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-   -   SSB Balun at TOP of Backstay (https://www.boatbanter.com/electronics/106852-ssb-balun-top-backstay.html)

Geoff Schultz June 11th 09 02:42 PM

SSB Balun at TOP of Backstay
 
I'm posting this for a friend from the forum on www.FreedomYachts.org. I
know that there are a lot of good radio people here and not many on that
forum.

-----------

I have one of these catketches, no shrouds and an overhanging mizzen boom.
In the next two years, I need to install an SSB transceiver antenna. I have
two stainless adjustable backstays with block and tackle at the bottom.
Normally, in their idle mode, they are athwart ships of the mizzen. When in
use, The luff backstay tackle is set on the luff transom corner and
tensioned. I know some people use this backstay as an antenna.

What I want to know is if someone has experience with positioning the balun
at the TOP of the backstay and feeding the coax cable from the top of the
mast down to below decks. Normally, the balun is at the bottom end of the
antenna and the coax is fed in from there. This is not possible (or at
least practical) with a backstay that is moved around at the bottom end. As
far as my limited knowledge goes, the coax has to be included in
calculating the required antenna length.

----------

-- Geoff
www.GeoffSchultz.org

Robert Miles June 11th 09 06:56 PM

SSB Balun at TOP of Backstay
 
You would probably have to install the ATU at the top of the mast as well,
and the voltage maximum would likely be at the deck level, and this might be
interesting for those leaning against the backstay?

Regards

Bob
GM4CAQ

Simply Blue Too
Clyde


"Geoff Schultz" wrote in message
.. .
I'm posting this for a friend from the forum on www.FreedomYachts.org. I
know that there are a lot of good radio people here and not many on that
forum.

-----------

I have one of these catketches, no shrouds and an overhanging mizzen boom.
In the next two years, I need to install an SSB transceiver antenna. I
have
two stainless adjustable backstays with block and tackle at the bottom.
Normally, in their idle mode, they are athwart ships of the mizzen. When
in
use, The luff backstay tackle is set on the luff transom corner and
tensioned. I know some people use this backstay as an antenna.

What I want to know is if someone has experience with positioning the
balun
at the TOP of the backstay and feeding the coax cable from the top of the
mast down to below decks. Normally, the balun is at the bottom end of the
antenna and the coax is fed in from there. This is not possible (or at
least practical) with a backstay that is moved around at the bottom end.
As
far as my limited knowledge goes, the coax has to be included in
calculating the required antenna length.

----------

-- Geoff
www.GeoffSchultz.org




chuck June 11th 09 11:32 PM

SSB Balun at TOP of Backstay
 
On Thu, 11 Jun 2009 08:42:32 -0500, Geoff Schultz
wrote:

I'm posting this for a friend from the forum on www.FreedomYachts.org. I
know that there are a lot of good radio people here and not many on that
forum.

-----------

I have one of these catketches, no shrouds and an overhanging mizzen boom.
In the next two years, I need to install an SSB transceiver antenna. I have
two stainless adjustable backstays with block and tackle at the bottom.
Normally, in their idle mode, they are athwart ships of the mizzen. When in
use, The luff backstay tackle is set on the luff transom corner and
tensioned. I know some people use this backstay as an antenna.

What I want to know is if someone has experience with positioning the balun
at the TOP of the backstay and feeding the coax cable from the top of the
mast down to below decks. Normally, the balun is at the bottom end of the
antenna and the coax is fed in from there. This is not possible (or at
least practical) with a backstay that is moved around at the bottom end. As
far as my limited knowledge goes, the coax has to be included in
calculating the required antenna length.

----------

-- Geoff
www.GeoffSchultz.org


Hi Geoff,

What is the purpose of the balun in the installations you described?
Both the coax and the antenna are typically unbalanced and a balun is
not required. Is the device an unun to transform impedances?

Chuck

Geoff Schultz June 12th 09 12:20 AM

SSB Balun at TOP of Backstay
 
Chuck wrote in
:

On Thu, 11 Jun 2009 08:42:32 -0500, Geoff Schultz
wrote:

I'm posting this for a friend from the forum on www.FreedomYachts.org.
I know that there are a lot of good radio people here and not many on
that forum.

-----------

I have one of these catketches, no shrouds and an overhanging mizzen
boom. In the next two years, I need to install an SSB transceiver
antenna. I have two stainless adjustable backstays with block and
tackle at the bottom. Normally, in their idle mode, they are athwart
ships of the mizzen. When in use, The luff backstay tackle is set on
the luff transom corner and tensioned. I know some people use this
backstay as an antenna.

What I want to know is if someone has experience with positioning the
balun at the TOP of the backstay and feeding the coax cable from the
top of the mast down to below decks. Normally, the balun is at the
bottom end of the antenna and the coax is fed in from there. This is
not possible (or at least practical) with a backstay that is moved
around at the bottom end. As far as my limited knowledge goes, the
coax has to be included in calculating the required antenna length.

----------

-- Geoff
www.GeoffSchultz.org


Hi Geoff,

What is the purpose of the balun in the installations you described?
Both the coax and the antenna are typically unbalanced and a balun is
not required. Is the device an unun to transform impedances?

Chuck


I'm not a radio person and am simply repeating the question. If you'd
like to ask directly, please go to

http://www.freedomyachts.org/viewtopic.php?f=7&t=10132

You'll have to register to reply, but that's quick.

-- Geoff
www.GeoffSchultz.org

Wayne.B June 15th 09 01:50 PM

SSB Balun at TOP of Backstay
 
On Thu, 11 Jun 2009 08:42:32 -0500, Geoff Schultz
wrote:

I'm posting this for a friend from the forum on www.FreedomYachts.org. I
know that there are a lot of good radio people here and not many on that
forum.

-----------

I have one of these catketches, no shrouds and an overhanging mizzen boom.
In the next two years, I need to install an SSB transceiver antenna. I have
two stainless adjustable backstays with block and tackle at the bottom.
Normally, in their idle mode, they are athwart ships of the mizzen. When in
use, The luff backstay tackle is set on the luff transom corner and
tensioned. I know some people use this backstay as an antenna.

What I want to know is if someone has experience with positioning the balun
at the TOP of the backstay and feeding the coax cable from the top of the
mast down to below decks. Normally, the balun is at the bottom end of the
antenna and the coax is fed in from there. This is not possible (or at
least practical) with a backstay that is moved around at the bottom end. As
far as my limited knowledge goes, the coax has to be included in
calculating the required antenna length.


Baluns are almost never used in a marine SSB installation. Their
primary use is for center fed horizontal dipole antennas which is
quite uncommon on boats.

Your friends best bet for an unstayed rig is to install a 23 ft whip
on the stern and feed it with an antenna coupler working against a
good ground system.


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