TESORO GOLDEN SABRE

[kt315]

yes, that means. with 8 AA you will have a time on hunting more than 10 times vs 2x9V. this is the advantage.

[sukri01]

owh, sorry that means it wont last long is it? thanks.. and sorry i am just a beginner..

[kt315]

8 pcs AA have 2500-2700 mA*h, 2 9V have 150-180 mA*h ---- >10X

[sukri01]

hi.. i need some advise.. if i want to use 2 9v batteries for tgsl, do i need to make any changes with the schematic? or can i justdirectly use them? can someone help. 8 pcs of AA battry takes a lot of space..

[pigeon]

BF 245

thank you verymuch

[Toros]

HI ALL

please what is the equivalent for J107?


thank you

BF 245

[pigeon]

HI ALL

please what is the equivalent for J107?


thank you

[sukri01]

allright.. tgsl working. thanks everyone.. might not get the best depth but 25 26 cm is satisfying for now. i think i need to make better coil for that.

next step vdi. can some one point me where to start? i think the vdi needs another thread coz too many pages to go through

[golfnut]

If co tuned its actually very stable, they jump into each others pockets and injection lock. They become unusable when you approach the ground with it. The Tx and Rx phases pull apart enough to false continuously. The Rx tanks phase response has a real steep gradient in this case.

Peak one out and give it a try. Maybe it does work and Im making this **** up.

This is what I said about - it dont work.

[paku]

I do believe it will work but will be unstable and not very sensitive. A lot of cheap units work in this manner I believe....Somewhere on this website is a proper explanation of the reasons it should not be used.....don't ask me where though!!!
Basically thats how a transformer works......
Regards
Andy

This Is The True

[der_fisherman]

Frequency differences

I do believe it will work but will be unstable and not very sensitive. A lot of cheap units work in this manner I believe....Somewhere on this website is a proper explanation of the reasons it should not be used.....don't ask me where though!!!
Basically thats how a transformer works......
Regards
Andy

[golfnut]

No, the signal the Rx gets is the Tx frequency..........



Thr Rx tank / front end has to be tuned between 50 to 80% of the Tx freq - either above it or below it.

Otherwise if the Rx front end is tuned to the Tx freq it cant work..
S

[sukri01]

one more thing..i can measure rx frequency on u101 pin 7 right?

[sukri01]

ok thanks.. i will try that..

[golfnut]

The Tx sounds ok .
Dont know how you measured the Rx coil tuniing..

Try for a decent null, say <100mV at preamp output.

Do air test on small coin. Record results.


Now add a 2n2 to Rx capacitor - whilst watching the preamp output. - If it gets bigger add another 1n etc

If it gets smaller when adding a 2n2 then try a smaller original cap and add to that.

When peaked to large as it gets - this is the RX Co tuned to the Tx - sometimes they injection lock together.




Air testing will show any improvement.

I would then walk the Rx cap up or down ( So Rx tank is above or below the Tx its no big issue. ) so you have good air test.


Make sure the Amplitude is 200mV or less and the initial phase of the preamp out and the Tx drive is within +/-20degrees.

This will almost guarantee you will be able to reject ferrite with the GEB tuner. And be able to reject Iron using the DISC.


Take outside and soil test with buried targets.

If over bare flat dry earth you cant keep it quiet you need to pull the Rx tank a little further off - try 0.5nF

This will sacrifice a small amoount of air test but make it usable in soil.

S