[AMRadio] DRIVER XFMR UPDATE

[russ dworakowski]

Mike there are  other caps  that  need replaced  as well.  remember  this is 
  50  years old.  Cathode bypass caps in  the speech amp,  also  
electrolytics in the bias supply and  LV and  HV supplies are all culprits  
down the road.    Change  these as a matter of  preventive
maint.  Russ.






>From: "MIke Wells" <mwells at gcea.coop>
>Reply-To: amradio at mailman.qth.net
>To: <amradio at mailman.qth.net>
>Subject: RE: [AMRadio] DRIVER XFMR UPDATE
>Date: Thu, 20 Feb 2003 16:38:59 -0700
>
>Hello guys,
>Just thought I would again say thanks to those that helped with comments on
>replacing the driver transformer in my DX-100. Bob, W4WSZ sent me out the
>exact replacement and I now have it in the unit and playing.
>
>A couple interesting things I found was the new 5V4 low voltage rectifier
>tube was bad, must of seen too much current. After replacing the 5V4 and
>testing the circuit I saw the 12BY7 was shorted and looked more like a 
>light
>bulb than a tube. I went looking and found the 680 ohm cathod resistor was
>burned open. Now I wonder if the resistor failed first, taking the 12BY7
>then smoking the driver xfmr causing the 5V4 to die. Or maybe it all
>happened when the xfmr went up in smoke. It is back on the air and Chuck,
>WA0ZHH and Lonnie W0GPZ said it sounded good.
>
>73
>Mike
>W0FD
>
>
>
>
>_______________________________________________
>AMRadio mailing list
>AMRadio at mailman.qth.net
>http://mailman.qth.net/mailman/listinfo/amradio


_________________________________________________________________
Add photos to your messages with MSN 8. Get 2 months FREE*.  
http://join.msn.com/?page=features/featuredemail