TESORO GOLDEN SABRE

[sdesic]

We are talking about TX and I am posting data on RX ... sorry
0,22 + 0,022F then

I was wondering about placing TX and RX coils in shell.
Is there any difference if TX and RX is switched ?
Or if TX and RX are placed wrong way - wound clockwise and placed differently.
Or if TX is lower or upper coil in shell ... as they are overlapping.

[sdesic]

It is OK to know that if I get one of those coils cheap.
15nF can be changed to 10nF or less
How do I calculate that value ?

[Silver Dollar]

Here's the chart;

Tesoro

Name TX-L TX-R (ohms) TX-fo TX wire RX-L RX-R (ohms) RX-fo RX wire Brown 8" 5.59mH 21.2 --- --- 6.23mH 22.1 --- --- White 8" 5.68mH 21.8 --- --- 6.36mH 22.8 --- --- White 4" 5.62mH 26.6 --- --- 6.13mH 28.2 --- --- uMax 9x8 5.74mH 24.6 --- --- 6.21mH 25.8 --- --- uMax 12x10 5.78mH 17.3 --- --- 6.15mH 18.9 --- --- Notice the TX Values

[Silver Dollar]

5.75 should be fine. If you look at the real original specs the TX's were a bit lower than shown here.
Just tune the TX for 14.7 khz or there abouts (by changing the small cap in the TX) and you should be
good to go!

I have successfully used a Tracker coil on my bandito. It uses 2.6mh TX AND 2.4mh RX...

[sdesic]

I melted glue from my old "non working" coil and measured TX.
It is 5.75mH 25 Ohms.... as it should be 6mH
Maybe damaged from "melting" glue.

Can I use it with RX that I made new - 6.5mH and 25 Ohms ?

[Silver Dollar]

I fired up the modified TGSL tonight. It draws 16 ma! That's approximately 1/2
of what it originally did. I lost depth though. The TX is only 10v P/P now though
on the Bandit that was plenty. I have been fighting a weak coil on it anyways but
still lost an inch or more so not sure if the OP97's are a viable option.

I'd like to find a low current strong oscillator for the original Tesoro coil. The minelab
style oscillator does a great job but requires a low resistance TX coil. It works on
a 6 ohm 2.4mh Tracker coil but not on the 20 ohm 6.1mh Tesoro. The Balanced H Bridge
does great too but it is trick to get the phasing pulses out of it without a bit of extra circuitry.

The new audio oscillator sound sweet too! It's a 430hz triangle and is smooth sounding compared
to the square wave original. You can make the original go deeper though as the narrow pulses can
sneak through the pulse filter and give a sound on deep stuff....

[Silver Dollar]

Well the National Datasheet says:

Fits 725/108A/308A, 741, AD510 Sockets

Which I believe implies it can be used in place of the LM308.
I've used it in my TGSL but it has never worked perfectly so I
cannot say definitively. It has similar goals of stability...

[seadoggy]

I had used OP07's instead of LM308's as the ones I bought were chinese imitations and
didn't work properly. Today I found some OP97's that are the same as the OP07's but
much lower power, reasonably good noise specs too! I'll change those out and try the
power to see how much current it draws.

The Bandito uses 15 ma and the TGSL was 30 when I started. I think the big 8v LDO
wastes 10 ma by itself and I probably saved a couple of mils with the OP97's so we
should be getting down near the Bandito spec...

hi silver! so i can replace LM308 with OP07 on TGSL board??

[Silver Dollar]

I had used OP07's instead of LM308's as the ones I bought were chinese imitations and
didn't work properly. Today I found some OP97's that are the same as the OP07's but
much lower power, reasonably good noise specs too! I'll change those out and try the
power to see how much current it draws.

The Bandito uses 15 ma and the TGSL was 30 when I started. I think the big 8v LDO
wastes 10 ma by itself and I probably saved a couple of mils with the OP97's so we
should be getting down near the Bandito spec...

[Silver Dollar]

My Bandito runs off a 9V battery. The TGSL is supposed to go deeper based on it's using
+8V and -7.5V from a 12V battery but mine doesn't seem to go deeper so I thought I'd
mod it to use one 9v battery. Some of the current draw is in the LDO 8V regulator so I'm
hoping to save some juice there. I also hope to remove some noise from the 4024 and
negative voltage generator. I found a MIC5207 laying around to make the plus 5 volts
and used a LCT1044 (similar to 7660) to make the negative voltages.

I stole the audio oscillator from the IDX by using the 1/2 LM358 available...

Here's a schematic of my current board;

[paku]

ok i will try resolder all pot and wire back

[Silver Dollar]

Try the machine gun circuit! But seriously that is a problem around the LM393 at the output.
The sens pot usually adjusts for that, maybe a broken wire on the sens pot?

Oscillations in the filters can do the same. I used to have that problem but now I have low
gain most of the time but once in a while I get a lot of chatter. I'm not sure where the problem
is as it appears in both channels. I tried resoldering all components today too. I have to hook
it up again to see if it helped any...

[paku]

now i have desolder my board then i resolder back
i got new problem when turn on my TGSL got sound like machine gun
what is problem

[sdesic]

I have problem with few beeps - false positive on swings or if coil is on rough terrain / bumpy - but I live with it.
Bump gives false signal ... thick grass or roots on contact - my coil is not in epoxy - used hot glue only.
Only two beeps are good signal.

[paku]

thanks manny77 i will try fix now

that is
PNP 2N2907
NPN 2N2222