Protek Gtx 711

[Geo]

Ok i just tested the Tx board.

800Khz oscillator tuned to 1.6Mhz 40V pk=pk between antenna and ground. Not so bad.

10.14Volts the output of Q11

7.5V the max output of LM317 when input is a battery of 12V. But i think here the problem is that i used a 10K trimer instead of 5K.

2N4427 runs hot!!! It needs cooling

Tx board looks that is working normally without any modification. I used an air core coil at the output.

Regards

Output must be tuned at 800Khz (Positron version) and 120...150 Khz for Protek version.

[Jeg]

Thank you Geo! I tuned there cause i saw the receiver's circuit at the input is tuned to 1.6Mhz (2.2uH and 3.9nF)

what is your opinion on the output voltage at the antenna?

[Geo]

If i remember right the inductance is 2m2 not 2u2.
Now about output voltage.... i don't remember good but i think that it is at least 100V.

[Jeg]

Thank you George! I really wonder how can this circuit give something more than 50-60 Volts as the Q factor of tank circuit is so heavily dumped! I will try some coils more!

[Jeg]

At the end of the day it was a matter of coil.I used a ferrite coil instead of an air core. A very nice shaped sinus at the antenna at 128V Pk-Pk @800Khz. It can not go higher at least with that coil. 2N4427 runs colder than before but again it needs a heatsink. It is time for the receiver, and i think that here there is a lot of room for improvements

[Geo]

So my memory is fine.....

[Jeg]

Thankfully it is great!!! Thank you for your valuable assistance!

[abdou2014]

THE TX IS GOOD WITH MOD THE RX IS BAD MUST CHANGE IT