Thread: Eric Dollard
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Old 12-21-2013, 05:50 AM
David G Dawson David G Dawson is offline
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Join Date: Mar 2008
Posts: 418
Crystal set Initiative - Tuning

Quiet and in need of some action.
Sometimes I wonder why I don't take up knitting or crochetry where it is a simple mindless boring routine where you can watch the TV and go insane - not so with Dollard electronics.
Went back to the set-up stage and peaked secondary to primary and now have only a 5 to 10mm gap where before I had 40 and had slipped down to 50.
The little 50 uA Meter with the 1N34 across the terminals can be used floating at the side of the setup with a short lead attached to the (+) terminal as you don't need a direct attachment for tuning.
Magnification factor is still only about 80 from 70 and just realised, the smaller the delta, the better, pointing to a high 'Q'.
The 1400pF variable condenser across the 1500pF fixed is tuning the Primary and is about 40% meshed and peak is easy to achieve.
Triode Driver adds some distance to the receiver which is now about 2 meters away and with only the pickup head, about 1 meter but notice the probe needs to be pointing at the Extra Coil.

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Have placed the required resistors in series with the Plate so that the 6SN7 is looking at the correct load - what this does is raise the HT to about 150 volt for the 110 at Plate and may not be necessary.
Still no lamps lit at secondary or extra but am doing this as per the original schematic and fine tuning as I go but Neons light at the primary and especially so between primary and ground and drops the HT accordingly.
Lots of radiated energy here but still need to read Eric's detail as he covers a great deal of ground in many Posts including Eric P Dollard Page 13, Post 389 'Notes On Tesla Transceiving 2'.
Appears the radiated energy is drawn up the secondary and then surrounds the Extra and I notice my body interference/capacitance has increased and need to stand further back when adjusting.

This is a picture of the CSI being driven and have named this a 'Mystery picture' as I am unsure of how it is being manifested - the pickup to the oscilloscope is a 3/4" coil of about 6 turns just dangling in mid air and the black leads are the ground connection but made no difference to the pic connected or not.
The circle size changes as you rotate the gain of the sig gen.

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While with the oscilloscope shots - this is one from a Tesla Hairpin spark gap and you can see what is going on across the gap.
Multiple arcs, about 12 to 15 but the spark you see is a brilliant ball of light but this is what it builds up to as the gap is adjusted.
Diffilcult sometimes to grasp a single shot as there are several images here and the connection was made to a metal screw on the wooden support frame.
Most of any oscilloscope work here is done through a 500pF Mica condenser or simply from a coil in space or a metal body nearby - too many instances of front ends of scopes being blown due to direct connection.
We have literally no idea of what the composition of some of these signals that we are being involved with.
Story is that most of the solid-state failures in circuitry is due to inductive kick - 'The Tesla Instant'.

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Getting back to basics with the CSI and reviewing all material presented and currently looking at the inductance of the primary and was going to calculate from the Eric P Dollard material that Gestalt presented on Page 13 (Eric's Page 3 circled) but lacking dimensions to use.
Sheet inductance is given by (for primary loop) (A/w)N2 x a Henry.
Anybody know of the inductance calculation dimensions for a SHEET Copper Primary? - Thanks.
ARRL and Langford-Smith not much help here.

Looks like I need to dis-assemble the condenser and go from there and will take pics in the process.

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