Help ID several dozen antennas from last week's site photos!

Cowboy · Post by **Cowboy** » Sun May 01, 2005 10:14 am

Snapped off a couple dozen pictures up at Deer Point last week while working on an interference issue. A lot of FM broadcast and TV broadcast on the site; lots of UHF LTR on Lower Deer Point.

http://www.idascan.org/gallery/deerpoint
Add your comment as to your opinion on the whatever antenna(s) are in each picture. I'd do it manually but that would take out half the fun

Here's a couple thumbnails:

Cowboy · Post by **Cowboy** » Sun May 01, 2005 12:01 pm

Sorry about that... Try accessing the URL again. My version of Gallery was out of date, causing memory limit errors that locked up the PHP application all together.

http://www.idascan.org/gallery/deerpoint

n5tbu · Post by **n5tbu** » Sun May 01, 2005 2:31 pm

Somebody's making a killing on the space rentals at that site!!
mod

Cowboy · Post by **Cowboy** » Sun May 01, 2005 2:57 pm

n5tbu wrote:Somebody's making a killing on the space rentals at that site!!
mod

I count a minimum of 13 FM broadcast arrays, 2 analog TV brodcast arrays plus some DTV gear.

Forest Service operated site...

kcbooboo · Post by **kcbooboo** » Sun May 01, 2005 3:31 pm

At least that many FM broadcast antennas, and tons of gain, too. Typically two bays give you 3dB gain, but some of the older ones used this many bays for unity gain. It has to do with polarization. I wonder why they didn't go with some kind of combiner and one shared antenna.

Bob M.

OX · Post by OX » Sun May 01, 2005 5:16 pm

while working on an interference issue

I couldn't imagine an interference issue at that site. I pitty any flying animal nearby. Can you say "extra crispy"?

Cowboy · Post by **Cowboy** » Sun May 01, 2005 6:58 pm

kcbooboo wrote:It has to do with polarization.

Right hand circularly polarized dipoles... Hence the turnstyle design.

kcbooboo wrote: I wonder why they didn't go with some kind of combiner and one shared antenna.

The highest power output of a commerically available transmit combiner I've seen was 100 W... Half of the stations on that hill are class C3 stations putting probably 10-25 kW out at the PA... The top TV broadcast antenna appeared to be fed with 6" Heliax. Heaven forbid they color coat at the base bulkhead where the feedline entered the building.

tvsjr · Post by **tvsjr** » Sun May 01, 2005 8:15 pm

Transmit combiners for that class of transmitter can be had, but they're definitely not cheap. A friend is an engineer for a local TV station (top 10 market), and they've got a 3-channel combiner at their main transmit site. The room for *just the combiner* is about 40 feet square and 20 feet tall.

Hoseman292 · Post by **Hoseman292** » Mon May 02, 2005 7:26 am

I'm curious... who makes the high power continuous duty transmitters for television and radio stations?

Thanks,

Tim

kcbooboo · Post by **kcbooboo** » Mon May 02, 2005 7:57 am

Several companies make broadcast equipment: Harris, Continental, Broadcast Electronics, QEI, Nortel, NEC, the list goes on and on. Back in broadcasting's glory days, there were names like Westinghouse, GE, RCA, Collins, Gates.

TV station combiners are much more complex due to the bandwidths required. FM broadcast combiners are certainly available - I'm sure there was one on the World Trade Center and there must still be one on the Empire State Building, since there's no room for a dozen FM antennas plus half as many TV stations.

Bob M.

techie · Post by **techie** » Sun May 29, 2005 7:35 pm

I just get a page saying the domain is parked..

mr.syntrx · Post by **mr.syntrx** » Mon May 30, 2005 5:49 am

The digital TV transmitters in my old town are all Rohde & Schwarz.