From what you have said, it sounds like the only constant in your comparison was the bridge. That's kind of like asking why one coil using a particular spark gap produces weak sparks , when a different coil can produce strong sparks using the same spark gap.
We would need more details of the other components as well as an explanation of how you determined "for sure" that both setups were ideally tuned before guesses could start to become useful analysis or diagnostic test suggestions.
There is a thread on 4hv dealing with low impedance vs high impedance DRs. A low impedance setup will typically have a much larger primary cap than a similarly sized high impedance primary - and then the secondary can also be high/low impedance. Multiple coilers have successfully demonstrated either approach - spark length is still primarily determined by input power for a well designed and built coil.
From: Buds mohrstamping mail <bud@xxxxxxxxxxxxxxxx>
To: tesla@xxxxxxxxxx
Sent: Friday, May 27, 2016 11:50 AM
Subject: [TCML] solid state tesla coil question
I recently finished the minibrute tesla coil and have it running well. The question is why does this coil operate better with a large primary capacitor size of .21uf vs. a smaller cap size of say .005uf. I have tried this setup two different ways by using two different secondaries and at .005uf the arcs are very weak and small. At .21uf the arcs are bold and long. I know for sure that the primary and secondary were in tune on both setups.
Bud mohrman
Forrest Mohrman
Engineer
bud@xxxxxxxxxxxxxxxx || 440.647.4316
www.mohrstamping.com
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla