<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Many thanks to everyone who provided me with technical information on the DX100. This group is an awesome resource. The problem, at least with the audio driver, is now solved. Who would have thought the coupling cap between the 12AX7 and the grid of the 12BY7 would have had a high resistance short (for goodness sake, the cap is a mica part – they’re supposed to last forever)? With no voltage applied, the grid to ground resistance on the 12BY7 was fine. Things were not so good when the circuit was powered since there was a POSITIVE bias on the driver tube. This is likely what caused the driver transformer to fail.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Again, thanks for the help. I’m sure I’ll have more questions as the process of getting this sixty year old transmitter up and running.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Dave, N7TC.<o:p></o:p></p></div></body></html>