ARADO 120 SCH& PCB

[ApBerg]

Hello Andreas,
Nice work, just a creasy idée…… can this circuit work as a 2 box ?
Best regards.
Ap

[WM6]

This is not essential. Depending on the diameter coils and knowledge freq-osc
we have different induction for resonate osc-circuit .
Here we want osc work 4,68KHZ
Only we must be try for make out this freq.

Yes, Andreas, but I mean for those who have some old factory coils and maybe wish to try it with Arado. They can nothing to rewind only to compare inductance if suit or not.

[Esteban]

This is not essential. Depending on the diameter coils and knowledge freq-osc
we have different induction for resonate osc-circuit .
Here we want osc work 4,68KHZ
Only we must be try for make out this freq.

No problem if you wish post different coils for differents frequencies too.

[ANDREAS]

Hello Andreas,
Nice work, just a creasy idée…… can this circuit work as a 2 box ?
Best regards.
Ap

Hi Ap
2-box, create idea, but if work or not i don't know
best regards

[ANDREAS]

Yes, Andreas, but I mean for those who have some old factory coils and maybe wish to try it with Arado. They can nothing to rewind only to compare inductance if suit or not.

If you use old coils, it's easy resonate Rx coil, but don't work fine osc. This MD work with antifashe signal 90 degree. All parts are calculation from freq 4-6KHZ. In this size you can make "null" work meter and discrimination , but don't work voice circuit.
It's better make two new coils from this MD. This is only my opinion. You can try and i wish for best results.
best regards

[ANDREAS]

No problem if you wish post different coils for differents frequencies too.

Hi Esteban
Do you work Arado with other coils and other osc-freq?
You know i have not free time for modification. Your opinion please
Best regards
Andreas

[Fred]

Thank you andreas for this new project.
It would be nice to see those complete and tested projects all together here, with the essential information on how to build them, like the TGS, DP, surmaster, and now this one, there is probably some more.

[Esteban]

Hi Esteban
Do you work Arado with other coils and other osc-freq?
You know i have not free time for modification. Your opinion please
Best regards
Andreas

This is because you're old as me (50).

[ANDREAS]

This is because you're old as me (50).

O.K Now i wait first member now , build this. Only in practice i can publish, method calibration this MD.
A tip PCB don't put capacitors C17,C18. We need here for calibration
best regards

[Esteban]

O.K Now i wait first member now , build this. Only in practice i can publish, method calibration this MD.
A tip PCB don't put capacitors C17,C18. We need here for calibration
best regards

Yes, those are high values capacitors due low frequency, 4.68 Khz.

Best regards

[ANDREAS]

Yes, those are high values capacitors due low frequency, 4.68 Khz.

Best regards

Thank you Esteban, we need here your help.
Finish for me , I wait first PCB and start again in practice
Best regards

[Esteban]

Thank you Esteban, we need here your help.
Finish for me , I wait first PCB and start again in practice
Best regards

Do you remember the variant with electronic capacitor for to helping the tune?

Best regards.

[ANDREAS]

Do you remember the variant with electronic capacitor for to helping the tune?

Best regards.

Yes, but is not time for this. We wait the first PCB

[technos]

Do you remember the variant with electronic capacitor for to helping the tune?

According to Ivconic, there is a large variable capacitor connected accross the TX/RX coils. After some thought, this does not make sense to me. I do not have (or had) access to this UK machine, so I do not know how this works.

Other coils use a trimmer cap, or more commonly a fixed value capacitor connected in this way accross the coils. If it is something that needs very infrequent adjustment, it makes sense to use a trimmer cap on the circuit board rather than an expensive mounted tuning capacitor.

I searched parts sources, and the large varicap diodes have become rare and/or are too expensive (as much as the tuning capacitor!). So that doesn't seem practical either.

If there is a need for an occasional tuning, it would make sense to use a trimmer in parallel with a smaller (and cheaper) available varicap diode.

I hope Andreas keeps us informed on this!

[ANDREAS]

According to Ivconic, there is a large variable capacitor connected accross the TX/RX coils....

Yes is true , but my Arado build two years ago, i don't put this variable capacitor.
You know is very difficult resonate same two coils Tx/Rx. For this application Arado use this variable capacitor.. etc
My method is simple for your all. After you build PCB , you must build a electronic-cap with range 50-300n. With this electronic-cap we can make a fine tune Rx coil.If you find this parts (example 101,5n) then replace with normal capacitor/capacitors and only difficult point is a "null" Tx/Rx. With this method we don't need variable capacitor between Tx/Rx
best regards