Mentor needed

[Tickfawriver]

Hello, I have been an electronics technician forever; graduated trade school back in '80 and worked in communications in the Gulf of Mexico for 20 years before moving on to other electronic fields. I am a newly licensed ham and really enjoy the homebrew aspect of the hobby. I am itching to build an HF linear amp using either one or two 3-500G tubes. I am studying schematics and understand 80% of what is going on but the remaining 20% is proving to be very elusive. I am searching for a mentor, someone who has built amps and would be willing to provide some guidance, not looking for someone to "hold my hand" but to answer a few questions now and then via email. Please pm me if you are interested.

Best regards,

 

[Eldorado828]

Welcome to wwdx and I can say that you're in the right place. Lots of tried and true knowledge in here.

 

[nomadradio]

Asking questions like that here on the forum puts you in touch with multiple mentors, and a few smart-aleck hangers on. Just the same, relying on just one expert is not the only way to go.

I would start with a copy of the book "Radio Handbook" by William Orr. Pretty sure the 23rd edition was the last. Found it for twenty bucks and change on Amazon.

The design of input and output tuned circuits gets explained, along with component values for each band's input tuned circuit, and the output side as well.

Pretty sure there is a complete how-to for building a box with two 3-500Z tubes.

No need to invent the wheel when complete plans can be had that cheap. And Bill really was good at explaining this stuff.

73

 

[Tickfawriver]

Thanks for the suggestion on the book, I will order it today. I agree about not reinventing the wheel, after all, my talents lie in fixing things, not designing.

 

[SuperLid]

The 1970's ARRL handbook has a 2x 3-500Z project. However, I would discourage going that route these days. 3-500S's are only available from China and they are not what the Eimac's were. I would go the LDMOS route, if I were going to build.

 

[Tickfawriver]

What keeps me away from the LDMOS is that any more than about a 1w input blows them and the fact that I would also have to buy a tuner. At least, this is how I understand it.

 

[BayouRadioAmplifier]

back in the late 70's "Solid State Design for the Radio Amateur" was the book for me. It gives examples of designing little RF amplifiers, and shows
what you need to know.

also some other book, "RF Circuit Design"

so Tickfawriver, I am down here near Thibodaux, and also worked in the G.O.M.
on comuunications/radar/steering on the boats and ships down here.
Used to be lots of work.

 

[Tickfawriver]

Definitely a tale of 2 G.O.M.'s I lived in Thib. in the 80's while working in Morgan City and driving Blood Alley. Do you have an amplifier? Did you build it?

 

[BayouRadioAmplifier]

Yes, have an 811H I use on the Amateur bands. and I have some
amplifiers I am repairing for others. But have built MOSFET
class-E H.F. AM transmitters, antennas, transmatches, etc.

 

[Cable Guy]

I would start with a copy of the book "Radio Handbook" by William Orr. Pretty sure the 23rd edition was the last. Found it for twenty bucks and change on Amazon.

I second this, this book should be in everyone's library. I've hoarded and read many technical books and arrl pubs but this one is very different. I wish I had gotten hold of it sooner so thanks for this referral @nomadradio.

 

[Shadetree Mechanic]

Asking questions like that here on the forum puts you in touch with multiple mentors, and a few smart-aleck hangers on. Just the same, relying on just one expert is not the only way to go.

I would start with a copy of the book "Radio Handbook" by William Orr. Pretty sure the 23rd edition was the last. Found it for twenty bucks and change on Amazon.

The design of input and output tuned circuits gets explained, along with component values for each band's input tuned circuit, and the output side as well.

Pretty sure there is a complete how-to for building a box with two 3-500Z tubes.

No need to invent the wheel when complete plans can be had that cheap. And Bill really was good at explaining this stuff.

73

Thanks for the book recommendation, I just got mine last week.