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The GatesAir FLX-40 transmitter

The GatesAir FLX-40 transmitter is my first liquid cooled transmitter installation.  Previously, I have installed an air cooled Nautel NV-40, a V-40 and a couple of BE FM-35T/20T units.  The WEBE transmitter site in Bridgeport, Connecticut is an interesting facility.

Smoke Stack, Bridgeport Energy, Bridgeport, CT

Smoke Stack, Bridgeport Energy, Bridgeport, CT

This coal fired power plant smoke stack which currently holds up the six bay, half wave spaced Shively antenna.  The old BE FM35A transmitters are getting little bit long in the tooth.  Thus, we picked one to scrap, the other will be kept for backup service.

Scraping 34 year old BE FM30A transmitter

We saved a whole bunch of parts to keep the other FM35A on the air in backup service.

BE FM30A power supply cabinet

The power supply cabinet with that 500 pound plate transformer was the last to go.

On second thought, that plate supply transformer is a good spare to have

On second thought, that plate supply transformer is a good spare to have

The FLX-40 came on a large truck.  Fortunately, we were able to open the side gate at the power plant and get the truck to the front door of the transmitter building easily.  The transmitter consists of two large cabinets, each with two 10 kilowatt power blocks.  There is also a pump station and an outdoor heat exchanger.

FLX-40 cabinet two off the truck

FLX-40 cabinet two off the truck

FLX-40 cabinet one

FLX-40 cabinet one

FLX-40 in place, cabinets bolted together

FLX-40 in place, cabinets bolted together

This transmitter design is based on the Harris digital TV transmitters.

FLX-40 pump station

FLX-40 pump station

The pump station and heat exchanger are the same systems used for TV transmitters.  Liquid cooled units require a bit more planning on the installation end.  The coolant piping should have a high spot from which everything else slopes down hill.

Send and return coolant lines

Send and return coolant lines

I put a 1/4 to 12 inch pitch on everything.  Of course, there are several low points, the heat exchanger, pump station and bottom power blocks.

Holding steady at 18 PSI for 24 hours

Holding steady at 16 PSI for 24 hours

After assembling the cooling system, we pressure tested it for 24 hours.

Installation debris in the coolant line strainer

Installation debris in the coolant line strainer

Following that, we flushed the system with distilled water for several hours before we filled it with 40/60 glycol/water mix. Record low temperature in Bridgeport is -7 F (-22 C), thus a 40/60 mix will give protection down to -15 F (-26 C). The more water in the coolant, the better heat transfer capacity it has.

At the highest point in the system, there is a sight glass and an air purge valve

At the highest point in the system, there is a sight glass and an air purge valve

The pump station is controlled by the transmitter, which speeds up the pumps according to how much heat needs to be moved. In turn, the pump station control the fan speed on the heat exchanger outside.

FLX-40 pump station on line

FLX-40 pump station on line

The pump station runs with one motor most of the time. The other pump motor will run in the event of failure or if there is not enough flow through the power blocks. Each of the four power blocks has a flow rate meter on the return line.

Heat Exchanger Fan motor controllers, Variable Frequency Drive modules

Heat Exchanger Fan motor controllers, Variable Frequency Drive modules

Variable Frequency Drive (VFD) fan motor controllers show them running at half speed.

50 KW heat exhanger

50 KW heat exhanger

GatesAir 50 KW heat exchanger mounted on concrete pad behind the building. Air flows out from the motor side.

One of several shipping containers with modules and other parts for the FLX-40

One of several shipping containers with modules and other parts for the FLX-40

As with most things, some assembly required.  The RF modules needed to be placed in the power blocks according to their serial numbers on the test data sheet.  This insures that the information on the test data sheet matches the installed transmitter configuration.  The power combiner between the two cabinets as well as the reject load and directional coupler all need to be installed.

RF modules with large aluminium heat spreaders.   Coolant flows through each module.

FLX-40 power amp module

FLX-40 power amp module

WEBE, Bridgeport, CT GatesAir FLX-40 on the air for the first time

WEBE, Bridgeport, CT GatesAir FLX-40 on the air for the first time

On the air!

FLX-40 into the antenna

FLX-40 into the antenna

We ran the transmitter for several hours into the antenna yesterday afternoon. The coolant system is still purging air, so we periodically needed to add water/antifreeze to the pump station to keep the pressure between 12-18 PSI. Eventually, the TPO will be 34 KW with the HD carrier(s).

All in all, I would say that this was a fun project. The liquid cooled transmitter had a few extra steps during the installation process, but not too difficult.

The Gates Air FAX-10, Numero Dos

This is the second Gates Air FAX-10 that I have installed. This one is in the shipping container transmitter site from the previous post of the same name.  In this case, we dispensed with the equipment rack that came with the transmitter and installed it in a standard Middle Atlantic rack.   The Harris rack configuration wastes a lot of space and since space is at a premium, we decided to do it our own way.

Gates Air FAX-10 in Middle Atlantic rack

Gates Air FAX-10 in Middle Atlantic rack

The bottom of the rack has the transmission line dehydrator. The top of the rack has the Dielectric A60000 series 1 5/8 inch coax switch, a Tunwall TRC-1 switch controller and the Burk ARC-16 remote control.  I cut the rack panel top to accommodate the coax switch.  The racks were removed from an old studio site several years ago and were in storage since that time.

Gates Air FAX-10

Gates Air FAX-10

The Gates Air FAX-10 transmitter on the air, running a sports-talk format.

Dummy load and Broadcast Electronics FM10B transmitter

Dummy load and Broadcast Electronics FM10B transmitter

View from the other side showing the test load and BE FM10-B transmitter.  This transmitter had a problem that I have run into before with BE FM transmitters.  The jumper between the exciter and IPA had the wrong phase rotation causing reflected power.  I added a foot to it’s length and that problem disappeared.

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

*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.

North Adams tower update III

And final.

It has been a year and a half since the tower collapse in North Adams, Massachusetts.  Since that time, WUPE-FM (Gamma Broadcasting), WNNI and W266AW (New England Public Radio) have been operating with STAs at lower than licensed power.   We have completed the installation of the combined antenna, filters and combiners and now all stations are back to full power.  Here are a few pictures of the transmitter room:

WUPE-FM and WNNI transmitter racks, North Adams, MA

WUPE-FM and WNNI transmitter racks, North Adams, MA

WUPE-FM (left hand rack) is using a Crown FM-2000 transmitter, loafing along at 1,060 watts. WNNI (right hand rack) is using a Gates Air Flexiva 2 running at 1,650 watts. Those stations are combined with a Shively Combiner:

Shively combiner

Shively 2 way star junction combiner

We are still doing some grounding and neatening work behind the racks:

Behind racks

Behind racks

The Shively versa tune antennas that were mounted to the wooden utility pole as emergency antennas will be retained as backup antennas for both stations.

Transmitters for WUPE, WNNI and W266AW

Transmitters for WUPE, WNNI and W266AW

We share the room with Access Plus, which is a wireless internet service provider in western Massachusetts. There stuff is in the open frame racks to the right of WNNI.

Another view:

Transmitter racks for WUPE-FM, WNNI and W266AW

Transmitter racks for WUPE-FM, WNNI and W266AW

TL;DR: Tower collaspes, facility is rebuilt better than before.

Meltdown

After one of our clients had an FM station go off the air over the weekend, I investigated and found this:

Transformer melt down

Transformer melt down

Looks like something one might find in the reactor room at Chernobyl or Fukushima.

Transformer melted down

Transformer melted down

This is at one of those sites with three phase open delta power.  Needless to say, the transformer is toast, perhaps the entire transmitter too.  This will be another fun transmitter scrapping project.  I was thinking about this; over the last five years, I have scrapped at least ten to fifteen old tube transmitters.  The old tube types are going away fast, as are those that can still work on them.

The side mounted FM antenna

In an interesting development, the FCC has taken notice of some pattern distortion from the side mounted FM antenna of KFWR, Jacksboro, Texas.  For those, like myself, not familiar with Texas Radio, that is in the Dallas/Fort Worth market.  The crux of the issue is co-channel interference to KCKL in Malakoff, Texas.  These two locations meet the spacing requirements in 73.207 (215 km).  The issue is with the side mounted ERI antenna and what appears to be intentional pattern optimization.

From the FCC order to show cause:

ERI’s president, Mr. Thomas Silliman, acknowledging that KFWR’s antenna “was mounted in a favorable direction, but… has not been directionalized and therefore is legal.” Mr. Silliman adds that the custom lambda tower at the top of the new KFWR tower was specifically designed for operation at KFWR’s frequency of 95.9 MHz, and that the tower’s lattice structure is “repetitive at the half wave of the specified FM frequency.” Thus, “if one picks a favorable mounting position on the tower, every element in the array sees the same favorable mounting result. Mr. Silliman also states that vertical parasitic elements are used to make the vertical radiation pattern “more circular” and reduce the vertically polarized gain to the east. In a subsequent pleading, ERI elaborates that its computed values “are relative to an RMS measured field of 1.0.” Mr. Silliman concedes that the mounting of the antenna on a certain tower face constitutes “pattern optimization,”arguing later that this is a common practice used by all antenna manufacturers, but states that it is the ERI’s policy “not [to] increase the directivity of the antenna pattern.”

The FCC concludes that the directionality of the side mounted antenna, in this case, is clearly intentional. The radiated power towards co-channel KCKL was calculated to be 274.5 KW, which is in excess of the 100 KW limit and orders KFWR to reduced TPO from 25 KW to 9.1 KW.

We have lots of these out in the field:

Side-mounted Shively 6810 antenna.  WSPK, Mount Beacon, NY

Side-mounted Shively 6810 antenna. WSPK, Mount Beacon, NY

In fact, I believe the majority of our FM stations use side mounted antennas.  Some of them are mounted to a leg and some are mounted to a face.  Usually, I try to place the antenna on the tower so that the bays are facing the desired audience.  This information is given to the manufacture when ordering the antenna so that proper mounts can be furnished and the mounting distance between the tower and antenna properly calculated.  That is about the extent of any “optimization” that is allowed.

As the FM band gets jam packed with FM signals, this may become more of an issue in the future, particularly around dense signal areas around major metropolitan areas.

Transmitter site re-hab

One of the reasons for the recent lack of posts; I have been busy rehabilitating several transmitter sites for various broadcasting companies. These are mostly FM transmitter sites and vary in power from one kilowatt to twenty six kilowatts ERP.  I enjoy project work, but I have been driving hither and yon, racking up 27,000 miles on my new car since last August.

Subaru Crosstrek XV at remote transmitter site, somewhere in rural New York

Subaru Crosstrek XV at remote transmitter site, somewhere in rural New York

So, here is one transmitter site that I just finished; WFLY, Albany, New York.  Removed Collins 831F2 transmitter which was functioning as a backup and installed new Broadcast Electronics FM20S.  The Continental 816R2 is becoming a little bit long in the tooth for a main transmitter, being new in 1986.  Thus, it was time to install a new unit, and I like the Broadcast Electronics solid state and tube designs.  With the BE AM and FM solid state units, their simplicity is their beauty.  We service many BE transmitters, some are thirty years old and are still supported by the manufacturer.

WFLY transmitter building, New Scotland, NY

WFLY transmitter building, New Scotland, NY

The BE FM20S transmitter is actually two FM10S cabinets combined with one controller.  Each cabinet requires a 100 amp three phase mains connection.  This station’s TPO is 11.5 KW, so there is plenty of head room in case the owner’s ever want to install HD Radio or replace the three bay antenna with a two bay unit.

WFLY main transmitter, Broadcast Electronics FM20S

WFLY main transmitter, Broadcast Electronics FM20S

In transmitter cabinet two, above the exciter is room for HD equipment.

BE FM20S exciter housing

BE FM20S exciter housing

I also reworked the coax switches to provide easier implementation of the backup transmitter.  Basically, the main transmitter is on the main antenna, the backup transmitter is on the backup antenna.  We can move the second coax switch to test the backup into the dummy load.  We can move the first coax switch to change antenna feeds.

WFLY backup and main transmitters

WFLY backup and main transmitters

Pretty standard setup.

WFLY RF path diagram

WFLY RF path diagram

We moved the Collins 831F2 from Albany to here to replace another, dead Collins unit at WKXZ in Norwich, New York.  This transmitter is forty years old, but still runs reliably.  Of course, doing this work in the dead of winter added a degree of difficulty to the job, as the roads to both the WFLY and the WKXZ transmitter sites needed work to make them passable for a moving truck.  In the end, we used a skid steer with forks on it to get the transmitter up the final hill and into the small WKXZ transmitter building.

Collins 831F2 transmitter, WKXZ, Norwich NY

Collins 831F2 transmitter, WKXZ, Norwich NY

Collins 831F2 transmitter

Collins 831F2 transmitter

The WKXZ transmitter building interior is floor space challenged. It is located next to a former TELCO microwave site which has a guyed tower.

Winter! Is upon us….

What better time to take the gondola to K-1? None, none at all.  We do work for the two radio stations that are on the peak of Mount Killington, near Rutland, Vermont.  In the summer, usually we can drive up there in a four wheel drive truck.  In the winter, the gondola is the way to go.  On this day, there was a 48-56 inch base, light north winds and air temperature around 10° F (-12° C) .

This is not my video, I did not have enough memory on my SIM card to film a video and I didn’t bring my expensive camera. However, this is a good example of the ride:

Not a bad way to get to a transmitter site, all things considered.

Ride up to Killington Peak

Ride up to Killington Peak

View from Killington Peak

View from Killington Peak

View from Killington Peak

Transmitter buildings on Killington Peak

View from Killington Peak

View from Killington Peak

View from Killington Peak

Tower from Killington Peak

Killington STL dishes

Killington STL dishes

ERI antenna, WZRT/WJJR Killington VT

ERI antenna, WZRT/WJJR Killington VT

The reason for the trip today; repair work on the Nautel VS2.5 transmitter. All three power supplies and the power supply summing board needed to be replaced.

Village seeks repayment from Energy Onix

This saddens me a little bit.  Apparently, the Village of Valatie, NY is seeking repayment of a $500K loan from Transmitter Manufacturer Energy Onix.  Since the passing of Bernie Wise, the company has basically folded.

The village may foreclose on the building if necessary, said Mayor Diane Argyle.

Located at 1306 River St., Energy-Onix was founded in 1987 by broadcast pioneer Bernard Wise, who is known for bringing the “grounded grid” to radio broadcasting. The company designed, manufactured and sold radio transmitters and tubes.

More from the Columbia-Greene Register Star.

Sadly, there goes support for many Energy Onix and CCA transmitter still in the field.  I know of several of those old CCA transmitters that are still cranking away, 40 or more years after they rolled out of the factory in Gloucester, NJ.   I have tried, several times, to call Energy Onix since Bernie passed last year and the phone goes unanswered.  I wonder if we could pick up the the field support and service for these units.  I wonder if there are any spare parts left at the old factory building?

 

 

Longest tube life?

We may be going for a record here; this Broadcast Electronics FM20T was placed in service on June 6, 2001:

Broadcast Electronics FM20T, WYJB, Albany, New York

Broadcast Electronics FM20T, WYJB, Albany, New York

The original 4CX15000A tube is still in use.  I wrote about this a few years ago in this post: Longevity.

I thought by now, we would have changed out that tube.  A few quick calculations shows that the tube has been in use for 118,289 hours or 4,929 days or 13 years 6 months and 3 days.  Anyway you look at it, that is a long time for one tube in nearly continuous use.  I noticed the hour meter is lagging a bit:

Broadcast Electronics FM20T hour meter, WYJB, Albany, New York

Broadcast Electronics FM20T hour meter, WYJB, Albany, New York

Reads 113051.24, which is 5,238 hours different than what I calculated from the maintenance log.  I noticed a slight discrepancy in hours two years ago and attributed it to various off air periods.  However, between then and now, this transmitter has not been off at all.  Thus, the hour meter is wearing out before the tube.  I would say that this is because of excellent filament voltage management,  but I think we simply have a really good tube.

Has anyone else had a tube that lasted this long or longer?

Axiom


A pessimist sees the glass as half empty. An optimist sees the glass as half full. The engineer sees the glass as twice the size it needs to be.

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
~1st amendment to the United States Constitution

Any society that would give up a little liberty to gain a little security will deserve neither and lose both.
~Benjamin Franklin

The individual has always had to struggle to keep from being overwhelmed by the tribe. To be your own man is hard business. If you try it, you will be lonely often, and sometimes frightened. But no price is too high to pay for the privilege of owning yourself.
~Rudyard Kipling

Everyone has the right to freedom of opinion and expression; this right includes the freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers
~Universal Declaration Of Human Rights, Article 19

...radio was discovered, and not invented, and that these frequencies and principles were always in existence long before man was aware of them. Therefore, no one owns them. They are there as free as sunlight, which is a higher frequency form of the same energy.
~Alan Weiner

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