General – Page 6 – Engineering Radio

One of the perks

Occasionally, I get to go for a nice walk in a snowstorm. No, I am not being sarcastic. It is the middle of March and winter has decided to make an appearance. One of the FM stations we take care of went off the air and the remote control was not able to get the transmitter to come back on, so a stroll through the woods was necessary. This station is located at Sam’s Point Preserve, in Craigsmore NY.

Self-supporting tower has ATT and a Low Power TV station

The site is owned by Vertical Bridge. There are a few tenants on the tower and fortunately, somebody left the gate open before it snowed. I was somewhat dreading trying to wrestle with it when I got to the site.

The problem itself seems to be due to a power hit; the main transmitter was off and the remote control, a wheezing Genter VRC-2000, was not able to control either the main or the backup. Those should be replaced at some point.

There are several other towers up here for various cell carriers, 911 dispatch, etc.

My SO decided to come along.

My phone said we walked 2.7 miles round trip, which sounds about right. The station is back on the air. When I can get up there with a vehicle in a few weeks, I will look into the remote control problem.

Continental 816R2 still chugging along

Had to do some work at a transmitter site today and had to put the backup transmitter on the air for a few minutes.

These were good units in their day and many continue on. This transmitter was new in 1986 and served as the main transmitter until 2015 or so. This unit still has the tube driver (4CX250B) which tended to use a set of tubes every year or so. The PA tube normally lasted 4 years or so.

I miss the analog meters sometimes. There is something satisfying watching all the meters come up together when the plate on button is pushed.

RIP Ray; you were a good guy

By now, most have heard of the passing of Ray Topp, publisher of Radio Guide magazine. I was shocked when I first learned about it in the middle of February. The family has decided to cease publishing the magazine, which is understandable, but also a loss for the industry. The goal of Radio Guide was to provide “real-world technical information.” When I wrote an article, I always thought about the various people I worked with over the years and what they were concerned with.

If you have not read the Radio World article: Ray Topp, Publisher of Radio Guide Dies

The last I heard from Ray was the third week in December. He said he had a bout of COVID and there were some complications. He said he was trying very hard to get the January/February 2023 issue done. I sent in my article in early January but never heard anything back, which is unusual. When the publishing date came and went, I thought that perhaps he was still recovering. Unfortunately, that was not so.

My final article for Radio Guide was to be titled: Learning with the Libra VNA

learning with a Libra VNA Download

Since it was never published, I figured perhaps some might find it useful.

FLX20KFAX50K+HD

Greetings from the Roxborough tower farm, a place with roots. It is slightly northwest of Philadelphia, PA, and is home to many TV and FM stations. The public road that cuts through the tower farm is called Domino Lane because if one tower falls, they all fall. A comforting thought to those that live in the vicinity I am sure.

View from the residential neighborhood next to the site

The reason for the visit; this rather nice GatesAir FLX20 transmitter:

Newly installed FLX20+HD, WRNB Philadelphia, PA

I must admit, I am growing rather fond of these transmitters. This unit is being installed because the station had to move from its old site, just down the hill. The tower owner is taking down the tower and building due to the age of the tower. Thus, it was moved into the KYW-TV building. If Wikipedia is to be believed, KYW-TV is the oldest TV station in Philadelphia, signing on in 1932.

The site is still being built as we were installing this transmitter. These days, the electricians are having supply chain problems like everyone else. There were delays getting the large electrical panel board and other necessary things for the build-out.

Cooling system high point, sight glass, and air purge valve

Overall, the installation went well. This system is using flexible hoses for the coolant loop. We have installed two of these liquid-cooled transmitters with 1 1/2 copper pipe. These days, copper pipe is expensive, so most are opting for flexible hose installation.

Topping off the pump station after 50/50 fillup. After the initial system fillup, it takes a while for all of the dissolved air to come out of the Heat Transfer Fluid (HTF). The extra steps with a liquid-cooled system are worth it, especially if the station is running HD. With the HD carrier on, the transmitter efficiency is 54% AC to RF. With a TPO of around 15 KW, that is a whole lot of heat that needs to be dissipated during operation. It is much cheaper to pipe the heat outside to a heat exchanger than to use several tons of AC to remove it from the room.

Overall, this was a fun project.