Smartuner Location

[SV Someday Came]

Hello

Can a Smart auto tuner be located close to either a battery charger or an electrical panel? And I mean within 4 inches or so. Or does an autotuner for an HF rig need to be in an isolated spot?

Thank you for your help.

Michael

[Wotname]

The tuner should be very close to the antenna feedpoint. Normally that requirement keeps it well away from the electrical panel and battery chargers.

Hope this helps

[westsail42]

Originally Posted by Wotname

The tuner should be very close to the antenna feedpoint. Normally that requirement keeps it well away from the electrical panel and battery chargers.

Hope this helps

What he said.

Electrically speaking the antenna "starts" at the antenna output of the autotuner (DO NOT use shielded coax wire to connect the autotuner to your external antenna, unshielded GTO-15 I think is the recommended wire). Therefore, as close to your external antenna feed point as possible. As an example, if you are using your insulated backstay as an antenna, mounting the autotuner underdeck as close to the stay's chainplate is ideal, keeping the feedline as short as possible.

The further from the feedpoint, the greater risk of poorer performance.

[SV Someday Came]

Thanks for the replies. I am having a rigger install a block at the top of the mast so I can use a halyard to raise 35 feet of sheathed stainless steel life line. That will be my antenna. It will run parallel to my backstay. I am not going to cut my backstay.

I read about the parallel antenna here on CF and spoke to Bill about it as well.

That being said when I had the boat rewired the Protech 1220i [battery charger] was wired in that port aft area.

I was planning on having the feed point for the antenna right about the level of the boom. That would make the antenna about 35 feet long but that would mean the distance from the external antenna feedpoint to the tuner output would be about 12 feet.

I could shorten that distance by lengthening the antenna. I wanted the antenna to be at boom level and above so that no one would grab it. I was thinking about RF burns.

By making the antenna terminate close to the base of the backstay that I would shorten the distance between the feedpoint of the antenna and the output of the antenna to about 5 feet.

Is 12 feet acceptable or do I need to shoot for 5 feet? When you folks here say "as short as possible" are you really thinking in terms of inches?

The charger is in that proximal aft area as will be the compressor for the fridge. Will the Smartuner be adversly affected?

I can locate the tuner on the starboard afte side but that would make the distance from the tuner to the icom about 20 feet.
Thank you for feedback

Michael

[btrayfors]

Michael,

Locate the "alternate backstay" as far as you can from other standing rigging, e.g., to the stern quarter or to the pushpit.

Make the GTO-15 feedline between the tuner and the antenna as short as possible. If you're worried about RF burns, put some PVC covering over the lower portion of the antenna.

In my experience RF burns are an extreme rarity aboard sailboats. I've actually never heard of one, not even second- or third-hand.

To get an RF burn and do any damage you'd have to be hanging onto the antenna or ground at just the right place and at just the right time while actual transmission is taking place, and hold on right through a very distinct tingle/shock for several seconds. IMHO, that just isn't gonna happen (when you feel the water from a spigot is too hot, do you just keep your fingers there?).

Bill

[SV Someday Came]

Thanks Bill. I had taken a lot of notes during our conversation but I had missed that piece about locating the antenna on the pushpit on the quarter. Thanks for the memory jog! You were right about the Smartuner. That is one well made piece of equipment. I looked at both at HRO and I could see that the icom would have locked me into icom and it would have required power from the icom to power the unit. I like the way the Smartuner is powered directly from the DC panel.


Michael