Simple 2m amplifier.
I built the PA board for this when I was a foundation licencee, but under the foundation licence, you must only use comercially made transmitters. Since getting my intermediate licence, I have put it in a box, and added an RF sensing switch so I can use it. It uses a 2N6084 RF transistor, and will produce 50w output max. It is a class C amplifier design, and therefore good for FM mode only. I have tried using the 2N6084 in class A, but amplifier gain was down to about 4dB and it seemed a but pointless!
[table]
Input Power,Output Power
2.5w,10w
4w,20w
7w,30w
10w,40w
13w,50w
[/table]
Some people requested a schematic of the PA board, so I drew one up – PA Schematic
Inside the box
RF Sensing circuit & DPDT relay switch
PA Stage
Back
Schematic of the PA board. CLICK IT FOR LARGE VERSION!
Schematic of RF sensing switch circuit.
what is the power requirement for this unit?
12VDC, Amp ??
A 10A PSU would be plenty.
i wish i could have some one make this for me but i know that u cant but my questions is that power out say i have hand held that is 7 watts going in is the what ever watt is it going out to the antenna
Yes, you should get around 30w at the antenna with 7w input to the amplifier.
Cheers, John.
John,
I’m looking for a RF sensing switch to add to my 430 mhz preamp for satellite use. I found your site here. Will the RF sensing switch you have here work for 430 mhz?
Possibly, but I have not tested it at UHF.
Hi John, what about if i use 143 -144 frek? Will it be okey?
Best regards.
Yes, will be fine.