Please reconsider your use of expanding foam to replace the tar. 1. The expanding foam is an insulation . So the box may feel 'cooler' because the foam isn't conducting heat to the exterior as well. 2. I would be shocked if the dielectric strength of the polyurethane foam is anywhere near that of the tar. 3. Having worked in a factory that builds radio units for utility companies, the potting compound used now is still has properties remarkably similar to tar. Even though it is epoxy based and far better spec's overall the tar is still a better choice for the coil box than polyurethane foam I suspect. Good video. 👍
The smaller, 630V capacitors at 8:11 appear to be the incorrect type (Metalized Polyester Film type; eg. Panasonic Type ECQE(F)) with low dV/dt rating; if so, they will likely fail with use in the Model T ignition coil application. The larger, lower voltage; 400V capacitor at 8:25 appears to be the correct type with dV/dt rating >600V/us which is required for the ignition coil application. The next important step is point adjustment for equal and consistent firing time. For that, there is no better tool than the ECCT. It is the only coil tester that actually measures dwell time to fire spark. More information here: www.modeltecct.com
The foam is a very poor substitute for tar. The tar is to hold the solder joints and everything else from vibration. I have repaired many with either nothing or foam added when rebuilt and come to me with solder joints just broken with vibration and never one returned that was completely full of tar...with nothing left to vibrate.
Please reconsider your use of expanding foam to replace the tar.
1. The expanding foam is an insulation . So the box may feel 'cooler' because the foam isn't conducting heat to the exterior as well.
2. I would be shocked if the dielectric strength of the polyurethane foam is anywhere near that of the tar.
3. Having worked in a factory that builds radio units for utility companies, the potting compound used now is still has properties remarkably similar to tar. Even though it is epoxy based and far better spec's overall the tar is still a better choice for the coil box than polyurethane foam I suspect.
Good video. 👍
The smaller, 630V capacitors at 8:11 appear to be the incorrect type (Metalized Polyester Film type; eg. Panasonic Type ECQE(F)) with low dV/dt rating; if so, they will likely fail with use in the Model T ignition coil application. The larger, lower voltage; 400V capacitor at 8:25 appears to be the correct type with dV/dt rating >600V/us which is required for the ignition coil application. The next important step is point adjustment for equal and consistent firing time. For that, there is no better tool than the ECCT. It is the only coil tester that actually measures dwell time to fire spark. More information here: www.modeltecct.com
You commented on the capacitor type but you did not say what value the Micofared cap should be. What is the cap value used in this coil?
@@neutrodyne capacitor value is 0.47uF
The foam is a very poor substitute for tar. The tar is to hold the solder joints and everything else from vibration. I have repaired many with either nothing or foam added when rebuilt and come to me with solder joints just broken with vibration and never one returned that was completely full of tar...with nothing left to vibrate.
по сути обыкновенные катушки Румкорфа были использованы на форде модель Т и простой механический коммутатор
Appreciate the video but looking at your meter its at 30 and the scale ix x100. Isn't that 3,000 ohms not 30,000?
My coil measures about 3K
I have 3 coils they all measure in the 3 thousand range-3200 -3600ohm
re you selling coils? if soo how much or how much to rebuilt mine
paper clip is steel...better to use copper
Very interesting :)