[Collins] Re: Collins digest, Vol 4 #213 - 1 msg

[kwylow zinjanthropus]

Try one of those high power National RFC chokes. I suspect it MIGHT do but then again, double check. Be sure to get the one that is designed not to react to the 15 meter band like it's predecessor. 
 
By the way (and I know this might offend some of the diehard Collins collectors out there): don't be afraid to substitute in non-Collins parts or non-Collins contract parts. If you can, shoehorn it in and if necessary, create an adaptor bracket so the mod becomes bolt in and easily changeable should you run across the right part down the line. 
 
It just makes sense to use whatever you can get in light of the fact that THEY JUST DON'T MAKE REPLACEMENT PARTS FOR THESE RIGS THESE DAYS. 
FWiW:
Cal, N6KYR. 

LorinH@aol.com wrote:
Dear Friends,

Last night, when checking out a KWS-1 which I am restoring I tuned it up at 
full power on all bands, when I reached LOW 10 meters I suddenly heard a loud 
"Crack" which was then shortly accompanied by some smoke coming out of the 
final compartment. 

When I opened the bottom of the chassis and PA compartment I discovered that 
L 403, the Plate RF Choke had cracked in two,, It broke quite near where it is 
attached to the right side (looking down) of the compartment. I did not see 
anything else that had burned, but will check. This of course raises several 
questions.

Does anyone know of a source or the 90 UH ceramic RF choke? Surplus Sales 
has one that is advertised as being for the KWS-1, but after speaking with Bob 
Grinell we concluded that it is a 45 UH choke, different in design and would 
not serve. 

If a new one cannot be purchased, repair becomes the only option. Is it safe 
to glue this ceramic core together, using some form of high temperature epoxy 
or other (super)glue? Does anyone have experience with this, and can advise 
as to the type of substance to use?

This all begs the question of why the choke cracked in the first place. Heat 
is the most likely answer. (This choke was, of course, the subject of the 
service bulletin which reported its failing in the field, and advised removing 
the fiberglass insulation because it trapped moisture.) The blower seems to be 
operating well, but things still do get quite hot around the finals 
especially after periods of "tune" with key down. 

I am very grateful for any ideas or advice,

Also, in another domain, I am about to align my 75A-4 (I have owned both rigs 
for 48 years) and am most interested in alignment information which is based 
on the wisdom born of common shared personal experiences. I own the Electric 
Radio compendia, and have read many of the reflector posts. I own Butch's 
HI-RES tape, (4 hours) and would enjoy sharing ideas. 

I am also looking for a RF signal generator. Any out there where might be 
rented or purchased for a reasonable price? 

Just wanted to share.

Thank you all.

Lorin 

WA1PGB
Sponsored by the Collins Radio Association
http://www.collinsra.com

---------------------------------
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---