Yes, Senior Road feedline work is done...one more bit of work coming up the weekend of July 8-10th.....where the antenna itself is checked for leaks and patched, etc. Stations will have to be off for that weekend.....including HDs again.
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Yes, Senior Road feedline work is done...one more bit of work coming up the weekend of July 8-10th.....where the antenna itself is checked for leaks and patched, etc. Stations will have to be off for that weekend.....including HDs again.
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AnyHuman
Guest
Why all this maintenance to the antennas? Sounds a bit overkill. What would it be leaking?
The annual inspection of the antenna is by the manufacturer.
In small markets, stations will often run equipment to failure. In the major markets, we really try to get out in front of failures and prevent them.
The main antenna system of a station has no redundancy (such as two transmitters on hot switch) and auxiliary transmitters & antenna backups often / usually produced more limited coverage.
The coax and the antenna for a common antenna site are exposed to the elements, including high winds, icing, temperature variations and lightning. Damage is often not immediately detectable.
The combiner for a common antenna is never shut down except in the case of failure or maintenance.
A fail in any of the locations would take all the stations off the air. Emergency repairs on 1000' and above towers is very dependent on very good weather for a period of time adequate to make repairs. That means that preventative and planned maintenance can save what perhaps could be weeks off the air in periods of bad weather.
Remember that damage such as arcing in a coax section or an antenna panel or element requires pulling very heavy items up the tower, resulting in considerable wind loading considerations, too. A section of coax is a rigid section or tube of copper with heavy fittings at both ends that looks like a large, large water pipe, not a coil of wire.
Especially now that we are in hurricane season. Service going out during a hurricane would be catastrophic. The auxiliary site won't cover the same area as the Senior road tower and people out in the suburbs would be out of luck.
The antenna at SR Road is a two part...stations can go to one half (upper OR lower) if needed....but then are limited to half TPO which creates 1/4 ERP....going to a full power aux is best in this case...but still any signal that can sell a commercial is better than none 
If the stations are on the top half, the bottom half can be serviced with no issues....but if the top needs servicing, they cannot run on the bottom half as the workers have to climb through the field of the bottom to reach the top...so everyone has to go off the site for that
If the stations are on the top half, the bottom half can be serviced with no issues....but if the top needs servicing, they cannot run on the bottom half as the workers have to climb through the field of the bottom to reach the top...so everyone has to go off the site for that
The antenna at SR Road is a two part...stations can go to one half (upper OR lower) if needed....but then are limited to half TPO which creates 1/4 ERP....going to a full power aux is best in this case...but still any signal that can sell a commercial is better than none
If the stations are on the top half, the bottom half can be serviced with no issues....but if the top needs servicing, they cannot run on the bottom half as the workers have to climb through the field of the bottom to reach the top...so everyone has to go off the site for that
Are there separate coax runs for the two half-sections? And what is the diameter of the coax?
I would think that stations would need to reduce power even more ... perhaps to 10% if workers are servicing the lower half of the antenna system.
Even at a distance of 100', there would be significant RF in the near-field lobes of the antennas.
Even at a distance of 100', there would be significant RF in the near-field lobes of the antennas.
The transmission lines are pressurized with nitrogen to keep moisture out.
Moisture leads to reflected power (VSWR) which leads to arcing, which in turn burns up the line and/or antenna.
If you don't run nitrogen through the line you still have some sort of dehydrator always present, because again, moisture does bad things.
Preventative maintenance pays dividends.
Yes...9 inch to both....
With the top half active and stations at 1/2 TPO and thus 1/4 ERP, its been measured to be safe on the lower section....
They weren't working on the antenna. They were replacing the watchband springs on the bullets for the entire transmission line. The upper half of the antenna has its own 9" line, and the lower half has the same.
Nobody was broadcasting from the stick at all until the crew was over 200' away from the antenna.
I like listening to both Top 40 and the Good Time Oldies channel but with the HD signal being so unreliable, I switched my Top 40 loyalty to more reliable KHMX even when listening on an analog radio. Every time KRBE's HD signal was down for maintenance, I was forced to listen to Oldies 107.5 when I felt like listening to oldies. Unlike KRBE, KHMX always has a very reliable signal even when power was lowered for maintenance or transmitting from their backup site after storms.
KRBE transmits from the same main antenna as KHMX...while there are some flucuations in the antenna pattern over the range, it's not that much..the aux sites are also the same for CBS and KRBE...the ATC tower just next door...
The difference is KHMX transmits with roughly 4X as much HD power as KRBE.
KRBE-HD broadcasts at the original -20 dBc power level. KHMX-HD broadcasts at the more recently authorized -14 dBc.
In other words, KRBE's IBOC ERP is down 20 dB from their analog ERP. KHMX's IBOC ERP is down 14 dB from their analog ERP.
In even simpler terms, for a 100kW ERP, a -20 dBc station has a digital ERP of 1kW. A -14 dBc station has a digital ERP of 3.98kW.
I was talking about the analog signals..I expect KRBE will up the power on the HD with the new Gates transmitter coming
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