[AMRadio] 813 Final Problem

Paul Baldock paul at paulbaldock.com
Thu Mar 19 14:16:44 EDT 2015

Are you suggesting the problem I am seeing is normal, and that it 
will go away once I connect the modulator tubes to the transformer primary?

Did I make it clear that the arc is on the HV connector to the RF PA, 
not the HV connector to the (yet to be built) modulator? That side of 
the transformer is currently completely disconnected from everything.


- Paul

At 11:08 AM 3/19/2015, Jim Tonne wrote:

>Assuming you don't have an actual modulator connected yet,
>only the modulation transformer, short the modulation transformer
>Of course when you get the modulator running later some time,
>be sure to remove the short  :-)
>- Jim Tonne W4ENE
>On 3/19/2015 1:45 PM, Paul Baldock wrote:
>>I am building a 15 meter 2 x 813 class C final. HV is 2200V. With 
>>16mA grid drive I can comfortably get 400W (and more) out.
>>Every thing works fine until I insert the Mod transformer secondary 
>>in the HV lead to the PA. NOTHING is connected to the input (audio) 
>>side of the transformer. When I apply rf drive to the PA my High 
>>Voltage connectors arc over. It seems this must be caused by some 
>>sort of inductive spike. Any suggestions?
>>- Paul  KW7Y
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