Engineer Killer

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

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

Seems about right.

For many, many reasons, this is a bad thing to do.  First of all, that 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 of 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 transmitter, especially tube type transmitters.

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, 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 in 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 principals.  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.

OET65? What is that?

Readers of this blog will know that I enjoy history.  Old photos are great things to study, as they say, picture… thousand words… etc.  Here is one that I found on the RadioMarine website:

WER radio, 192X?
WER radio, 192X?

Here we have three gentlemen at work at an early radio station.  It seems like a posed shot, nobody can study a meter that intently.  They are sitting directly in front of the transmitter and it looks like the antenna tuning coils are behind the operating position.  Notice the open wire and transmission line, presumably all under power when this picture was taken.  There seems to be no concern about RF or electrical safety, I suppose it was trial and error back then, with a heavy price paid for error.  Meter boy should be careful not to back up too far, if he does, he’ll get a little behind in his work.

We’ve been a little busy this last week, I’ll catch up on the blogging this weekend, there are many things to tell.