The AM Forum
July 25, 2014, 07:02:05 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Vintage VOA article  (Read 3246 times)
0 Members and 1 Guest are viewing this topic.
W7TFO
WTF-OVER in 7 land Dennis
Contributing
Member
*
Offline Offline

Posts: 1812


IN A TRIODE NO ONE CAN HEAR YOU SCREEN


WWW
« on: February 27, 2011, 12:45:51 PM »

Another broadcast engineer type friend of mine, Barry Mishkind down in Tucson, does a blog called the BDR.

Here is a link to a story about VOA Bethany (Mason, Ohio).

Now there is an AM ham shack!

http://www.thebdr.net/articles/prof/history/HPH-VOA.pdf

73DG
Logged

Wind is as the air, only pushier...
W2XR
Contributing
Member
*
Offline Offline

Posts: 861



« Reply #1 on: February 27, 2011, 01:18:59 PM »

Thanks for sharing a great story and photos of the early days of the Bethany, OH VOA transmitter site.

Particularly interesting was the fact that several of the early rigs were designed and built in-house during the war years by the WLW engineering staff.

I had forgotten about the deliberately slow vocal delivery and limited vocabulary (1500 words) the VOA announcers had to comply with for those broadcasts in English that were intended for transmission to foreign countrys.

73,

Bruce
Logged

Real transmitters are homebrewed with a ratchet wrench, and you have to stand up to tune them!

Arthur C. Clarke's Third Law: "Any sufficiently advanced technology is indistinguishable from magic".
k4kyv
Contributing Member
Don
Member
*
Offline Offline

Posts: 10065



« Reply #2 on: February 27, 2011, 02:01:09 PM »

That was known as "Special English".  They also broadcast in regular English. I always found it fascinating to listen to the foreign language broadcasts, and hear them announce what language it was. I was soon able to readily identify several languages, even if I couldn't understand a word.

I recall listening to the VOA transmissions when they identified the transmitters by call letters.  Some of the ones I remember included WLWO, Cincinnati, KCBR Delano CA, KGEI somewhere in CA, WRUL in Scituate MA, WBOU Bound Brook, NJ. There was one in Dixon, CA, but I don't recall if that was KGEI.

Most if not all these transmitters were leased from private owners, and for a while, they would announce the company that operated the transmitter.  Example: "This is Voice of America station WLWO, operated by the Crosly Broadcasting Company"

WRUL was operated by General Electric, and also broadcast as the "World Wide Broadcasting Company" when not in use by VOA, calling itself Radio Boston.

By the time the big VOA facility in NC was built by the government, the VOA had quit announcing the call letters of its transmitters.
Logged

Don, K4KYV                                       AMI#5
Licensed since 1959 and not happy to be back on AM...    Never got off AM in the first place.

- - -
This message was typed using the DVORAK keyboard layout.
http://www.mwbrooks.com/dvorak
K6JEK
Contributing
Member
*
Offline Offline

Posts: 1024


RF in the shack


« Reply #3 on: February 27, 2011, 02:19:46 PM »

"The high efficiency re-entrant rhombic antennas were developed to eliminate the problem of dissipating up to 50% or 100kw of transmitter power in the antenna termination. This was accomplished by proper control of the phasing and impedance matching of the return power and recirculating it back into the antenna input. A typical high efficiency re-entrant rhombic antenna would have 200 kW input, 275 kW of circulating power and 200 kW radiated toward the target area."

I had not heard of this not that I have space for a rhombic.  I can't say I understand it either.  I know the maritime station out here, KPH, used stacked rhombics.   I wonder it that had the same effect.
Logged
W7TFO
WTF-OVER in 7 land Dennis
Contributing
Member
*
Offline Offline

Posts: 1812


IN A TRIODE NO ONE CAN HEAR YOU SCREEN


WWW
« Reply #4 on: February 27, 2011, 02:25:48 PM »

KB1SG has it nailed down:

http://www.mapability.com/ei8ic/rhombic/text.php

Last paragraph.

All we need now is a whole lotta' land and our own substation!

73DG
Logged

Wind is as the air, only pushier...
W2XR
Contributing
Member
*
Offline Offline

Posts: 861



« Reply #5 on: February 27, 2011, 02:26:14 PM »


Most if not all these transmitters were leased from private owners, and for a while, they would announce the company that operated the transmitter.  Example: "This is Voice of America station WLWO, operated by the Crosly Broadcasting Company"

WRUL was operated by General Electric, and also broadcast as the "World Wide Broadcasting Company" when not in use by VOA, calling itself Radio Boston.

By the time the big VOA facility in NC was built by the government, the VOA had quit announcing the call letters of its transmitters.

In the late 1940s and through the 1960s, CBS leased transmitter time from the Mackay Radio (also known as ITT World Communications) WSL transmitting site in Brentwood, NY, for what I recall were VOA broadcasts to South America and to Europe. If I further recall correctly, and this was told to me by the late Chief Engineer of the facility, Lee Hoffman, the plate modulated transmitter was built by Federal Electric of Newark, NJ and ran 50 KW output. The antenna was an enormous Sterba curtain, suspended between a pair of 450-foot tall steel lattice towers, and was located directly adjacent to the Long Island Expressway. I think they used a Rhombic for transmission to South America. The Federal Electric transmitter and the Sterba curtain and it's supporting structure were removed at some point in the very early 1970s.

Sadly, the entire 1100 acre WSL Brentwood transmitting site was sold off incrementaly beginning in the early 1970s and through the mid-1980s for real estate development. No roadside marker or placard marks the significance or location of the former WSL facility.

73,

Bruce
Logged

Real transmitters are homebrewed with a ratchet wrench, and you have to stand up to tune them!

Arthur C. Clarke's Third Law: "Any sufficiently advanced technology is indistinguishable from magic".
KE5YTV
Contributing
Member
*
Offline Offline

Posts: 209



« Reply #6 on: February 27, 2011, 02:44:46 PM »

Thanks for the post. I love the history lessons that show up here from time to time.

Mike
Logged

Mike
KE5YTV  Dallas, TX
"The longest trip begins with a stop at the ATM."
k4kyv
Contributing Member
Don
Member
*
Offline Offline

Posts: 10065



« Reply #7 on: February 27, 2011, 05:34:04 PM »

"The high efficiency re-entrant rhombic antennas were developed to eliminate the problem of dissipating up to 50% or 100kw of transmitter power in the antenna termination. This was accomplished by proper control of the phasing and impedance matching of the return power and recirculating it back into the antenna input. A typical high efficiency re-entrant rhombic antenna would have 200 kW input, 275 kW of circulating power and 200 kW radiated toward the target area."

I had not heard of this not that I have space for a rhombic.  I can't say I understand it either.  I know the maritime station out here, KPH, used stacked rhombics.   I wonder it that had the same effect.


Basically, instead of burning up half the power in a terminating resistor, the rf is recycled back to the antenna, while the input gate to the network is designed to look like a non-reactive load of the proper resistance, so the rhombic sees the network as a terminating resistor, but instead of converting the rf to heat, the network feeds the otherwise wasted power back into the input to the antenna.  Kind of like reflected power being resubmitted to the antenna and bounced back over and over again until it is all dissipated in the radiation resistance.
Logged

Don, K4KYV                                       AMI#5
Licensed since 1959 and not happy to be back on AM...    Never got off AM in the first place.

- - -
This message was typed using the DVORAK keyboard layout.
http://www.mwbrooks.com/dvorak
Steve - K4HX
Guest
« Reply #8 on: February 27, 2011, 06:34:19 PM »

You would do far better with an LPDA or stacked LPDAs and use far less space.


KB1SG has it nailed down:

http://www.mapability.com/ei8ic/rhombic/text.php

Last paragraph.

All we need now is a whole lotta' land and our own substation!

73DG
Logged
K6JEK
Contributing
Member
*
Offline Offline

Posts: 1024


RF in the shack


« Reply #9 on: February 27, 2011, 06:36:59 PM »

"The high efficiency re-entrant rhombic antennas were developed to eliminate the problem of dissipating up to 50% or 100kw of transmitter power in the antenna termination. This was accomplished by proper control of the phasing and impedance matching of the return power and recirculating it back into the antenna input. A typical high efficiency re-entrant rhombic antenna would have 200 kW input, 275 kW of circulating power and 200 kW radiated toward the target area."

I had not heard of this not that I have space for a rhombic.  I can't say I understand it either.  I know the maritime station out here, KPH, used stacked rhombics.   I wonder it that had the same effect.


Basically, instead of burning up half the power in a terminating resistor, the rf is recycled back to the antenna, while the input gate to the network is designed to look like a non-reactive load of the proper resistance, so the rhombic sees the network as a terminating resistor, but instead of converting the rf to heat, the network feeds the otherwise wasted power back into the input to the antenna.  Kind of like reflected power being resubmitted to the antenna and bounced back over and over again until it is all dissipated in the radiation resistance.
Thanks, Don. Googling away led me to W8JI's description of his curtain, similar to those used at VOA and Radio Free Europe.  The curtain now outranks rhombics on my fantasy antenna list.  However, the size and complexity of this antenna are daunting.

http://www.w8ji.com/curtain%20sterba%20USIA%20array.htm
Logged
k4kyv
Contributing Member
Don
Member
*
Offline Offline

Posts: 10065



« Reply #10 on: February 27, 2011, 06:51:51 PM »

I remember back in the 1950s a magazine (Radio and Electronics?) had a DIY antenna project for fringe area TV reception, using a rhombic using doorbell wire stapled to the joists in the loft, pointed towards the distant station.  They said it was superior to a conventional rooftop job, and small enough to fit into the attic of a typical suburban cracker box of that era.
Logged

Don, K4KYV                                       AMI#5
Licensed since 1959 and not happy to be back on AM...    Never got off AM in the first place.

- - -
This message was typed using the DVORAK keyboard layout.
http://www.mwbrooks.com/dvorak
KB5MD
Contributing
Member
*
Offline Offline

Posts: 411


« Reply #11 on: February 27, 2011, 06:59:35 PM »

I'll never forget the time I was driving to the Dayton Hamfest and came upon the VOA site at Bethany.  Being the country boy from south Arkansas, I had never seen anything like that.  I didn't realize it was VOA but knew that someone had one hell-of-an antenna system in that pasture.  Someone at Dayton informed me that it was VOA. Grin Grin
Logged
W1ATR
Resident HVAC junkie
Member

Offline Offline

Posts: 1134


« Reply #12 on: February 27, 2011, 07:41:37 PM »

Here's a good video I enjoyed on youtoob covering the history of voa as well.

http://www.youtube.com/watch?v=icrr6lZBMuQ
Logged

Don't start nuthin, there won't be nuthin.

Jared W1ATR


Click for radio pix
WA2AJM/3
Member

Offline Offline

Posts: 177


« Reply #13 on: February 27, 2011, 10:00:49 PM »

By the time the big VOA facility in NC was built by the government, the VOA had quit announcing the call letters of its transmitters.

VOA facilities owned by VOA itself don't fall under FCC jurisdiction, the NTIA has jurisdiction.  The VOA facility in Greenville was built as three facilities.  The only one that's operating now is Greenville-B. The tx site called Greenville-A was mothballed a few years ago, and the rx site called Greenville-C was sold off to a university somewhere in the south. The remaining Greenville-B facility is on the list for closure next year. I believe Dixon is in mothballs too, and has not been dismantled because of political pressure.

Our firm does some consulting work with VOA, and I know they have been reevaluating how they review their transmitting stations for closure. They are long down the road of de-emphasizing shortwave, but they admit they made some stupid mistakes in closing stations.  Whatever becomes of Greenville and Dixon, the longer range plans call for outsourcing of all HF transmission needs (when practical) with VOA programs passing through private or leased foreign gov't owned facilities.

73, Jim
WA2AJM/3
Logged
k4kyv
Contributing Member
Don
Member
*
Offline Offline

Posts: 10065



« Reply #14 on: February 27, 2011, 11:01:46 PM »

I'll never forget the time I was driving to the Dayton Hamfest and came upon the VOA site at Bethany.  Being the country boy from south Arkansas, I had never seen anything like that.  I didn't realize it was VOA but knew that someone had one hell-of-an antenna system in that pasture.  Someone at Dayton informed me that it was VOA. Grin Grin

If you had looked across the field you would have seen WLW's diamond-shaped Blaw-Knox tower off in the distance. Last time I passed by there I couldn't see it.  Not sure if trees or new building construction on the old VOA site have blocked the view. I was driving and maybe just couldn't keep my eyes off the road long enough to spot it.
Logged

Don, K4KYV                                       AMI#5
Licensed since 1959 and not happy to be back on AM...    Never got off AM in the first place.

- - -
This message was typed using the DVORAK keyboard layout.
http://www.mwbrooks.com/dvorak
W8EJO
Member

Offline Offline

Posts: 461



« Reply #15 on: February 28, 2011, 09:20:11 AM »

If you had looked across the field you would have seen WLW's diamond-shaped Blaw-Knox tower off in the distance. Last time I passed by there I couldn't see it.  Not sure if trees or new building construction on the old VOA site have blocked the view. I was driving and maybe just couldn't keep my eyes off the road long enough to spot it.

The WLW tower is still there.

I lived about 3 miles from the old VOA site from 1990 - 2002. The VOA land was pretty much vacant back then accept for the massive arrays, a few softball & soccer fields & two large ponds. It was about a square mile of land. There were several paths that ran throughout the property & we locals would use it to walk our dogs, jog etc. There was a model airplane club that met there on the weekends. When they shut down the VOA they auctioned off all of the towers that were used to support the arrays.

Now the area looks like any other suburban shopping district. They did keep a city park on the North end of the property.

 
Logged

Terry, W8EJO

Freedom and liberty - extremist ideas since 1776.
I remember when this was a free country.
Todd, KA1KAQ
Administrator
Member

Offline Offline

Posts: 3768


AMbassador


« Reply #16 on: February 28, 2011, 10:01:52 AM »

Great article, Dennis. TNX for sharing. Great info and great photos. It always amazes me the lengths they went to to build and finish even a transmitter building. First rate, all the way.
Logged

known as The Voice of Vermont in a previous life
AB3L
Contributing
Member
*
Offline Offline

Posts: 427



« Reply #17 on: February 28, 2011, 10:41:46 AM »

Thanks for the two links. I'll make sure my 16 year old history buff looks at this tonight. Gave me a twang of American pride watching this.
Here is a link for the VOA site. Must have been high noon when they did the satellite shot, I can't see any long shadows from the Blaw-Knox




http://maps.google.com/maps?f=q&source=s_q&hl=en&q=VOA,&aq=&sll=39.356459,-84.356568&sspn=0.001713,0.003428&ie=UTF8&t=h&rq=1&ev=p&radius=0.11&split=1&hq=VOA,&hnear=&ll=39.355563,-84.356605&spn=0.001713,0.003428&z=18
Logged
k4kyv
Contributing Member
Don
Member
*
Offline Offline

Posts: 10065



« Reply #18 on: February 28, 2011, 04:18:51 PM »

The WLW tower is still there.

I lived about 3 miles from the old VOA site from 1990 - 2002. The VOA land was pretty much vacant back then accept for the massive arrays, a few softball & soccer fields & two large ponds. It was about a square mile of land. There were several paths that ran throughout the property & we locals would use it to walk our dogs, jog etc. There was a model airplane club that met there on the weekends. When they shut down the VOA they auctioned off all of the towers that were used to support the arrays.

I know the WLW tower is still there, but not sure if there is still a clear view of it from I-75. I remember seeing it a couple of years ago, but couldn't spot it on the way to Dayton  last year.

I wonder if any of the bid winners of the VOA towers actually salvaged any of them, or if they just cut the guy wires and let them fall, to be sold as scrap.  I doubt anyone would have gone to the expense of carefully disassembling the tall towers that held up the curtain arrays, but there were many shorter towers looked to be 100' to maybe 300' tall, and some of those would have been worth dismantling and re-using.  Some nice 160m vertical material there. Plus, there was all the guy wire, feed-lines, hardware and insulators that would have been re-usable if carefully taken down from the site.
Logged

Don, K4KYV                                       AMI#5
Licensed since 1959 and not happy to be back on AM...    Never got off AM in the first place.

- - -
This message was typed using the DVORAK keyboard layout.
http://www.mwbrooks.com/dvorak
W8EJO
Member

Offline Offline

Posts: 461



« Reply #19 on: February 28, 2011, 05:46:24 PM »

I wonder if any of the bid winners of the VOA towers actually salvaged any of them, or if they just cut the guy wires and let them fall, to be sold as scrap.  I doubt anyone would have gone to the expense of carefully disassembling the tall towers that held up the curtain arrays,

Agreed!


I thought about it (briefly) since I was so close but it would have been cost prohibitive. Most of them were mounted in massive concrete pods that were 4-5' high & must have weighed several tons each  The only practical way would have been to cut them down. You would have needed a massive block & tackle to prevent damage.  A few of the concrete pods remained on the site the last time I was out there. 
Logged

Terry, W8EJO

Freedom and liberty - extremist ideas since 1776.
I remember when this was a free country.
K9PNP
Member

Offline Offline

Posts: 368



« Reply #20 on: March 02, 2011, 01:41:00 PM »

Thanks for the interesting information. 

I remember when in high school years ago listening to VOA and Radio Moscow both on the S-85.  Then listening to the 'news' on broadcast radio and TV.  Figured out if I added up the info from VOA and RM and divided by 2 I had a reasonable idea of what was really going on in the world.  IIRC, some of the comrades on RM spoke better English than VOA staff did.  Now I know why, with the 'Special English' info.
Logged

73,  Mitch

Since 1958. There still is nothing like tubes to keep your coffee warm in the shack.

Vulcan Theory of Troubleshooting:  Once you have eliminated the impossible, whatever remains, however improbable, must be the truth.
WA3VJB
Contributing
Member
*
Offline Offline

Posts: 1878



« Reply #21 on: March 02, 2011, 01:50:36 PM »

I used to work a guy who was among the former engineers at the Bethany, Ohio VOA site.  Bill, WA8LXJ. Been about ten years now since I've heard him on. But he had a lot of great stories from working there.

About 20 years ago, somehow he obtained as "junk" one of the VOA site's point-to-point transmitters, a Collins 231D used as an "interagency transmitter." 

Described it as a 3-cabinet rig, and 3-30Mc autotune, wow.
(see page 74 of the 1952 Handbook for a picture)

The card I have on him shows a pair of 450TL modulating a pair of 750TL, and he got it out of there and rebuilt it. I worked him on 80M with the thing and it sounded excellent. I also show a pair of 833A modulating a pair of 450TL, so he may have moved things around a little as part of dropping it from 3-phase to single for home use.
Logged

--Paul/VJB
W7TFO
WTF-OVER in 7 land Dennis
Contributing
Member
*
Offline Offline

Posts: 1812


IN A TRIODE NO ONE CAN HEAR YOU SCREEN


WWW
« Reply #22 on: March 02, 2011, 04:25:28 PM »

Great article, Dennis. TNX for sharing. Great info and great photos. It always amazes me the lengths they went to to build and finish even a transmitter building. First rate, all the way.

Indeed.  A gent named Lou Hardenberg lived across the road from me, and worked for Western Electric as a broadcast installer for several years.  He said the usual job took a year, and they would set up living apartments if far from home.  Sadly he passed last year at 84.

73DG
Logged

Wind is as the air, only pushier...
flintstone mop
Contributing
Member
*
Offline Offline

Posts: 4418


« Reply #23 on: March 03, 2011, 05:29:39 AM »

I think I would have been overwhelmed with excitement to be part of projects like that. Knowing that once it was on the air, the USA had a powerful voice in the problems of the world at that time.
It was that unmistakeably DO attitude of the USA to build these outrageous transmitting sites.
There was a vid on Youtube on the sign off of Bethany.
Fred
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone 2001-2014
Powered by SMF 1.1.19 | SMF © 2013, Simple Machines
Page created in 0.312 seconds with 18 queries.