What kind of cable to connect AT-140 to backstay?

[le chat beaute]

Use a Kearny nut to attach got to stay. They are used to attach ground cable to ground rods. Long last and the proper metal. Then cover from environment.

[skenn_ie]

Originally Posted by sv_pelagia

GTO-15 cable (NOT coax)

Note, the length of GTO-15 to your backstay is part of the antenna.


https://ca.binnacle.com/p7786/Ancor-...duct_info.html

https://www.westmarine.com/buy/ancor...pool--16274953

Suggestion: Shouldn't you have Co-ax to backstay with screen connected to the uninsulated part ? Part of the antenna at right-angles to the main wouldn't do any favours. Alternatively, a coil to bring that wire up to 1/2 wavelength ?

[team karst]

Originally Posted by skenn_ie

Suggestion: Shouldn't you have Co-ax to backstay with screen connected to the uninsulated part ? Part of the antenna at right-angles to the main wouldn't do any favours. Alternatively, a coil to bring that wire up to 1/2 wavelength ?

That feed would make a OFF CENTER fed dipole. It is done in other spaces, but not popular on boats. I suspect the end of the short section may have quite a high voltage on it, depending on freq and tuning.

On tuning, the ATU has quite the assortment of reactive goodies to effect a tune.

[Jammer]

Originally Posted by skenn_ie

Suggestion: Shouldn't you have Co-ax to backstay with screen connected to the uninsulated part ? Part of the antenna at right-angles to the main wouldn't do any favours. Alternatively, a coil to bring that wire up to 1/2 wavelength ?

Backstay antennas are, electrically, random-length wire antennas that are not designed to be operated and their resonant frequency.


https://udel.edu/~mm/ham/randomWire/


Backstay antennas aren't very good antennas, electrically. People use them because there are no better options on a sailboat, at least not for a permanently installed antenna that works on a wide variety of bands and frequencies.



The AT-140 tuner has an RC network used to match impedance so that a reasonable amount of power is actually radiated, at least on the bands most widely used by cruisers (generally 7 MHz and higher frequencies).


There are people who experiment with resonant, half-wave dipole antennas, aboard, at HF. It is necessary to have a number of antennas and hoist whichever one is needed. This complicates communications in an emergency because durability and windage make it impractical to leave these in place permanently.

[team karst]

Icom tuners use an array of L’a and C’s for matching, not R’s. Prolly a typo there.
But I think the point is arguable. On 7MHz band, I get rave reviews, of course propagation dependent. Seawater makes an excellent launch pad for these signals, and I will bet a backstay over ocean rig will beat a fixed 43’ vertical on ground, a popular ham setup ashore.
Actually, I use a 23’ whip aboard, so its shorter than many backstay setups. That doesnt help efficiency.