Tallest Tower ? ?

[davideduardo]

Of course, if you're looking for signal reach, the number you would want is HAAT (height above average terrain (sp?)) where most western stations use a nearby mountain. The most extreme I know is Albuquerque where you have 80 ft. towers on top of Sandia Crest overlooking the city at more than 4100 ft. (Now, THAT's a tower.) ;D

Any others more extreme than that? (even outside USA)

HCTM1, the first FM in Northern South America (95.1, air date 1966) was relocated after about two years on the air to a site up the Pichincha mountain, at about 13,500 feet above sea level and about 4,000 feet above Quito, its city of license. We built everything... tower, antenna, transmitter, stereo generator, STL, locally in our shop.

LA's Mt Wilson is around 5100 feet, and the LA basin is from 0 to about 600 feet.

 

[pianoplayer88key]

Of course, if you're looking for signal reach, the number you would want is HAAT (height above average terrain (sp?)) where most western stations use a nearby mountain. The most extreme I know is Albuquerque where you have 80 ft. towers on top of Sandia Crest overlooking the city at more than 4100 ft. (Now, THAT's a tower.) ;D

Any others more extreme than that? (even outside USA)

HCTM1, the first FM in Northern South America (95.1, air date 1966) was relocated after about two years on the air to a site up the Pichincha mountain, at about 13,500 feet above sea level and about 4,000 feet above Quito, its city of license. We built everything... tower, antenna, transmitter, stereo generator, STL, locally in our shop.

LA's Mt Wilson is around 5100 feet, and the LA basin is from 0 to about 600 feet.

Wow... with a HAAT that high, would it be possible for their "local-grade" coverage (on a 50kW or a 100kW) to extend farther than the distance at which a DXer with a beverage antenna could still detect a signal from a 50kW on 540 kHz with a 1/2-wave antenna over a saltwater path?

Also, speaking of coverage, assuming constant ground conductivity and equal local noise levels (just to make it simpler), how much farther does an AM station's coverage extend beyond the contour at which most non-DXers listen (you've mentioned 10-15mV/m in L.A.) before a DXer would have difficulty ID'ing the signal, assuming he's using the same radio and antenna as the non-DXer?

 

[radioman148]

Of course, if you're looking for signal reach, the number you would want is HAAT (height above average terrain (sp?)) where most western stations use a nearby mountain. The most extreme I know is Albuquerque where you have 80 ft. towers on top of Sandia Crest overlooking the city at more than 4100 ft. (Now, THAT's a tower.) ;D

Any others more extreme than that? (even outside USA)

HCTM1, the first FM in Northern South America (95.1, air date 1966) was relocated after about two years on the air to a site up the Pichincha mountain, at about 13,500 feet above sea level and about 4,000 feet above Quito, its city of license. We built everything... tower, antenna, transmitter, stereo generator, STL, locally in our shop.

LA's Mt Wilson is around 5100 feet, and the LA basin is from 0 to about 600 feet.

Wow... with a HAAT that high, would it be possible for their "local-grade" coverage (on a 50kW or a 100kW) to extend farther than the distance at which a DXer with a beverage antenna could still detect a signal from a 50kW on 540 kHz with a 1/2-wave antenna over a saltwater path?

Also, speaking of coverage, assuming constant ground conductivity and equal local noise levels (just to make it simpler), how much farther does an AM station's coverage extend beyond the contour at which most non-DXers listen (you've mentioned 10-15mV/m in L.A.) before a DXer would have difficulty ID'ing the signal, assuming he's using the same radio and antenna as the non-DXer?

How well do you receive KRTH in San Diego? They are on Mount Wilson & run 51KW.
Radio Locator has their HAAT at 3,100 ft.

 

[stormy01]

HCTM1, the first FM in Northern South America (95.1, air date 1966) was relocated after about two years on the air to a site up the Pichincha mountain, at about 13,500 feet above sea level and about 4,000 feet above Quito, its city of license. We built everything... tower, antenna, transmitter, stereo generator, STL, locally in our shop.

LA's Mt Wilson is around 5100 feet, and the LA basin is from 0 to about 600 feet.

It would be interesting to know how electric service was connected to that high of a transmitter site, the transmitter power output, the effective radiated power of the antenna system and the radius of the signal!

 

[pianoplayer88key]

Of course, if you're looking for signal reach, the number you would want is HAAT (height above average terrain (sp?)) where most western stations use a nearby mountain. The most extreme I know is Albuquerque where you have 80 ft. towers on top of Sandia Crest overlooking the city at more than 4100 ft. (Now, THAT's a tower.) ;D

Any others more extreme than that? (even outside USA)

HCTM1, the first FM in Northern South America (95.1, air date 1966) was relocated after about two years on the air to a site up the Pichincha mountain, at about 13,500 feet above sea level and about 4,000 feet above Quito, its city of license. We built everything... tower, antenna, transmitter, stereo generator, STL, locally in our shop.

LA's Mt Wilson is around 5100 feet, and the LA basin is from 0 to about 600 feet.

Wow... with a HAAT that high, would it be possible for their "local-grade" coverage (on a 50kW or a 100kW) to extend farther than the distance at which a DXer with a beverage antenna could still detect a signal from a 50kW on 540 kHz with a 1/2-wave antenna over a saltwater path?

Also, speaking of coverage, assuming constant ground conductivity and equal local noise levels (just to make it simpler), how much farther does an AM station's coverage extend beyond the contour at which most non-DXers listen (you've mentioned 10-15mV/m in L.A.) before a DXer would have difficulty ID'ing the signal, assuming he's using the same radio and antenna as the non-DXer?

How well do you receive KRTH in San Diego? They are on Mount Wilson & run 51KW.
Radio Locator has their HAAT at 3,100 ft.

I'm on the wrong side of a hill (500-ft elevation, 3/4 mi NW of me is 900-ft peak), so their signal isn't as good here as it is in other areas of the county. It can be heard, but rarely if ever trips the stereo on my PL-606.

 

[davideduardo]

HCTM1, the first FM in Northern South America (95.1, air date 1966) was relocated after about two years on the air to a site up the Pichincha mountain, at about 13,500 feet above sea level and about 4,000 feet above Quito, its city of license. We built everything... tower, antenna, transmitter, stereo generator, STL, locally in our shop.

LA's Mt Wilson is around 5100 feet, and the LA basin is from 0 to about 600 feet.

It would be interesting to know how electric service was connected to that high of a transmitter site, the transmitter power output, the effective radiated power of the antenna system and the radius of the signal!

I got electrical power from HCJB TV, which had strung lines up the mountain several years before and they had also built the "road," which was a classic zig-zag on a mountain face, with 9 turnabouts. ERP was around 1 kw, and it could be heard well from Tulcán to Ambato where there were no obstructions. Since there was nothing else on the band outside Quito for over a thousand miles (except a few STLs in Colombia with 10 watts), there were no interfering stations. Polarization was vertical only, and the antenna used hand-cranked mechanical beam tilt.

By 1969, this station was #2 in the sales demo (meaning upper income level, not age range).

 

[davideduardo]

Wow... with a HAAT that high, would it be possible for their "local-grade" coverage (on a 50kW or a 100kW) to extend farther than the distance at which a DXer with a beverage antenna could still detect a signal from a 50kW on 540 kHz with a 1/2-wave antenna over a saltwater path?

That was not HAAT, that was altitude. The market averaged around 10,000 feet altitude, and the backside of the mountain was even higher than 13,500 feet, so no coverage to the west. Going more than 50 to 60 miles east dropped you to the jungle, with no significant population, so that was useless. Most other population was along the Andean corridor to the north and south. All areas were between 8000 and 12000 feet above sea level, and very mountainous.

We limited to 1 kw power as higher levels produced wicked multipath, even with pure vertical polarization. Nobody built a transmitter or fans or other components rated above about 7,500 feet at the time so everything was built locally, and parts were carried in assemblies to the site in a Land Rover. At the time in the US most FMs were not profitable or were minimally so, meaning that there was not a lot of research done on things like high altitude at that time.

 

[cyberdad]

How well do you receive KRTH in San Diego? They are on Mount Wilson & run 51KW.
Radio Locator has their HAAT at 3,100 ft.

I can tell you from my business trips there, that the San Diego terrain causes a number of dead spots. But for the most part, KRTH is very listenable in much of San Diego and points north on a good car radio. Most of my customers were situated essentially in a corridor from La Jolla to Carlsbad. I'd regularly have KRTH on in the car radio. No problems to speak of.

 

[radioman148]

How well do you receive KRTH in San Diego? They are on Mount Wilson & run 51KW.
Radio Locator has their HAAT at 3,100 ft.

I can tell you from my business trips there, that the San Diego terrain causes a number of dead spots. But for the most part, KRTH is very listenable in much of San Diego and points north on a good car radio. Most of my customers were situated essentially in a corridor from La Jolla to Carlsbad. I'd regularly have KRTH on in the car radio. No problems to speak of.

When I was in the Palm Springs area years ago I found that as you went east away from Mount San Jacinto, KRTH came in very well.
One time in the 80s I drove from LA to Phoenix & heard KRTH to about 50 miles west of Blythe.

 

[crainbebo]

If you're talking HAAT, KPQ-FM 102.1 Wenatchee, WA is also a state blaster. 35kw at 2,654 feet HAAT allows it to be heard from Northern Oregon (Blue Mountains area), Eastern and parts of Western Washington minus KSWW 102.1 on the coast, and even some parts of BC. I heard many years ago (in the 80s) they had 100kw at 2,654 feet and could be heard to W Montana. I can get KPQ here in spots sometimes little static at 90 miles.

-crainbebo

 

[w9wi]

I heard many years ago (in the 80s) they had 100kw at 2,654 feet and could be heard to W Montana.

That wouldn't have been authorized -- the maximum permissible HAAT is 2,000'. Higher antennas require derating of power. Just how far I can't tell, because the FCC website redesign seems to have lost the "FMpower" program... I'd believe 35kw for an HAAT of 2,654'.

 

[davideduardo]

That wouldn't have been authorized -- the maximum permissible HAAT is 2,000'. Higher antennas require derating of power. Just how far I can't tell, because the FCC website redesign seems to have lost the "FMpower" program... I'd believe 35kw for an HAAT of 2,654'.

This late 60's grant is not old enough to have been grandfathered, so the talk of 100 kw would just be inaccurate.

 

[w9wi]

Found the "FM Curves" program. The answer is 48 kilowatts -- the maximum power permissible for a HAAT of 2,654'.

As David says, if it had been authorized before the current rules structure went into effect in 1964, higher power might have been possible.

 

[OKCRadioGuy]

Here's one that's REALLY up there at a full 100kw: http://www.radio-locator.com/info/KISZ-FM

 

[w9wi]

Here's one that's REALLY up there at a full 100kw: http://www.radio-locator.com/info/KISZ-FM

KISZ is a wimp(grin). Seriously, 399m height above average terrain really isn't all that exceptionally high, there are a fair number of stations operating at the maximum of 600m.

The height above sea level is way up there though!

If the area was flat, that height above sea level would be pretty meaningless. Having your antenna 10,184' ASL doesn't do much for coverage if you're on a 9,700-foot plain. A station on the Gulf Coast with antenna 1,000' above sea level would cover better.

Of course, southwest Colorado isn't exactly flat! At that point height above average terrain ceases to be quite as good a predictor of coverage. With the limited computer power available in 1964, there really wasn't any better way of regulating things.

I believe probably the biggest station, in terms of overall curves-predicted coverage, is KVYB 103.3 Santa Barbara. It was authorized before the 1964 rules, for 105,000 watts at 908m HAAT. That delivers a predicted interference-protected 60dBu radius of 104 kilometers. Under the post-1964 rules, a station with antenna that high would be limited to 6,700 watts and an interference-protected radius of 73km.

In practice I would imagine a 100kw-600m station near Des Moines would cover a lot more inhabitable land and a fairly larger number of people.

The highest antenna (HAAT) in the FCC FM database is KKUA-90.7 Wailuku, Hawaii at 1,685m HAAT. Nearly all of that is terrain - the tower is only 15m (about 50') tall. The next highest antenna is a translator in Utah at 1,661m, then KKRB-106.9 Klamath Falls, Oregon at 1,536m. (and a 31m - 100' - tower) After that you find the numerous transmitters serving Albuquerque from Sandia Crest.

 

[crainbebo]

That wouldn't have been authorized -- the maximum permissible HAAT is 2,000'. Higher antennas require derating of power. Just how far I can't tell, because the FCC website redesign seems to have lost the "FMpower" program... I'd believe 35kw for an HAAT of 2,654'.

This late 60's grant is not old enough to have been grandfathered, so the talk of 100 kw would just be inaccurate.

Hmm...maybe I was wrong. But it did have 100kiw however. I think the 2,654 feet is on top of one of the Cascade mountains, but I'm not 100% sure.

-crainbebo

 

[jd]

Sorry to disappoint, but it looks like KPQ-FM has been 35kW at their current height since they signed on in 1967. In fact, a check of FCC records reveals that the KPQ-FM file is quite boring, consisting mainly of renewals, with no applications for power or HAAT changes.

 

[davideduardo]

Sorry to disappoint, but it looks like KPQ-FM has been 35kW at their current height since they signed on in 1967. In fact, a check of FCC records reveals that the KPQ-FM file is quite boring, consisting mainly of renewals, with no applications for power or HAAT changes.

This sounds like some promotional material that said "The equivalent of" in small letters and "100,000 watts" in much bigger ones. Some of us recall when the FCC would intervene if a station exaggerated coverage or power... and when gas was two bits a gallon.

 

[w9wi]

Hmm...maybe I was wrong. But it did have 100kiw however. I think the 2,654 feet is on top of one of the Cascade mountains, but I'm not 100% sure.

Most likely, David is right -- "The equivalent of" appeared in small print.

Either that, or it was 2,654' above sea level and quite a bit less above average terrain.

 

[radiorob2.0]

Since the topic has moved this direction, let me add a representation from east of the Mississippi. WHOM Mt. Washington, New Hampshire is famous for its coverage, but let's not forget about WMIT Black Mountain, North Carolina. Their transmitter location is atop of Mt. Mitchell. The height above sea level is 6745 feet and operates at 36,000 watts. WMIT has an interesting history documented here along with other high power FM stations: http://jeff560.tripod.com/fm-max.html