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SSB question

J

just me

Jan 1, 1970
0
I'm preparing to install a SSB and have been advised to hold the antenna
cable off the backstay an inch or so until it actually connects to the
backstay above the lower isolater. Any ideas what I might use for
standoffs?
Thanks

--
 
B

Bruce in Alaska

Jan 1, 1970
0
just me said:
I'm preparing to install a SSB and have been advised to hold the antenna
cable off the backstay an inch or so until it actually connects to the
backstay above the lower isolater. Any ideas what I might use for
standoffs?
Thanks

Small blocks of teflon work well, as do plastic clothspins....

Bruce in alaska
 
L

Lynn Coffelt

Jan 1, 1970
0
just me said:
I'm preparing to install a SSB and have been advised to hold the antenna
cable off the backstay an inch or so until it actually connects to the
backstay above the lower isolater. Any ideas what I might use for
standoffs?
Thanks
or.............. short lengths of 1/2" PVC (or other small plastic tube)
used as a stand-off. Tying the GTO-15 antenna cable to the lower backstay
with black, UV resistant nylon ties, both legs of the tie running through
the short tubes. (and around both the backstay and the antenna cable, of
course). That way you can choose, or easily change the clearance distance to
whatever you can live with.
Old Chief Lynn
 
L

Lynn Coffelt

Jan 1, 1970
0
Mark / Amy Read said:
I have installed my ICOM SSB as Chuck described, where the lower
Isolater is 12 to 16 inches from the bottom of the deck. The wire from
the ICOM tuner runs right up the backstay to the Isolater. I used zip
ties to hold the wire in place, and then used rigging tape to hold it
all in place. I have not used any type of PVC pipe or other cover for
the backstay for heat protection. My thinking is that it only gets hot
when you are transmitting. Someone would really have to lean way out
to touch it and it would have to be at that random moment when I am
transmitting on the SSB. The rigging tape wrapped around the backstay
for three or four feet is more than enough to keep from any accidental
burns.

All of this is to say that I am very pleased with the unit and the
installation. One final thought for putting the lower insulator low to
the deck is that this increases the length of your backstay (antenna).
The longer your antenna the farther your signal will go and the better
you can get signals.

-Mark Read
www.GoReads.Com

Sounds great, Mark!
As a practical matter, having the backstay isolator mounted lower won't
change the effective antenna length much at all, since the radiating antenna
length starts right at the antenna tuner, and includes the entire length of
the feedline as well as the backstay.
The only difference might be the added capacity to ground for the
distance the antenna feedline and the lower, grounded part of the backstay
are parallel. The reduction in that capacitance (and slight radiation
pattern alteration) is why most installers recommend some sort of spacing
between the two where they run near each other.
Old Chief Lynn
 
D

Dennis Pogson

Jan 1, 1970
0
just said:
I'm preparing to install a SSB and have been advised to hold the
antenna cable off the backstay an inch or so until it actually
connects to the backstay above the lower isolater. Any ideas what I
might use for standoffs?
Thanks

Bike shops sell plastic clips for attaching tire pumps and cable clamps etc.
Some of these may be the right diameter for your purpose.
 
B

Bruce in Alaska

Jan 1, 1970
0
Mark / Amy Read said:
All of this is to say that I am very pleased with the unit and the
installation. One final thought for putting the lower insulator low to
the deck is that this increases the length of your backstay (antenna).
The longer your antenna the farther your signal will go and the better
you can get signals.

-Mark Read
www.GoReads.Com

And just where did you learn your RF Electronics? The length of the
antenna starts at the HV Connection of the Antenna Tuner, and ends at
the farthest point of the wire at it's insulator. It makes very little
difference to the radio if that is mostly Backstay, or GTO-15 feedline.
It is the totality of the wire that counts, not which section is which.
Just how close any one section gets, to any Grounded item, is also
somewhat important, as this adds Output Capacitance to the tuners
constraints and can cause the tuners autotune algorythem to do funny
things, if there is to much.

Bruce in alaska
 
P

Peter Bennett

Jan 1, 1970
0
I have installed my ICOM SSB as Chuck described, where the lower
Isolater is 12 to 16 inches from the bottom of the deck. The wire from
the ICOM tuner runs right up the backstay to the Isolater. I used zip
ties to hold the wire in place, and then used rigging tape to hold it
all in place. I have not used any type of PVC pipe or other cover for
the backstay for heat protection. My thinking is that it only gets hot
when you are transmitting. Someone would really have to lean way out
to touch it and it would have to be at that random moment when I am
transmitting on the SSB. The rigging tape wrapped around the backstay
for three or four feet is more than enough to keep from any accidental
burns.

The backstay should not get thermally hot while you are transmitting -
but it may be electrically "hot" - anyone touching it while you are
transmitting may get a nasty RF burn - the "reachable" portion of the
backstay (and any other part of the antenna wiring) should be
electrically insulated to prevent shock or RF burns, not because of
any temperature concerns.



--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
 
G

Glenn Ashmore

Jan 1, 1970
0
That is one of the neatest installation I have found and will probably use
it unless I can find a product I saw at the Annapolis show a few years ago.

It was a black plastic extrusion about 2" wide. Along the edges was a
series of C shape clips about 2" long spaced about 6" apart. One side was
just large enough to snap over the GTO and the other that snapped over the
back stay. Neatest installation I have ever seen but I have never been able
to find a source.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com
 
L

Larry

Jan 1, 1970
0
The backstay should not get thermally hot while you are transmitting -

It won't if you turn off the big linear and just run 150 watts from the
radio...(c;

Sorry, Peter, I couldn't help myself...(c;

73 DE W4CSC/MM2
 
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