Suggest an RF source with 81.36Mhz, 300W Output

[ITP]

Hi all,
I am not an expert in RF design but have a requirement of RF source for an RF-excited CO2 laser. The RF source required is of 81.36Mhz frequency with a power output of 300W. Please suggest an RF source or a practical circuit or this application.
Thanks and regards
Itp

 

[vfone]

This could be the exciter:

26.55US $ 10% OFF|Diy kits 5W 7w FM Transmitter Radio Station PLL Stereo Digital frequency KITS + lcd Digital Display SMD soldered already|Earphone Accessories| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

And this could be the 300W power amplifier:

264.86US $ 19% OFF|80 110Mhz 300w FM transmitter FM transmitter board FM radio amplifier 300W power amplifier|Radio & TV Broadcast Equipments| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

As you mentioned, if don't have much RF experience I think this would be a better (and cheaper) option than trying to design your own circuit.

 

[KlausST]

Hi,

I just did an internet search...amd found exactly what you are looking for.
Why didn't you do the same? ... or at least tell us about your search and what is wrong with the results?

Klaus

Added:
But if you are not experienced with HF, there is a good chance that you build a jamming station.
Maybe you become visited by some authorities

 

[volker@muehlhaus]

From what I have seen, RF sources for such plasma use are more complex than the 50 Ohm devices from aliexpress. The variation of load impedance seems to be a real issue.

 

[BigBoss]

Forget about aliexpress, those circuits are not appropriate and reliable at all.. They are for radio amateurs, maybe even not..
I'm agreed with volker, Load is not purely 50 Ohm and varies much and an not appropriate amplifier will release a smoke in few seconds due to strong reflection.The output must be very reliable and hard to burn against load variations.And it should have an Isolator at the output.

 

[ITP]

Hi,
The RF Power source of our CO2 laser has gone bad. Unfortunatley the OEM is not suporting it and also most of the
components like RF MOSFETs are obsolete. So it is dificult to repair it. So my idea is to design a new RF Power source by integrating an rf-exciter with a rf power amplifier with impedance matching networks.
If you can suggest some modules or circuit or reserch papers it will be very help full.
Thanks and Regards
Itp

 

[vfone]

Perhaps there are millions of RF power amplifiers from China that have the same performances as similar ones from any part of the world, and the only difference is the price. This is a fact, and not an amateur radio story.
If don't have experience designing and manufacturing and evaluating a high power RF amplifier (as ITP mentioned), the PA will not die in few seconds, but will die in few milli-seconds.
If you burn a $200 MMRF1308HR5 transistor bought from NXP you get nothing, but AliExpress give total refund in less than a week for products that doesn't work when you receive them, so the risk losing money is minimum.
And when you get a PA with 300W on 50 ohms, you can start thinking what to add at the output (isolator, circulator, tuner, etc.) to get the desired performances.