GOLDSCAN 5 SCHEMATIC QUESTION

[dbanner]

Yes, I saw this 1.5nF on schematic TDI PRO PROTO, this is mistake I think. Other schematic have 47nF, and yet another have 22nF. 1.5nF is way too low.

[saba]

cap. is 1,5nf as shown in the schematic

[dbanner]

The front end is supposed to be fairly straightforward. If you are reading 32Khz correctly on scope then you maybe put 2.2nF cap.(202) instead of 22nF(203)? This would result in somewhere around 32Khz.

[saba]

Hi thanks, i will recheck everything, can someone try to simulate this section?

[waltr]

Hi dbanner, on breadboard, freq. and pulse i see on osciloscope, i want test every section separately and finaly draw pcb

Possibly you read the O'scope time/division wrong- re-check as this is easy to do wrong.
Other possibility is wrong value components like the Caps that set 555 Freq. Easy to mix 0.047uf for 0.47uF - re-check.

The O'scope should have a Calibration output. Use that to check frequency you measure.

[saba]

Hi dbanner, on breadboard, freq. and pulse i see on osciloscope, i want test every section separately and finaly draw pcb

[dbanner]

3.27khz is about right. Maybe you read pps wrong? What board you used? Which schematic?

[saba]

Hi guys, i tested 555 TX timer on TDI board, it work on 32,7khz and pulse width is 13us, what hapen, maybe some mistake on sheamtic?

[Orbit]

GS5 with a processor Time like TDI ..SL

[dbanner]

This one

[Idefix]

Hi,
What kind of VCO do you choosen, finally?

[dbanner]

Maybe someone might find this layout useful.

[dbanner]

The LM394 with an opamp will do nothing better in a TDI /GS5 , comparing to a modern opamp. At least the same. The noise from 1000 ohms is worse than the one of the amplifier, 4.1 nVsqrHz@ 25°.

I was referring to single cap integrator implementaion or mods done on TDI (https://www.youtube.com/watch?v=s0DXQFCF8F0) for noise reduction.

[Idefix]

I was looking at possible modifications to GS5. But I like the sd2000 audio circuit. LM394 is no problem. Suitable replacement can be found.

The LM394 with an opamp will do nothing better in a TDI /GS5 , comparing to a modern opamp. At least the same. The noise from 1000 ohms is worse than the one of the amplifier, 4.1 nVsqrHz@ 25°.

[Geo]

Hi Geo,

The first TDI's used 4538's, and later switched to a microcontroller. Some where on one of the forums Reg or Carl mention that there was a first run of TDI's with through hole components and not smd. I recall it was less than a 100 units.

Here is a photo of a proto type just like the one I have

I agree but these TDI are collectively now