[AMPS] from Joe K0BX jduerbus@marz.com

[Will, K6NDV]

Please reply direct to Joe. 
73 Will,  K6NDV

from Joe K0BX jduerbus@marz.com

Maybe you guys can help me?  I am having a problem with my Drake L-7
Amp.  Here is what it is doing:

1.  In the CW mode, HV 1900 no load, idling plate current 0.170 amps.
Just like the book.
2.  After tuning up in CW, HV 1760 volts, plate current .565 and grid
.220, power output about 700 watts just like the book.
3.  Then when I go back to standby,  I get a Negative Grid current and
about .160 plate current.  This should indicate a filament-to-grid short
in a tube?  But I checked the tubes with a VOM and found no short.  I
replace the tubes with another set of tubes (Used) and same thing.
4.  I also noticed at the junction of the filament choke and one side of
the filament transformer that it was drawing excessive current and
really getting hot!

Before I buy some new tubes, I just wanted to get any words of wisdom
from the group.

Thanks

Joe K0BX  jduerbus@marz.com





--
FAQ on WWW:               http://www.contesting.com/ampsfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm