TESORO GOLDEN SABRE

[simonbaker]

...and I have dung things deep enough that I am comfortable with it...

we get the picture...

[Virdi_248]

Sorry.. I see now. All you guys are right! I switched black and red and rewired Rx start and Rx stop to keep the right phase. Ground shield should be tied to R13 that goes to pin 6 (inverting)of u101a . Still 29cm on 1e coin. Audio seems to be slightly improved and sensitivity control seems to have more effect. Does make a difference! I have heard some comment that it does not make a difference, but now I believe that it does.
This is my second TGSL. I have to go check my first one now to see if that one is wired wrong as well.

I have been relic hunting with TGSL#1 already and I have dung things deep enough that I am comfortable with it. Usually if I take a shovel full of dirt and I find something still in the hole I have good comfort level with the machine.

I have been working a large Spanish -American war camp here and Pennsylvania and the farmer just powed today. Time to hit the fields a little..

Simon, I bought my IC sockets from Digikey (see attached).

ED90048-ND 8 PIN SOCKET $0.92
ED90049-ND 14 PIN SOCKET $1.42

Don

dfbowers, excuse my ignorance, this comment raises questions. If you will kindly confirm if you need to connect eventually land in the places indicated in the photo would be very grateful.

I just have this and once I finish the circuit. Thank you

[dfbowers]

dfbowers, excuse my ignorance, this comment raises questions. If you will kindly confirm if you need to connect eventually land in the places indicated in the photo would be very grateful.

I just have this and once I finish the circuit. Thank you

Rx "land" (Ground) is correct
Tx "land" (Ground) is not

[dfbowers]

Thanks. And what do you use for the cable in your picture?

Regards,

-SB

USB-2 seems suitable. 4 conductor + copper ground along with foil and braided wire mesh.

[dfbowers]

Thanks. Good luck hunting. I'll bet's it's nice there in PA. Be interested what TGSL finds.

lunamay would like to get a TGSL circuit diagram showing voltages at all points. Since you have a good one, maybe some time you can show us what you measure. Of course some points depend on pots, which makes more work; CCW, Middle, CW probably needed. I'll do it if ever get hot machine.

Regards,

-SB

A few relics.. Camp Meade - 1898 .. Most found with Shadow X5, but a several dozen found with TGSL!

[simonbaker]

USB-2 seems suitable. 4 conductor + copper ground along with foil and braided wire mesh.

Thanks. I tried a cheap S-Video cable once -- decided to cut it open and look. The shield wire was just a bare wire running alongside the others, no shielding effect, just a ground connection. Cheap!

-SB

[lunamay]

hi to all
i would like to confirm some mesurements that i made..
i've got:
current to pcb= 26.7-27mA
from 7808=>7.98V
tx=7.29V DC(got no scope)
tx freaq:
-for 9.36mH-9.4mH,25.6ohm==>14.6kHz
-for 9.41-9.55mH,27.2ohm===>13.7kHz
(both coils just for mesurement..i know that they should be 6.5 and 6mH)

do You know how to mesure coil in and nuil it in the same time?..i mean i get 10 windings and mesure..another 10 and mesure again..??
thx
best regards to all
lunamay

[simonbaker]

A few relics.. Camp Meade - 1898 .. Most found with Shadow X5, but a several dozen found with TGSL!

Looks like excellent hunting there! Hope you put a thread somewhere describing the items.

Regards,

-SB

[simonbaker]

hi to all
i would like to confirm some mesurements that i made..
i've got:
current to pcb= 26.7-27mA
from 7808=>7.98V
tx=7.29V DC(got no scope)
tx freaq:
-for 9.36mH-9.4mH,25.6ohm==>14.6kHz
-for 9.41-9.55mH,27.2ohm===>13.7kHz
(both coils just for mesurement..i know that they should be 6.5 and 6mH)

do You know how to mesure coil in and nuil it in the same time?..i mean i get 10 windings and mesure..another 10 and mesure again..??
thx
best regards to all
lunamay

Your measurements look very good and normal, although I wonder if your inductance measurements are correct? The frequency is right, but inductance very high. Maybe your .022 capacitor C2 is actually lower than spec. What inductance is your Receive coil?

It's hard to make the correct inductance of coils, just experience mainly. Follow experience of others, then make small adjustments. Binding (tightly wrapping and compressing) the coil can raise the inductance by up to 1 or 2 mH, so it's tough. I usually scrape a small spot of insulation on the wire, measure, then tape or coat with some insulator and wind some more, and plan for about 1 mH increase of inductance when wrapping. Or you can wind a lot and then measure and unwind if too much inductance -- that's probably best but wastes wire. It's the darn wrapping that is hard to predict, you need to try a few and see how it goes.

Regards,

-SB

[lunamay]

i think that your idea of making coil is very good..now i'm waiting for a wire and ..with some patients and good equipment i 'll make a good coil
regards

[ik5pwr]

My coil have this features :
TX Cx = 479 pF Lx = 6042 uH R=17,7 ohm wire = 0,3 mm
RX Cx= 437 pF Lx= 6509 uH R = 18,7 ohm wire = 0,3 mm
but when connect to the TGSL frequency of Tx is 17,8 khz , what is wrong ?
may be a series cap (C1 and C2) there are out of specific ?

[porkluvr]

My coil have this features :
TX Cx = 479 pF Lx = 6042 uH R=17,7 ohm wire = 0,3 mm
RX Cx= 437 pF Lx= 6509 uH R = 18,7 ohm wire = 0,3 mm
but when connect to the TGSL frequency of Tx is 17,8 khz , what is wrong ?
may be a series cap (C1 and C2) there are out of specific ?

Maybe what is wrong is that you used the wrong parts.

TX capacitor 479pf? Which capacitor are you referring to?
There are two capacitors affecting frequency in the TX circuit. Neither one is supposed to be anywhere close to 479pf.

But that's not all. Where have you ever seen anyone here suggest that 437pF be used in the RX circuit?? What is wrong with using 15nF as called for in the schematic?



Your coil numbers look pretty good, but those capacitors are bad wrong.

[ik5pwr]

Sorry , the capacitance was refer to coil measured with LCR meter.
it's important to verify a internal capacitance of the coil for a best performance ? or not ?

[simonbaker]

Sorry , the capacitance was refer to coil measured with LCR meter.
it's important to verify a internal capacitance of the coil for a best performance ? or not ?

Internal capacitance of coil is usually ignored. Maybe it is more important than we think, but no one understands how, or if, it matters. If you follow the methods described for making coils, then it should not matter.

Internal capacitance is not easy to control. Maybe you can change it by type of insulation on wire, how you arrange the windings, and how tightly you bind the coil. But mostly it is out of our control. However, I think it is an interesting measurement and maybe we need to check it and see if it is different when comparing a "good" coil with a "bad" coil.

Regards,

-SB

[porkluvr]

Sorry , the capacitance was refer to coil measured with LCR meter.
it's important to verify a internal capacitance of the coil for a best performance ? or not ?

Ahhhh, that explains it, why didn't you say so!
Naah, don't worry about the coil's internal C. When you wrap 100 or so turns of wire together, you will have some interwinding capacitance. Nothing to worry about (here).

From what you wrote it looks like you did a good winding your coils, so...

Yes, measure the TX oscillator capacitors. I'm betting that either the 220n or the 22n capacitors will read VERY low. Maybe both of them.