Bruce's Coil

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This is the coil I built for my brother.


TCBOR/RQ Static Gap Construction


RQ_Gap_1.jpg (30979 bytes)  RQ_Gap_2.jpg (25759 bytes)  RQ_Gap_3.jpg (27243 bytes)

The 3/4" copper electrodes have been tapped and the fan mount completed.


RQ_Gap_6.jpg (41254 bytes)

Drilling the holes for the electrodes and milling slots for air to escape.


 RQ_Gap_4.jpg (33622 bytes)  RQ_Gap_5.jpg (27634 bytes)

The unit is complete and ready to go!


Completed Secondary

bruce1.jpg (25539 bytes)


Secondary Measurements and Calculations

Freq Meas Setup.jpg (25791 bytes) Base Drive Secondary.jpg (14904 bytes) ant.jpg (20473 bytes)

Scope, signal generator, frequency counter, and antenna set up to measure the unloaded resonant frequency of the secondary coil. Secondary is being base driven from signal generator and the signal is being picked up via a 1-foot antenna hanging from a 10x probe.


Unloaded Secondary Coil.jpg (19007 bytes) Meas Freq Ctr and Sig Gen.jpg (24702 bytes)  Meas Freq Ctr.jpg (20704 bytes) Meas Scope.jpg (25297 bytes)

The unloaded Frequency measured 1.018mhz.


Loaded Secondary Coil.jpg (20848 bytes) Meas w Toroid Freq Ctr.jpg (19439 bytes)  Meas w Toroid Scope.jpg (23999 bytes)

The loaded frequency (with a 10.5" x 4" Toroid) measures 582khz.


Secondary Specifications

Form Diameter

Form Type 2" Sched 40 PVC
Winding Length 16.22"
Wire Gauge 24 awg (.022"od)
Turns Per Inch (TPI) 45
Wire Length 714'
Under Coating Spray on Electrical Varnish
Top Coating Pour on Epoxy (two light coats)


Inductance (Lsec) 4.1 mH
Self Capacitance (Cself) 6.0 pf
Resonant Frequency (unloaded) 1,014 khz
Resonant Frequency (loaded) 527 khz (w 10.5"x4" toroid)
Inductance (Lsec) 4.1 mH
DC Resistance 12.0 ohms
Resonant Frequency (unloaded) 1,018 khz
Resonant Frequency (loaded) 582 khz (w 10.5"x4" toroid)


Download Initial Calculations and Detailed Spreadsheet

Complete Unit 1.jpg (30676 bytes) Complete Unit 2.jpg (43757 bytes)

Inside 2.jpg (45257 bytes) Inside 3.jpg (38423 bytes)

MMC 1.jpg (34361 bytes) MMC 2.jpg (32505 bytes) MMC 3.jpg (34434 bytes)

NST-SG-RQgap 1.jpg (40100 bytes) NST-SG-RQgap 2.jpg (44099 bytes) NST-SG-RQgap 3.jpg (38897 bytes)


Questions and comments                Copyright 1997,2006 Brian D. Basura                This site was last updated 04/02/06