Built-in Antenna Tuner

[*Death*]

On one hand i`ve a TS-450 hf radio with built-in antenna tuner. Id like to install it into my Bristol 32 sailboat. really everything I read tells me to use an stand alone tuner near the antenna. In truth I have a outbacker antenna that I plan to gingerly install on the stern rail. Can I run coax to it and use my built-in tuner?
Jeannette B32 San Francisco kc6jet

[Drain-o Martini]

In summary is whitch the builded-in tuner on the TS450 is only good for comfortably tuning antenas which are allready fairly close to 52 Ohms--i.e. In my opinion where the SWR is lower than about 3:1. Luckily the issue about external antenna tunerts with non-resonant atnenas is a complicated one. Feel free to cotnact me via email if you have further qeustoins.

[bong]

What you are describing will probably not work very well. The feedpoint resistance of a very short antenna like the outbacker is very low and the built in antenna tuner in the TS-450 will probably not be able to match the impedance. So if you want any kind of transmitting performance you`ll need a conventional external, antenna tuner mounted at the base of the antenna. Having a very good ground system (such as 100 sf of copper mesh in the hull) is also essential for good transmitting performance with any end fed antenna, such as a backstay or outbacker.
Bob - K9KKY Professional Yacht Delivery Offshore Sailing Instruction Naples, FL 800-329-4884

[Ravidel Terrant]

I think you will find that it will work reasonably well though it is not very convenient. The outbacker will load up though it is still a short antenna. Note though that you have to move the jumper and maybe the SS whip to change bands.
I would not want to go messing around the transom on a dark and stormy night to move my HF from 20 to 40 meters. Just messy.

[Kagewolf]

Besides what Bob says, these built-in tuners are usually designed to allow the operator to use the whole amateur band on a given frequency band when using short verticals which usually allow a spread of only 100 or 200 Hz at the lower bands like 7 MHz. john n2zoa

[Nick_Shunda]

Hi Jeanette, It will probably work well in the ham bands. By adjusting the plug the antenna can be made resonant in each band. The stinger (whip) is also adjusted in and out for lowest swr. The outbacker is a solid weather proof portable antenna. Generally the antenna can only be adjusted for a segment of the band, e.g phone or CW. Two other thoughts, the antenna works against a ground plane so assure the best RF ground possible. I used a similar arrangement with loaded whips mounted on the push pit which itself was an insufficient ground. Dropping a length of chain in the water attached by wire clamped to the pushpit with a battery clamp improved things immensely. This just an example, there are many things to try. Secondly be sure there is a solid connection from the radio Ground terminal to ground. This the ground the tuner will work against. Isuggest using braid. Don`t buy it just strip what you need from a piece of coax.
Enjoy and 73, Scott W7GSM 1971 Grampian 26 FinelyFreee 1972 Columbia 30 ScottsFreee

[kevin467]

In particular if you modified the radio to work on the Marine bands, than the tuner will also proportionately tune the Outbacker Marine & Ham antennae. I singularly modified a TS-940 & it works perfect.