coil generator : tester of coils

[kt315]

[kt315]

also, you may try another sch.

[kt315]

220 nanoFarad caps go in delta pulse. BTW i can set 330nF in DP too but then people will ask me why i set them LOL! i do not want
excess hype around.
some people ask me to send 'some caps' with DP board. if i set 330nF in the generator that do nothing.
pleasure.

[dgm]

Hi Mr. KT, I noticed that you used three 330kpf capacitors in your pcb and not 220kpf as shown in the diagram, I ask you this question because I solved it by changing the capacity of one of the three capacitors of the circuit. Thanks for your reply.

[dgm]

Thanks I will

[kt315]

i can suggest to check every resistor on value. esp-ly 2.2 MOhm and 10 Ohm.

[dgm]

The coil of the Idx use a 33K capacitor. Thanks for replying

[kt315]

hi
limitation according the article for this sch is 100mH. so 35.5 has to be normal. what capacitor value you use with the coil testing?

[dgm]

Hi Mr. KT315, I made this circuit, and it works very well, only if I measure the coil rx of the Idx 35.5 mh I have no result! I can not understand. Thanks for your kind reply.

[SkyeHi]

I know this is the wrong forum to discuss TOTeM, but I thought it was worth a mention.

Possibly not bang on with topic but I find it still has some relevance to this thread, if developing a piece of test gear and desire/need accuracy.
The link above, referring to the Pelz circuit, had another link within it looking at the relaxation effect of LC oscillators. Whilst KT's Russian/German circuit might not suffer from this effect and the resulting inaccuracy, at the frequencies we are operating would be small. I notice that V1 and V2 of the circuit is in emitter follower mode, it could allow the Base Collector diode effect to give a "false" resonance. The authors solution was to connect diodes in series with each base, in forward bias. Does'nt look very elegant but he says that it works.
I'm not in a position to build and test any of these circuits just now but I am interested in what you think and will start building them very soon. The relaxation link;

https://www.radiomuseum.org/forum/relaxation_oscillations_in_lc_oscillators.html

[Qiaozhi]

Had a look around some achive stuff, many interesting things but none 100% relevant. Then looked again at KT's link to the circuit and thought it looked like a Peltz osc. with modified feedback.
Found this quoting from an earlier "funkschau" magazine about exciter circuits for checking the resonance of IF coils, it includes a Peltz circuit. See what you think;
https://www.radiomuseum.org/forum/if...?language_id=2

This is interesting, as I [re]discovered this when nulling the TX and ferrite coils for TOTeM in Chapter 14 of ITMD Edition 1.
However, my conclusion was that the angle was 45 degrees, but I must admit I never measured this very accurately. The actual nulling point was found by trial and error during construction.
I know this is the wrong forum to discuss TOTeM, but I thought it was worth a mention.

[SkyeHi]

Had a look around some achive stuff, many interesting things but none 100% relevant. Then looked again at KT's link to the circuit and thought it looked like a Peltz osc. with modified feedback.
Found this quoting from an earlier "funkschau" magazine about exciter circuits for checking the resonance of IF coils, it includes a Peltz circuit. See what you think;

https://www.radiomuseum.org/forum/if_filters_in_early_french_superheterodyne_radio_receivers_1.html?language_id=2

[kt315]

guys
Now this project is fully opened, you can order boards.

good luck

[SkyeHi]

My youth disappeared a long time ago ��

[WM6]

I will have a look through an archive site containing UK and American electronic magazines.
The UK ones would often copy/use articles from other magazines.

Thanks. If you are somewhat bored in quarantine, OK, otherwise don't trow away your youth on paper search.