Typical reactance rule of thumb is 5 to 10X the input impedance of the
tube(s).
In some cases it is much less and the 160M input network is modified to
compensate.
#18 or 20 enamel wire would be suitable for 4A and be a lot easier to wind
than 12 and require a lot less ferrite.
Carl
KM1H
Mike(W5UC) & Kathy (K5MWH)
Sent: Wednesday, January 09, 2013 4:37 PM
To: [email protected]
Subject: Topband: Heater Choke Value
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
_________________
Topband Reflector
