TESORO GOLDEN SABRE

[ivconic]

BD140 is PNP, yes. Did i used wrong symbol there!????
Let me see.....YES I DID!?!?
Sorrrrrryyyyyy! My mistake!

[simonbaker]

Thanks for answers.

I don't want to bother you, but can you check the CScope schematic? Because it really looks like the collector and emitter should be interchanged, according to normal circuits.

I could not find any circuit (common base, common collector, common emitter) where the emitter points to the +V supply like that -- just looks like mistake ?

Cheers,

-SB

Ok, I think I see problem.

BD140 is drawn on schematic as NPN transistor, but is really PNP, right?

I'll fix schematic and upload if you think that is correct.

Regards,

-SB

[simonbaker]

Referring to your "TGSL Final" schematic audio amplifier section:

1. Did you try using an MPSA13 or other Darlington in place of the two BC547 transistors? Or is there a good reason to have the two BC547?

2. Why is emitter of TR3 (BD140) connected to +V, instead of collector? The circuit seems very unusual, how did you decide on it?

Regards,

-SB

Sorry i missed that question!
1. No i havent tried MPSA13 or any simillar there.
2. Ha,ha,ha,ha! Guys from Cscope decided that much more before me!

Thanks for answers.

I don't want to bother you, but can you check the CScope schematic? Because it really looks like the collector and emitter should be interchanged, according to normal circuits.

I could not find any circuit (common base, common collector, common emitter) where the emitter points to the +V supply like that -- just looks like mistake ?

Cheers,

-SB

[ivconic]

"...Also on simpler way to disable inputs on unused u107b I mentioned previously?..."

For example it may be used as battery monitor. Or...it may be "neutralised" simply as on pic...

[ivconic]

Referring to your "TGSL Final" schematic audio amplifier section:

1. Did you try using an MPSA13 or other Darlington in place of the two BC547 transistors? Or is there a good reason to have the two BC547?

2. Why is emitter of TR3 (BD140) connected to +V, instead of collector? The circuit seems very unusual, how did you decide on it?

Regards,

-SB

Sorry i missed that question!
1. No i havent tried MPSA13 or any simillar there.
2. Ha,ha,ha,ha! Guys from Cscope decided that much more before me!

[Ultimate_Haze]

Hi,
Max.
You can see this in post #3546 picture 2!
This is for my test coil #3.
I will make some more pictures.
The coil disc good.Only sensitivity is poor.
Thanks for your attention.

[Max]

Hi,
My probe is X10.
So its OK.
First I tought that I should count the devisions and multiply.
Now its clear.
What next?

Then use tx signal to trigger the scope (channel1) and get rx signal at output of preamp (on channel2): you'll spot the phase between tx and rx signal when no metal near... that's interesting measuring phase angle to know if your coil is made properly and you can disc the correct way...

Kind regards,
Max

[simonbaker]

Hi Ivconic -

Referring to your "TGSL Final" schematic audio amplifier section:

1. Did you try using an MPSA13 or other Darlington in place of the two BC547 transistors? Or is there a good reason to have the two BC547?

2. Why is emitter of TR3 (BD140) connected to +V, instead of collector? The circuit seems very unusual, how did you decide on it?

Regards,

-SB

Hi Ivconic:

Can you comment on audio circuit questions? Also on simpler way to disable inputs on unused u107b I mentioned previously?

(I'm still trying to make a final PCB that is simplest and fits my components -- glaciers move faster...)

Cheers,

-SB

[Ultimate_Haze]

Yes,
I am using the last version.

[simonbaker]

Hi,
Max.
I have try to adjust like you show.But I can see this relationship only in chop.Is this normal or my oscilloscope is not working properly?
I see that my TX signal have some distortion in peak.Can this be the source of my problems?
Here are some pictures:

If you used TGSL Final version of Ivconic's, you will have notch because there is no feedback-regulating JFET in oscillator. The benefit is you get larger voltage. With original circuit, you can get rid of notch by adjustments.

Regards,

-SB

[Ultimate_Haze]

Hi,
My probe is X10.
So its OK.
First I tought that I should count the devisions and multiply.
Now its clear.
What next?

[Max]

Hi,
Ok.Thats easy.As you can see on first picture for chanel one 16 X 0,5V=8Vp-p.
Its too low.
you say 14-16.
What could be the reason?

Hi,
it's about 3 square height, the square value is 1, the 5 divisions on squares are 0.2 each, but you must consider your probe also:
if probe is 1:10 attenuated you must consider 10 times what you read on screen.

Now, if 1:1 you have (roughly) 3x0.5 = 1.5V (it's unreal you get such 1.5V)
but I suppose probe is set at 1:10 (attenuated 10 times) so you have actually 3x0.5x10 = 15V peak to peak

If so... 15Vpp are about close to "perfection"!

Kind regards,
Max

[Ultimate_Haze]

Hi,
Ok.Thats easy.As you can see on first picture for chanel one 16 X 0,5V=8Vp-p.
Its too low.
you say 14-16.
What could be the reason?

[Max]

Hi,
Ivconic.
Thanks for the fast reply!
So TX is ok.
I am shame but its my first steps with oscilloscope and still ALOT to learn.Plus I dont have manual for this.So how to understand what is my p-p voltage?
On second picture there is TX signal/collector 2907/ VS 353 pin7 this is in chop.Anyway I will make some more pictures.
But still my sensitivity is too low.
I have noticed before that there is a small diferance in voltages somewhere in RX section.I will check again and will give some more info.
Have a great day.

Hi,
p-p, or peak-to-peak voltage is the vertical distance between positive and negative peaks (up to down or down to up peak).

You count squares and squares' divisions... then multiply by the V/div setting on the panel: that multiplication gives you the voltage p-p.

Kind regards,
Max

[Max]

Hi,
Max.
I have try to adjust like you show.But I can see this relationship only in chop.Is this normal or my oscilloscope is not working properly?
I see that my TX signal have some distortion in peak.Can this be the source of my problems?
Here are some pictures:

Hi,
the little notch, like Ivconic already stated, is just a small non-linearity at oscillator, mine is the same... are all about the same cause transistors aren't ideal devices... and small non-linear behaviour is normal.

Also, if you simulate in LTspice, as example, you get same shape with notch... cause transistor models are accurate and close to reality.

About chopper mode... you use it depending on frequency, in some cases alt mode is better to see the two signals but TGS runs at 14Khz and up (VLF, so very low frequency) so you'll be fine in chop mode with your scope.

Check the amplitude of signal at TX, must be 15 to little less than 16 V peak-to-peak , if so you have correctly running oscillator then will check other signal (rx one) for details.

Kind regards,
Max