top-fed SSB backstay antenna??
 

Over the holidays I killed some time looking through a few back issues of
Cruising World. In the April 1986 issue a boat-based ham operator said he
used a top-fed backstay antenna with excellent results AND he had no in-hull
ground plane. He said he connected the shield from his feed wire to the
mast-side of the backstay and this allowed the mast and all the standing
rigging to act as a ground plane. He didn't say anything about using
stand-offs between the feed wire and the mast. I would think you would get
a lot of signal loss over that much length if you didn't use stand-offs?
If a person could put up with the appearance and make sure the whole set-up
didn't get torn down by sails/running rigging, would this really give good
performance? I don't recall reading about this type of set-up so I guess
its not too common on recreational boats but maybe it could be worth
considering in some situations?

That's a slightly different animal. It is acts essentually like a dipole
which is a balanced antenna. Balanced antennas do not need a
ground plane. Standoffs are not needed because the mast is part of
the ground side of the antenna which is what the shield on the coax
is. I experimentd with a real dipole by stretching it between the masthead
and the radar arch. It was fed in the middle with a balun. Worked well, but
keeping the feedline out of harms way proved to be a problem.

If the antenna in question was fed with coax, a balun would be
desirable.

Doug, k3qt
s/v Callista

"Gordon Wedman" wrote in message
news:6wAEd.61994$nN6.13173@edtnps84...
Over the holidays I killed some time looking through a few back issues of
Cruising World. In the April 1986 issue a boat-based ham operator said he
used a top-fed backstay antenna with excellent results AND he had no
in-hull ground plane. He said he connected the shield from his feed wire
to the mast-side of the backstay and this allowed the mast and all the
standing rigging to act as a ground plane. He didn't say anything about
using stand-offs between the feed wire and the mast. I would think you
would get a lot of signal loss over that much length if you didn't use
stand-offs?
If a person could put up with the appearance and make sure the whole
set-up didn't get torn down by sails/running rigging, would this really
give good performance? I don't recall reading about this type of set-up
so I guess its not too common on recreational boats but maybe it could be
worth considering in some situations?

Thanks Doug
So it would work well as an antenna for marine SSB?
If so I'm a bit surprised more people don't use this instead of trying to
achieve that elusive ground plane in the hull. Sounds like you could just
run the feed wire inside the mast if you don't need standoffs and the whole
installation would be pretty slick.

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
That's a slightly different animal. It is acts essentually like a dipole
which is a balanced antenna. Balanced antennas do not need a
ground plane. Standoffs are not needed because the mast is part of
the ground side of the antenna which is what the shield on the coax
is. I experimentd with a real dipole by stretching it between the masthead
and the radar arch. It was fed in the middle with a balun. Worked well,
but
keeping the feedline out of harms way proved to be a problem.

If the antenna in question was fed with coax, a balun would be
desirable.

Doug, k3qt
s/v Callista

"Gordon Wedman" wrote in message
news:6wAEd.61994$nN6.13173@edtnps84...
Over the holidays I killed some time looking through a few back issues of
Cruising World. In the April 1986 issue a boat-based ham operator said
he used a top-fed backstay antenna with excellent results AND he had no
in-hull ground plane. He said he connected the shield from his feed wire
to the mast-side of the backstay and this allowed the mast and all the
standing rigging to act as a ground plane. He didn't say anything about
using stand-offs between the feed wire and the mast. I would think you
would get a lot of signal loss over that much length if you didn't use
stand-offs?
If a person could put up with the appearance and make sure the whole
set-up didn't get torn down by sails/running rigging, would this really
give good performance? I don't recall reading about this type of set-up
so I guess its not too common on recreational boats but maybe it could be
worth considering in some situations?

Well, the tuners that come with marine sidebands (AT-140 etc) are
designed for end-fed long wires. Also, dipole lengths are specific to
the band one is working. Multiband operation would require some sort
of traps in both the backstay (sort of easy) and also matching traps
in the mast (really hard!). So in short, you can eliminate the ground
plane, but you also inherit less flexability. You also need to get an
antenna tuner that can tune a dipole. There has been some discussion
about tuning the entire rig (W4CCC) but I have no experience in
that area. Larry (W4CCC) also seems to have vanished from this
forum. I hope it was not a result of RF burns or that someone pointed
out there is no record of his ham licence in the FCC database :)

The elusive groundplane in the hull is a myth. Run foil from the tuner and
radio
to a thruhull and you are done. Make sure the thruhull is not part of a
bonding
system, it must be isolated. I wrapped the foil around a cockpit scupper
seacock and secured it with a hose clamp. I get excellent signal reports
and had no problems doing email from The Bahamas to dozens of land
station inside the US and Canada. Let me know if you want to arrange
for a QSO to check out my signal.

Doug, k3qt
s/v Callista

"Gordon Wedman" wrote in message
news:xhDEd.91279$KO5.69231@clgrps13...
Thanks Doug
So it would work well as an antenna for marine SSB?
If so I'm a bit surprised more people don't use this instead of trying to
achieve that elusive ground plane in the hull. Sounds like you could just
run the feed wire inside the mast if you don't need standoffs and the
whole installation would be pretty slick.

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
That's a slightly different animal. It is acts essentually like a dipole
which is a balanced antenna. Balanced antennas do not need a
ground plane. Standoffs are not needed because the mast is part of
the ground side of the antenna which is what the shield on the coax
is. I experimentd with a real dipole by stretching it between the
masthead and the radar arch. It was fed in the middle with a balun.
Worked well, but
keeping the feedline out of harms way proved to be a problem.

If the antenna in question was fed with coax, a balun would be
desirable.

Doug, k3qt
s/v Callista

"Gordon Wedman" wrote in message
news:6wAEd.61994$nN6.13173@edtnps84...
Over the holidays I killed some time looking through a few back issues
of Cruising World. In the April 1986 issue a boat-based ham operator
said he used a top-fed backstay antenna with excellent results AND he
had no in-hull ground plane. He said he connected the shield from his
feed wire to the mast-side of the backstay and this allowed the mast and
all the standing rigging to act as a ground plane. He didn't say
anything about using stand-offs between the feed wire and the mast. I
would think you would get a lot of signal loss over that much length if
you didn't use stand-offs?
If a person could put up with the appearance and make sure the whole
set-up didn't get torn down by sails/running rigging, would this really
give good performance? I don't recall reading about this type of set-up
so I guess its not too common on recreational boats but maybe it could
be worth considering in some situations?

Oh, and I forgot. I don't use an insulated backstay. I have a 23' whip
mounted
on the transome.

Doug, k3qt
s/v Callista

"Gordon Wedman" wrote in message
news:xhDEd.91279$KO5.69231@clgrps13...
Thanks Doug
So it would work well as an antenna for marine SSB?
If so I'm a bit surprised more people don't use this instead of trying to
achieve that elusive ground plane in the hull. Sounds like you could just
run the feed wire inside the mast if you don't need standoffs and the
whole installation would be pretty slick.

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
That's a slightly different animal. It is acts essentually like a dipole
which is a balanced antenna. Balanced antennas do not need a
ground plane. Standoffs are not needed because the mast is part of
the ground side of the antenna which is what the shield on the coax
is. I experimentd with a real dipole by stretching it between the
masthead and the radar arch. It was fed in the middle with a balun.
Worked well, but
keeping the feedline out of harms way proved to be a problem.

If the antenna in question was fed with coax, a balun would be
desirable.

Doug, k3qt
s/v Callista

"Gordon Wedman" wrote in message
news:6wAEd.61994$nN6.13173@edtnps84...
Over the holidays I killed some time looking through a few back issues
of Cruising World. In the April 1986 issue a boat-based ham operator
said he used a top-fed backstay antenna with excellent results AND he
had no in-hull ground plane. He said he connected the shield from his
feed wire to the mast-side of the backstay and this allowed the mast and
all the standing rigging to act as a ground plane. He didn't say
anything about using stand-offs between the feed wire and the mast. I
would think you would get a lot of signal loss over that much length if
you didn't use stand-offs?
If a person could put up with the appearance and make sure the whole
set-up didn't get torn down by sails/running rigging, would this really
give good performance? I don't recall reading about this type of set-up
so I guess its not too common on recreational boats but maybe it could
be worth considering in some situations?

Hello Gordon,

The 20th edition of the ARRL Antenna Handbook has some
information on a 40 meter, masthead half-sloper as you
described. You might find that interesting.

As Doug mentioned, this is basically a single-band antenna,
except that it would probably work ok on odd harmonic
frequencies. And it would very definitely radiate on other
frequencies in an emergency, provided you used an
appropriate tuner.

Good luck!

Chuck












Gordon Wedman wrote:
Over the holidays I killed some time looking through a few back issues of
Cruising World. In the April 1986 issue a boat-based ham operator said he
used a top-fed backstay antenna with excellent results AND he had no in-hull
ground plane. He said he connected the shield from his feed wire to the
mast-side of the backstay and this allowed the mast and all the standing
rigging to act as a ground plane. He didn't say anything about using
stand-offs between the feed wire and the mast. I would think you would get
a lot of signal loss over that much length if you didn't use stand-offs?
If a person could put up with the appearance and make sure the whole set-up
didn't get torn down by sails/running rigging, would this really give good
performance? I don't recall reading about this type of set-up so I guess
its not too common on recreational boats but maybe it could be worth
considering in some situations?

Hi Chuck
I kind of suspected that it would only work well over a limited frequency
range and that the typical antenna tuners would not help. Thanks to Doug
and yourself for confirming this. I'm not planning on installing one as I
have a conventional backstay arrangement but I was just wondering if anyone
actually used this kind of setup as I'd not seen it discussed.
I guess if you are a Ham and tend to work only one band this might be a good
arrangement for your boat.

"chuck" wrote in message
...
Hello Gordon,

The 20th edition of the ARRL Antenna Handbook has some information on a 40
meter, masthead half-sloper as you described. You might find that
interesting.

As Doug mentioned, this is basically a single-band antenna, except that it
would probably work ok on odd harmonic frequencies. And it would very
definitely radiate on other frequencies in an emergency, provided you used
an appropriate tuner.

Good luck!

Chuck












Gordon Wedman wrote:
Over the holidays I killed some time looking through a few back issues of
Cruising World. In the April 1986 issue a boat-based ham operator said
he used a top-fed backstay antenna with excellent results AND he had no
in-hull ground plane. He said he connected the shield from his feed wire
to the mast-side of the backstay and this allowed the mast and all the
standing rigging to act as a ground plane. He didn't say anything about
using stand-offs between the feed wire and the mast. I would think you
would get a lot of signal loss over that much length if you didn't use
stand-offs?
If a person could put up with the appearance and make sure the whole
set-up didn't get torn down by sails/running rigging, would this really
give good performance? I don't recall reading about this type of set-up
so I guess its not too common on recreational boats but maybe it could be
worth considering in some situations?

Actually, as a ham I tend to work many bands. Probably more thatn a typical
marine SSB operator might. So, a single band antenna on a boat is probably
too limiting in many cases.

Doug, k3qt
s/v CAllista

"Gordon Wedman" wrote in message
news:dNxFd.99492$KO5.42998@clgrps13...
Hi Chuck
I kind of suspected that it would only work well over a limited frequency
range and that the typical antenna tuners would not help. Thanks to Doug
and yourself for confirming this. I'm not planning on installing one as I
have a conventional backstay arrangement but I was just wondering if
anyone actually used this kind of setup as I'd not seen it discussed.
I guess if you are a Ham and tend to work only one band this might be a
good arrangement for your boat.

"chuck" wrote in message
...
Hello Gordon,

The 20th edition of the ARRL Antenna Handbook has some information on a
40 meter, masthead half-sloper as you described. You might find that
interesting.

As Doug mentioned, this is basically a single-band antenna, except that
it would probably work ok on odd harmonic frequencies. And it would very
definitely radiate on other frequencies in an emergency, provided you
used an appropriate tuner.

Good luck!

Chuck












Gordon Wedman wrote:
Over the holidays I killed some time looking through a few back issues
of Cruising World. In the April 1986 issue a boat-based ham operator
said he used a top-fed backstay antenna with excellent results AND he
had no in-hull ground plane. He said he connected the shield from his
feed wire to the mast-side of the backstay and this allowed the mast and
all the standing rigging to act as a ground plane. He didn't say
anything about using stand-offs between the feed wire and the mast. I
would think you would get a lot of signal loss over that much length if
you didn't use stand-offs?
If a person could put up with the appearance and make sure the whole
set-up didn't get torn down by sails/running rigging, would this really
give good performance? I don't recall reading about this type of set-up
so I guess its not too common on recreational boats but maybe it could
be worth considering in some situations?

Gordon Wedman wrote:
Hi Chuck
I kind of suspected that it would only work well over a limited frequency
range and that the typical antenna tuners would not help. Thanks to Doug
and yourself for confirming this. I'm not planning on installing one as I
have a conventional backstay arrangement but I was just wondering if anyone
actually used this kind of setup as I'd not seen it discussed.
I guess if you are a Ham and tend to work only one band this might be a good
arrangement for your boat.

"chuck" wrote in message
...

Hello Gordon,

The 20th edition of the ARRL Antenna Handbook has some information on a 40
meter, masthead half-sloper as you described. You might find that
interesting.

As Doug mentioned, this is basically a single-band antenna, except that it
would probably work ok on odd harmonic frequencies. And it would very
definitely radiate on other frequencies in an emergency, provided you used
an appropriate tuner.

Good luck!

Chuck












Gordon Wedman wrote:

Over the holidays I killed some time looking through a few back issues of
Cruising World. In the April 1986 issue a boat-based ham operator said
he used a top-fed backstay antenna with excellent results AND he had no
in-hull ground plane. He said he connected the shield from his feed wire
to the mast-side of the backstay and this allowed the mast and all the
standing rigging to act as a ground plane. He didn't say anything about
using stand-offs between the feed wire and the mast. I would think you
would get a lot of signal loss over that much length if you didn't use
stand-offs?
If a person could put up with the appearance and make sure the whole
set-up didn't get torn down by sails/running rigging, would this really
give good performance? I don't recall reading about this type of set-up
so I guess its not too common on recreational boats but maybe it could be
worth considering in some situations

I think it's a great idea. If you tune to some "off" freqs, you
could try orienting the AE different ways by turning the boat. You
may be surprised to find directivity nodes here and there at certain
freqs.

I have often wondered why I don't get a ham set, or even a decent
receiver, so I can fool around with some weird AE Ideas. How about a
loop using the fore and back stays, insulated at the top, a balanced
twinax feed and connected from fore peak to transom by an insulated
bilge wire on spacers away from the bottom of the hull?

Alternatively, my mind says "Why not feed at the centre of the
bilge lead, or even off centre, and maybe not bother insulating the
stays at the top?" The shrouds would not be connected to anything
at the chain plates.

I suspect directivity trials could yield a neat plot showing odd
peaks and strange directivity. Some of those nodes may be surprising
and even useful.

Loops are particularly quiet on Rx. Ever try one for Tx?

Has anybody actually done any of this wierd stuff?

It seems to me that some software should be able to predict all
this. Anybody know?

Terry K

Lines: 26
Message-ID:
X-Complaints-To:
X-Abuse-Info: Please forward a copy of all headers for proper handling
X-Trace: pcpocbcnbdmdhgfgdbdpiflmbcekedmfhojhikkbagflhcbohh ibjflpfdbofondpeiphjjefhhdbmabaehccnnlhdmkmldebofc pfnccacfhjdbakngmmneimggmmdkmfhccnbbcldpjkkccfdped gmlaehoiol
NNTP-Posting-Date: Fri, 14 Jan 2005 00:10:42 EST
Organization: BellSouth Internet Group
Date: Fri, 14 Jan 2005 05:10:42 GMT
Xref: number1.nntp.dca.giganews.com rec.boats.electronics:58302


On 2005-01-13 dNxFd.99492$KO5.42998@clgrps13 said:
Thanks to Doug and yourself for confirming this. I'm not
planning on installing one as I have a conventional backstay
arrangement but I was just wondering if anyone actually used this
kind of setup as I'd not seen it discussed. I guess if you are a
Ham and tend to work only one band this might be a good
arrangement for your boat.
IF I were at sea (and I am a ham) I'd still want more than one band
capability, especially were I at sea on a boat. One of the distinct
advantages of ham radio over most services is its ability to choose
the right band for prevailing radio conditions and the path one wants
to work. Being that the ability to summon assistance when needed on
freqs such as 2182 is limited these days I'd want multiband capability
for my hf marine gear when away from land.




Richard Webb, amateur radio callsign nf5b
active on the Maritime Mobile service network, 14.300 mhz
REplace anything before the @ symbol with elspider for real email

--