To: file

From: Jon Hagen

Date: 12-26-04

Subject: 430 tasks

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Modulator:

Protect pilot light on breaker box (blows out, probably due to transient when modulator is turned off). Install varistor and resistor/capacitor protection.

Arrange one spot for all modulator spare parts: dp11s, transformers, fiber optics, other tubes, breakers, fuses, parts list.

High Voltage:

Rebuild the bleeder tower using series of doubly paralleled resistors. Use resistors at half rated power so that a blown resistor won't cause its partner to blow. The partner will discolor at otherwise indicate excess heating. allowing the blown resistor to be identified and changed.

Resistors: Select total dissipation = 2kW. Then R = V^2/P= 90^2 E6/2E3 = 8100 k/2 = 4050k.

Let each resistor pair dissipate 100W, so we need 20 pairs. Each pair will have resistance

4050/20 = 405/2=202k so each individual resistor should be 400k. Voltage across each R = 90kv/20=4.5kV.

Time constant = RC= 4050k x 20E-6 =80 sec. I= 90kV/ 4050k = 9/405A =22mA

Voltage across a blown resistor = 22ma x 400k = 9kV. Dissipation in remaining resistor = 22ma x

9Kv = 198 W, so resistors should be 400k @ 200W.

Alternate resistors:

Select total dissipation = 4kW. Then R = V^2/P= 90^2 E6/4E3 = 8100 k/4 = 2025k.

Let each resistor pair dissipate 100W, so we need 40 pairs. Each pair will have resistance

2050/40 = 205/4=51k so each individual resistor should be 100k. Voltage across each R = 90kv/40=2.25kV.

Time constant = RC= 2025k x 20E-6 = 40 sec. I= 90kV/ 2025k = 9/202A =44mA

Voltage across a blown resistor = 44ma x 100k = 4.4kV. Dissipation in remaining resistor = 44ma x 4.4kV = 193W. So resistors should be 100k @ 200W.

Use the tower for hv metering. Remove the old metering tower.

Oil cooler - finish this project!!!

Console:

Install oil and water temperature gauges on console

Interlock chain: troubleshoot dim lights when y-switch hasn't closed. Provide easy bypass to

turn on hv for tx maintenance during AST observations.

Check list - parts one and two. Finish and practice. Refine. Use regularly.

Timing generator: fix all the blinker circuits (reverse the caps and remove the diodes). Install the

beam-to-rf delay.

Mezzanine: clean it up!!!!

Inductrol: check it out completely. Slow down the motor.

E-H Tuner: slow down motors, add read-out devices.

Install digital output peak power meter.

Install VSWR meter.