TGSL Tuning & troubleshooting

[Qiaozhi]

It appears as if you used up all the space for your attachments. You may want to politely ask Carl to do something about it.

That's not the problem.
I suspect he just took too long to upload the files before attaching them. There's a one hour limit, after which any unused attachments are automatically deleted.

[sdesic]

Davor,
resistance is 14,94k ohm

Simon,
I bought LRC meter few months ago
VICHY DM4070
I will try to measure those graphs again...

Thank you all for your patience!

[simonbaker]

Switched to disc. mode
tx and pin 1 353
tx and pin 7 353
tx and pin 7 393

Unfortunately we cannot see phase easily because time scale is too long -- can you "zoom in" by using faster sweep or magnifying the time scale?

I would like to see details of signal at Gate of TR4, TR5, but I think maybe your scope bandwidth is too small. The signals should be square wave for GB sync pulse (at gate TR5) and DISC sync pulse (at gate TR4). Sometimes the DISC signal has spikes which usually don't cause a problem. ALL METAL (gate of TR4 also) signal usually looks like a triangle wave.

Any distortions to these signals, or level problems would be interesting to know. Usually the max value of the sync pulses is approximately 0 V (ground).

Anyway, I'm hopeful you can find the problem because it is not sensitive to cables -- something more definite is wrong. Because it was a kit, it would seem you are using all the right parts.

What did you use to measure the inductance of your coils?

-SB

[Davor]

It appears as if you used up all the space for your attachments. You may want to politely ask Carl to do something about it. Those scope shots were all jpg. Unfortunately. For all screenshots you get 10 times smaller files, and in incredibly better quality if you save them as gif.

Anyway...

There might be a logical explanation after all. Guess you have some decent ohm meter at hand. I want you to switch off your device, and measure resistance between LM393 pin 7 and ground. With device switched off, of course.

Edit ... you can find ground at pin 5 of LM393.

[sdesic]

I don't understand why delay of 50s when powering up ... detector is getting power ... there is no tubes inside to warm up
if I move coils it detects on fist second from powering detects other coil or cable
other things is detecting after 50s

OK, that's it from me and "scope" for today

[sdesic]

LM393 pin 7 while rotating the GB pot




I made a mistake by connecting pins 7 and 8 of LM393 and detector stoped working
then it responded to ferrite and I was able to noch it with GB trimmer
(or just lower sensitivity to all)
I shocked it with 8V to pin 7 ... after minute it was beeping again ...
it is not fried...

[sdesic]

input to LM393 U102a pin 2 while rotating the DISC pot
and TX graph




Davor,

I am using KIT from Silverdog ... he has supplied me with BF245B

[Davor]

What FETs do you use?

[sdesic]

small signal GATE TR4 and GATE TR5 is from TX coil
when it is not connected there is no signal - this scope can't read TR4&5 ?
GB trimmer on middle

[sdesic]

Switched to disc. mode
tx and pin 1 353
tx and pin 7 353
tx and pin 7 393

[sdesic]

captured few more
TX and pin 7 393 close to GB (I am thinking that lower one is noise only - even if not connected there is similar signal)
TX and gate of TR4 and TR5
all metal mode

[sdesic]

Replaced USB cable with RCA high grade audio cable (two coaxial cables connected)
nothing changed... tried GND in head of coil and tried connecting shielding wires to one of TX and then to one of TX wires ...
same thing happens... it is stable when overlap of coils is over 3.5 cm

moving on

[sdesic]

>Are you measuring the TX or RX signal as reference (your scope screen says RX)?
>Most useful to start with is measurements vs the TX signal.
that is TX graph sorry ... it was early in the morning typo in photoshop...

>Have you tried moving the cable in different configurations, touching it with your hand, etc. to see effect on beeping?
tried varius combination of wires in USB cable... it is not responsive to touch

>Do you have some RCA audio cables you can try as a substitute?
to separate TX from RX... OK will try that also
STP - UTP ?

>Probably not easy to help you troubleshoot without good equipment. Obvious ideas are to double-check your solder joints; make sure >no solder across traces; clean resin off PCB.
cleaned few times... MD works with more overlap ... no disc. mode

>I would still want to see all signals I mentioned compared to TX, to get phase relationships,
>although the PC scope may be interfering somewhat.
will post rest of them today...

[golfnut]

If this had XY mode - This is the closest to a homemade deus we have

have a detector module into atod's and BT it to Galaxy

http://projectproto.blogspot.com/2010/09/android-bluetooth-oscilloscope.html

[sdesic]

>Can you use a higher resistance resistor to measure the TR4, TR5 gate voltages,
>and find what resistance is required to cause the beeping again?
tried connecting more resistors to gate of TR4 and to my scope
beeping continues after 100k resitor in my probe... I tried trimmer 50k but it won't stop ... if I disconnect it it stops
if I touch gate of Tr4 or middle connector of disc. switch it stops beeping

this is not effective for TR5 in all metal mode and in disc.

in disc. mode TR4 is not able to stop beeps ...