Am transmitter site – Page 2 – Engineering Radio

Cellular work on a skirted tower

Cell carriers generally do not like working on AM towers. It is out of their comfort zone and adds a layer of complexity to the project. However, sometimes they don’t have a choice, mainly when there is an existing site and they need to make changes. We have also had mixed results with tower contractors employed by various cell carriers. In one incident, a contractor showed up and re-tensioned the guy wires breaking all of the porcelain insulators. Another time, a contractor showed up to install footings 10 feet away from the tower and ripped up all the ground wires. One tower climber found one of the skirt wires was in his way, so he cut it off with a hack saw.

Those experiences demonstrate that it is far less expensive to have somebody on site while tower contractors are doing installation work on any skirted AM tower. And so it was today.

AT&T 5G sector assembled waiting for lift

This tower has two AM stations diplexed as well as two FM translators combined into one Nicomm antenna. We did before measurements on the AM stations using an OIB-3. Once the installation is done, we will do the after-measurements and then assist the licensee with any FCC 302 filings if the base impedance has changed significantly.

With each lift, I went out to the base of the tower and made sure that the skirt wires were clear of the mounting brackets and not touching anything else. The tower crew was Russian speakers. When they asked if the transmitter was still on, which was kind of comical (he motioned to the skirt wire, made like he was grabbing it, then jerked around like he was being electrocuted). I had to wrack my brain to try and remember: Передатчик выключен. The literal translation is “Not working.” The difference between “working” and “not working” is one consonant at the beginning of the second word which is pronounced soft for off and hard for on.

This site was the subject of a previous post: A tale of five signals.

Another Ask

This one is targeted mostly toward my European readers (however, read on).

I received the following email from Olkesandr in Ukraine, it seems the Russians stole his transmitter:

Hello!

My name is Oleksandr (last name redacted). I am chief editor of Ukrainian radio station CCR 648 AM. We are looking for an used am transmitter 25 or 50 kwt. Probably Your company has one for sale?

That is interesting. I asked for a few more details and received the following:

I am originally from Crimea. But in 2014 I had to leave my native town. I have been living in Kyiv since 2014. In 2017 our team of journalists launched informational broadcasting to the occupied Crimea from Chongar (it’s 1 km from Crimea in Kherson region). First we started broadcasting on 105.FM 5 kwt. But in 2018 our signal had been jammed by russians occupants. In 2019 we started broadcasting on 648 AM (10 kwt). In 2021 we increased the power to 25 kwt. But in February 2022 our transmitter was captured by russians. Now we are looking for an 25-50 kwt AM transmitter. We are going to install it in Kherson region (in controlled by Ukraine territory). I supposed we’ll be able to cover by our signal all Kherson region, Zaporizhzhya and Crimea.

Digging around, I found two news stories about it: Apparently, the Russians removed the Transmitter. By the way, Krym (pronounced cream) is Crimea in Ukrainian and Russian.

Missing Harris DX-50 transmitter, serial number MPS104705-00001

Missing Harris DX-50 transmitter

A little bit more digging around and I found some more pictures of the transmitter site: Radio Crimean Community transmitter site

Google Maps Link: Chongar

That is an interesting setup; the FM antenna is a stack of six, looks like 1/2 wave spaced six-element yagis, vertically polarised. The AM is a slant wire that goes almost to the top of the tower.

That area is still occupied by the Russians. As it is one of the two usable land transportation routes, it is likely that it will be unusable for some time after it is deoccupied.

So, here is the ask; I know that many Medium Wave transmitters have been turned off in Europe over the last several years. Is there any in that power range that is available to be moved to Ukraine? Preferably something that is still in good working order and on or close to 648 KHz. It is a long shot, but worth asking.

New transmitter building for an old station

UPDATE:

What the site looks like now with the old building removed:

Putting the finishing touches on another transmitter site rebuild, this time in central NY. This station for many years used this rambling white residential-looking structure for both the studio and transmitter site:

Former studio and transmitter site for WDLA, Walton, NY

Unfortunately, over the years, the building has deteriorated beyond economical repair. A few years ago, the studio facility was moved to a new location in town. Now the transmitters are being moved to this repurposed cellular building:

Former NEXTEL building, now WDLA AM/FM transmitter site

This was purchased used from a local crane company, which had dozens of them on their lot after NEXTEL was absorbed by Sprint. During the permitting process with the town, they referred to it as a “Circular Use.”

They are actually nice buildings, coming prewired with a 200 amp single phase service, two working Bard HVAC units, ready-made coax entry ports, etc. My only complaint (so far), is the light switch timer. I like the idea, the lights get switched off automatically and are not left on for months at a time when nobody is at the site. However, the timer only goes up to 2 hours. Thus, when we were doing the installation work, periodically there would be an audible click, then everything would go dark. Not terrible.

There are also two other FM stations that have an STL transmitter here.

STL equipment for two additional stations

All in all, an enjoyable project.

Material safety at Transmitter Sites

Recently, while working at a transmitter site built in the early 1940’s I noticed some fluorescent lights were out. Upon closer examination, I noticed that the bi-pin holder on one side of the bulb was damaged. This led to the removal of the fixture for repair, discovering these devices:

General Electric PCB Fluorescent lamp ballast

As this was made in Schenectady, NY, it is almost certainly original to the building. According to the EPA website, each one of these ballasts contains a capacitor with 3-4 ounces of PCB. There were 16 total fixtures, each with one ballast. The ballasts were removed and the fluorescent lamps were replaced with T8 120 Volt LED units. Any defective bi-pin lamp holders were replaced at the same time.

The danger posed by PCBs is minimal unless they leak or there is a fire. Partially burned PCB results in the production of dioxins, which are really bad. The old GE ballasts were properly disposed of.

The PCB capacitors and transformers were removed from the site many years ago. Other things that might have PCBs; are caulking and window glazing compounds.

That made me think; what else is around here? Several things came to mind.

The fluorescent bulbs themselves contain a small amount of mercury. This is not a problem unless the bulb breaks. If the bulb does break, the EPA recommends leaving the room for 15-20 minutes. Then carefully clean up the broken glass and place it in a plastic bag. Smaller particles can be cleaned up with the sticky side of masking tape or duct tape. Do not use a regular vacuum to clean up the broken glass, this will spray mercury around the room.

The fluorescent bulbs should be disposed of as hazardous waste.

Hot water pipes with lagging (insulation)

Asbestos lagging on the hot water/heating pipes. As long as the lagging is intact, there is no problem. All of the pipe lagging in this building is intact and in good shape. With asbestos, the problems start when things are disturbed. Any type of work on those pipes will require a mitigation plan. Something to keep in mind if there are any building modifications being planned.

If old-style pipe lagging like this is falling off or has been partially removed, it is best to have an asbestos survey done. Newer style lagging will be either closed cell foam, open cell foam, or fiberglass insulation with a cardboard cover.

Other things that can have asbestos are floor tiles and siding.

The halon fire suppression system can be hazardous if one is in the building when it discharges. Of course, fire itself is also a hazard. It is something to be aware of if the alarm goes off.

Since this building was constructed way before 1978, lead paint is likely on the walls. Not a huge problem unless it is chipping off and you accidentally eat the lead paint chips or inhale pulverized lead paint dust. To clean these up, use a vacuum cleaner with a HEPA filter. Alternatively, wear a HEPA filter and use a dustpan and brush. Do not use a regular vacuum cleaner.

If building modification work is being done in areas that may contain lead paint, a properly certified lead paint mitigation contractor should be hired to remove the hazardous material.

None of these situations pose a direct safety threat, however, one should be aware of these potential issues in their work environment.