Not exactly HAM related but interesting none the less.

[KB1TPX]

My wife is a Military retiree of the Air Guard and prviously a Navy Radioman and TACAMO Flight Crew Supervisor. She recently received news of former shipmates being electrocuted while servicing a Power Amplifier for a VLF transmitter.
Does very low frequency require more output power than HF or VHF? Or does the Navy amplify the signal that much because of the distance and necessity of precision and clarity? She told me that she had to remove any rings or metallic objects before going anywhere near th PA (power amplifier) or the antennas.
Any thoughts?

Here's the note that she received:

Hey, Shipmates. I just returned from DC visiting this place. The curator asked me to go back out into the community and seek the names, rates, and dates associated with the two Sailors who were killed in the line of duty working on the VLF PA. They have a special section dedicated to those who lost their lives in the Cold War. Nothing will be said about them other than that they were TACAMO ATs, killed in the line of duty. I believe we lost two shipmates, both from VQ-4 when the PA got them during maintenance. I also know one near KIA of an officer who was nearby when it arced and burned his thigh

 

[Beetle]

VLF requires a greater power output because of the lack of ionospheric propagation at these frequencies. The Navy uses VLF for communicating with submarines while the boats are where they're supposed to be: under the water. It requires huge amounts of power to punch a signal through rock and water, and at VLF, the transmission speed is very slow because the frequency is literally within the audio spectrum (although it's transmitted as an electromagnetic signal like any other radio signal). I'm not aware of any VLF transmitters aboard any aircraft of any service (not saying it's not used there, but certainly not at any great power level).

Removing rings, watches and other metallic items is a MUST DO for anyone working around high voltage, whether it's in a multi-megawatt radio transmitter or a 5-tube tabletop radio receiver.

I was stationed for just a couple of weeks at Navy Radio Station Jim Creek (NLK), near the town of Oso, WA. Also had a chance to transfer from my ship to the brand new (at the time) Naval Communications Station Harold E. Holt, North West Cape, Australia. I would have had to reenlist in order to get this, and I decided against it.

Check out these (and other) VLF sites on Google Earth. I'm pretty sure that QRN will be along soon. If you PM him, he might send you a KML file he has on VLF sites around the world (and also standard time sites like WWV). Check out the antennas at these places. Particularly North West Cape, Australia. Picture a perfect hexagon over half a mile along each side, up in the air about 1200 feet...

 

[W5LZ]

Removing metal jewelry is a fairly common requirement around any high voltage/power/magnetic field devices, and just good sense. People with metal 'pins' connecting bones, teeth fillings, those sort of things, seldom stay around large generating dynamos, or power generating plants very long.
Another dangerous activity is getting onto or off of antenna towers in the arctic. Jumping on/off is very common cuz you don't wanna be standing on the ice and grab a tower. You won't do it twice.
Once went through the facility that build VOA transmitters. The discharge gap 'balls' were in a locked cage. Can't see why anyone in their right minds would ever go into that cage after seeing them discharge just once, it would deafen you (just north of Dallas by the way). Those @#$ things would "Reach out and touch someone!" like you wouldn't believe.
Knew someone who worked on radar that made a habit of carrying around a candy bar in their shirt pocket. If it ever got 'soft', he was off that thing in a very large hurry. Not exactly the smartest thing in the world, but oh well.
A medium to small amplifier is the most I want to be around, too chicken for the big stuff...
- 'Doc

 

[Captain Kilowatt]

Once went through the facility that build VOA transmitters. The discharge gap 'balls' were in a locked cage. Can't see why anyone in their right minds would ever go into that cage after seeing them discharge just once, it would deafen you (just north of Dallas by the way). Those @#$ things would "Reach out and touch someone!" like you wouldn't believe.
- 'Doc

Hey Doc, would that have been the Continental Electronics Corporation plant in Dallas? They make some pretty top notch broadcast transmitters for AM/FM and SW.