TESORO GOLDEN SABRE

[cristiano.sar]

In Brazil, the best source of original ci's is electronic scrap.

Thanks, some time ago I bougth an old TV but can't find any usable components for the MDs I'm building, but I will keep an eye in other used electronic devices.

[cristiano.sar]

After changing the TL071s to LM308s, now I have much better sensitivity, but it is only usable when the sens pot is at almost minimum. If I increase it, the detector becomes very unstable, a continuous beep can be heard, you can see it in the video:
https://www.youtube.com/shorts/ENlC_If9tP8

[cristiano.sar]

Another doubt, I'm my EDU board, there are some small holes that are not connected, should I connect them with bridge wires? Thanks

[Toros]

Another doubt, I'm my EDU board, there are some small holes that are not connected, should I connect them with bridge wires? Thanks

These are through holes from one side of the board to the other. Don't touch them.

[ivconic]

I can't see RX capacitor 15nF on the pcb?
Without it it will work similar as on your video.
Coils are not shielded?
Behavior on video is typical when the last comparator goes into self oscillation.
To mitigate this to some extent; use 32-64 ohm speaker.
But first things goes first; shield the coils, shorten the wires that comming from pcb and put the pcb into shielded enclosure.
If not the whole enclosure, at least make sure the pots and switches are all tied to metal front panel and grounded.
Keep in mind; those old Tesoros are all coming into metal enclosures well grounded.
And all use 32-64 ohm speakers.

[kt315]

Coils are not shielded?

if a coil is not moving (in space), rests on a table, static, then the shielding is unnecessary. just you take the coil and move it up down - you have to shield the coil.

[cristiano.sar]

Thanks.

The coils are not shielded yet. I want to shield them inside the casing, with graphite.
The 15nF RX capacitor is connected to the coil wires so I could change it easily, that why you dont see it in the photo.
I will try other speaker (I'm using a piezo buzzer) and shield the enclosure.

Thanks.

[cristiano.sar]

Has anyone a picture of a built TGSL-EDU board so I can compare the components with mine? After a long time without touching the project, I decided to return to it and I'm still with the same issue reported in previous posts: I can only use the sensitivity pot at minimum, it i turn it higher a constant tone is heard (https://youtube.com/shorts/tP9NpLMGQfM). Coil is not shielded for now as i'm only testing it statically. Thanks.

I've just found the problem, something with the LM308s, I changed them to supposed original versions and it worked ok now.

[cristiano.sar]

I have a new doubt. When setting the GB trimmer, I've read that the sensitivity pot should be at minimum. I am able to reject the ferrite with this setting (GB trimmer at middle and sens at minimum). Although, when I move sensitivity to max, the ferrite is detected. Is this normal? Thanks.

[Carl-NC]

It is normal. If you want to get the best ferrite rejection then do the trimming at max sensitivity. But it really doesn't matter much if you are trimming an otherwise fixed GB because ground will vary a bit and you will always be a little bit off.

[cristiano.sar]

Thank you.

Today I have experienced really the difference between "fake" and original components. After changing the LF353, LM393 and LM358 by original components bought on mouser, the detector goes too much deeper and with less noise in the RX waveform.

[MOR_AL]

Thank you.

Today I have experienced really the difference between "fake" and original components. After changing the LF353, LM393 and LM358 by original components bought on mouser, the detector goes too much deeper and with less noise in the RX waveform.

I think my post #6252 was helpful.
I'm glad it helped you.
MOR_AL

[Adam24]

Thank you.

Today I have experienced really the difference between "fake" and original components. After changing the LF353, LM393 and LM358 by original components bought on mouser, the detector goes too much deeper and with less noise in the RX waveform.

How did fell to fake components

[Aleks85]

Hi everyone, I did this test and already shared the results... It turned out to be a simple method, but it can be used to determine whether a microcircuit is original or fake.

Sorry, the language is only Russian, and I'm writing here only through an online translator.

[growdude]

Does anyone have diagram for wiring coils for the tgsl?