Bruce & Larry,
Ok the whip won't cut it. The back stays are 90'+ each. Do I use 1 inverted
V or do I use each back stay as antennae?
Steve

"Bruce in Alaska" wrote in message
...
In article ,
"Steve Lusardi" wrote:

Larry,
The 23' whip sounds like an elegant solution to my problem. I have a
steel
60' sloop that I built myself. On this I have an ICOM 700 with the AT130
and
a SEA 330 with the 1630 coupler. What would you recommend for this
installation? There are twin 5/8 rod back stays and an 11' wide antenna
bridge behind the center cockpit. Lots of room in this area as well as a
solid continuous 1 1/4" stainless rail all around the boat at a height of
30" . Perhaps an antenna switch and a common antenna, as I will never use
more than one radio at a time.

Thanks in advance,
Steve

Steve, if you try and use the SEA330/SEA1630 with just 23 Ft of Antenna
you will be dissapointed with the result on any Frequency below 6 Mhz.
Look around your vessel for ANY way to put 35 Ft of wire under that 23'
Whip, and your experience will be considerable better. Sea330's are
a bit of a Power Hawg when operating at 300 Watts PEP Output, but they
sure to "Talk" well, when the bands are marginal, if the antenna is
reasonable.

Bruce in alaska who installed a bunch of SEA330's all over alaska...
--
add path before @

Bruce in Alaska wrote in news:fast-F610FA.11361118122007
@netnews.worldnet.att.net:

operating at 300 Watts PEP Output

300 watts?......Oh, wait, I forgot to turn on the linear....(c;

Larry
--
"Power is our FRIEND!" - Robert Mitchell, owner, paging company.

You can tell when your ham station is gittin' out because it dims the
lights in your NEIGHBOR's house!

"Steve Lusardi" wrote in
:

Bruce & Larry,
Ok the whip won't cut it. The back stays are 90'+ each. Do I use 1
inverted V or do I use each back stay as antennae?
Steve



Parallel them. Put an insulator about 3' from the upper end, not too
close to the metal up there, then an insulator on each of the bottom ends
right above the deck but not so the backstay touches bimini tops, etc.
That wonderful steel hull is the finest ground plane on the planet hooked
to that ocean like it is. No grounding blocks or other nonsense is
necessary. RF goes right through bottom paint on steel hulls.

Put the tuner in the middle of them at the bottom and be SURE to use
EQUAL LENGTH FEED WIRES to the base insulators of each so they are fed in
phase. This creates an effective radiating conductor diameter as wide as
these are far apart....making it broadbanded as hell, a really good
thing.

"Feed Wires" ARE part of the ANTENNA and are NOT a transmission line. Do
not try to use coax cable all neatly tywrapped to the grounded rigging
between the tuner antenna insulator and the backstays. This is CRAZY!
Use #10 or larger insulated conductors, NOT SHIELDED, as short as you can
get them and as far away from anything metal as you can get it.

If you come through the steel hull with these antenna wires, we need a
fairly large hole with a feed-thru insulator to guide the RF away from
the grounded hull.
http://www.surplussales.com/Antennas/Antennas-6.html
Look at ICR 9548 near the top of this insulator page. The 4" "beehive"
goes on the outside of the boat. This makes a very long leakage path in
the wet outside environment and the smaller inside-the-hull side keeps
the hot RF wires away from the hull. Try NOT to come off these at 90
degree angles on either end. RF doesn't like to turn corners....come off
the insulator straight out with a bent lug then make a smooth curve where
you have to go, as much as practical. The hole in the hull is large to
reduce the capacitance between the high impedance RF high voltage and the
grounded hull sucking off your signal.
NO - sticking a piece of the center conductor covered with its poly core
in a hole in the hull is NOT acceptable. The poly won't last a year in
the sun, anyways.

Notice how important it is to keep the antenna wire between the tuner and
backstays away from the metal:
http://www.surplussales.com/Antennas/Ceramic_stof.html
Ol' Navy sure does a nice job of it....(c; DO NOT TYWRAP THE ANTENNA
WIRE TO ANYTHING METAL! Standoff insulators can be nicely made of common
white PVC water pipe and fittings. 3-4" stood off is great but only for
SHORT distances.

Your insulated backstay antenna is like most AM broadcast stations,
except AM stations use a resonant tower. Your 90' long backstay will be
self resonant on 234/90 = 2.6 Mhz and will radiate like mad around that
frequency in the old 2 Mhz marine band.... If we move the insulators down
from the top so there is great radiation in the 4.1 Mhz marine band, the
insulators should be 234/4.1 = 57' of backstay between them. The tuner
will make it tune the other bands by adding inductance and capacitance in
series and parallel. But, nothing radiates as good as a resonant
antenna. At 57' 1" long, that top insulator will also be far away from
the RF-draining mast. Go for it!..(c;

I like the 4 Mhz tuning because most all Caribbean yachties talk on that
band. It's useless in the daytime but at night you get solid coverage
from where you are straight out 500 miles in all directions. 4 Mhz
tuning also resonates the antenna at 3/4 wavelength on 12.3 Mhz, the best
DAYTIME marine band, too. You get two great resonant points at 57' 1".

Larry
--
QUOTE OF THE MONTH:
"I have been to several major Chinese cities and have seen first hand
shops crammed with obviously fake American products." - Jon Dudas,
Undersecretary of Commerce for Intellectual Property Rights.

How can they be fake? The Chinese make all "American Products" I use!

Larry,
Thank you very much. I can do this easily, as the deck is contructed as a
steel space frame underneath and the deck is marine ply covered in teak. In
the aft cabin, I have 8' of headroom and can fasten the coupler to the
deckhead in the center of the span between the chain plates. I can maintain
a 6 inch spacing between the antenna feeds and any steel structure.
Steve

"Larry" wrote in message
...
"Steve Lusardi" wrote in
:

Bruce & Larry,
Ok the whip won't cut it. The back stays are 90'+ each. Do I use 1
inverted V or do I use each back stay as antennae?
Steve



Parallel them. Put an insulator about 3' from the upper end, not too
close to the metal up there, then an insulator on each of the bottom ends
right above the deck but not so the backstay touches bimini tops, etc.
That wonderful steel hull is the finest ground plane on the planet hooked
to that ocean like it is. No grounding blocks or other nonsense is
necessary. RF goes right through bottom paint on steel hulls.

Put the tuner in the middle of them at the bottom and be SURE to use
EQUAL LENGTH FEED WIRES to the base insulators of each so they are fed in
phase. This creates an effective radiating conductor diameter as wide as
these are far apart....making it broadbanded as hell, a really good
thing.

"Feed Wires" ARE part of the ANTENNA and are NOT a transmission line. Do
not try to use coax cable all neatly tywrapped to the grounded rigging
between the tuner antenna insulator and the backstays. This is CRAZY!
Use #10 or larger insulated conductors, NOT SHIELDED, as short as you can
get them and as far away from anything metal as you can get it.

If you come through the steel hull with these antenna wires, we need a
fairly large hole with a feed-thru insulator to guide the RF away from
the grounded hull.
http://www.surplussales.com/Antennas/Antennas-6.html
Look at ICR 9548 near the top of this insulator page. The 4" "beehive"
goes on the outside of the boat. This makes a very long leakage path in
the wet outside environment and the smaller inside-the-hull side keeps
the hot RF wires away from the hull. Try NOT to come off these at 90
degree angles on either end. RF doesn't like to turn corners....come off
the insulator straight out with a bent lug then make a smooth curve where
you have to go, as much as practical. The hole in the hull is large to
reduce the capacitance between the high impedance RF high voltage and the
grounded hull sucking off your signal.
NO - sticking a piece of the center conductor covered with its poly core
in a hole in the hull is NOT acceptable. The poly won't last a year in
the sun, anyways.

Notice how important it is to keep the antenna wire between the tuner and
backstays away from the metal:
http://www.surplussales.com/Antennas/Ceramic_stof.html
Ol' Navy sure does a nice job of it....(c; DO NOT TYWRAP THE ANTENNA
WIRE TO ANYTHING METAL! Standoff insulators can be nicely made of common
white PVC water pipe and fittings. 3-4" stood off is great but only for
SHORT distances.

Your insulated backstay antenna is like most AM broadcast stations,
except AM stations use a resonant tower. Your 90' long backstay will be
self resonant on 234/90 = 2.6 Mhz and will radiate like mad around that
frequency in the old 2 Mhz marine band.... If we move the insulators down
from the top so there is great radiation in the 4.1 Mhz marine band, the
insulators should be 234/4.1 = 57' of backstay between them. The tuner
will make it tune the other bands by adding inductance and capacitance in
series and parallel. But, nothing radiates as good as a resonant
antenna. At 57' 1" long, that top insulator will also be far away from
the RF-draining mast. Go for it!..(c;

I like the 4 Mhz tuning because most all Caribbean yachties talk on that
band. It's useless in the daytime but at night you get solid coverage
from where you are straight out 500 miles in all directions. 4 Mhz
tuning also resonates the antenna at 3/4 wavelength on 12.3 Mhz, the best
DAYTIME marine band, too. You get two great resonant points at 57' 1".

Larry
--
QUOTE OF THE MONTH:
"I have been to several major Chinese cities and have seen first hand
shops crammed with obviously fake American products." - Jon Dudas,
Undersecretary of Commerce for Intellectual Property Rights.

How can they be fake? The Chinese make all "American Products" I use!

"Steve Lusardi" wrote in
:

Larry,
Thank you very much. I can do this easily, as the deck is contructed
as a steel space frame underneath and the deck is marine ply covered
in teak. In the aft cabin, I have 8' of headroom and can fasten the
coupler to the deckhead in the center of the span between the chain
plates. I can maintain a 6 inch spacing between the antenna feeds and
any steel structure. Steve



Man, that's gonna be one LOUD voice in the darkness....(c;



Larry
--
QUOTE OF THE MONTH:
"I have been to several major Chinese cities and have seen first hand shops
crammed with obviously fake American products." - Jon Dudas, Undersecretary
of Commerce for Intellectual Property Rights.

How can they be fake? The Chinese make all "American Products" I use!

On Mon, 17 Dec 2007 23:42:49 +0100, "Steve Lusardi"
wrote:

Perhaps an antenna switch and a common antenna, as I will never use
more than one radio at a time.

I wouldn't do that myself, but I like dual everything, just in case
something breaks. I have flown single engine planes at night when I
was young and devil may care. I have gotten more chicken since then.

Casady

Larry,
I suspect this will be one hell of a radiator, but the real performance of
the set will be in the antenna's ability to listen.
Steve

"Larry" wrote in message
...
"Steve Lusardi" wrote in
:

Larry,
Thank you very much. I can do this easily, as the deck is contructed
as a steel space frame underneath and the deck is marine ply covered
in teak. In the aft cabin, I have 8' of headroom and can fasten the
coupler to the deckhead in the center of the span between the chain
plates. I can maintain a 6 inch spacing between the antenna feeds and
any steel structure. Steve



Man, that's gonna be one LOUD voice in the darkness....(c;



Larry
--
QUOTE OF THE MONTH:
"I have been to several major Chinese cities and have seen first hand
shops
crammed with obviously fake American products." - Jon Dudas,
Undersecretary
of Commerce for Intellectual Property Rights.

How can they be fake? The Chinese make all "American Products" I use!

In article ,
Larry wrote:

Bruce in Alaska wrote in news:fast-F610FA.11361118122007
@netnews.worldnet.att.net:

operating at 300 Watts PEP Output

300 watts?......Oh, wait, I forgot to turn on the linear....(c;

Larry

Bzzzt, Wrong conclusion, Larry, would you like to try for what is behind
Door #3.......

Yes the SEA330 is a 300 Watt PEP Output Transceiver. It was designed
for Commercial Vessel and BaseStation Installations. It can be
configured for Multiple Full Function Control Heads. (Up to 8, with
Special Firmware, and 3000 Wire feet TR Box to Control Head, with #22
4 Pair Wire, with Special Conversions) and is fully GMDSS Certified with
the SEA GMDSS Controller. The campanion SEA1630 Autotuner is qualified
for 300 Watts, on Steel Hulls, and 35' Antennas, on any Frequency above
3.6Mhz. Oh, how I wish SEA had made a SEA330 version of their
SEA325 Tranceiver. Now that would be a Commercial Radio worth owning....

I have installed a Pile of them, as Limited Coast Stations, all over
Alaska, and a bunch of them on the bigger Catcher/Processor Vessels
that roam the North Pacific and are SOLAS/GMDSS Required.

Bruce in alaska
--
add path before @

"Steve Lusardi" wrote in news:fkeai0$100$01
:

the antenna's ability to listen.


I learned with regret you had RF transparent decks. This means the
electronic controls of the stuff inside the boat can get to the
antenna outside the boat. Sorry.....


Larry
--
QUOTE OF THE MONTH:
"I have been to several major Chinese cities and have seen first hand
shops crammed with obviously fake American products." - Jon Dudas,
Undersecretary of Commerce for Intellectual Property Rights.

How can they be fake? The Chinese make all "American Products" I
use!