Tesoro Cibola high and low tones

[Sven]

Does anyone know what Tesoro does to change the tone from low to high?

I heard they re-program a chip? Or do they just put in a different chip that has a diff. resistor capacitor value somewhere in it?

Just curious.

[Sean_Goddard]

Yes, The -ve voltage is generated using a 4024 divider chip and a push pull stage (as per all their other machines). On THREE of the outputs of this chip is a diode OR matrix which combines the outputs into one then to the audio amp stage. Move ONE of these diodes along ONE leg on the chip so instead of dividing Ftx by say 64 to give the audio base tone, it divided by 128 (half the frequency as an output) and thus a lower overall tone.

This mod costs a stupid £40+ in the UK and takes three minutes. If someone posts CLEAR photos of BOTH sides of the PCB. I may be able to tell you which diode to move.

[Sean_Goddard]

Like this;

Find pin 5 and move the end of the diode that is connected to it to pin 6. Job done three minutes = LOW pitch mod (and NO profit for rip off modders)

http://www.pulsar-electronics.co.uk (the ONLY place in Europe to get your detector modded or repaired - Our mods and repairs don't affect your Tesoro, or Whites warranty)

(Sorry for the commercial plug all)

[eclipse]

Is it the same if I remove the diod connected to Pin5? If i understand right to
do this mod you need to connect those 2 diodes parallel.
What is the advantage of having high tone instead of low tone?

[Sean_Goddard]

NO!!

Disconnect the ANODE of the diode which is connected to PIN5 of the IC and connect it instead to PIN6. This will LOWER the tone. IF you want a higher tone, then disconnect the ANODE of the diode from PIN 9 and connect it to PIN 11. This will give a HIGHER tone.

No advantage EXCEPT that the standard tone is around 800Hz, the higher one around 1600 (or soemthing like that). The mod moves the tone into the range where the ear is usually most sensitive to small changes in amplitude, thus, in theory, giving the user better aural sensitivity to small signal changes

[Sven]

Thanx.

I will be opening up the Cibola again shortly to add ground balance and an all metal/disc toggle.

I will take photos of both sides of the pc board and post it before I do the mod.

Thought somewhere on the web, there was two wave files with both tones to listen to. Can't find it any longer.

[eclipse]

Highly valued information i will try it for sure, appriciate it Sean. Thanks!

[ivconic]

Yup!
Take datasheet from 4024 and mark all the pins which outs divided values.
Make experiments. Not harming at all.
But guys from Tesoro did most proper choice.Hard to find better combination than 5,6,9 cause those are forming prety "harmonical" composite tone.
If you remove one of those (or two) you'll get interesting change...but also loose on threshold and loudness too.
I was thinking to add some buffer stage for buffering and amplifying those outs in manner to preserve better threshold at TGSL.
Yet...worth of experimenting..

[Sean_Goddard]

U R welcome. Glad to be able to help.

Why not add a DIP switch, then you could experiment until you found a tone you liked.

Can anyone say VCO also??

[grayfray]

Pics

Thanx.

I will be opening up the Cibola again shortly to add ground balance and an all metal/disc toggle.

I will take photos of both sides of the pc board and post it before I do the mod.

Thought somewhere on the web, there was two wave files with both tones to listen to. Can't find it any longer.

Hi Sven, did you ever do the tone mod on the cibola? I agree with Sean Goddard we get ripped off for modifications here in the UK

[Sven]

Hi Sven, did you ever do the tone mod on the cibola? I agree with Sean Goddard we get ripped off for modifications here in the UK

No, did not do the tone mod. I would rather hear what the high tone sounds like first on some one else's detector. The low tone that comes from the factory sounds fine to me right now.

Just looking at my board photo and can't see the 4024 chip.

[Sean_Goddard]

Hmmm I think we need Carls help here, he started to draw out the Golden Sabre I think and that diagram might give us a clue. Carl is you still have that can you post if in this thread please?

The Cibola and Silver Sabre will most likely be similars in code used in the PIC, I suspect tht if it doesn't use the 4024, then it may be done, as you suspected by the PIC (which would mean I was wrong..Sorry).

It may be a re-programming of the PIC. If this IS the case then Tesoro are breaking EU law, as to allow competition they would have to release the code so that third party repairers can do this mod (IF it's an official mdod). They haven't so that makes them criminals in Europe Shame.