? ... use 3.5" to 4" copper foil or strip to connect those elements 1" too skinny. If you can pass the copper around the boat under the cabinetry that would work as well. Some boats have an aluminum toe rail or hull to deck join. If you connect those to the counterpoise with some foil they work great. External copper plate is not as effective as interior foil distribution and subject to corrosion. Some boats expoxied or painted vinylester resin under and over the foil to protect it against physical and corrosive damage.
You might also pass the foil from your keel/engine block to a through hull fitting. That will better help connect you with the sea. But there should be no other reason the FC40 does a bad tune to any Freq the 857D can tune to. Note if your cabin lights and engine alarms come on while you transmist your connection to and your
counterpoise is inadequate. Start transmitting at low power and work up. Don't start right out at 100W until you know the FC40 is happy.
Happy sailing!!
JD
--- On Mon, 9/21/09, GUILLOT JC wrote:
From: GUILLOT JC
Subject: [YaesuTuner] Re: AH3 vs FC40
To: YaesuTuner@...
Received: Monday, September 21, 2009, 1:21 PM
?
My backstay is 13.7 meter long which puts limits to my isolated backstay, I thought to 12.5 meter as the 20 meter band will be my favourite band (mostly digital traffic with Pactor modem but also SSB operation on various sailors Pacific nets).
As counterpoise I plan to link my keel and diesel engine by wide (around 1 inch wide) flat copper ribbon to the FT897D tranceiver and the FC40 ATU. The keel is about 1.85 meter deep, made of steel covered by epoxy and weights about 1 300 kilograms, between 2 and 3 square meter area. I think this should work well by capacitive effect with the surrounding salt water, for the moment I do not intend to have a grounding brass plate outside but I can change my mind.
Any comments will be appreciated.
73s to all.
FK8IH
--- In YaesuTuner@yahoogro ups.com, JD Baillie wrote:
>
> On my sailboat I have no idea what lenth the backstay was. Where I found a point that the system wouldn't tune I felt the problem was inadequate counterpoise inside the boat. Upgrading the counterpoise solved all tuning problems.
>
> What do you plan to use for a counterpoise?
>
> JD
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