[TenTec] Scout 555 - no output

Stuart Rohre Rohre at arlut.utexas.edu
Tue Dec 4 14:47:35 EST 2018


Mike and interested Scout buffs:
It is easy to by pass the finals if you have the 50 watt radio.
You will be left with about 5 watts output from the driver stage and its 
power transistor on the heat sink/ board.

Remove the slip on wrap around case leaving the front panel alone.
Inside the radio in vacinity of the two power transistors mounted to the 
board and heat sink, you will spot RG type 1/8 inch coax going to a slip 
on connector. The other end of this cable goes to the plug in band 
modules section to use the band modules AFTER the finals.  You move the 
slip on plug and re connect it to the driver power transistor. 
Disconnect the red wire that goes to a 2 watt resistor in the finals 
section, and tape it up so you can't put power on the finals.

Now you can test to see if the driver transistor gives you 5 watts or so 
to the output via the cable you moved.  If you now have 5 watts of 
drive, measured at the type UHF back panel connector, it means you blew 
the final power transistors or some other component in the finals board 
opened up an open circuit. It might just be an inadequately soldered 
joint going into a hole in the circuit board.  A high intensity pen 
light and a loupe magnifier will help check those connections, as will 
having an ohm meter.

There should be video on the web on how to test the Scout this way, or 
stills showing the cable , slip on connectors, etc.

GL, hope you are near a ham club who have "Elmers" to help first time 
repairs.

Stuart Rohre
K5KVH


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