[Kenwood] TM-241A - Stop transmitting

[Richard Knoppow]

----- Original Message ----- 
From: "Ziv Amit" <ziv at radion.co.il>
To: <kenwood at mailman.qth.net>
Sent: Wednesday, April 04, 2012 5:12 AM
Subject: Re: [Kenwood] TM-241A - Stop transmitting


> Hi
>
> Thanks for your following email...
>
> I open the power module and looked under a x20 microscope 
> all traces are ok. I would also thing that if a trace 
> would be open there would be no power at all, but I can 
> get the high power running in the first 10-15 min of 
> regular QSO..
>
> After ~ 15min there in no output and then after another 
> 10-15min I can get the power back on...
>
> The power module I well connected to the heat-sink with 
> conductive temperature paste.
>
> Any Idea?

     No specific ideas since I am not very familiar with the 
equipment but this sounds typical of something heat cycling. 
It could be anything including a loose ground. Resistors can 
do this when the leads do not quite make good contacts or if 
the element is cracked.  Freeze Mist is hard to come by 
these days but you can often accomplish the same thing by 
using a can of canned air turned upside down.  Alternate use 
of a heat gun with a small area of application and cooling 
will often discover the cause of problems like this. 
Sometimes just poking  at the components with an insulated 
stick will find them.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com