[Yaesu] FT-900 50% power output intermitten & T/R relay

[David Jordan]

Open up the transmit section...chances are good the heat sensor on the 
driver has lifted off the top of the transistor and is giving false 
readings causing the protectin circuits to respond to a false positive.  
That is what occurred on my FT-900.  While I was in there I installed a 
pot to adjust the fan speed, haha.

73,
dave
wa3gin

Mark Tyler wrote:

>The FT-900 has been mobile since '97. The auto is housed in a garage where lately the temperature varies from 40 to 60°F. In the mornings when the rig is turned on the output power indicates about 50% output on cw, 7Mhz. After the rig warms up it is at full power. The T/R relay only takes one action before it starts working. Audio output sounds like no antenna. Transmit and T/R relay working OK. Once the problem goes away it stays gone until the radio is turned off. This is very difficult to trouble shoot when the problem appears only twice a day. 
>
>Currently, I am waiting for the frequency of occurences to increase before trouble shooting problem.  
>
>any suggestions?
>
>Mark 
>K5GQ
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