Something is not right

The Goddamnitnotagain edition:

PA module with burned open output transformer

I went to do maintenance at one of our sites and noticed that a certain transmitter was running at half power. Followed the path of the fault log and found this. When I mentioned it to the station staff, they said, “Yeah, we noticed it sounded a little funny…”

This is the second time this has happened with this particular transmitter. In any case, this is what I get paid for, so I am certainly not complaining. If only every problem where this easy to find.

When I get back out there to replace this, I will bring out my network analyzer and sweep the antenna and transmission line to make sure there are not issues with that. In addition, I will double check all the grounding to make sure the copper thieves have not made off with any critical components like the ground buss bar or #2 solid down lead wires.

GatesAir FLX-40 one year in

I was at the WEBE transmitter site recently and took the time to look over transmitter we installed last year:

GatesAir FLX-40 transmitter, WEBE Bridgeport, CT
GatesAir FLX-40 transmitter, WEBE Bridgeport, CT

Overall, I would say that this transmitter has been very reliable.  We had to install a UPS for the exciter and HD Radio exporter, but that is not a big deal. During the first power outage, the exciter went dark first. It took longer for the transmitter controller board to lose power, in the interim the controller turned the transmitter power all the way up. When the generator came on line 10 seconds later, the transmitter returned to operation at 41.5 KW. This, in turn, caused one of the other field engineers to freak out and nearly lose his mind (stay away from the brown acid, FYI).

I installed the UPS a few days later.

WEBE TPO 35.3 KW with HD Radio carriers on
WEBE TPO 35.3 KW with HD Radio carriers on

Transmitter power output is 35.3 KW, which is getting into the semi-serious range. The reflected power goes up when it gets warm out and goes down in colder weather.  Over the winter, it was running about 50 watts.  Even at 138 watts, that represents 0.004% reflected power. The TPO forward goes to the 6 bay, 1/2 wave spaced antenna side mounted, 470 feet (143 meters) AGL. The station covers pretty well.

WEBE Pump station
WEBE Pump station, pump is running 2/3 speed and fans are running at about 1/2 speed

Overall, I would give the liquid cooling system an A grade. The transmitter still dumps a fair amount of heat into the room from the RF combiners and PA power supplies. Most of the heat, however, ends up outdoors. Previously, we had two Bard 5 ton AC units running almost full time. Now, only one AC unit cycles on and off except for the hottest days of the year. Outside temperature when this picture was taken was 81 degrees F (27.2 C).

Next year, we will have to send a sample of the coolant off to be analyzed.

Gates FLX-40, WEBE Bridgeport, CT
Gates FLX-40, WEBE Bridgeport, CT

I have had good experiences with the GatesAir FLX/FAX series transmitters. I would recommend this to a friend.

Decommissioning transmitters

I was at a transmitter site a few days ago scrapping a Continental 814-R1 transmitter and started thinking (always a dangerous thing) about how many of these units I have decommissioned over the years.  It turns out, quite a few:

Make/Model Year new* Year removed Station Disposition
GE BT25A 1948 1994 WPTR Donated/scrapped
Gates BC5P 1960 2004 WWLO Donated
Harris MW5A 1982 2000 WLNA Scrapped
Gates BC1T 1961 2001 WLNA Donated
Harris FM20H3 1972 2001 WYJB Scrapped
RCA BT1AR 1960 2001 WROW Donated
Harris BC1G 1972 2001 WDFL Abandoned
Harris FM20H3 1971 2005 WHUD Scrapped
BE FM30A 1988 2005 WHUD Cannibalized
Harris FM5G 1972 2008 WSPK Scrapped
Mc Martin BF3.5K 1976 2011 WCTW Scrapped
RCA BTF-10ES 1978 2011 WRKI Scrapped
Gates BC1T 1964 2011 WINE Scrapped
Continental 315F-R1 1985 2013 WVMT Donated
Collins 813F 1975 2014 WKXZ Scrapped
RCA BTA1AR 1965 2014 WCHN Scrapped
Collins 813F2 1978 2015 WKXZ Scrapped
Collins 830D-1A 1968 2014 WKXZ Scrapped
Harris FM20H3 1972 2013 WYJB Scrapped
Harris BC5HA 1973 2013 WROW Scrapped
Harris FM10H 1971 2013 WMHT-FM Scrapped
Harris FM2.5H3 1973 2015 WEXT Scrapped
Mc Martin BF3.5K 1972 2014 WSRK Scrapped
CCA FM5000G 1980 2015 WTBD Scrapped
RCA BTF1E 1972 2016 WZOZ Scrapped
QEI 695T3.5 1996 2015 WBPM Scrapped
QEI 695T5 1996 2015 WBPM Scrapped
Harris HT3.5 1997 2015 WUPE-FM Scrapped
Harris Z5CD 1997 2015 WXPK Cannibalized
Energy Onix SSA1000 2000 2015 WDHI Cannibalized
Harris MW1 1982 2016 WPUT Abandoned
Mc Martin BF1K 1982 2016 WSUL Scrapped
Mc Martin BF3.5K 1982 2016 WSUL Scrapped
Continental 814R1 1980 2016 WDBY Scrapped
Broadcast Electronics FM35A 1986 2017 WEBE Cannibalized
CCA FM-1000D8 1973 2018 WDLA Scrapped
Collins 828E 1978 2018 WSYB Scrapped
Gates BC-1H 1971 2018 WHUC Scrapped
Gates BC-1J 1954 2019 WBEC Scrapped
Gates BC250GY 1969 2019 WSBS Scrapped

*In some cases the “Year New” is a guess based on when the station went on the air.  Before you write me and say “But model XYZ transmitter wasn’t made until 19XX, I did not look at every name plate and write all the information down as I did this.

Like everything else, there is a process to this.

RCA BTA-10U AM transmitter
RCA BTA-10U AM transmitter

First of all, if the transmitter was made before 1978, the possibility of PCB capacitors and transformers exists. In the case of the GE BT25A, massive amounts of PCBs needed to be disposed of properly. According to current federal laws, ownership of PCBs and PCB contaminated items cannot be transferred. Thus, the transformer casings were cleaned out and taken to Buffalo to be buried in a PCB certified landfill.   Otherwise, most other transmitters, such as the RCA BTA-10, may have a few PCB capacitors in them and perhaps the modulation transformer.  Those items can be disposed of by calling an authorized environmental disposal company like Clean Harbors.

The rest of the transmitter is stripped of any useful parts.  Things like vacuum variable capacitors, rectifier stacks, blower motors (if they are in good condition), HV power supply contactors, unique tuning parts, whole control and metering boards, tube sockets, etc.

The remaining carcase is then disassembled and hauled off.  I got a guy that will do this for relatively little money.  He takes the transmitter back to his warehouse and cuts it up, sorts all of the various metals out, then takes it to the scrap yard.  This includes things like cutting all of the windings off of transformers and power supply chokes, sorting out the brass and copper tuning parts, etc.

The inglorious task of AM antenna array maintenance

AM radio stations are rough customers. They frequently operate on the margins, both in terms of ratings and revenue. Their transmitter plants are complex and very often have been on a reduced maintenance schedule for years, sometimes decades.  Those of us that understand the operation of AM transmitter plants and all their quirky behaviours are getting older.  I myself, feel less inclined to drop everything and run off to the AM transmitter site when things go awry.  Seldom are such efforts rewarded, much less acknowledged.  Station owners are also finding that their previous demands are unrealistic.  For example, time was that any work that takes the station off the air had to be done after midnight.  These days, I can tell you, I will not be working at your radio station after midnight.  You can find somebody else to do that work.

Thus, today, we took this particular AM station off the air from Noon until 3 pm to diagnose and repair a problem with the four tower daytime array.  Once again, this involved a shift in common point impedance and a drastic change in one tower’s current ratios.

Antenna Tuning Unit, mice have made a mess
Antenna Tuning Unit, mice have made a mess

In all fairness to the current owner, this ATU reflects years of neglect. At some point, mice made a home in here and created a mess. The ATU smells of mouse shit, piss and mothballs.  It is full of mouse droppings, grass seeds and fur.  All of the ATUs in this array are in similar condition.

Paper wasp, inside ATU
Paper wasp, inside ATU

It was warm enough that the wasps were active, if not a little bit lethargic.

Broken stand off insulators in ATU
Broken stand off insulators in ATU

This coil is being held up by the tubing that connects it to other components. When the ATU was built, no nylon or cork bushings were used between the insulators and the wall of the ATU they were mounted on. Heat cycling eventually did all of the insulators in.

Catwalk to the other towers
Catwalk to the other towers

Catwalks to the other towers. At least the swamp grass has been cut this year, it is only four feet tall instead of ten.

Tower base
Tower base

The tower bases are all elevated above the theoretical maximum water level. The ATUs are also up on stands with platforms build for maintenance access.

ATU Work "platform"
ATU Work “platform”

I cannot even blame the current owner, who has spend considerable money to make repairs and upgrades to this site. It is very difficult and very expensive to catch up with deferred maintenance. Sadly, most AM stations we encounter have similar or worse problems.

I think it is too late to save many of these AM stations.  The technical issues, lack of revenue, perceived poor quality, lack of good programming are all taking their toll.  At this point, the hole is so deep there is no hope of ever getting out.  The FCC’s faux interest in “revitalization” followed by two years of stony indifference seems to be a final, cruel joke.