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Assembling and Testing the Prototype Capacitor

Capacitor Assembly (1.5-2 hours)

Required tools: 
  • Fine tooth metal file or rotary file
  • 11/32" small open end wrench
  • 8 mm small open end wrench

Assembly steps:

  1. Deburr raw plates with fine tooth metal file
  2. Base
  3. Screw with nut
  4. Two washers
  5. Plate on each side
  6. Two nuts on each outside rod (thread doesn't catch)
  7. Rotor plate shaft (center) double nut - nuts thread - tighten first, then second nut
  8. Two 8-32 nuts on each of the 4 stator rods (threads do not catch)
  9. Continue steps 5 through 8
  10. When installed the desired number of rotor plates, put nuts (8mm wrench to tighten) the 4 stator rods, then install the plexiglass side piece.
  11. Assure that rotor plates are centered between the stator plates before securing the rotor shaft position with the reduction drive set screws and the nuts on the rear end of the rotor shaft.
  12. Carefully bend the plates as necessary to assure correct position and spacing throughout the shaft rotation.

Assembly of capacitor with 0.1 inch plate spacing using two 8-32 nuts as spacers (Version A)

Capacitor Version A assembly - Click to enlarge

Rotor shaft parts (left to right): (2) 8-32 nuts, rear plexiglass plate (smooth aluminum tube bearing in center hole), (2) #8 flatwashers, 7x[8-32 nut, rotor plate, 8-32 nut], 8-32 nut, 8-32 tapped ¼ inch aluminum tube, front plexiglass plate, reduction drive.

Stator rod parts (left to right): 6-32 nut, rear plexiglass plate, 6-32 nut, 7x[(2) 8-32 nuts, stator plate], #6 flatwasher, 6-32 nut, front plexiglass plate, 6-32 nut.

One 8-32 nut and two #8 washers as a 0.22 in. spacerTwo 8-32 nuts as a 0.24 in. spacerOptionally, you may use a caliper to assure regularity and uniform thickness of the spacers. Given the 0.04" thickness of each plate, two 0.12" 8-32 nuts yield (0.24" - 0.04")/2 or 0.1" rotor to stator plate spacing. One 0.12" 8-32 nut flanked by two 0.05" #8 washers measure 0.22" and yield (0.22" - 0.04")/2 or 0.09" rotor to stator plate spacing. Closer spacing would require custom precision spacers and more critical plate alignment. Using stacked #8 washers as spacers may excessively narrow the air gap between the stator plates and the rotor shaft.


Tuning Enclosure Assembly

Required tools: 
  • Drill, bits and hole enlarger
  • Screwdriver
  • Pliers
  • Diagonal cutter
  • Soldering gun & rosin core solder
1. Here is the prototype Monarch capacitor (with reduction drive attached), built by Chuck W6FT, using 7 sets of 3 inch Monarch plates.  Two #8 nuts are used to space the plates on the 8-32 threaded rod rotor shaft.  The stator plates are assembled on 6-32 threaded rod and also spaced by two #8 nuts.  8-32 tapped ¼" aluminum tubing is threaded onto the end of the rotor shaft.  The measured spacing between rotor and stator plates is 0.1". Prototype Monarch Capacitor
2. The 1.6 L Really Useful Box is drilled.  Two SO-239 connectors are mounted with 6-32 screws and nuts.  Two ½ inch PVC conduit clamps are mounted on the bottom of the enclosure with #10 hardware. Tuning Capacitor Enclosure
3. A large hole is drilled in the opposite end of the enclosure to accommodate the round brass plate of the reduction drive and the ends of the two 6-32 screws are secured to the box with #6 nuts.  (The angle bracket has been removed from capacitor and was not used). Capacitor mounted in box
4. Two 2 inch lengths of 10 AWG stranded wire are tinned and a #6 ring terminal soldered to one end of each. Prepping the leads for the connectors
5. The SO-239 connectors are removed from the enclosure, one side of each shell is prepped and tinned, and the tinned wire soldered to it using a 100 watt soldering gun as shown.  The center pin of each SO-239 is left unconnected. Lead soldered to SO-239 connector
6. One lead with an SO-239 connector is attached to each stator section of the capacitor.  No electrical connection is made to the rotor plates. Leads and connectors are attached to the capacitor
7. The connected parts are mounted inside the enclosure.  Both leads of the NE-2 neon glow lamp are attached together to the same stator section (the high radio frequency voltage present there at resonance is sufficient to make the neon lamp glow with no other connection).
The parts assembled in the enclosure
8. The antenna is tuned with a vinyl Mini Blind Wand that is secured to the reduction drive shaft with a small hose clamp.  Do not touch the bare metal shaft during transmission as any imbalance in the loop may place dangerously high radio frequency voltage on the shaft.
*Adjust the capacitor only with clockwise rotation to avoid loosening the tapped aluminum tube from the threaded shaft.
A Mini Blind Wand is attached to the reduction drive shaft with a small hose clamp for tuning the antenna
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River City ARCS,
May 2, 2012, 6:46 PM
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