safety – Engineering Radio

This is fine

How’s the weather? Well today, it will be orange outside.

No need to panic, however. Something or other about wildfires in eastern Canada is the cause.

Fortunately, I have some protective gear in the vehicle. I always carry a hard hat, high vis vest, steel towed boots, and this mask. It comes in handy if there is mold or in this case smoke. A P-100 respirator will filter out Organic Vapors/ Acid Gases (chlorine gas, hydrogen chloride/sulfur dioxide or chlorine dioxide or hydrogen sulfide) – Class 1 and Particulate.

The P-2.50 Particulate monitor had a peak of 248 micrograms per cubic meter, which is very unhealthy.

I had to do my normal weekly outside maintenance items. Looks silly, I know, but I feel great! This was about three o’clock after the worst of the orange had passed.

This, on the other hand, is slightly worrying…

Engineer Killer

That was the title of the email with this photo attached:

Disabled high voltage shorting bar, Collins 820D-2 AM transmitter. Courtesy Pete Partinio

That seems about right.

For many, many reasons, this is a bad thing to do. First of all, the shorting bar is the last point of discharge for the high-voltage power supply. When all else fails, this is designed to route the 3,500-volt plate supply safely to ground. Having a stray 3,500 volts floating around inside a transmitter is never a good idea. Fortunately, it was spotted and removed before anything bad happened.

Secondly, it looks like somebody used a 12 VDC cigarette lighter plug as an insulating device. Wow, did they get lucky. This could have started a fire.

As to exactly why it was there in the first place, I cannot rightly say.

And this is why only properly trained people should be working on transmitters, especially tube-type ones.

Man electrocuted putting up a pirate radio antenna

A south Florida man was electrocuted when the antenna he was putting up struck a power line. Police say 42-year-old Jean Adelphonse was working in the dark Monday night when part of an antenna to be used for an unlicensed radio station collapsed and struck a power line. The Fort Lauderdale Sun-Sentinel reported that he was working on the roof of an office building where his other businesses were located.

That is rather unfortunate and completely preventable. The first red flag here is working in the dark. The second would be working alone. Safety is always paramount; whether it is working on a transmitter, putting up an antenna, working on a ladder, or environmental conditions such as heat, weather, etc. In my younger days, I had gotten away with a few careless moments mainly due to blind luck. I cringe thinking about it today. Nothing on the radio is worth killing yourself or anyone else over.

This type of thing used to happen more often when almost every house had an outside TV antenna.

Let’s be careful out there.

Do radio transmitters have the capability of electrocuting copper thieves?

I found that question while perusing my search engine statistics today. The short answer in theory is yes. If you are a copper thief, it will most likely look like this:

That being the case, however, it is much more likely that an RF burn will result if one comes in contact with an energized antenna or transmission line. Even small RF burns are painful, large ones can be nasty things. RF burns occur because of the skin effect, that is to say, the higher the frequency of the AC waveform, the closer to the surface of any given conductor the current will flow. It is the reason why five-watt STL transmitters on 950 MHz use 7/8 or 1 5/8 inch cable to reduce losses.

When a human body part comes in contact with an energized RF antenna, the body part becomes part of the circuit, thus it follows the same principles. The extremity that is making contact will have its skin burned off. It also smells bad.

Getting an RF burn is a painful lesson on what not to come in contact with around a transmitter site. But, that is not all. Simply being in close proximity to radiating elements of antennas will induce body tissue heating, just like a microwave oven. This can lead to all sorts of short-term and long-term damage to organs and other problems.

Therefore, the best thing is to avoid radio and cellular towers if you do not know what you are doing. Stay out of fenced-in areas around tower bases. No matter how tempting that copper may look, you could be seriously injured or killed if you cut the wrong thing.