Ever see a Continental AM Broadcast transmitter? In some of the models you
will find the last stage to be a big linear amplifier. Of course those were
used long ago when we weren't worried about heat or the electric bill.
Centurion inefficient??? It's output is about 1000 to 1200 watts PEP with an
input of about 2300 watts. That's about 54% or so. The Omni VII runs about
40% efficient on SSB at 100 watts PEP. Even my 1 KW class C AM transmitter,
being pair of 4-400's modulated by a pair of 4-400's will have a PA
efficiency of about 65%.
Don't knock linear amplifiers in terms of efficiency. The secret to a
clean AM signal is to use a linear amplifier that is indeed "linear".
Proper tuning along with correct drive is the key to this success. The
nay sayers of course will say otherwise.
Remember, it takes a bit of cherry color on the plates to burn the gas out
of the envelope. It is actually good for the tubes.
73
Bob, K4TAX
----- Original Message -----
From: <bcarling@cfl.rr.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Friday, August 01, 2014 10:02 PM
Subject: Re: [TenTec] Centurion and AM
I tune my Centurion 422 with enough drive for 1 KW out.
Then I feed it about 20 - 25 watts of carrier and start modulating.
Currently using the OMNI
VII. DON'T overdrive it! Keep an eye on the plates and let them only
glow a little. You don't
want them melting! Your mileage may vary.
You will get lectured by the purists on how "terribly inefficient" this
is, but if it works I don't
knock it!
Bry, AF4K
On 1 Aug 2014 at 20:59, Timothy Johnston wrote:
I would be feeding it with 25w of AM from a TS-590. So.. exactly what
would
the safe procedure be?
73 de Tj, K4TFJ ...
On Fri, Aug 1, 2014 at 8:46 PM, Barry N1EU <barry.n1eu@gmail.com> wrote:
> On Sat, Aug 2, 2014 at 12:28 AM, george fritkin via TenTec <
> tentec@contesting.com> wrote:
>
> > 200 to 250 watts AM results in 800 to 1000 watts PEP at 100%
> > modulation.
> > Three 811 tubes can not handle that power.
> >
>
> How about two 3-500Z's?
>
> 73, Barry N1EU
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