Attaching GTO15 Cable to Antenna Tuner

[cburger]

I am installing a new Icom 802 SSB with an antenna tuner. There is an isolator on top of the tuner that you run the GTO15 coaxial cable to the backstay from. Icom provides a crimp type ring connector to attach to the cable. Can someone please tell me the proper meathod for attaching to coax to the crimp connector?

[fairbank56]

GTO-15 is not coaxial cable. There is a single center conductor with no outer shield conductor. Just crimp the the provided terminal lug to the center conductor.

Eric

[AnchorageGuy]

We always use a copper bolt clamp for attaching to the backstay, they can be found at most hardware stores and are used to clamp electrical grounds. They are like these, http://tinyurl.com/2f2ln5c. Be sure and buy one for the size wire you are clamping.

[cburger]

so if I understand you correctly there will be no copper braid just the center wire?

[S/V Illusion]

Originally Posted by cburger

so if I understand you correctly there will be no copper braid just the center wire?

GTO15 is stranded copper wire with a pvc jacket; no braid - single conductor.

Coax is different.
http://www.westrimproducts.com/produ...lyers/wire.pdf

[cburger]

It all makes sense now regarding the crimp fitting. For the PL95 connectors I assume I just twist the copper strand, insert into the fitting, solder and trim the excess?

[S/V Illusion]

There are all kinds of wrong ways to properly connect a PL259 to coax so I suggest you do a search as there are lots of step-by-step instructions with diagrams and pictures. All I'd add is don't use crimp connectors on coax and use the proper size soldering iron or you will easily melt the dielectric.

[cburger]

I thought the GTO was not a "Coax"

[osirissail]

Ignore S/V Illusion post #7 - they may be thinking about the coax from the actual radio to the tuner not the GTO-15 which is run from the tuner output to the antenna/backstay. As stated above GTO-15 is a copper stranded conductor that is surrounded by a thick coating of flexible plastic insulation. The insulation is to prevent anybody getting shocked should they grab the cable while the radio is in transmitting mode.
- - A simple ring-type terminal lug is used. The end of the GTO-15 insulation is stripped back to expose the bare copper wire. That is inserted into the terminal lug and then you use a crimper tool (like a pair of pliers) to squeeze the metal terminal to mechanically grasp/grab the GTO-15 copper wire. Then the terminal lug is attached to the large insulated "cone" output terminal of the tuner.
- - The other end of the GTO-15 cable is stripped back and the copper conductor is attached to the antenna/backstay using whatever works best. Normally then this connection is buried under self-vulcanizing electrical tape to keep water and oxidation to a minimum.
- - All of the GTO-15 cable is an active "antenna" from the place where it leaves the tuner to where it is attached to the external antenna/backstay. So it should be as short as possible and the portion underneath the boat's deck should be kept to a minimum. Additionally it is recommended that when running the GTO-15 cable up any shrouds or stays that it be attached by 4" stand-offs. These "stand-offs" prevent the broadcasting RF signal from being absorbed by the grounded shroud or stay and allow the maximum RF to be transmitted by the antenna/backstay.

[cburger]

Osirissail thanks for your input, can the GTO also be used for the run from the base to the tuner? If not what cable would you reccomend? What would be a good way to get the antenna to stand off until I tie it to the insulated section? Thanks all for your input.

[S/V Illusion]

Originally Posted by cburger

Osirissail thanks for your input, can the GTO also be used for the run from the base to the tuner? If not what cable would you reccomend? What would be a good way to get the antenna to stand off until I tie it to the insulated section? Thanks all for your input.

Don't be so quick to ignore my prior suggestion (as was so kindly suggested...) as this (between the radio and tuner) is where you will need coax.

There are lots of different spacers made specifically for the purpose of separating the feed wire from adjacent objects which you can find on an internet search, however, I'd suggest you use some imagination and simply go to a hardware store to find any non-conductive material.

[osirissail]

S/V Illusion is absolutely correct in that you need a good quality coaxial cable to connect from the output of your radio (main box) to the input of the antenna tuner. Use the best you can find and good PL-259 coaxial connectors - sometimes known as "UHF" connectors for some strange reason.
- - There are 4 connections that the tuner needs. First is the coaxial cable mentioned above. Second is the "control cable" that has several small wires that supply power and then signal to initiate "tuning" when you key the microphone or press the "tune" button. Third is the GTO-15 output from the tuner to the antenna/backstay. Fourth and last is a ground cable/ribbon from the ground terminal of the tuner to the ship's best "rf" ground. This particular "cable/ribbon" is best made from flat copper ribbon about 3 inches wide. You double back the end and punch a hole in it and connect that to the ground lug/terminal of the tuner. Then lay/attach the flat copper ribbon material along the inside of the boat to some good underwater ground such as a sintered bronze plate or even the engine if it has a good underwater ground.
- - Stand-offs for the GTO-15 from grounded/bonded shrouds or stays can be made from fiberglass dowel or even very small rigid plastic tubing or waterproofed wooden dowels. You cut off 4 inch lengths and "notch" the ends and drill a tiny hole through the dowel at both ends. You use monel metal seizing wire (sold in boat stores as anchor shackle seizing wire) to tie the cable to one end of the dowel and another piece of the seizing wire to tie the dowel to a stay or shroud. ** If you are going directly up the backstay to the "insulated" section you may be able to cut loose the "bonding wire" from the backstay chainplate and then simply tape the GTO-15 cable directly to the "un-grounded" backstay. It is only if the backstay or a shroud is "grounded/bonded" that is, the bonding wire is attached to the chainplate that you need the stand-offs.

[fairbank56]

Originally Posted by osirissail

Use the best you can find and good PL-259 coaxial connectors - sometimes known as "UHF" connectors for some strange reason.

Because at the time of their invention in the 1930's, UHF referred to frequencies over 30Mhz and the name UHF connector has stuck ever since. It was designed for frequencies up to 300Mhz.

Eric

[cburger]

Gentleman, Thank you one and all for your input. I went to a local radio communications guy who out of the goodness of his heart sold me 30' of LMR 400, (The cable reccomended by ICOM) and actually crimped the correct connectors on the cable for me, all for the whopping price of $35.00. Every once in a while you run into people like this that make me want to come to the game for another day. It's good to hear I don't have to hold off on the backstay as it is ungrounded. It absolutly amazes me that for the money the customer is spending for the radio and my labor that ICOM doesn't have these details in the installation brochure??

[hooligan6a]

I am confused. I want to install a back stay antenna to my Kenwood 460, with a built in Antenna tuner. What kind of connector do I use to attach the GTO-15 to the radio?