[BC] CCA still Low modulation CHanges made

[DANA PUOPOLO]

Try setting the choke on a couple of telephone books - but DON'T TOUCH  it's
frame!!!!!!

-D



------ Original Message ------
Received: Fri, 09 Dec 2005 03:13:58 PM PST
From: Lewis Munn <looey323 at yahoo.com>
To: Broadcast Radio Mailing List <broadcast at radiolists.net>
Subject: Re: [BC] CCA still Low modulation CHanges made

Bob,
   
  Correct me if I am wrong.
   
  You can determine if it is shorted, or open, or "about right" with an
ohmmeter.
   
  My concern was that if the plate current is normal for a "typical" 1KW
transmitter...i.e. about 500 mA, 900 ohms would be dissipating about 225 watts
in the choke,. which would be enormous.  And earlier, if the choke is nearly
shorted, it would be feeding the audio to ground and overloading the modulator
tubes, hence the plate material being evaporated to the envelope in the one
modulator.
   
  I agree that a more ideal way would be use of an inductance bridge for value
and Q, and resistance checks both of the winding and to the core and mounting
for making sure of no obvious "other" paths.  Possibly even a HiPot check
   
  Sticks in my mind the usual modulation chokes I have looked at quick and
dirty had 20-50 ohms of resistance.  But, like you, long time ago.
   
  Thanks for calling quick and dirty troublehooting to account vs precise
analysis!
   
  Looey Munn
  Roundup, MT
   
  
Bob Groome <bobgroome at yahoo.com> wrote:
  Just in case.....

You don't measure a modulation reactor's value with an ohm meter.

			
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