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hi all. i have solve the problem. the problem was the pcb board that hasn't much ground on it's surface. When i change the board the linear hasn't oscillation problems, and i achieve to have 500w r.f power at dummy load with 110vdc - 11A voltage. i post the new pcb board.
Also here you can see...
hi i am radio amateur at 160m. the problem is that when i operate my transmitter the transmitter create interference to the telephone.
i am thinking to put a circuit at telephon's line. My first thought is to put capacitors (10nf) which will ground the r.f. signal what do you think about this...
i have a linear amplifier which is using VK200 r.f choke (at input voltage). I would like to ask you which is the maximum current? Because when i operate the linear (7A current) the VK200 r.f choke is very very warm. thank you
hi, i have this linear amplifier project https://tzitzikas.webs.com/irf640-1.JPG with 2 irf640 mosfets.
My problem is, when i adjust the both mosfets drain's current at 400mA (current without input signal), after some minutes
when the heatshink is warm (with input signal), the current becomes...
Hello, i have done this project. It is an experimental oscillator - modulator for mw frequencies. The schematics are here:
oscillator:
https://tzitzikas.webs.com/oscillator-1.JPG
modulator:
https://tzitzikas.webs.com/modulator-1.jpg
The problem is that the designer told me to use an 1kohm...
yes i am sure it is one turn. look the prototype here:
http://www.tzitzikas.webs.com/linear_first.jpg
this turn is with blue thin cable. it's 1 turn only
the manufacturer is using only one turn. and the other radio amateur amateur for primary coil of T3. They claim that their amplifiers gives at 110vdc 450-500w r.f power(the current is 13A).
But my amplifier gives only 190w at 106vdc (6A current). The only difference is that i am not use...
look at here to understand how the T3 is connected.
http://www.tzitzikas.webs.com/connections.JPG
the black line is the +1 turn. is insulated wire
R8=10ohm resistor/2watt
The presentation of this linear amplifier is in Greek language, but you can see a photo of the prototype amplifier and the T3 transformer. 25r means 25ohm coaxial cable.
http://www.tzitzikas.webs.com/linear_first.jpg
The follwing photos are from the same linear, which have been constructed by...
HI. i have constructed this linear amplifier 500w rms (2kw pep) (50ohm) with 12 mosfet irfp360, https://tzitzikas.webs.com/linear500w.jpg for 160m band.
When i gave 3watts of driving r.f power, it gave to output only 190w at 106VDC (6A current). Two radio amateurs who have construct this linear...
https://tzitzikas.webs.com/linear500w.jpg
i sorted all connections.
When i gave 3watts of driving r.f power, it gave to output only 190w at 106VDC (6A current). Two radio amateurs who have construct this linear claim tha it gives 500w
r.f power at 110vdc.
But when i tried to give 4watts of...
hi. I would like to construct a Chebyshev 5-Element Low-Pass Filter (between linear and antenna) for 1431 khz. I would like to use standar capacitor values, which are easy to find. My problem is to find how many turns with 2mm diameter wire i need for the two coils of the filter. The filter is...
Hi. the mosfet that i am using (IRFP360) are no name. Do you believe that the linear gives less power than the prototype because the mosfet are no name instead of the prototype which is using International Rectifier mosfet?
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