?
thanks & 73,
Al, W8UT
New Bern, NC
BoatAnchors appreciated here
http://www.thecompendium.net/radio/
http://www.hammarlund.info




_______________________________________________
List Administrator: Duane Fischer, W8DBF **for assistance**
dfischer at usol.com
----
Hallicrafters Collectors International: http://www.w9wze.org
----
http://mailman.qth.net/mailman/listinfo/hallicrafters