[Boatanchors] DX 100 and DX 100 B

lee pulsarxp at embarqmail.com
Mon Oct 31 14:23:07 EDT 2011


I think I asked this once before but got no real answer.   If the 4 watt 25K 
driver pot goes South in a DX-100, replacements are hard to find.  That 
said, WB2SYQ has a nice mod on the internet called, "Low Cost Drive Pot 
Replacement".  All it is is a 1 meg linear pot hooked to a pass transistor. 
The transistor he used looks like it is in a TO-5 case.  He says use a TV 
Horizontal Output Driver Transistor.  OK, sounds good, but which Horizontal 
Output transistor?  (There are zillion of them out there with different 
configurations).  I am no engineer.  It would seem to me, the transistor 
used must be a power transistor and good for high voltage.  I would think a 
pass transistor used in a power supply such as a 2N3055 would not be good as 
it's voltage rating would be too low even though it's current rating would 
be just fine.


Anyone on here who can supply a real transistor number for a transistor 
which will work in WB2SYQs circuit?  (The circuit shows it to be a NPN 
transistor).  The article gives no real transistor number.  You can find the 
article at:     http://www.frn.net/tech/mods/heathdx100/

Lee, w0vt 



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