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In the Forum: Melquiades Amplifier
In the Thread: More 6E5P-6C33C amps.

Post Subject: Actual SE OPT prformance limitsPosted by Bud on: 10/28/2010

Hi Panos,

Romy asked me for a sanity check on your stated performance limits for your SE OPT's. It is good to see someone paying some attention to what is in the Radiotron Designers Handbook for high performance coils. What you are doing, winding five coils and stacking them up the central core shaft of core is not done very often outside of radio frequency transformers, in this "modern" age. Are you using a tape wound cut core or E/I laminations, or perhaps L core? If you are using commercial grade E/I core I can suggest a distributed gap, utilizing three gap sectors. For lowest distortion above 250 Hz any core form that shoves the gaps out beyond the coil winding limits is a plus. This can be done with tape wound cores, but it is a pain, becomming either a J core or, in your case, having 3 coils on one side and 2 on the other of a central cut gap, with about 3mm of distance from the coil winding edge to the gap. Stick winding all five coils is also a possibility, though nearly a lost art now days.

Were it me , I would find a way to mold a CE 6500 style shrouded bobbin. One for each Primary, Secondary, Primary coil set, and make use of the inherent safety agency delight and greatly enhanced control over the E Field moments provided by a complete dielectric enclosure. If you have access to vacuum polyester resin impregnation you can then construct a dielectric circuit to better focus the E Field across the dielectric barriers. This will roughly triple your coherent information transform and provide you with a startlingly dense signal retention. Will also allow the plates to work more efficiently.

So, yes Romy, it is quite likely that Panos is actually building OPT's that will allow his tubes to remain stable enough to provide the frequency response he is claiming. The only down side I see is the fiendishly complicated interconnect between the coils and then making that entire event something that the EU safety agencies will allow him to sell commercially, in the EU community. Not beyond possibility, but only commercially viable where labor costs are quite low.

Bud

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