Hi Steve (and amps),
-
The Palomar 300a is a 40-10 meter amplifier with
six sweep tubes in grounded grid. In low power
mode, the exciter drives the final quartet and it's
SSB operation with 40 watts drive is similar to
the many handbook projects published in ARRL
and W6SAI handbooks.
-
In high power mode, the two tube driver stage
is placed in operation (bypassed in the low
power mode) and the drive requirement is
reduced to 4 watts.
-
This amplifier layout works very well, the
amplifier is/was very popular with the 10 watt
rated (turned down to 4 watts drive) HF radios
made in the 70's and 80's. It would also be
very nice with the brand new Icom 703 qrp
rig that is coming out (most of you don't
know about it yet, a qrp version of the 706).
-
The power supply is a very well done doubler
circuit, replacement transformers are sold by
Peter Dahl. This amplifier along with many
other SSB rated units rely upon a measure of
peak supply voltage for an extra few watts out.
Swan also employed "peak power" in some
of their circuits.
-
The amplifier has a matched input, a nice pi
output, is legal for operation in the amateur
bands. A diagram is available at the
www.cbtricks.com web site.
-
This is one of the first amplifiers I've seen
with instructions to the user to rotate the
Loading cap after tune up to increase Linearity. .
-
A stock unit with 4 watts CW input would
output about 325 watts with fresh tubes.
It is an AB2 amplifier so SSB operation
works very well. I have at least 3 of the
various models made in my collection.
The black face unit was first, followed by
one mixed and one white faces version.
-
Hope that helps
-
skipp
-
> steve garner <stevegadget@juno.com> writes:
> Hi
> I wrote last week asking info on a Palomar that I did not have
> the model for. Since then I have found out the model no.
> It is a 300A. I would like to know the specs for the P.S.
>
> I did hook up a transformer and managed to get 200
> watts out of it then smelled smoke... the transformer is
> too small... at least I know it works.... I just need a bigger
> transformer. Any help would be appreciated.
> Steve KD5EPZ
>
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