Topband: VOA
Jim
wa3mej at comcast.net
Mon Apr 11 14:20:58 EDT 2016
Some years ago I worked for a government EMC laboratory (ECAC) in Annapolis, MD. One of the problems we had to mitigate was over at the old Navy Transmitter site on Greenburry Point. They ran 1.5MW ERP and the antenna was installed on bedrock. Ground wave was Greenwich England. In any event the CO told us he was having a problem with RF getting into his lighting in the transmitter room. They had installed fluorescent lightening throughout the area in addition to incandescent bulbs. Well in typical Navy fashion they went through the ritual of darken ship whereby they turn all the white lights off and turn red lights on. Well they told me they had to spend an hour taking all the bulbs out of the lightening fixture for darken ship... well the didn't mind this but what really ticked them off was they had to put them in the closet because they still glowed and spoiled their nice red lights.
I spend some time chuckling under my breath with this. First because they were on land and still going to darken ship and secondly because they used the wrong kind of lightening in a transmitter facility but most of all because they had stacked all the flourescent bulbs in the closet
Jim WA3MEJ
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Today's Topics:
1. VOA Antennas (dick.bingham)
2. Re: VOA Antennas (Mike Waters)
3. Re: VOA Antennas (Chuck Hutton)
4. Re: VOA Antennas (GALE STEWARD)
5. Re: VOA Antennas (Mike Waters)
6. Re: VOA Antennas (Lloyd - N9LB)
7. Re: VOA Antennas (Mike Waters)
----------------------------------------------------------------------
Message: 1
Date: Sat, 9 Apr 2016 10:40:52 -0700
From: "dick.bingham" <dick.bingham at gmail.com>
To: "topband at contesting.com" <topband at contesting.com>
Subject: Topband: VOA Antennas
Message-ID: <5E4BEC94-49EC-4726-BDE5-E0CFB7BD3D61 at gmail.com>
Content-Type: text/plain; charset=us-ascii
What was the gain/beamwidth of these arrays ? The ERP must have been incredible given the high power transmitters used plus the antenna gain . Migratory Geese could have warmed themselves as they flew thru the region.
73 Dick/w7wkr CN97uj
---------------------------------------------------------------------------------------------
------------------------------
Message: 2
Date: Sat, 9 Apr 2016 14:00:55 -0500
From: Mike Waters <mikewate at gmail.com>
To: "dick.bingham" <dick.bingham at gmail.com>
Cc: "topband at contesting.com" <topband at contesting.com>
Subject: Re: Topband: VOA Antennas
Message-ID:
<CA+FxYXhcjXHCertrUkaaCe_P5h3vrYGh3N-Fh9zdtYcSRy_G1A at mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
The Sterba curtain at the old Bethany, Ohio VOA had 20 dB of gain. I saw it
up close during a ham club trip years ago.
Hams that worked there would sometimes drive out next to it at night, and
connect their mobile transceivers to it for a night of DX fun.
The RF field in front of that antenna was so intense that one could
sometimes hear the program audio emanate from tiny arcs in a low, rusty
barbed wire fence along the road in front of that huge Sterba.
That enormous antenna, fed with huge Collins and Crosley transmitters
re-defined the word "awesome". :-)
Across the road from that fence were a number of newer houses, BTW. Helps
prove that shortwave never hurt anyone, doesn't it?
73, Mike
www.w0btu.com
On Sat, Apr 9, 2016 at 12:40 PM, dick.bingham <dick.bingham at gmail.com>
wrote:
> What was the gain/beamwidth of these arrays ? The ERP must have been
> incredible given the high power transmitters used plus the antenna gain .
> Migratory Geese could have warmed themselves as they flew thru the region.
>
> 73 Dick/w7wkr CN97uj
>
------------------------------
Message: 3
Date: Sat, 9 Apr 2016 19:21:19 +0000
From: Chuck Hutton <charlesh3 at msn.com>
To: "topband at contesting.com" <topband at contesting.com>
Subject: Re: Topband: VOA Antennas
Message-ID:
<BY2PR1001MB1221788C9F44F24B2DBE696BFC920 at BY2PR1001MB1221.namprd10.prod.outlook.com>
Content-Type: text/plain; charset="iso-8859-1"
And for those that like to be closer to a lot of power while producing arcs:
https://www.youtube.com/watch?v=bNawh4faZM8
Chuck
________________________________________
From: Topband <topband-bounces at contesting.com> on behalf of Mike Waters <mikewate at gmail.com>
Sent: Saturday, April 9, 2016 7:00 PM
To: dick.bingham
Cc: topband at contesting.com
Subject: Re: Topband: VOA Antennas
The Sterba curtain at the old Bethany, Ohio VOA had 20 dB of gain. I saw it
up close during a ham club trip years ago.
Hams that worked there would sometimes drive out next to it at night, and
connect their mobile transceivers to it for a night of DX fun.
The RF field in front of that antenna was so intense that one could
sometimes hear the program audio emanate from tiny arcs in a low, rusty
barbed wire fence along the road in front of that huge Sterba.
That enormous antenna, fed with huge Collins and Crosley transmitters
re-defined the word "awesome". :-)
Across the road from that fence were a number of newer houses, BTW. Helps
prove that shortwave never hurt anyone, doesn't it?
73, Mike
www.w0btu.com
On Sat, Apr 9, 2016 at 12:40 PM, dick.bingham <dick.bingham at gmail.com>
wrote:
> What was the gain/beamwidth of these arrays ? The ERP must have been
> incredible given the high power transmitters used plus the antenna gain .
> Migratory Geese could have warmed themselves as they flew thru the region.
>
> 73 Dick/w7wkr CN97uj
>
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
------------------------------
Message: 4
Date: Sat, 9 Apr 2016 20:08:30 +0000 (UTC)
From: GALE STEWARD <k3nd at yahoo.com>
To: "topband at contesting.com" <topband at contesting.com>
Subject: Re: Topband: VOA Antennas
Message-ID:
<1369686021.669435.1460232510334.JavaMail.yahoo at mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8
WOW! That is wild! Not sure that I'd want to be standing that close...
Stew K3ND
From: Chuck Hutton <charlesh3 at msn.com>
To: "topband at contesting.com" <topband at contesting.com>
Sent: Saturday, April 9, 2016 3:21 PM
Subject: Re: Topband: VOA Antennas
And for those that like to be closer to a lot of power while producing arcs:
https://www.youtube.com/watch?v=bNawh4faZM8
Chuck
________________________________________
From: Topband <topband-bounces at contesting.com> on behalf of Mike Waters <mikewate at gmail.com>
Sent: Saturday, April 9, 2016 7:00 PM
To: dick.bingham
Cc: topband at contesting.com
Subject: Re: Topband: VOA Antennas
The Sterba curtain at the old Bethany, Ohio VOA had 20 dB of gain. I saw it
up close during a ham club trip years ago.
Hams that worked there would sometimes drive out next to it at night, and
connect their mobile transceivers to it for a night of DX fun.
The RF field in front of that antenna was so intense that one could
sometimes hear the program audio emanate from tiny arcs in a low, rusty
barbed wire fence along the road in front of that huge Sterba.
That enormous antenna, fed with huge Collins and Crosley transmitters
re-defined the word "awesome". :-)
Across the road from that fence were a number of newer houses, BTW. Helps
prove that shortwave never hurt anyone, doesn't it?
73, Mike
www.w0btu.com
On Sat, Apr 9, 2016 at 12:40 PM, dick.bingham <dick.bingham at gmail.com>
wrote:
> What was the gain/beamwidth of these arrays ? The ERP must have been
> incredible given the high power transmitters used plus the antenna gain .
> Migratory Geese could have warmed themselves as they flew thru the region.
>
> 73 Dick/w7wkr CN97uj
>
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
------------------------------
Message: 5
Date: Sat, 9 Apr 2016 15:27:15 -0500
From: Mike Waters <mikewate at gmail.com>
To: topband <topband at contesting.com>
Subject: Re: Topband: VOA Antennas
Message-ID:
<CA+FxYXjOODFLMyEBo2YTvBn0t0nL8y0L56Sop0nJAzuNpR4ZoA at mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
According to the VOA employee who was conducting the group tour, those hams
connected directly to the Sterba curtain. (My guess is that they used an
antenna tuner between the rig and the feedpoint.) They also used the many
Rhombic antennas on that site.
I forget exactly what he said about how well they did into Europe(?), but
one can imagine. Not only did they have 10,000 watts of ERP, but can you
imagined what they must have HEARD with that kind of gain in both
directions?! :-)
There's some more fun facts we learned on that fascinating tour, but I
don't have time to share them right now. Maybe later.
W8JI was also in our group. If he comes back here, he can share much more
that I can.
73, Mike
www.w0btu.com
Thanks for your 'reflections' about those arrays. Regarding the guys that
> drove out there at night to have some mobile fun, did they actually couple
> directly to the array or just get close enough to have their RF get coupled
> into and re-radiated ?
>
------------------------------
Message: 6
Date: Sat, 9 Apr 2016 15:50:33 -0500
From: "Lloyd - N9LB" <lloydberg at charter.net>
To: <topband at contesting.com>
Subject: Re: Topband: VOA Antennas
Message-ID: <000001d192a1$75fed540$61fc7fc0$@charter.net>
Content-Type: text/plain; charset="us-ascii"
I am a retired broadcast engineer. When we'd give tours at the transmitter
site in the evening, I'd hand out fluorescent light tubs to all attendees,
then we'd all walk out near the tower bases ( but definitely NOT touching
anything ). When we get to within a few feet of the towers, people would
freak out when the fluorescent tubes they were holding magically lit up in
their hands. Once lighted, you could walk quite a ways away from the tower
before they would extinguish. There was no sensation of heat or burning.
Of course the light would flicker a bit with modulation. Looked kind of
like the light-sabers from star wars.
BTW - I see the second comment on the u-tube video says: "hope you had kids
!! -- and insurance has leukemia coverage --". Experience and time have
shown that this is an unfounded fear for MW and HF. I've been around both
for close to 50 years and no cancer, and yes I have kids too. Our local
ham clubs have members who have been making RF since they were kids are now
well past the median life expectancy age. Obviously they have not been
adversely affected by RF.
I really like RF!
73
Lloyd - N9LB
-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Chuck
Hutton
Sent: Saturday, April 09, 2016 2:21 PM
To: topband at contesting.com
Subject: Re: Topband: VOA Antennas
And for those that like to be closer to a lot of power while producing arcs:
https://www.youtube.com/watch?v=bNawh4faZM8
Chuck
________________________________________
From: Topband <topband-bounces at contesting.com> on behalf of Mike Waters
<mikewate at gmail.com>
Sent: Saturday, April 9, 2016 7:00 PM
To: dick.bingham
Cc: topband at contesting.com
Subject: Re: Topband: VOA Antennas
The Sterba curtain at the old Bethany, Ohio VOA had 20 dB of gain. I saw it
up close during a ham club trip years ago.
Hams that worked there would sometimes drive out next to it at night, and
connect their mobile transceivers to it for a night of DX fun.
The RF field in front of that antenna was so intense that one could
sometimes hear the program audio emanate from tiny arcs in a low, rusty
barbed wire fence along the road in front of that huge Sterba.
That enormous antenna, fed with huge Collins and Crosley transmitters
re-defined the word "awesome". :-)
Across the road from that fence were a number of newer houses, BTW. Helps
prove that shortwave never hurt anyone, doesn't it?
73, Mike
www.w0btu.com
On Sat, Apr 9, 2016 at 12:40 PM, dick.bingham <dick.bingham at gmail.com>
wrote:
> What was the gain/beamwidth of these arrays ? The ERP must have been
> incredible given the high power transmitters used plus the antenna gain .
> Migratory Geese could have warmed themselves as they flew thru the region.
>
> 73 Dick/w7wkr CN97uj
>
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
------------------------------
Message: 7
Date: Sat, 9 Apr 2016 16:14:58 -0500
From: Mike Waters <mikewate at gmail.com>
To: topband <topband at contesting.com>
Subject: Re: Topband: VOA Antennas
Message-ID:
<CA+FxYXhu7_iO9_ikUfk_gumEdnPVT5Quq1yEyij6zJWTPchxqg at mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
I fully agree, Lloyd! Below 30 MHz, not to worry.
- There have been thousands of AM and SW broadcast engineers, each with a
lifetime of intense RF exposure, none of whom have been harmed in the least.
- And that doesn't count the residents living near the transmitters, such
as those houses --with families living in them-- directly in the path of
that Sterba curtain's 25 megawatt RF field!
- Or us Topbanders! :-)
I firmly believe that the FCC standards for HF exposure were composed with
an overabundance of caution (or should I say paranoia?). Too many lawyers.
And too many greedy idiots eager to hire them.
The exception might be diathermy, a medical treatment which intentionally
uses a very strong and concentrated RF field to heat and treat human tissue.
73, Mike
www.w0btu.com
On Sat, Apr 9, 2016 at 3:50 PM, Lloyd - N9LB <lloydberg at charter.net> wrote:
> ... Experience and time have shown that this is an unfounded fear for MW
> and HF. I've been around both for close to 50 years and no cancer, and
> yes I have kids too. Our local ham clubs have members who have been
> making RF since they were kids are now well past the median life expectancy
> age. Obviously they have not been adversely affected by RF.
>
------------------------------
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