[Milsurplus] TCS 9

[k4elv at bellsouth.net]

First of all I want to thank each of you who repsonded to my request for help with an arcing problem in my TCS 9.  It really was amazing how many of you took the time to offer your ideas.  Several members who did not have any specific ideas asked that I let the group know of the results.  So here goes.  The good news is the symptoms have been resolved - no more arcing.  The bad news is I still have no idea of the original cause.  I tried all of the suggested fixes including temporary replacement of C128 A&B, C119, C120 and 130.  I adjusted the relay so that the antenna portion activated just before the voltage side hit. Reduced the plate voltage to 400V.  No change.  The voltage side of the relay continued to put on quite a display.  So much so that the conacts were noticeably pitted and need to be filed.  As a last resort I put a .01 cap in series with a 470 ohm resistor across the contacts.  The arcing was almost completely stopped.  I then changed the cap to .02 uf and the symptoms were completelt gone!!  The original cause remains a mystery.  I was able to key at about 20 WPM on CW with a very nice sig heard in a nearby rcvr.  Next went to AM using a NOS T19 ( which isn't supposed to sound like much).  It sounded great.  So thats the story to this point.  Perhaps eventually something will fail completely and reveal itself as the original cupert.  In the meantime I\m just going to get one the air.  73 to all  Mike K4ELV