Engineering Radio – Page 132 – One Hundred percent Human Generated Content for your Reading Enjoyment

Hot Elbow

Found this 3-inch rigid elbow to be a little warm when we were removing a dividing wall as a part of an AC upgrade:

As measured with my Fluke 62 mini IR thermometer, the temperature is 163°F (72.7°C) at the clamp and drops down in both directions.

This is at WEBE and this particular section of the transmission line is running 34 KW into the analog/digital combiner in the next room. The clamps are tight, but you can see a little scorch mark on the stainless steel clamp right over the slot in the field flange. That is where there is a gap between the outer conductors, which possibly means the inner conductor was cut slightly too long during installation. I suspect this and or a problem with the bullet is causing the heating issue. I was never (and still am not) a fan of those field flange-type elbows, I’d much prefer the flanged type with a field flange on the straight line section.

34 KW is getting into the semi-serious power level for FM broadcasting. At those levels, even small impedance mismatches can lead to big problems. We have a new elbow, field flanges, and bullets on order. Unfortunately, we will have to take the station off the air to replace this.

WEBE transmitter site with partition removed

This is all a part of an air conditioning project. There was a plywood partition wall between the front and the back of the transmitters which was impeding airflow. All of the HVAC contractors who bid on the AC job identified it as a problem that needed to be addressed before the big 5-ton wall-mount AC units were installed.

Update: Replaced elbow last night (8/4). Went off at 10 pm and back on at 10:25. Found the inner conductor had been pushed out of place and was off center on the outside (toward the wall side) of the elbow. This was an older elbow that did not have the nylon inner spacers on the center conductor. The inner conductor was dark purple. Before replacement, the elbow was 138°F (59°C) under full power (34 KW). After replacement, it was 97°F (36°C) as was the rest of the transmission line. At these power levels and frequencies, even small, minor imperfections cause impedance shifts and become issues.

I cleaned up and reused the bullets and the outer conductor with scotch brite. I also used more support wires because I believe the elbow was starting to pull apart, which can sort of be seen in the first picture.

Things that make you go hmmm, part III

Continuing the series, this is a picture of an ice bridge installation I recently saw:

On an otherwise neat installation, it appears there is something wrong with the way these ground wires are connected to the support poles of an ice bridge. I am not sure how effective that connection will be if lightning hits anything nearby. Generally speaking, those wires are CAD welded (exothermic welding) to the support poles or whatever else is supposed to be grounded. I’d bet that whoever packed the truck for the job simply forgot to throw the CAD weld shots on the truck.

Now they have to come back.

It will be interesting to see how long it takes whatever tower company to return to the site and finish the job.

So, you call this work?

A trip to the WSPK transmitter site on a pleasant day, or, one could say, another day at the “office.” Tower painting season is here, I’ll post some more about that later. This is a nice set of pictures from the top of Mt. Beacon, in Beacon, NY.

Hudson Valley looking north from Mt. Beacon

South Mount Beacon with the old fire tower:

Mount Beacon looking south at the old fire tower

Tower farm; two TV stations, Media Flow, one radio station, three translators, several cell carriers, one paging company, some government two-way gear, and a few microwave relays. The 320-foot guyed tower in the center holds the main (top) and backup (bottom) antennas for WSPK:

Tower climbers ascending a 320-foot tower. This picture (and all the others as well) was taken with my HTC smartphone camera, proving the old adage, sometimes it is better to be lucky than good:

View from the ATC site at the very top of North Mount Beacon of the tower workers painting the top of the tower:

Tower workers painting torque arms on 320 foot guyed tower

Another view from the ground:

All in all, not a bad day.

New York State passes Anti Pirate Radio law (S-5739, A-326)

I wrote about this before, garnering several negative comments, both from the cost and effectiveness perspectives. Prompted by the New York State Broadcasters Association, the Senate and Assembly passed the legislation on Wednesday. It was refined somewhat, with frequencies specified in the AM broadcast and FM broadcast bands. The revised writing softens the criminality somewhat, making the first offense a class A misdemeanor and subsequent offenses class D felonies.

It also broadens the enforcement actions to allow the seizure and destruction of radio transmission equipment, antennas, computers, and studio equipment used during the act. The law provides no provision for part 15 broadcasting, which is defined as license-free operation under FCC rules.

The law amends the NY State Penal code, by adding section 190:

S 190.72 UNAUTHORIZED RADIO TRANSMISSION IN THE SECOND DEGREE.
 A PERSON IS GUILTY OF AN UNAUTHORIZED RADIO TRANSMISSION IN THE SECOND
 DEGREE WHEN SUCH PERSON:
 1.  KNOWINGLY  MAKES OR CAUSES TO BE MADE A RADIO TRANSMISSION IN THIS
 STATE, ON RADIO FREQUENCIES ASSIGNED AND LICENSED BY THE FEDERAL  COMMU
 NICATIONS  COMMISSION  FOR USE BY AM RADIO STATIONS BETWEEN THE FREQUEN
 CIES OF 530 KHZ TO 1700 KHZ, OR FM RADIO STATIONS BETWEEN  THE  FREQUEN
 CIES  OF  88  MHZ TO 108 MHZ, WITHOUT FIRST HAVING OBTAINED A LICENSE OR
 OTHER AUTHORIZATION FROM THE FEDERAL COMMUNICATIONS COMMISSION, OR  DULY
 AUTHORIZED FEDERAL AGENCY; OR
 2.  KNOWINGLY  CAUSES,  EITHER DIRECTLY OR INDIRECTLY, INTERFERENCE TO
 ANY AM RADIO STATIONS BETWEEN THE FREQUENCIES OF 530 KHZ TO 1700 KHZ, OR
 FM RADIO STATIONS BETWEEN THE FREQUENCIES OF 88 MHZ TO 108  MHZ  WITHOUT
 AUTHORIZATION  BY  THE FEDERAL COMMUNICATIONS COMMISSION OR DULY AUTHOR
 IZED FEDERAL AGENCY.
 ANY EQUIPMENT, INCLUDING BUT NOT LIMITED TO THE TRANSMITTING  ANTENNA,
 TRANSMITTER, MASTER CONTROL, SERVERS AND COMPUTERS, USED TO PROVIDE SUCH
 ILLEGAL  RADIO  TRANSMISSIONS  SHALL  BE  SUBJECT  TO  SEIZURE AND, UPON
 CONVICTION, SUBJECT TO DESTRUCTION  PURSUANT  TO  ARTICLE  FOUR  HUNDRED
 SEVENTEEN OF THIS CHAPTER.
 UNAUTHORIZED  RADIO  TRANSMISSION  IN  THE  SECOND DEGREE IS A CLASS A
 MISDEMEANOR.

S 2. The penal law is amended by adding a new section 190.73  to  read
 as follows:

S 190.73 UNAUTHORIZED RADIO TRANSMISSION IN THE FIRST DEGREE.
 A  PERSON  IS  GUILTY  OF UNAUTHORIZED RADIO TRANSMISSION IN THE FIRST
 DEGREE WHEN HE OR SHE COMMITS THE CRIME  OF  UNAUTHORIZED  RADIO  TRANS
 MISSION  IN THE SECOND DEGREE PURSUANT TO SECTION 190.72 OF THIS ARTICLE
 AND HAS PREVIOUSLY BEEN CONVICTED WITHIN  THE  PRECEDING  TEN  YEARS  OF
 UNAUTHORIZED  RADIO  TRANSMISSION  IN  THE SECOND DEGREE. ANY EQUIPMENT,
 INCLUDING BUT NOT LIMITED  TO  THE  TRANSMITTING  ANTENNA,  TRANSMITTER,
 MASTER  CONTROL,  SERVERS  AND  COMPUTERS,  USED TO PROVIDE SUCH ILLEGAL
 RADIO TRANSMISSIONS SHALL BE SUBJECT TO SEIZURE  AND,  UPON  CONVICTION,
 SUBJECT  TO  DESTRUCTION  PURSUANT  TO ARTICLE FOUR HUNDRED SEVENTEEN OF
 THIS CHAPTER.  UNAUTHORIZED RADIO TRANSMISSION IN THE FIRST DEGREE IS A CLASS D
 FELONY.

S 3. The penal law is amended by adding a new article 417 to  read  as
 follows:
 ARTICLE 417
 SEIZURE AND DESTRUCTION OF TRANSMITTING ANTENNA, TRANSMITTER,
 MASTER CONTROL, SERVERS AND COMPUTERS, USED TO PROVIDE ILLEGAL
 RADIO TRANSMISSIONS
 SECTION 417.00 SEIZURE  AND  DESTRUCTION OF TRANSMITTING ANTENNA, TRANS
 MITTER, MASTER CONTROL, SERVERS AND COMPUTERS, USED  TO
 PROVIDE ILLEGAL RADIO TRANSMISSIONS.

S  417.00  SEIZURE AND DESTRUCTION OF TRANSMITTING ANTENNA, TRANSMITTER,
 MASTER CONTROL, SERVERS AND COMPUTERS, USED TO PROVIDE ILLEGAL RADIO TRANSMISSIONS.
 ANY EQUIPMENT UTILIZED IN VIOLATION OF SECTION  190.72  OR  190.73  OF
 THIS  CHAPTER MAY BE SEIZED BY ANY POLICE OFFICER UPON THE ARREST OF ANY
 INDIVIDUAL IN POSSESSION OF THE SAME. UPON FINAL  DETERMINATION  OF  THE
 CHARGES,  THE COURT SHALL, UPON NOTICE FROM THE DISTRICT ATTORNEY, ENTER
 AN  ORDER  PRESERVING  ANY  TRANSMITTING  ANTENNA,  TRANSMITTER,  MASTER
 CONTROL,  SERVERS  AND  COMPUTERS,  USED TO PROVIDE ILLEGAL RADIO TRANS
 MISSIONS FOR USE IN OTHER CASES, INCLUDING A CIVIL ACTION.  THIS  NOTICE
 MUST BE RECEIVED WITHIN THIRTY DAYS OF FINAL DETERMINATION OF THE CHARG
 ES.  THE  COST  OF STORAGE, SECURITY AND DESTRUCTION OF ITEMS SO ORDERED
 FOR PRESERVATION AND USE AS EVIDENCE IN A CIVIL  ACTION,  OTHER  THAN  A
 CIVIL  ACTION  UNDER  ARTICLE  THIRTEEN-A  OF THE CIVIL PRACTICE LAW AND
 RULES INITIATED BY THE DISTRICT ATTORNEY, SHALL BE  PAID  BY  THE  PARTY
 SEEKING  PRESERVATION  OF  THE  EVIDENCE  FOR A CIVIL ACTION. IF NO SUCH
 ORDER IS ENTERED WITHIN THE THIRTY DAY PERIOD, THE DISTRICT ATTORNEY  OR
 CUSTODIAN  OF THE SEIZED PROPERTY MUST CAUSE SUCH ITEMS TO BE DESTROYED.
 DESTRUCTION SHALL NOT INCLUDE AUCTION,  SALE,  OR  DISTRIBUTION  OF  THE
 ITEMS IN THEIR ORIGINAL FORM.

The law takes effect on November 1, 2011.

In order to gain a conviction, some amount of evidence would be needed. Signal strength measurements and or spectrum analysis would be a minimum requirement, in addition to any equipment seized.

Discuss.