Protek Gtx 711

[GOLDEN LILLY]

Hello Guys, I just want to know if anybody had the schematics of Protek gtx 711 lrl. There is an existing thread on this one but none of them gives the correct details. All i know is that this lrl is like a two box MD but long range in category. I build it based on the schematics found somewhere in this forum but not sure if the schematic i got is the same principle used in the original protek. All i know is that the original used a colppits oscillator for its transmitter and i don't know if the tx is modulated... Any help is highly appreciated...

[GOLDEN LILLY]

This is my project. I used a 534 khz ceramic oscillator instead of 800 khz as the latter is very difficult to find. Also, the receiver has difficulty of receiving the transmitter signal unless the receiving coil is positioned near to the tx coil. I think the Rx needs more pre-amp. Please i need assistance...

[Geo]

Prototype has very sensitive receiver.
Maybe schematic has errors or it is not complete

[GOLDEN LILLY]

Please explain to me how is this thing works...

[Geo]

I don't know.
I am not the inventor of it

[Pahom]

Good night !!!! Radio engineers, explain the scheme of the transmitter. I understand correctly that the LM 741 acts as a carrier generator ???

[abdou2014]

This is my project. I used a 534 khz ceramic oscillator instead of 800 khz as the latter is very difficult to find. Also, the receiver has difficulty of receiving the transmitter signal unless the receiving coil is positioned near to the tx coil. I think the Rx needs more pre-amp. Please i need assistance...

THE RECEIVER IS LIKE THE ARDF DIRECTIONAL ANTENNA

[Pahom]

THE RECEIVER IS LIKE THE ARDF DIRECTIONAL ANTENNA

In the photo, the receiver, to search for transmitters. Fox Hunt!

[humhum]

Please explain to me how is this thing works...

Tx all time send Wave , also time Rx receiver one parts from this wave , wneh is so , You will fine Calibrated and reset noll your Receiver and search around place for anomaly .

[Geo]

Good night !!!! Radio engineers, explain the scheme of the transmitter. I understand correctly that the LM 741 acts as a carrier generator ???

It is AGC amplifier.
Output of transmitter must be very stable!!!

[Pahom]

Thanks Geo !!!! So it’s like a generator and so on quartz. It is not clear that the AGC amplifier. There is a full name or purpose of such an amplifier.

[Geo]

Thanks Geo !!!! So it?s like a generator and so on quartz. It is not clear that the AGC amplifier. There is a full name or purpose of such an amplifier.

It is clear agc ampl.
At some models there was a resistor parallel to C24(feedback).

[Pahom]

Nevertheless, a tunable carrier frequency generator was assembled on the LM741. So far I figured it out. Thank you I will further study the operation of this device.

[Geo]

Many years ago (15++) i met the inventor of this detector.
He told me how it works and i constructed one...
Also i have opened 3 of them at my lab.
It is a very dificult to adjust detector and also it is very heavy and sensitive to human that operate it.

[Pahom]

I understand you. maybe ...... maybe I'm wrong. But that I will be mistaken. You went through all this. For years and costs. With your results. HAPPY NEW 2020 !!! !!!!! All treasure seekers !!!!