shunt fed AM Sticks
 

Hi NG People,

Does anyone know where there is a good site on the web for info on Shunt fed
towers and the like?

Regards,

peter

Hello Peter,

Does anyone know where there is a good site on the web for info on Shunt fed
towers and the like?

I'm sure you'll find something in the archives at the BE site:

http://www.broadcast.net/

Use the drop-down menu.

Also consider joining one of their mailing lists. Full of experienced
engineers who I'm sure can point you to other published work.

Who is Station X AM?
--
Philip de Cadenet G4ZOW
Transmitters 'R' Us
http://www.transmittersrus.com

Does anyone know where there is a good site on the web for info on Shunt fed
towers and the like?


I doubt if you could get a new shunt excited tower licensed today.

However, in the mid-1960s Broadcast Engineering had an article (or was it
articles) on shunt excited towers.

In article , inch (Peter
H.) wrote:

Does anyone know where there is a good site on the web for info on Shunt fed
towers and the like?

I doubt if you could get a new shunt excited tower licensed today.

What is the problem that would prevent licensing today?


Regards,

John Byrns


Surf my web pages at, http://users.rcn.com/jbyrns/

Curious to know what the objections to shunt feed would be...



"Peter H." wrote in message
...


Does anyone know where there is a good site on the web for info on Shunt
fed
towers and the like?


I doubt if you could get a new shunt excited tower licensed today.

However, in the mid-1960s Broadcast Engineering had an article (or was it
articles) on shunt excited towers.

Thanks heaps guys,

I'm in the land down under. We have here a licensing category where they
issue the top end of the broadcast band between1611 to 1701 for what is
called Narrowband Area Services. This in Australia is outside the "official"
broadcasting bands. Also we are on 9khz steps here. All this is inline with
the ITU rules. So it leaves the gap where you finsh at 1710.

I'm not sure of the exact politics but here we follow the same specs as
Europe under the conventions of the ITU. We also have TWO regulators here
one for RADIO Emmisions (two ways / CB etc etc etc). The other one
"regulates" everything termed "broadcasting". This is the Australian
Broadcasting Authority the other is Australian Communications Authority.

As one can see one needs to operate within the other for issueing of TV
AM/FM radio licenses. When you ask for a freq NOT within the Broadcasting
Bands the fun starts! SW here is not concidered viable but the ACA sees alot
of HF Spectrum going to waste so issues TXer licenses. The same thing
happened with the little golden bit on top of our Broadcast Band 1611 to
1701. The ACA will issue licenses to TRANSMIT on them under specs less than
broadcast and more like a two way quality (no one does though).

By definition you are operating a "broadcasting service" as seen by the
ABA,but you don't need to worry about the ABA's silly rules as you are not
under their area of control. If they really want to get you they could, on
content regardless but you are not running an illegal TX this is covered by
the ACA.

Station X runs as a netcaster currently from Australia. I've got a few of
these NAS licenses at 400 watts and one SW on 2368khz designed mainly for
domestic HF coverage.

There is not much available in Australia on tricky aerial designs. The
station is not any really big operation so the investment needs to be
comparible. Setting up a 40 meter mast (although needed ) is not going to
happen. We have an interesting rule here for town planing that says Amateur
Radio operators can erect a tower up to 100 feet without council
permisssion. If it was for commercial purposes no dice needs approval----oh
dear?????

A power pole and conduit carring the MF wires up with a beam on top some guy
wires coming down at 45 degrees sounds like an amatuers setup.

so thanks heaps guys.

www.stationx.com.au to read up on the "X"

What is the problem that would prevent licensing today?


The polar plot is not circular (which it is, for series excited towers).

Nevertheless, there is at least one DA which uses shunt excited towers.

Incredibly enough, the day and night patters are mirror images of each other
(null towards the west during days, null towards the east during nights).

The problem isn't with shunt feed in particular. The increasingly
popular folded vertical on a grounded base tower is actually a form of
shunt feed.

A lot of people associate the term shunt feed with slant wire feed.
Slant wire feed is where the problem lies. While there are many of these
systems still operating due to grandfathering (KFBC in Cheyenne WY for
example) the FCC will generally not allow any new installations with
this feed arrangement because the slant wire itself introduces an
unwanted directional component into the radiation pattern. However, I
have heard that the FCC has allowed a few slant wire feeds for daytime
only stations under an STA.

Patrick Griffith, N=D8NNK, Westminster, CO

http://community.webtv.net/N0NNK/
http://community.webtv.net/AM-DXer/

Peter,

Station X runs as a netcaster currently from Australia. I've got a few of
these NAS licenses at 400 watts and one SW on 2368khz designed mainly for
domestic HF coverage.

This would be part of the old HF marine band here in the UK.

Out of interest do Australian broadcasters use AM on this band and if so
which make of transmitter?
--
Philip de Cadenet
Transmitters 'R' Us
http://www.transmittersrus.com

Phil,

AM broadcasting here is on the 521 to 1602 khz for normal broadcasting
stations. The 2368Khz is concidered a SW freq here although the lowest of
them. Yes here it is "shared" with "broadcast" and "mobile or fixed"
services. I'm not sure on the exact freq limits but this is the first of the
Shortwave Bands as designated by the ITU. It isn't concidered anything too
usefull for the purposes of International Broadcasting. That happens from
about 5 mhz upwards plus needs to be shared on a time table basis as you
would know.

So here we find a lot of long distance two way system for long distance
trucking companys and a system here called the Royal Flying Doctor Service.
Also a mob that are a FWD club have a network of stations around the
country. Alot of this is all done now on Sat phones etc, so the ACA are
looking at what to do with stacks of HF spectrum being left dorment.

Here TXers are AWA / Blyth / RVR / Rhode & Shcwarz / Harris -------thats
about as far as memory goes for now! ;)

Peter,

AM broadcasting here is on the 521 to 1602 khz for normal broadcasting
stations. The 2368Khz is concidered a SW freq here although the lowest of
them. Yes here it is "shared" with "broadcast" and "mobile or fixed"
services. I'm not sure on the exact freq limits but this is the first of the
Shortwave Bands as designated by the ITU. It isn't concidered anything too
usefull for the purposes of International Broadcasting. That happens from
about 5 mhz upwards plus needs to be shared on a time table basis as you
would know.

So here we find a lot of long distance two way system for long distance
trucking companys and a system here called the Royal Flying Doctor Service.
Also a mob that are a FWD club have a network of stations around the
country. Alot of this is all done now on Sat phones etc, so the ACA are
looking at what to do with stacks of HF spectrum being left dorment.

Here TXers are AWA / Blyth / RVR / Rhode & Shcwarz / Harris -------thats
about as far as memory goes for now! ;)

Very interesting.

Don't forget Barratt HF transceivers, I have one:-)

AWA must be locally made!

I'm familiar with typical coverage of the above band.

The HF spectrum must be busier here in western Europe than down in the
Pacific. Our UK government do not issue HF broadcast licenses - period.
People have tried, unsuccessfully, to apply.

There again, we now live in a police state.

Thanks for the info.
--
Philip de Cadenet G4ZOW
Transmitters 'R' Us
http://www.transmittersrus.com

Interesting this is to me Phil!!!!

See in this part of the world WE (Australia) are largely on our own!!! By
this I mean the size of this place is mind blowing to most European people.
Driving from one side of the country to the other is measured in WEEKS not
hours.

Also in a "broad" sence we are as far away from the technologicaly developed
countries as you can get without coming back closer. Plus we "almost are"
the only ones in the race for the southern hemisphere. Over your way the
SKIP potential would be more pronounced. Thus causing the authorities to
think the way they do. I got it here when asking for a HF Domestic license
on the 2368.5 KHZ.

We tolerate the night time extension in coverage given the d layer. As you
know the groundwave is not too favourable so I was asked a lot of suss
questions for wanting one.

Here the "general idea" is everything needs to be big to cover enough area
to get a workable audience size. So anything that reduces the effective
coverage area is not liked too much with the engineering people.

Also I've bookmarked your site. I'm on the hunt for gear to set up the
licenses i have.

Regards

Peter

PS AWA = Amalgmated Wireless Australia (I think-----yes local fellas) Also
R.M.E. =Radio Manufacturing Enigineers (Local fellas too---not sure if still
around)

Peter Tate wrote:

Also in a "broad" sence we are as far away from the technologicaly developed
countries as you can get without coming back closer. Plus we "almost are"
the only ones in the race for the southern hemisphere. Over your way the
SKIP potential would be more pronounced. Thus causing the authorities to
think the way they do. I got it here when asking for a HF Domestic license
on the 2368.5 KHZ.

In South America, there are a lot of broadcasters using the 120 meter
band down in that area. Stations have a very large coverage area, and
often are the only communication at all, so 120 meter and 60 meter shortwave
broadcast is used for local programming.

We tolerate the night time extension in coverage given the d layer. As you
know the groundwave is not too favourable so I was asked a lot of suss
questions for wanting one.

The night time extension is the wonderful thing about these bands, of course.

Here the "general idea" is everything needs to be big to cover enough area
to get a workable audience size. So anything that reduces the effective
coverage area is not liked too much with the engineering people.

Also I've bookmarked your site. I'm on the hunt for gear to set up the
licenses i have.

How much power are you licensed for? Fair Radio Sales right now has a
bunch of wideband broadcast transmitters for reasonable money. Are there
type acceptance requirements in your country for that band? If not, you
might consider using higher grade amateur gear. Even HCJB is running a
little Viking II transmitter on one band, and it gets out nicely and is
apparently reliable.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Interesting this is to me Phil!!!!

Snip

I got it here when asking for a HF Domestic license
on the 2368.5 KHZ.

We tolerate the night time extension in coverage given the d layer. As you
know the groundwave is not too favourable so I was asked a lot of suss
questions for wanting one.

Here the "general idea" is everything needs to be big to cover enough area
to get a workable audience size. So anything that reduces the effective
coverage area is not liked too much with the engineering people.

Also I've bookmarked your site. I'm on the hunt for gear to set up the
licenses i have.

OK, so do you intend to broadcast with AM on the above frequency?

Musical format, maybe some non copyrighted stuff so no copyright fees?

Had a colleague succeed attaining a UK T & D (Testing and Development)
license for somewhere around your frequency. This was to carry out some
antenna development work. Or at least that was his story!

Played I do believe some old jazz from the 50's which was not copyright.

Now a nice Franklin antenna would do you well for some serious ground
wave coverage. I wonder how tall that baby would be on 2368KHz.

Now I've talked to Aus from my mobile ham station on numerous occasions
on 160m (1.8-2MHz) albeit on SSB.

If your frequency is clear here in the UK there's no reason you could
not be received here under favourable conditions early in the morning.

I searched in vain for both the Aus companies!

I'd be interested therefore what equipment you'll use and if it has to
meet any type approval spec.

there's just not many manufacturers out there who offer broadcast
transmitters that go as low as 2MHz.

Rhode & Schwarz, but don't ask the price.

Contact Brian Blythe in New Zealand:

http://www.blyth.co.nz/index.html

I'm sure you know of his fine medium wave rigs.

I'm his Euro distributor as you'll see.

He may be able to move one of his boxes down there!

I'm afraid it's pretty much impossible for the 'small guy' to get into
station ownership here in the UK.

It's for that reason I'm looking to invest in another US 'small-town' AM
or AM/FM combo though the fed's allow only a max of 20% station
ownership by foreigners.

Hope I'm not boring you to death. We can take this off list if it's
upsetting anyone.
--
Philip de Cadenet G4ZOW
Transmitters 'R' Us
http://www.transmittersrus.com