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Old 09-27-2014, 02:19 AM
David G Dawson David G Dawson is offline
Senior Member
Join Date: Mar 2008
Posts: 420
Hendershot Detail

Dragon, thx1138,
Some good exchanges between you two and most impressed.
Dragon, an excellent build and one which works even if not full time.
Good to see someone else has built the capacitors as my unit is fully completed, not working and need to change the capacitor former to a soft Iron.
Also good that you are using the original Aho schematic.

The twin coil bell ringers, I now have 11 in my collection, are all of 500 ohms each and have been able to induce voltage up to about 3.5v simply by moving a magnet along their length.
The reason for buying these is also for the Dollard 'Cosmic Ray Detector' (CRD) but also for a Tesla Mechanical Oscillator.
Still not able to get the 'resonator' to work as per the Hendershot detail and still working on that.
thx1138 as been most helpful in the realisation that the Magnet is of the 3 pole Radar type.

Not happy with using a laminated power transformer due to frequency limitations for the 5:1 step up and am using two horizontal deflection types out of old Blaupunkts - luckily, I had two.
There is a picture somehwere of these but probably back at the other Forum.
These are of the Ferrite type with many windings and are adjustable with respect to reluctance.
Although, what Lester is using appears to be of the general laminated form but there would be some design feature incorporated that would make it more appealing for the higher frequency used in TV deflection circuits up to 15 Khz.
This may need to be researched in some detail.

Building the Hendershot Generator in itself was a lesson in construction ability and technique in particular with the basketweave coils and home-made capacitor and will not ever regret not building.
Still here waiting for another approach but too time limited as I am into a Steven Mark TPU but of a contractive type and not his expansive.

I should be asking some questions here like what was the final capacitance value of your caps and what did you use as the former?
What did you actually use as the 'resonator' and what voltage were you able to achieve out of the twin coils?
I didn't see a 'resonator' in your picture.

All the best with your builds.

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