Topband: Heater Choke Value

[Mike(W5UC) & Kathy (K5MWH)]

Hello Fellow Topbanders:

I have just started the process of converting a MLA-2500 amplifier from 
it's original 8875 tubes to Gi-7b tubes.  Current;y I can run only abut 
400 watts on Topband, (not from the MLA=2500,  I have no tubes for it)  
The conversion requires a RF Choke in the filament lines.  I have 
searched the Handbook, and looked at several schematics with no luck.

Please, can someone out there advise the value of reactance required for 
this effort.  Most construction articles recommend #12 wire, which in 
this case, appears to be significant over kill, as the heater current is 
only 4 amps total.

Thanks & 73,
Mike, W5UC