1570 AM Power Question

[davideduardo]

I guess I was putting together a couple of transmitter accounts from disparate sources. John Price's famous "Superpowers and Borderblasters" piece in RP&P back in '79 stated that XERF had installed "a 250kw RCA Ampliphase, reportedly never at full power" during the station's heydays in the 60s.

The RCA, I confirmed with the manager in that decade, was installed in mid to late '61 per his recollection... he said it took nearly a year to install due to the fact that the building was constructed prior to that time with all walls being load bearing, so they had to put in beams to make a big room out of smaller areas, without distrurbing the old transmitter. He does say that it was pretty much always on full power. Adjustments allowed it to go over 250 kw and under by about 10% or so, but if they could not run the RCA, they ran the older rig which was about 150 kw as he recalls.

The ross-revenge/uk site lists an Ampliphase chronology including a listing of a 250kw unit for XERF, delivered somewhere around 1960, which did not have a model number, which was certainly very unusual for RCA. There is also a catalog page showing a beefed up BTA-50H, designated a BTH-100, which was a standard broadcast-band RCA Ampliphase with an additional PA cabinet to make 100kw. The 'BTH' nomenclature is the only departure from standard model designation for RCA which otherwise invariably assigned model numbers to its transmitters as '"BTA" for AM and "BTF" for FM rigs, as in "broadcast AM" and "broadcast FM." The ross-revenge site is very detailed and echoes accounts found elsewhere about ongoing problems with the high-power export Ampliphases:

The "H" was the standard letter for powers higher (H for High) than US limits. The 3 100 KW SW transmitters at HCJB which I saw in 1964 for the first time were all HF transmitters with an H in the series name.

"Very few of these 100Bs appear to have been made, possibly as few as 4 or 5 with the first three being shipped in 1961 to overseas customers and all seem to have been regarded as prototypes." The two accounts quoted, taken together, seem to indicate that the XERF unit was the only 250kw Ampliphase RCA ever built. (If someone reading this knows otherwise please PM me, since I'm kind of an Ampliphase history fan.)

RCA did not have much luck selling against the big high power folks outside the Western Hemisphere. I seem to recall that they sold MW 100's in Chile (1060) and Argentina (870 and 950) and a 250 in Brasilia (980 I think) as well as a couple of 100's in the later 60's in Mexico City, maybe 730 and 940. They did "sell" the three 100's for HF use to HCJB, pretty much at shipping cost, as they could not get them to work. HCJB did, and the deal was that RCA would receive the modification schematics and descriptions at no charge in exchange.

The high-power Ampliphase page on ross-revenge's site includes a photo of the BTH-100 in the transmitter gallery of the M/V Mebo with the caption stating the Ampliphase "was prone to overheating" and noting it was removed after relatively short service, then shipped to Libya.

It's funny that 100 kw is low power in Europe, Asia and Africa, while conisidered high power in the Americas. Still, in the 60's there were few 100 kw transmitters in the Americas, a couple each in Chile and Argentina, one megawatt that was first in CR and then in Venezuela, 500 kw TWR on Bonaire, 100 kw (old Nazi transmitter) in the Windward Islands (135 kw) and about 10 of 100, 150 or 250 kw in Mexico.

There were quite a few Amplifuzz 5's and 10's all over Latin America. They kept the good engineers employed, too.

 

[Savage]

Yeah, we had a pair of 5kw Ampliphases at WKTQ in Pittsburgh in the 70s. Yikes. The solid-state exciter was definitely an improvement over the tube version but the build quality of the rest of the transmitter was so cheapened compared with the 50G and 50H that the exciter upgrade was negated by the rest of the crappy box.

Thanks for this, David, very interesting.

Other American TX manufacturers didn't fare too well overseas either during this period. Barry Mishkind's old-gear site says Gates only sold three copies of its BC-50B, one to KXEL in Waterloo, IA, with the other two going to Mexican stations. I think one was XEG. The BC-50B was essentially a copy of the General Electric plate-modulated 50 of the late 1940s.

 

[davideduardo]

Yeah, we had a pair of 5kw Ampliphases at WKTQ in Pittsburgh in the 70s.

Was that because NBC had put them in prior to selling to Cece Heftel?

Other American TX manufacturers didn't fare too well overseas either during this period.

One of the problems was that the US manufacturers had, in this Hemisphere, no support or manuals in Spanish or Portuguese. In the TV arena, in the 60's and 70's when Latin American TV was expanding madly, NEC took almost all the transmitter business because they trained their staffs in Spanish and Portuguese and had manuals and such in those langauges. They even learned to label cable harnesses and panel nomenclatlure in Spanish or Portuguese.

Most engineers in Latin America did not speak English. They bought European or Japanese gear, as the sellers and the documentation was in Spanish. I was even offered Czech 60 and 120 kw transmitters in the late 60's... the Czech seller spoke decent Spanish, but was accompanied by an obvious Politburo character in the worst black suit I have ever, ever seen.

Barry Mishkind's old-gear site says Gates only sold three copies of its BC-50B, one to KXEL in Waterloo, IA, with the other two going to Mexican stations. I think one was XEG.

XEG was 150 kw at night, 50 day, so this might be the day transmitter. The Quincy Tin Works was not making very pleasant equipment in the 60's, from the Cartritape machines to the transmitters. The guaranteed widowmaker Vanguard floor furnace was definitely the worst. Dangerous high voltage in a lousy tight and hot case... ugh.

The BC-50B was essentially a copy of the General Electric plate-modulated 50 of the late 1940s.

I saw lots of Westinghouse transmitters in Colombia and Venezuela. Some guy in their sales department did documents in Spanish, and he spoke Spanish... one company, Caracol, in Colombia put a half dozen of these on the air... I saw 3 of them, and they were really nice. Pictures of one at http://www.davidgleason.com/Colombia Photos.htm along with a nice view of a two tower directional with no phaser.... just equal electrical length feed lines and proper tower to tower spacing (I built one of those with a 5 kw on 660 in Ecuador to do N-S coverage up and down the Andean zone and to protect my co-channel in Guayaquil.

 

[Savage]

I believe so. The transmitter site had been relocated from the Banksville section west of the city proper, where new studios were located, and the old 2-tower site was sold to the Borough for a park - one of the freestanding towers was left standing for public service, fire and police paging.

The new site, also two towers DA-N, was located out in the eastern borough of Swissvale on land that was reclaimed near a steel plant - the "land" was actually a huge field consisting of slag with a thin veneer of topsoil. Slag, the waste product of steel smelting, has an electrical conductivity of ZERO. You can imagine how the ultra-load sensitive Amplifuzz transmitters liked that. As the slagsite dried out you could hear the bandwidth of the station tapering off. 13Q was of course 5kw on 1320; our main competitor, WTAE, also a 2-tower 5kw DA-N on 1250, sounded like a 50kw local while 13Q by comparison often sounded like it was coming on a skywave skip from Whatchacallistan. We used to joke that we needed a remote control position: channel 9 RAISE, "sprinklers on."

Both the cramped studio and transmitter sites were slapped together hastily by NBC to expedite sale of a "nice new facility" to Heftel, which we Nationwide types inherited. Everything was slapdash, obviously tossed together by NBC union techs who knew they were wiring themselves out of jobs. Sometime after I left in 1978 the transmitter site burned to the ground, taking the Amplifuzzes to perdition where they belonged. I had heard various stories that lightning, aluminum wiring or vandalism were causes. IIRC the site was rebuilt with dual Continentals.

 

[davideduardo]

Both the cramped studio and transmitter sites were slapped together hastily by NBC to expedite sale of a "nice new facility" to Heftel, which we Nationwide types inherited.

Nationwide... that's an operator I miss... if we are talking about the insurance folks from Columbus. The head of the radio division in 1963, Herbert Evans, was the one responsible for my ending up in Ecuador in 1964. Through his contacts, I found a school there and a family to live with. Amazingly, when I drove to Columbus to meet him, he took extra time to talk with a 16 year-old kid who was fascinated by radio; his offices were int he WRFD building, complete with a "huge" tower in the back.

 

[Savage]

Clark Pollock was the VP of radio when I was a Nationwide PD; I was actually hired by Dick Janssen for Pittsburgh. They were very nice people, but Nationwide was terrified at the time by an ongoing push to nationally unionize its insurance adjusters. The company was militantly anti-union. We had the good luck :to inherit the only union shop owned by the company - of course, being in Pittsburgh, 13Q was AFTRA and NABET. The pressure from Columbus was relentless. But I did like the people.

WRFD - didn't that eventually become the comapny's flagship WNCI?

 

[davideduardo]

WRFD - didn't that eventually become the comapny's flagship WNCI?

RFD was the 880 farm station... NCI at some point went CHR and with the grandfatherd signal pretty much owned the market for a while.

 

[schmave]

A bit off topic ... WNCI still is a huge player in the Columbus market. It's almost always up there with WTVN, at least ever since I can remember (past 15 years or so). That signal isn't as impressive as one might think for 175K, but it serves central Ohio well.

 

[radioguybroadcasting]

Wow, this was an interesting thread, thank you all, especially David Eduardo for the information!