Cable between Auto tuner & Antenna HF

[mags71]

Hi, can any one please tell me what kind of cable/wire should be used between an Auto tuner & antenna. The antenna tuner is a Barrett 911 ( 911 Automatic antenna tuner )

the antenna we have is a 18-20 foot aluminium vertical with just a single screw for connecting the wire from the tuner to.

it is used for 2,4,6,8 MHZ

Thanks.

[dkostrey]

From the description of that tuner:

The 911 is supplied complete with fully terminated control cables having an overall length of 6 metres. This comprises of a 1.5 metre stub cable with a 4.5 metre extension cable for connection to the transceiver. The cable is a composite design incorporating coaxial, power supply and control cables. Additional extension cables are available as required.


Use of cables not meant for the tuner could (will) damage the unit. Contact the manufacturer for the proper cable.


Good luck ...

[mags71]

Hi.

I actually mean the wire/cable from the ATU ~ The Antenna.


Not the cable from the Radio ~ The ATU.

[prcguy]

The wire between the tuner and the antenna is part of the antenna and will radiate RF so it should be routed away from other metal objects. In a marine environment its a good idea to use stranded insulated wire to protect from corrosion and goop the connections with RTV Silicone. Any good outdoor rated insulated wire is fine and #12 would be a god size for up to 1kw. If there is a chance people might come in contact with the wire while your transmitting you can use solid core spark plug wire, just make sure the actual wire is a reasonable size and not something like #30. One thing most people forget is the tuner needs a good counterpoise (ground plane) to work against. If the tuner is located near the water line and there is a very short and direct connection available to a zinc, that may work. Otherwise run several wires along the perimeter of the hull for the length of the hull if possible, you want the most wire under the vertical radiator as possible. If the tuner will not tune and it keeps hunting for a match that's a good sign the counterpoise is not adequate. In this case sometimes changing the length of the counterpoise a few feet can make it happy.
Good luck with your install.
prcguy

[rfradioconsult]

I second the HV spark plug wire as a connector; I've found the best place to find copper spark plug wire is at a small engine (lawnmower) shop. The wire from autoparts stores is usually high resistance TVRS type cable, not actual wire. Some folks advocate using a piece of RG-8 coax with the shield attached to the ground; BAD idea, do not use RG-8. The inner conductor to shield capatance will act as an AC path to ground and actually shunt your signal to ground.

[RKG]

The cable you want to use is a special form of high voltage conductor known as GTO-15. See West Marine: GTO 15 High Voltage Cable, per FT Product Display