Tower take down pictures

A few years ago, I was involved in removing and rebuilding an AM radio station tower in Gainesville, Florida.  The old tower was a hollow leg tower that was rusting from the inside out.  It was installed around 1960 or so, but the actual records were sketchy, as the original studio building burned down in 1984.  In 2005, the tower climbers came out to relamp it and refused to climb it because one of the legs was rusted through.  Therefore, a replacement tower was ordered and delivered.

Prior to starting work, a temporary wire antenna was constructed.  Since there were two radio stations diplexed to this tower, it became a bit of a chore to get both signals (980 and 1430 kHz) tuned into the same temporary antenna.  In the end, the components available could not create a good load for the 1430 station, so a separate temporary wire antenna was erected for that station.  Both stations ran at 1 KW into their respective antennas until the new tower was finished.

WDVH, 980 Gainesville, FL.  Top of tower coming down
WDVH, 980 Gainesville, FL. Top of tower coming down

Top section of a 240-foot guyed tower on its way to the ground. This tower had an inner and outer set of guy anchor points. The top section came down after the last guy wire on the outer anchor was cut.

Remains of WDVH tower
Remains of WDVH tower

Truncated tower.

Last section of WDVH tower falling
Last section of WDVH tower falling

Bottom section of tower on its way to the ground.

Old WDVH tower on the ground
Old WDVH tower on the ground

Tower on the ground. In keeping with the theories on tower failures, this tower fell within about 1/3 its height.  The wire antenna supports and the new tower sections can be seen in the background.  It took the tower company about a week to stack the new tower.  This was done in July, therefore the average daytime temperature was about 100° F  (37° C) with frequent afternoon thunderstorms.

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.

Troubles at the Tower

3 tower AM directional array
3 tower AM directional array

Troubles at the AM tower; I don’t know why, it won’t switch power.
Over the phone I can tell, the program director’s day is not going very well.
Press the “day” button but there is no kerchunk, the directional coupler shows the load is junk.
Out into the big field, I go to find the problem quickly and fix it just so.
The wind is cold, the snow is deep, I think of the contract terms I must keep.
Reaching the tuning house, take out the keys, lock, do not be frozen, please.
Once inside, there I find, no big surprise, the mice have been a working this pre-sunrise.
A nest they have build in a most inconvenient place, in the back of the phasor wiring chase.
Oh, the wires they have chewed, the circuit’s destroyed, all for the lack of mousetraps deployed.
As I reach in to clean out the mess, the smell of mouse makes me gag, I confess.
The fuses are blown, the contactor is jammed, perhaps, if I am lucky, I can move it by hand.
A large screwdriver strategically employed, I pry up slowly, further damage to avoid.
The bar thunks up, the contacts engage, the transmitter is ready to apply amperage.
Call on the cell phone, tell them it’s fixed, stand back and watch the base current meter, transfixed.
Then; Up it goes! Wonderful radio frequency current flows!
I clean up, lock the door, lock the gate, carrying bad news the owner will hate.
The damage is grave, the repair bill is steep, if a good relationship with the FCC you desire to keep.
Business is off, the accounts are low, is this really necessary, he wants to know.
The terms of the license are your obligation to keep, getting caught out of tolerance will not be cheap.
Looking forlorn, the owner says in disgust, it is only the AM, but fix it if you must.
Happy as a lark, with a song in my heart, I dig though the manual and order the part.
Time to go home, eat breakfast, brush teeth, take a shower. I have another client to see before the noon hour.

40 amp RF contactor
40 amp RF contactor

Dedicated to all those who have been there, done that and the breed of RF men and broadcast engineers who are slowly fading away.

At a crossroads

This is a situation that is and will be playing out over and over throughout the country as the decay advances. W*** signed on the air in March 1963. I believe this is the original tower:

W??? tower
W*** tower

As you can clearly see from this picture, this tower has several problems. Aside from the loose guy wires, the rust, and general structural decay, it is bent in several places.  Currently, the forces are in equilibrium, but for how long, no one knows.  It is certainly not safe to climb.  At 144 feet, it is no longer required to be marked or lit, thus, over the years, the paint peeled, the weep holes filed up, and the guy wires rusted and loosened, which leaves us with the situation today.

At the transmitter building, there are other issues with the basement flooding, mold, etc.  Truth be told, this station makes no money on its own.  It would cost several tens of thousands of dollars to fix all these issues, and for what; a high end of the broadcast band class D AM station which has not shown up in the ratings for fifteen years.  Once upon a time, it was a surviving, perhaps not thriving, local radio station. Those times have long since passed.

The question is; what to do with it?  Sign it off and surrender the license?  Fix all the problems and continue to broadcast?  Donate it?  If so, who would take it?  Or, more likely, wait until the tower collapses and deal with it then.

I’d imagine that there are many others just like it dotting the country.  On the whole, the AM broadcasters that are viable would be better off if this dead wood was cut away and discarded.