April 2014
M T W T F S S
« Mar   May »
 123456
78910111213
14151617181920
21222324252627
282930  

Archives

Categories

ATT Long Lines Site, Rock City NY

Another one of those former ATT Long Lines sites which has been re-purposed. This site was known as Rock City and as the name suggests, it is a fairly remote location. These locations were chosen by ATT to facilitate microwave relay between cities.  Some of the more remote rural locations are so far off the beaten path that they do not make good wireless carrier sites today.  Such is the case here, there simply are not enough people around to turn this into a profitable cell site.

Former ATT long lines site, Rock City NY

Former ATT long lines site, Rock City, NY

This site is useful in other ways, the local township purchased it and has put it to use for E911 dispatch and other uses such as WKZE translator W290BZ.

Former ATT long lines Western Electric Tower, Rock City NY

Former ATT long lines Western Electric Tower, Rock City, NY

The tower is less than 200 feet tall, therefore it is no longer painted or lit. These old Western Electric towers were really built. Under that peeling paint, the galvanizing is still in near perfect condition. The tower dates from 1968.

Former ATT tower, Rock CIty NY

Former ATT tower, Rock City, NY

The Western Electric KS-15676 microwave antennas and waveguide have been removed. The top platform is quite large, one could build a house up there. The W290BZ antenna is the cross polarized LPA attached to the center pole which is barely visible.

Former ATT long lines site, Rock City NY.  The big empty.

Former ATT long lines site, Rock City, NY. The big empty.

This room held the switch gear and TD-3 microwave radios.

Former ATT site, Rock City NY 100 KW generator

Former ATT site, Rock City, NY 100 KW generator

The original General Motors 100 KW diesel generator. The fuel tank was removed before the site was transferred from ATT to the new owners.  If reconnected to a fuel supply and the block heater turned on, I’d bet this unit would start and run.

ATT Rock City NY generator, Detroit Diesel straight six engine

ATT Rock City, NY generator Detroit Diesel straight six engine

ATT Rock City NY fuel tank cathodic projection unit.

ATT Rock City, NY fuel tank cathodic projection unit.

The tank had a Cathodic protection unit installed, which ran a small DC current through the tank to keep it from rusting.

The original visitors log book is still there, showing every ATT person who visited the site from 1968 until it was decommissioned in 1994.  This site was unmanned and remotely monitored and controlled from somewhere else.  Maintenance personal showed up at regular intervals or to fix specific problems.

Like many of its rural counterparts, this site sits mostly empty since the microwave equipment was removed in the early 1990’s.  This one seems to be well taken care of, others are in terrible shape.

Modern Art

After replacing a burned out FM antenna for one of our clients, the question became; what do we do with the old antenna?  There were several options:

  • Throw it behind the transmitter building and let weeds and poison ivy grow over it
  • Take it to the scrap yard to get what ever money we could for it
  • Give it away to somebody
  • Turn it into a fountain

I have scrapped these old antennas before, they are made mostly of hard yellow brass, which does not net too much at the scrap yard.  In fact, by the time I finished removing the Radomes and separating the metal, I had more time into the job than it was worth for both myself and the client.  Therefore, I present to you the ERI LPX lawn fountain:

ERI LPX2E Rototiller FM antenna used as a fountain

ERI LPX2E Rototiller FM antenna used as a fountain

Upon completion, my wife and daughter, who are natural born skeptics, even had kind words to say. It seemed like a simple project at first; enlarge the dry well for the basement sump pumps and install some type of mounting base for the old antenna. It turned into a little more than that.

Mounting base for ERI antenna fountain

Mounting base for ERI antenna fountain

It took several hours of backbreaking labor, a concrete form and a few bags of ready mix concrete to create the mounting base. Several wheelbarrow loads of gravel, some rocks from the old wall in the woods and a pond pump from the hardware store round out the installation.

ERI LPX2E Rototiller FM antenna fountain

ERI LPX2E Rototiller FM antenna fountain

I am not sure what else to say.

Friday Funnies: Frantic calls

Back when radio stations still had DJ’s, one would occasionally get the frantic “We off the air” call:

weve-tried-nothing

Nowadays, the unemotional monotone computer generated remote control voice says something like “Alarm, status channel 16, WXYZ silence…” or better still, the answering service.

In some ways, I miss the old days…

Troubleshooting an AM array

Today, there will be a quiz.

Recently, we had an AM antenna array go out of tolerance by a good margin.  This has been repaired, however, I though I’d post this information and see if anybody could identify the problem and the solution. Unfortunately, I don’t have a prizes to give away, however, you can show off your AM engineering prowess.

All of the information is pertinent:

  1. The station has two directional arrays (DA-2) using the same towers; the night time array is out of tolerance, the daytime array is not effected and is performing normally.
  2. There were no weather events connected with this event; no electrical storms, no major temperature changes, no rain events, no freezing or thawing, etc.
  3. The problem happened all at once, one day the array was performing normally, the next day it was not.
  4. Station management reports that some listeners were complaining that they could no longer hear the station.
  5. The ATU’s and phasor were inspected; all RF contactors were in the proper position, no damaged or burned finger stock, no evidence of damaged components (inductors or capacitors) was observed.  Several mouse nests were cleaned out of the ATU’s, however, this did not change the out of tolerance antenna readings.
  6. The towers are 1/4 wave (90 electrical degrees) tall.

Readings:

Tower Phase angle as licensed Current ratio as licensed Phase angle as read Current ratio as read
1 147.2 0.583 149.5 0.396
2 (reference) 0 1.00 0 1.00
3 -137 0.493 -125.8 0.798
4 107.5 0.481 92.7 0.355
5 -38.1 0.737 -60.2 0.623
6 -178.7 0.382 142.8 0.305

Licensed values for common point current is 13 amps, impedance is 50 ohms j0 and there is normally no reflected power on the transmitter.  On this day, the common point current readings were 8.9 amps, impedance 38.5 ohms +j5 the transmitter had 340 watts of reflected power.

This is the overall schematic of the phasor and ATU:

WDGJ overall RF schematic diagram

WGDJ overall RF schematic diagram, click for higher resolution

Aerial view of transmitter site, oriented north:

WGDJ aerial view showing towers as identified in schematic diagram

WGDJ aerial view showing towers as identified in schematic diagram

So, where would you begin?  Ask questions in the comments section.

The Shukhov Tower

A very interesting bit of broadcasting history in Moscow may disappear forever.  Designed and built by Vladimir Grigoryevich Shukhov, the Shukhov Tower was completed in 1922.  Since that time it has served as a AM broadcasting and later and FM broadcasting tower.  In the picture, one can see what looks like a massive FM panel antenna at the top.  According to this website: www.shukhov.org, the tower is in very poor shape and is slated to be demolished.

The tower itself is described as 160 Meters (525 feet) tall, hyperboloid steel lattice structure. The design is unique in that it is very strong, yet uses approximately 60-70 percent less steel than a comparable four legged structure like the Eiffel tower.  An amazing feat of engineering for its day, when everything was calculated and drawn by hand.

Shukhov Tower, Moscow, FSR

Shukhov Tower, Moscow, FSR.

The antenna is a little hard to discern, however, it looks like a horizontally polarized six or eight around 4 bay FM antenna. Could also be low band VHF TV.

Shukhov Tower antenna

Shukhov Tower antenna. Courtesy Wikipedia

Unfortunately, time is running out and little or nothing is being done to protect the steel structure from the elements. The last paint job was more than twenty years ago. The land it currently occupies has some value, and there is talk of putting up a high rise development in its place.

Article from the New York Times; An engineering landmark faces demolition in Moscow.

There are lots of videos on youtube and pictures from the wikipedia article.  It is an interesting bit of history, if it can be saved it will be a very close run thing.

WMHT’s former analog transmitter

During the digital TV conversion in the US, all broadcast television stations installed new transmitting equipment and antennas.  Most stations ended up on a different frequency than their original analog channel.  In Albany, New York, all of the TV stations moved to a common transmitter site and installed their antennas on a single tower.

home of WRGB, WTEN, WNYT, WXXA, WMHT, and WCWN

Albany DTV tower, home of WRGB, WTEN, WNYT, WXXA, WMHT, and WCWN

For more on the Albany DTV site, check out the NECRAT page: www.necrat.us/albdtv.html

So, what happened to the old Analog TV sites in Albany?

For the most part, after the analog turn off on June 12, 2009, the sites have sat empty.  Such is the case with the former WMHT site.

Sign outside of former WMHT transmitter building

Sign outside of former WMHT transmitter building

This old sign about sums up the end of analog television.

Former WMHT Comark analog transmitter

Former WMHT Comark analog transmitter

Former WMHT analog transmitter wide shot

Former WMHT analog transmitter wide shot

Former WMHT operator position

Former WMHT operator position

The former transmitter operator desk. Maintenance log is still open. From the looks of things, they opened the circuit breakers and walked away. Everything remains intact from the antenna to the klystrons and exciters. It does appear that the coolant has been drained from the system. Other than that, it seems like the whole thing could be restarted with minimal effort.

Former WMHT Onan DFN 350 backup generator

Former WMHT Onan DFN 350 backup generator

There were two Onan DFN 350 backup generators. With a TV transmitters, it is vitally important to run the cooling system after shutdown. The idea here is that both generators in parallel could run the whole station, if one generator failed, then the cooling system would still run and cool the klystrons.

Former WMHT site kitchen

Former WMHT site kitchen

Former WMHT tower, wave guide and WVCR antenna

Former WMHT tower, wave guide and WVCR antenna

The former WMHT tower, which currently holds the WVCR-FM, WXL-34 (NOAA weather radio), and W44CT-D (Three Angles Broadcasting) Low power TV transmitter.

Current site occupants; WVCR-FM and W44CT-D

Current site occupants; WVCR-FM and W44CT-D

These equipment racks and the NOAA weather radio transmitter in the other room are the only active equipment at this site.

WMHT-TV Chanel 17 (488-494 MHz) signed on 1962 from this site.  The Comark transmitter was installed in 1984.  The station’s analog ERP was 2000 KW visual, 200 KW aural.

It is an interesting site.

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

Free counters!