Be careful of the HV filter cap, Bill. With SS rectifiers, you may exceed
its rating. It's likely so old that it needs replacement, anyway, but as I
recall, EFJ only used a 2500V oil-filled cap (mounted horizontally, beneath
the chassis -- wonderful service location for a 140 pound amplifier). Oil
the blower and make sure it spins freely. Obviously, be careful about your
keying interface.
Use that amp on 230V only...on 115V, it draws about 20A, which will overload
your circuit as a near certainty.
Oh, and rest your back for a few hours after each moveabout of the
Thunderbolt. Unless you're Arnold Schwartzenegger, the damned thing is
awfully heavy.
WB2WIK/6
"Each success only buys an admission ticket to a more difficult problem." --
Henry Kissinger
> -----Original Message-----
> From: Bill Russell [SMTP:willy@global2000.net]
> Sent: Tuesday, November 06, 2001 3:28 AM
> To: amps@contesting.com
> Subject: [AMPS] Thunderbolt questions
>
>
> This is my first post to this group and I hope it works!
> I have a Johnson T'bolt, the hf version and have a few questions. Have not
>
> powered it up as yet as it needs a little work. Nothing serious I hope,
> just the usual for an old piece of equipment. As I get it working, I hope
> to get some comments/advice from members of the group as I go. First I
> would like some general comments about the amp. I hope to use it for
> mostly
> SSB and some AM. I have heard some comments such as the plate voltage for
> the 4-400's is a little low for the tubes (2200volts) and such. The first
> thing I am going to do is replace the HV rectifiers with solid state and
> go
> from there. I have a whole bunch of other questions but will stop here for
>
> now. I am looking forward to getting this thing going and doing any mods
> deemed necessary for reliable operation. Any comments are welcome.
> Bill KC2IFR
>
>
>
> --
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