[Milsurplus] BC-375/191 adjustment tool needed

[Laura and Jim]

Mike - I cleaned off the relay contacts using thin strips of 400 grit 
wet/dry paper and straight DeOxIt (from the needle applicator). Now I get 
100mA at 500VDC w/final dipped and antenna at resonance into 50 ohm dummy 
load.

May not have to tinker after all. Will install a replacement RF meter 
tonight.

Will apply full power tomorrow and experiment w/neutralization and the bias 
settings; listen to the CW note.

TNX and 73 DE JIM K6FWT
----- Original Message ----- 
From: "Mike Hanz" <aaf-radio-1 at aafradio.org>
To: "Laura and Jim" <mcenfalz at humboldt1.com>
Cc: <milsurplus at mailman.qth.net>
Sent: Friday, May 28, 2010 2:40 PM
Subject: Re: [Milsurplus] BC-375/191 adjustment tool needed


> On 5/28/2010 1:38 AM, Laura and Jim wrote:
>> Am refurbing the relay contacts in my BC-375E and expect to have to 
>> readjust the contact spacing when I'm done.
>>
>> All contact surfaces in this beast so far have been oxidized to the point 
>> of non-conductivity. I get a ripping 10mA total plate current at 500VDC. 
>> It dips and I can hear CW/MCW on the other side of the garage w/a '348, 
>> so it's not totally dead.
>>
>> Anyone have a custom set of needle-nosed pliers I can borrow for a few 
>> days (hope springs eternal, hihi!), or know where I can get one/fabricate 
>> one? The '191 manual says to just drill out a pair of regular 
>> needle-nosed pliers, but the steel on even the Harbor Freight cheapies is 
>> way too hard for the skinny drill bits and loosey-goosey drill press I 
>> have. Maybe a custom 2-fanged grabber tool out of piano wire?
>>
>
> Piano wire pliers won't cut it, Jim.  The lock nuts will very likely be 
> too tight after all these years.  For those of you wondering what he is 
> talking about, see 
> http://aafradio.org/docs/BC-375_&_BC-191_antenna_relay_tool_plans.pdf 
> from the July 1945 TM 11-4017.  The tool in the photo is a fairly standard 
> drop-forged pair of needle nose pliers that should drill without a problem 
> using a center drill, but my experience with the Chinese versions is that 
> you never know what kind of steel it is, and it is almost certainly not 
> drop forged to reduce stresses and strengthen the casting.  If it cuts 
> with a stroke of a small file, then it should be easy to drill.  If it 
> doesn't, look for another pair - it likely has a high (unknown and 
> variable) carbon content and may not even respond to annealing without 
> special equipment.  Imagine the tips drooping down when you get them hot 
> enough... :-)   Sometimes there is no substitute for quality steel.
>
> I've had good luck at garage sales looking for old tools like this to make 
> specialty pliers and the like.  Anything American or European made over 30 
> years old is usually golden.  The needle nose pliers I used to make this 
> same tool was one I found in a gutter while walking our dog!  A little 
> rusty but it cleaned up fine and drilled like butter with a carbide center 
> drill.  The pins are .063" in diameter...broken 1/16" drill bits are 
> perfect for this application - just lop of an appropriate amount with a 
> Dremel cutoff wheel.  If you drill the hole oversize, not to worry. 
> Loctite will fill a .002" gap quite nicely.
>
> Best 73,
> Mike  KC4TOS
>