Need some guidance with coils and electrical readings

[Darren J Wallace]

I'm rebuilding some 1912 Heinze coils and am using the new primary and secondary windings you can buy from the vendors. I had a new winding left over from an old batch I bought and put together a coil. I potted one coil before checking it (my stupid mistake) and of course, it didn't work at all. I did check the secondary before I took it apart and I was getting SAME reading as my photo with the new secondary shows. My Fun Projects "beep checker" barely makes any sound checking these new windings.

The other photo shows a coil I rebuilt a few years ago and my Fun Projects beeper screams when you test it, and I get a reading on the secondary more in line to Ron's schematic.

I just got a new batch of primaries and secondaries and to my confusion, I do not get a reading on the secondary that conforms with a schematic I got from Ron Patterson years ago. So before I proceed, can anyone tell me if these secondaries are any good from and electrical standpoint?

Also, none of the primaries I bought had iron cores in them, and I don't see that part listed anywhere separate. I wonder why?

I've rebuilt hundreds of "normal" coils and although I am not an electrician, I understand them "enough' to know how they work and rebuild them, but when it comes to some of the electrical complex details, that's where I get lost.

Thanking all you coils experts in advance for steering me in the right direction!

[Darren J Wallace]

I would also like to add that I'm only rebuilding these Heinze coils and their respective original wood box just for a fun project. Whether I actually use it or not on my car is up in the air. I like the challenge, and I want to have a "era correct" coil box for the car. I'm currently running a KW reproduction wood box I put together earlier in the year.

[Mark Gregush]

While you have had some views, you are not getting to the people that can help. Click on the pencil and add "1912 Heinze coils" to your title at the front of it.

[R.V.Anderson]

I would guess that your potted coil isn't working because you are getting arcing between the new primary and secondary windings. You need to insulate them from each other to prevent this. Wrapping the primary in good quality electrical tape should take care of that. Try connecting your windings as you have them in your photo, either in the opened-up case or outside it, in series with a known good coil and connected to a power source, then watch (and listen) for arcing.

[Darren J Wallace]

Thanks everyone for your help! I have a coil working, and I think RV nailed it! It seems to have the least amount of double sparks at 1.0 amps.
Please comment if you see anything I'm doing wrong so far. I've built many regular coils but this is a first time for me doing a Heinze. It's not potted yet and set up crudely just to test. The holes and such are to let the tar flow through when I'm ready. I also used the original iron core rods so my photos are a bit out of order and a process....

Here's a YouTube link below to see this coil in action:

https://www.youtube.com/watch?v=p9ZIT9V ... e=youtu.be