RF radiation leakage report.

In the Fall of 2005, CECOM gave you a heads-up in Ground Precautionary Message (GPM) 2005-005 about possible radio frequency radiation leakage in satellite communications terminals. The leakage was a significant health hazard to soldiers working inside the shelters near the high power amplifier.

So, if you operate satellite communications terminals AN/TSC-85C, AN/TSC-85D(V)1, AN/TSC-93C, or AN/TSC- 93D(V)1, it might be a good idea to make sure the advice given in CECOM GPM 2005-005 to find and correct the problem was followed.

The problem was cracks in the waveguide elbow that allowed radio frequency radiation to leak. The waveguide elbow gets a lot of flexing during maintenance so it's easy for cracks to appear.

But those cracks should have been found during routine quarterly radio frequency radiation leakage testing. But apparently some routine tests were not done as routinely as they should have been!

Why not do a quarterly radio frequency radiation leakage test right now? If you're using TM 11-5895-1433-12-12, you'll find the test in Section 4-6.1. If you're using TM 11-5895-1786-13, you'll find the test in Table 5-2 and Para 5-6 in Chapter 5.

If the tests show you have a radio frequency radiation leakage problem and no cracks are visible, you may need to replace a damaged or missing HPA waveguide gasket, NSN 5999-01-071-6256. You'll find the gasket between the HPA elbow waveguide and the waveguide that carries the RF to the waveguide switch, NSN 5985-01-056-2851.

While in the area, make sure the waveguide coupling, NSN 5985-00-569-5849, and proximity switch, NSN 5930-01-056-2855, are properly aligned.

And one final word: Do not permanently override the fault safety override switch on the fault alarm monitor unit. The override switch is to be used only when performing maintenance. It is not to be used so you can continue to use a terminal with a safety fault!

IF YOU FIND CRACKED WAVEGUIDES, REPLACE THEM!

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FOR MORE INFORMATION, SEE YOUR LOCAL CECOM LAR FOR A COPY OF THE GPM. YOU CAN ALSO CONTACT THESE CECOM POCS ...

[e-mail] [e-mail] DSN 987-7473 or [phone] DSN 992-8875 or [phone]

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