Palomar 300a

[KK4HGT]

I just purchased a Palomar 300a amp. The only thing is, it didn't come with the external transformer. Does anyone have the specs on this transformer?

73
Patrick Brown
KK4HGT
Orlando, Fl

[WB2WIK]

The transformer should be:

Primary 120Vrms 60 Hz
Secondaries: 12.6Vrms @ 9A (filaments) and 325Vrms @ 1.2A CCS (HV)

[N3JBH]

Patrick If you don't mind me asking what does one them cost ???

[KK4HGT]

Patrick If you don't mind me asking what does one them cost ???

I paid $160. It was a Craigs List ad.

[KB4QAA]

You just can't beat a BiLinear amp!

More things should be BiLinear.

[WB2WIK]

You just can't beat a BiLinear amp!

More things should be BiLinear.

I don't think we should be discussing sexual orientation.

[WB2WIK]

I paid $160. It was a Craigs List ad.

If it came without the transformer, that's a bit strange, since the transformer is part of the amp.

My guess is someone blew out the transformer; if so, there may be a lot more than that which is damaged. Have you looked inside it carefully yet?

[AF6LJ]

If it came without the transformer, that's a bit strange, since the transformer is part of the amp.

My guess is someone blew out the transformer; if so, there may be a lot more than that which is damaged. Have you looked inside it carefully yet?

That wold be my guess also.
The construction is kind of funky and while the output is bandswitched the driver isn't.

[WB2WIK]

That wold be my guess also.
The construction is kind of funky and while the output is bandswitched the driver isn't.

I know that amp pretty well, used to sell them and repair them as a kid when I worked for a retailer who sold both amateur and CB stuff.

It was built to be cheap-cheap-cheap and they used a voltage doubler to produce only about 1000Vdc, which always seemed silly to me. This was to save probably $2 on the transformer, at the time. They also did some other funky things like instead of switching from operate to standby bias, to go to standby they literally shut off the B+ altogether, using a relay. That seemed like an accident waiting to happen.

And if I recall correctly, this was a 2-driving-4 amp with a pretty powerful driver stage, so if you hit that with more than about 4W, you'd just blow up everything.

[KK4HGT]

If it came without the transformer, that's a bit strange, since the transformer is part of the amp.

This model has the transformer in an external cabinet with a connecting cable. Finding a replacement transformer has proven more difficult than I anticipated. All of the 300-330V transformers are less than 500mA. Most are around 20mA. If anyone has a suggested vendor I would appreciate it.