TM 808 White's

[Archi]

Tuning fork crystals

You want to repair old TM808 or you build new one?
I do not know that cause be of choice of frequency 26.37kHz by TM808 project engineers.
I have found many producers of resonators about this frequency.
However, I suspect that they are produced on order exclusively.
Employment of typical resonator is simplest solution.
These frequencies of standard resonators it closest 32.768kHz or 20.48kHz.Clock resonator 32.768 kHz is very easy for conquest,but it will cause decrease depth of detecting. Buying of resonator 20.48kHz is better solution. Unfortunately although is produced by many producers, shopping of single crystal is hard.
From scheme result that here employed crystal which has been constructed for Pierce oscillators specially ,for instance series CX-1V produce by STATEK –USA ,CC1V prduce by MICRO Crystal Switzerland,CX-1 from RAKON (GB) or SMD produced by EPSONTOYOCOM series MC-405-406.
Certainly employment of resonator about other frequency causes that you must change coupling transformers of both antennas. I do not know if change of reel L1 will not be indispensable also.

Greetings
Archi

[Satel]

Does enybody know, where to buy TM 808 crystal-26.37MHz?
Thanks

Sorry,26.37kHz

[Satel]

TM808 crystal

Does enybody know, where to buy TM 808 crystal-26.37MHz?
Thanks

[exciter]

Hi there,
anyone knows how to tune the pot R5 of the U1 MC33078???
Should be a Bandpass or so????

Greetings

[kt315]

Regards to all!
Esteban you done great job now! Thank you!
Here is scans....Origin files are HUGE!!! 27Mb's,
Regards

hello. can anyone put the files on http://zalil.ru/ or another site you know of?

thanking in advance

[kt315]

hi, ivconic,

I expect a people do not fully appreciate that CAVE mode is also DISC one. that it gives possibility to ignore out the small ferro objects. what you think?
may it be a main feature of TM-808?

hh

[ivconic]

Well....TM808 is not brainstorming device to adjust.
Follow posted photos and do the presets like i am suggesting here.
When finished, lift device up in air for 1.2 to 1.5m over the soil and press the reset knob. Hold for second and release.
Lower device down to normal operating position, holding it with one hand of course.
You will hear threshold sound. Now with threshold pot adjust it to mum sound...bairly audiable. And that is all. It is ready to work with.
That is the way i used it. Again this can be very subjective so you may find more proper way for you.
On some soils i have to repeat this oftenly, on some dont. Moisture affect it to much for my taste.
Personally i do not use it. I am very interesed in it due some other reasons;
first a lot of people asking me to make it...offering descent money for handmade, and second reason is educational. I want to fully examine this design and later maybe do some mod on it. Honestly i do like the way how White's did it. Pretty nice design.
Regards!

[kt315]

ivconic,
can you give more detailed info on the tuning? all these step-by-step manipulations to describe for newbie... what is your experience vision on that?
TIA

[detectoman]

kt315 I send soon the pictures of these tf600, my digital camera is wrong, i repair i sent the photos and you see the circuit burn lines if my conection problem
thanks regards
detectoman

[ivconic]

connecting in «DISCOVERY» TF-900 Automatic is MORE EFFECTIVE!

Thanks KT315!

Yes i agree. This one looks much better than one on TM808. I never liked connector at TM808. Sooner or later it will splendour and loos good conntacts. I had few cases where TM808 simply started to work pretty erratically - became absoulte unuseable. All those later turned to be due splendoured connector inside the main shaft. Only way to fix it was to replace connectors with conventional ones and use of better cable to connect with machine....
But yes, you are right, this one looks more effective...
Regards!

[kt315]

http://poisk.lukiland.ru/arxiv/moderniz.php

ivconic, you will find here another updates on mechanical and of Signal Balance pot.
in russian, but I think you will wise all on pix.

[kt315]

a coil was updated!

[kt315]

all photos here http://www.trizna.ru/phpBB2/viewtopi...=194500#194500

[kt315]

connecting in «DISCOVERY» TF-900 Automatic is MORE EFFECTIVE!

[kt315]

hello detectoman,

I believe TM600 and TM800 are braza-in-law. but sorry I have not the schematic. try open the box and put up the photo. may be it will be get up to a light by anybody... I hope. as these have one primogenitor.

'the water does not flow itself under a rock.' you may be in course of this indian rede.

all best wishes and kindest regards