Quote Originally Posted by mixedgas View Post
Google ISM frequencies...
Those are the worldwide (mostly) license free Throwaway Frequencies for industrial, scientific, and medical.

If your unit is totally shielded, and has RF line filters, and is tested to ensure it complies with emissions regulations, you can get away with just about anything you want except aviation, navigation, and safety of life/destress frequencies.
That compliance is costly if your RF engineer doesn't know what he/she/it is doing. If they do, compliance is cheap and is mostly sheet metal and a input line filter and some RF chokes. For a laser you need a good RF engineer anyways.
No, I don't do that anymore, but I have on a small lab scale in the past. Your product gets designed by a good RF engineer, with a 3200$ spectrum analyzer or ~6000$ network analyzer (used price) then approved by a testing lab with hundreds of thousands of Dollars worth of gear. It typically takes two trips to the certified approval shop. You'll end up butting heads against a conducted emissions LISN test, and radiated emissions test anyways.

Faraday shields, RF line filters, inductors on control and power cables, ferrite chokes, and copper sheet metal fingers for gap sealing are your friends.

Just say no to Tesla, say yes to an off the shelf RF amp from a place like Communications Concepts or similar. Modern industrial RF sources are amazingly efficient.

Tesla is a great way to flunk emissions testing before you even get there. Tesla coils spew noise like a volcano, and would be 1920s RF technology, horribly inefficient for what you want to do,

Find yourself a 1990s copy of the ARRL handbook and start reading on impedance matching and coaxial cable. There are 600,000 Ham Radio operators in the US, and 5-10% of them can do what you need in their sleep in terms of basic design.


You are awesome - I loved the deep communication there. I hear you...I had to work RF isolation, and it is quite tricky and elusive to solve. I swear RF can get through a hole the size of an atom. We did it with nested metal mesh 'donuts' in their own channels and lots of those copper fingers. Using hog-outs (milled parts) is the better way - combine parts, eliminate any separation possible.

Ok, so I'm going with 40.68 MHz then! Wow, information helps so much! Tesla no more!

I want to be able to buy the RF amp. I have a 30V power supply with enough amps, it is an actual laser power supply. How's this 40.68 board look?

The connectors on the board look like my TV RF cables. Is that ok? I'm making a 10W laser, so that power is good. Why don't they make boards with a built in signal. I mean, isn't that the only thing the board does? Why is it separate - does that add value somehow I am missing?

The datasheet for the RF board - looks like pure greek to me. Beside its output impedance, what else matters? It says it is made for lasers = good. I was hoping to stumble upon a mating mating network and signal source.....again, hoping for 'laser market' listed in the spec sheet like this RF board did. Anyway, the datasheet:


I know I said I have a 30V power supply, but the spec sheet said it was characterized between 30-50V, and I like the power supply I have, it is nice and high quality. I will be using push-pull, which this board does. Ok, so I'm skipping everything in that manual except for page 13 saying it is a 50 Ohm system. I'm expecting the lit impedance of the resonator o be about 25 Ohm, but don't know what impedance to expect from the un-lit. What do you think? Higher or lower? And, page 14, no idea what that is for. Wait, I'm looking at the Impedance test values on page 16. Is it possible that my laser would match within 20% of these values for make plasma? Is that totally wrong? It looks like from the chart on page 13 that the input Wattage is 0.5W.

I just ordered the 1993 ARRL Handbook, Hardcover, on ebay for $20.

Is this 'RF Explorer" any good?

You rock!