WSM Blaw-Knox tower

[W7TFO]

Maybe this will assure it standing a long time.

http://www.tennessean.com/article/20110414/NEWS/304140038/-1/MICRO0207/WSM-tower-selected-National-Register-Historic-Places

73DG

[Steve - K4HX]

Nice. I hope they do the same for WBT - they have three.

[k4kyv]

Here's more. But I doubt that it is true that the tower is "really two self-supporters stacked to create a very tall vertical antenna". As explained in the text below, the top section and bottom sections differ considerably. The transition at the 680' level is clearly visible in the photos, in the middle of the highest white segment. Notice that the taper changes, as does the pitch of the diagonal cross members.

Reportedly, when the WSM tower was built there were not any good roads leading to the site that would support heavy equipment, so it was hauled on location, a few pieces at a time, in mule-drawn wagons.

http://www.oldradio.com/archives/stations/ccs/wsmtwr.htm

[K5UJ]

Hugo knocked down two of BT's blaw knoxes; only one is "historic."

Hats off to WSM for continuing to broadcast music on AM and ignoring the IBOC nonsense, staying all analog.  you can checkout your rx audio quality with their signal.

In one corner of the tower is a staircase--it goes all the way to the top.  How cool is that but not for me, fear of heights here.

[W2PFY]

Hats off to WSM for continuing to broadcast music on AM and ignoring the IBOC nonsense

Up here in Albany, the Disney radio station stopped using IBOC.
I don't know if it broke or what?

Two others are still using it out of about 8 local AM stations. It never caught on big time in this area. WGY is  our 50KW talk station that used to talk it up but not any more. I wonder if the people at IBOC wanted all AM'er to use it or if it was an exclusive to a chosen few?  

I suppose it would only work on a digital transmitter, not an old iron modulated rig?

[KM1H]

This might piss a few off. Copied from another forum:

From the GE Super Radio III Yahoo Group: Bruce Carter wrote:

Very depressing - it would mean an end to DX as we know it, and
make all of our radios obsolete:

To the FCC, it's all going digital – everything. That's very clear in
remarks this week at the NAB in Las Vegas – the Commission sees
radio and TV headed all-digital, and leaving the analog world
forever. In the case of broadcast TV, now that it's digital, the next
move is re-packing the spectrum so the space can be auctioned off
for broadband. (That's probably a topic Chairman Genachowski will
dwell on, at this morning's Chairman's Breakfast.) As for radio, not
only does the FCC see it going all digital, so does influential group
head Dan Mason of CBS Radio. (It's worth recalling that he was
once a consultant to iBiquity.) Mason's not talking about just FM –
"Once digital takes over on AM, it completely cleans up the AM
band." But the slow pace of HD Radio conversions lately must
concern some of the group heads. They met yesterday for one of
their periodic gut-checks, and they must know the FCC statistics –
about 1,600 stations have applied for HD Radio broadcasting, most
of those in larger markets. Only about 225 have notified the
Commission they're taking advantage of the new option of raising
power by a fairly significant factor, four to six times current power
levels. That may be an indication of a tight economy and skimpy
cap-ex budgets, but still. Of course to CBS, Clear Channel,
Entercom and others, "digital" isn't just HD Radio – it's very much
online and mobile.

[K5UJ]

Sorry for the FUD but if FCC wants all mw bc stations to go 100% digital (assuming the motivation is to squeeze stations to get more spectrum) so they have something to auction off, then maybe ham radio is next?  if all analog is ever outlawed for hams it would mean the end of ham radio for me.   I might even have more interest in gardening than I have in digital s**t.

And digital signals where there is skywave just seems nothing more than assinine to me.  I wonder if this is more of the result of lawyers running the FCC.

[Steve - K4HX]

Mexico recently adopted the US HD standards.

[K2PG]

WADO in New York City also had a Blaw-Knox diamond-shaped tower at its transmitter site on Paterson Plank Road in Secaucus, NJ. It was used for nondirectional operation during the day, with a second, smaller tower added for directional operation at night. The transmitter power at the time was 5 kW at 1280 kHz.

That old tower was torn down a few years ago, when WADO increased daytime power to 50 kW and went to a four-tower parallelogram array. The site and old tower were originally used by WNEW when it went on the air in 1934 with 2.5 kW daytime and 1 kW nighttime at 1250 kHz. WNEW later swapped transmitter sites and frequencies with WOV on 1100 kHz. Both stations moved up 30 kHz during the AM broadcast band realignment in 1941.

WADO runs a news/talk format in Spanish. WNEW was sold, dropped its legendary standards and news format, and went to all-boring business news as WBBR. The WNEW site along the NJ Turnpike in Kearny (the old WOV site) was torn down and a new site was built in Carlstadt, NJ. It is still used by WBBR.

[K2PG]

Mexico recently adopted the US HD standards.

Given the legendary corruption in the Mexican government, I'm sure that iBiquity had an easy sell with the SCT in Mexico City. Now, if Cuba also adopts the U.S. "HD Radio" standard, they could get some dandy transmitters and "exporters" via third countries for the purpose of jamming those Miami stations that the Castro brothers don't want their people to hear. Around here, parts of the AM broadcast band sound like the 40 meter phone band at the height of the Cold War due to all the IBOC digital garbage spewed by WOR, WCBS, KYW, WIP, and other stations that bought the iBiquity snake oil. The digital hash reminds me of the Russian white noise jammers on 40 meters and of cicadas buzzing on a hot summer day.

HISSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS!

[K2PG]

Up here in Albany, the Disney radio station stopped using IBOC.
I don't know if it broke or what?

Two others are still using it out of about 8 local AM stations. It never caught on big time in this area. WGY is  our 50KW talk station that used to talk it up but not any more. I wonder if the people at IBOC wanted all AM'er to use it or if it was an exclusive to a chosen few?  

I suppose it would only work on a digital transmitter, not an old iron modulated rig?

The license fees charged by iBiquity for using their so-called "HD Radio" system are quite steep. In addition to charging equipment manufacturers patent royalty fees for incorporating their technology into transmitters and receivers, iBiquity charges broadcasters who want to put this crap on the air! If the inventors of FM stereo and NTSC color television followed that business model, we would still be listening to FM in mono and watching black and white TV. In addition to financial considerations, AM stations are limited by the bandwidth of their antenna systems and the transmitter must have low ICPM (incidental carrier phase modulation) and be able to pass a 30 kHz wide signal consisting of the regular AM analog carrier and sidebands, the phase modulated digital components near the center carrier, and the multiple OFDM carriers on either side of the analog sidebands. WHAT A MESS!

Reasons for stations to drop "HD Radio" include no added listenership, no added revenue from advertisers, and, for the FM version of "HD Radio", a whopping electric bill at the transmitter site due to poor transmitter efficiency.

[Bill, KD0HG]

BTW, it's been 50 years now since the standards for FM Stereo were put into the regulations. April 24, 1961.

On June 1, 1961 the first FM stereo broadcasts begin: WGFM Schenectady and 99.5 WEFM in Chicago. Owned by Zenith. Helped sell a few Zenith receivers, I'll bet.

[k4kyv]

The digital hash reminds me of the Russian white noise jammers on 40 meters and of cicadas buzzing on a hot summer day.

HISSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS!

Now that the USSR is long gone and broadcasters have supposedly vacated 7.1-7.2, the white noise jamming is coming from Ethiopia.  Reportedly, China furnished Ethiopia with four jamming transmitters to use to block broadcasts from Eritrea. The jamming usually begins at 0400 GMT until fade-out.  Eritrea broadcasts on multiple frequencies and frequency hops to dodge the jamming, so the noise is apt to appear at any time anywhere in the band.  The white-noise signal they use to block the 10 kc/s wide AM broadcast signal is anywhere from 20 to 30 kc/s wide, so it takes out a lot of spectrum off to the side. Sometimes, when they have all four transmitters going at once, the whole phone band below 7.2 is rendered useless.

The damaged Blaw-Knoxes from WBT were left partially standing.  Not sure if they re-built from ground up, or if they just repaired the damaged parts.  In any case, supposedly they still had all the blue prints from the originals, so the new ones should be exactly the same as the old ones, unless they took short cuts in the reconstruction.

I'd bet they paid several times more to re-construct those old towers than it would have cost to simply replace them with modern day cookie-cutter off-the-shelf, uniform cross section guyed towers. Insurance probably covered it.

[K2PG]

The damaged Blaw-Knoxes from WBT were left partially standing.  Not sure if they re-built from ground up, or if they just repaired the damaged parts.  In any case, supposedly they still had all the blue prints from the originals, so the new ones should be exactly the same as the old ones, unless they took short cuts in the reconstruction.

I'd bet they paid several times more to re-construct those old towers than it would have cost to simply replace them with modern day cookie-cutter off-the-shelf, uniform cross section guyed towers. Insurance probably covered it.

If they went to the modern towers, they would have had to do extensive (and expensive) engineering studies in order to redesign the array. A diamond-shaped tower has different radiation characteristics from those of a uniform cross-section tower.

[K2PG]

BTW, it's been 50 years now since the standards for FM Stereo were put into the regulations. April 24, 1961.

On June 1, 1961 the first FM stereo broadcasts begin: WGFM Schenectady and 99.5 WEFM in Chicago. Owned by Zenith. Helped sell a few Zenith receivers, I'll bet.

Don't forget WQXR-FM in New York City, WNTA-FM in Newark, NJ, and, possibly, KDKA-FM in Pittsburgh (the original one on 92.9, not the present-day KDKA-FM on 93.7).

WGFM was owned by General Electric, which had a hand in the design of the FM stereo system.

[k4kyv]

If they went to the modern towers, they would have had to do extensive (and expensive) engineering studies in order to redesign the array. A diamond-shaped tower has different radiation characteristics from those of a uniform cross-section tower.

Fortunate, for whatever reason, that some of the remaining few of those unique towers were preserved.

But they could have maintained the original radiation characteristics with uniform cross-section towers by installing outriggers on the towers, with wire cages that would have simulated the original shape of the towers.

[Steve - K4HX]

Or just built a new tuning unit.

If they went to the modern towers, they would have had to do extensive (and expensive) engineering studies in order to redesign the array. A diamond-shaped tower has different radiation characteristics from those of a uniform cross-section tower.

Fortunate, for whatever reason, that some of the remaining few of those unique towers were preserved.

But they could have maintained the original radiation characteristics with uniform cross-section towers by installing outriggers on the towers, with wire cages that would have simulated the original shape of the towers.

[k4kyv]

Probably wouldn't have satisfied the FeeCee's picky regulations, but in the real world, the different shape of the towers wouldn't have made any audible difference, in signal strength or in the nulls of the directional pattern.

[K5UJ]

The main difference with a wide tower is you get less change in Z over a frequency range.  To make it simple (for me, not for you) pretend you have a 90 degree tower and everything is nice on some frequency, such as 780 Khz.   36 ohms no reactance (bear with me on the fantasy component of the Z).  A fat tower, like one with a 10 or 12 foot face will get you not varying much from that up and down 10 or 20 KHz from 780.  A skinny tower, or worse, a wire, will be much more narrow.  I don't know if the BK diamonds deliver the fat advantage or not (the thing about them being fat to handle current at the halfway up point for 180 degrees is a myth) but the wide uniform towers do.   The stations that fired up IBOC with skinny towers would have their solid state transmitters trip off because the vswr would be higher than 1.2:1 at the edges of their signals out 15 KHz up and down from carrier.   A number of tx sites had to be reworked because of that.

I don't know how much truth there is to this but I once heard that the real old towers, i.e. pre WW2 had poorer quality steel because a lot was learned about steel on account of the war effort and that was put to use later on.  So a new tower would be more rugged supposedly.   

[flintstone mop]

Up here in Albany, the Disney radio station stopped using IBOC.
I don't know if it broke or what?

Two others are still using it out of about 8 local AM stations. It never caught on big time in this area. WGY is  our 50KW talk station that used to talk it up but not any more. I wonder if the people at IBOC wanted all AM'er to use it or if it was an exclusive to a chosen few?  

I suppose it would only work on a digital transmitter, not an old iron modulated rig?

The license fees charged by iBiquity for using their so-called "HD Radio" system are quite steep. In addition to charging equipment manufacturers patent royalty fees for incorporating their technology into transmitters and receivers, iBiquity charges broadcasters who want to put this crap on the air! If the inventors of FM stereo and NTSC color television followed that business model, we would still be listening to FM in mono and watching black and white TV. In addition to financial considerations, AM stations are limited by the bandwidth of their antenna systems and the transmitter must have low ICPM (incidental carrier phase modulation) and be able to pass a 30 kHz wide signal consisting of the regular AM analog carrier and sidebands, the phase modulated digital components near the center carrier, and the multiple OFDM carriers on either side of the analog sidebands. WHAT A MESS!

Reasons for stations to drop "HD Radio" include no added listenership, no added revenue from advertisers, and, for the FM version of "HD Radio", a whopping electric bill at the transmitter site due to poor transmitter efficiency.

Phil you took the words right our of keyboard........The fees charged by these guys are outrageous to an AM B'caster that's not making very much money. If the Am stations were playing music, this would be a fantastic jump in audio quality. The dropouts of the digital signal is much less than FM. FM's advantage is they can transmit two distinct stereo channels and it IS CD quality!!!
The technology may interfere with the nighttime reception of the analog signal, but the weak example of IBOC from the one AMer in my area is amazing. Too bad they changed the floormat to Sports-talk radio. It used to be a mixture of oldies, and an MOR type music.

Fred

[KM1H]

Charley seems to be less of a PITA these days. As long as the site maintains its initial performance report they dont care how its done. Rebuilds using elevated radials are allowed to reduce power as an example.

[K2PG]

Phil you took the words right our of keyboard........The fees charged by these guys are outrageous to an AM B'caster that's not making very much money. If the Am stations were playing music, this would be a fantastic jump in audio quality.

Not really. The AM stations that I have heard in IBOC digital sounded like a bad MP3 file, complete with a "watery" sound that was rather unpleasant to listen to.

[k4kyv]

I don't know how much truth there is to this but I once heard that the real old towers, i.e. pre WW2 had poorer quality steel because a lot was learned about steel on account of the war effort and that was put to use later on.  So a new tower would be more rugged supposedly.   

I read or heard somewhere that that's why most towers built in the 20s and 30s were 4-sided, and post-war towers are usually triangular. They were afraid that bending the old steel 120° to form the corners of the triangle would weaken it too much, so they bent it 90° and used 4-sided construction.