Hex Beam Installation

After giving up on my 35 year old Cushcraft A4, I ordered a Hex Beam from NA4RR.

Trap Dipole, VHF and UHF antennas installed

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Cushcraft A4 Repair (Fail!)

Shortly after I had repaired my Cushcraft A4 tribander beam the last time, I noticed that it appeared to have a loose connection somewhere.  Especially when the wind was blowing, I would hear something that sounded a little like static crashes, or pops in the receiver.  This was especially noticeable on 20 meters, but was apparent on all bands.

A4 coming down the tower

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TS-430 RF and IF Signal Paths

I’ve had some questions from readers about where to obtain the color annotated schematics for the TS-430 that I used in some of my previous posts.

Violet line indicates the missing SSW signal.

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8640b Power Supply Repair

Early in the repair cycle of the 8640b, when I had just finished the brass gearset installation, I ran into a problem during the first power up after reinstallation of the deviation and range module.  When I powered up the unit, I saw a flash from under the main board, and the unit came up with no led frequency display.  I suspected that I had lost one of the power supplies.  After finding the manual for the generator, I saw that there were 3 power supply boards with led indicators on them to indicate the various voltages were being generated.

5v indicator

5v indicator

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8640b Fine Tune Repair

Another item on the 8640b refurbishment project was the broken Fine Tune control.  I could rotate the control from the front panel, but it had no effect on the frequency generated.

After removing the bottom cover, I could see the problem.  The Oscillator Module was missing the shaft that connected the fine tube knob with the control on the rear of the main oscillator

Shaft missing

Shaft missing

The shaft should be near the top of the picture above.

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