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Old 22-12-2009, 09:47   #1
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Counterpoise for RF 23' 393 Shakespeare

Hello all,
I am sure this has gone around a million times before... I have a Yaesu ft 747 gx with 757 tuner and a 23' shakespeare antenna, I have read so much on this I am so confused I don't know where to start.. my question is, I need a good and simple counterpoise for this antenna.. it is a single termanation antenna... I really am lost here.. any help would be great. I live aboard a 41 Mainship..
john
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Old 22-12-2009, 10:10   #2
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Can’t help you John...but welcome to the forum...and happy holidays.
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Old 22-12-2009, 10:58   #3
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thanks, looking forward to this list... and happy holidays to you as well...
john
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Old 23-12-2009, 03:41   #4
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Shakespeare - Mainship

Hello John,
Over some 25 years as a controller for a mobile maritime net I can vouch for the Shakespeare Whip - probably the best transmission over different distances, different locations, different frequencies, different propagation periods have been with boats that have the very same antenna you are talking about. A few have been steel boats that provide a built in radio ground (counterpoise), others have installed grounds.
Not sure of what model and design of Mainship you have? What is it made of? Where is the radio and where is the tuner? A good principle is to work back from base of the antenna - tuner as close as possible connected by heavy gauge tinned copper wired sheathed in rubber - TUNER Grounded RG 58 coax from Tuner to radio.
When we know where the tuner will be located, can give options on RADIO grounding - counterpoise (NOT electrical ground)
Pse excuse detail John ( I am aware that you are a ham)
John-Mainship
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Old 23-12-2009, 04:25   #5
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Freqs

Hi John.
Forgot to ask what Ham and marine frequencies can you transmit on the Yaesu FT 747 GX?
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Old 23-12-2009, 07:37   #6
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Thanks for your help.. well, the Mainship is the Grand Salon, fiberglass hull, twin gas screws... I have my general and I am now working on my extra... my really weak point is antennas... course I am guessing you already know that... :-) from the antenna base to the tunner FC-757 AT might be 5 to 6' of antenna wire... the Ft- 747 GX is an open trans. and will transmit on all freq... great radio for what I want to do... now all this said, please feel free to explain to me as if you were telling someone that knows nothing of hooking this up... if I were on land this would be an easy task for me, but I am lost here... I have hooked up the antenna with RG-8 coax, the ground is not hooked to anything.. I do have gto-15, but was told I really did not need to use it... as you can see the more I read about hooking up this 393, the less I know... any help you can give me would be great... the power supply I am running is the Yaesu FP-757-HD
thanks for your help..
john orr
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Old 23-12-2009, 20:18   #7
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Quote:
Originally Posted by JOHN-MAINSHIP View Post
the Mainship is the Grand Salon, fiberglass hull, twin gas screws...

From the antenna base to the tuner FC-757 AT might be 5 to 6' of antenna wire...

I have hooked up the antenna with RG-8 coax,

the ground is not hooked to anything..

I do have gto-15, but was told I really did not need to use it...

The power supply I am running is the Yaesu FP-757-HD
Hi John,

"From the antenna base to the tuner FC-757 AT might be 5 to 6' of antenna wire... " does this mean Coax ?
This should be replaced with the GTO 15 wire. The length of GTO 15 wire that runs from the tuner to the base of the Shakespeare adds a little length to the antenna itself, It is attached to the side terminal at the base of the antenna - then can be wrapped with rubber splicing tape - least expensive is 3M's Splicing tape - NOT the tape that chandlers would have you buy. Only this single connection is made to the Shakespeare.

"I have hooked up the antenna with RG-8 coax" If this is the coax referred to above - then remove it from the antenna,

Coax Cable should be used to interconnect the 747 Radio to the 757 Automatic Tuner. Your RG-8 Coax is ok, IF it is suffixed as RG- 8A/U (RG-8/U often has contaminating jacket) Otherwise use RG-58A/U or RG58-C/U which is a smaller diameter than the RG-8A/U

The graphic showing the 757 radio connected to the 757 Tuner will be similar to the connections required for your setup RED arrow Goes to a RADIO Counterpoise ground (not electrical ground) BLUE arrow shows the coax connecting the two and the Green arrow shows the GTO 15 wire to the antenna.

Need to know precisely where the Tuner is located - in order to suggest options for a radio ground. If for example it is above a floor (Cabin Sole) and if the floor has a ceiling below it - then one could fix an array of copper 1.5 " strips along the ceiling, covering at least 30 square ft of ceiling (spacing between the strips around 4" all inter connected). The ground terminal on the tuner is connected to the copper strip array wherever convenient.

So need to know where the Power Supply/Radio/Tuner is located.
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Old 24-12-2009, 19:12   #8
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Counterpoise for RF 23' 393 Shakespeare

laidback,
here are a couple of pictures... 30 sq feet, that would be great, everthing I have read say's 100... I am not real sure if I can find 3 sq feet up under te soul deck... I will check on that tomorrow... I need to change the wire to the 393.. and go from there.. I have one pec of copper foil about 18" X 36", if you can explain to me how to add to this that would be great.. I have a roll of 50' X 2" copper strap... I hope you get a better idea of the shack.. the antenna is rigt on the other side of the wall... can't be 5' of coax..
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Old 25-12-2009, 00:00   #9
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Hi John,
The rig looks good -
The 2" copper strap -- would that be "Shim stock" a few thousands of an inch thick ?? cause that's what is needed.
The big piece of copper foil could be incorporated somewhere in the shim stock "array".
Also a picture of the rear panel of the tuner showing the Grounding Terminal/s is needed
I presume the Base of the Shakespeare is behind that brown cover ?
Richard
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Old 25-12-2009, 04:24   #10
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John,
PS , until we know exactly how long the present coax to Tuner to Antenna is, a how it is connected, leave it be. If the center core is soldered to the outer braid - it could be left - so install counterpoise ground first.
Richard
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Old 25-12-2009, 16:15   #11
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PPS. Instead of Shim stock - much cheaper to use Copper foil which also available in a roll - say 2" wide x 100' long here is link to McMaster Carr's listing
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Old 25-12-2009, 18:50   #12
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Counterpoise for RF 23' 393 Shakespeare

Richard,
Merry Christmas!
ok, here are some pictures of the back of all rigs... the one with the small cat sitting on top is the tuner, the one next to it is the radio, and the bottom, is the power supply.. yes, the copper strap is very thin, and very sharp.. :-) the copper foil is thicker, it is use for tool and die making.
was cheap.. :-) the coax that is hooked to the antenna is 4' long... the center line is the only line hooked to the antenna, the antenna is not grounded at all... I hope I have given you what you need, if not, please ask for more... and as little as I know about antenna's you can not hurt my feelings on how this is done.. the more you tell me the better I like it..
again my thanks for all your help
john
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Old 25-12-2009, 19:36   #13
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Richard, what ga. foil??? cheap over on McMaster-Carr !!!
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Old 26-12-2009, 22:04   #14
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Part Number: 9053K34
$74.82 Each
Material
Multipurpose Copper (Alloy 110)
Alloy
110
Finish/Coating
Unpolished (Mill)
Shape
Foil
Thickness
.005"
Thickness Tolerance
±.0008"

Length
100'
Length Tolerance
+8'
Width
2"
Width Tolerance
±1/64"
Hardness
Not Rated
Condition/Temper
Cold Rolled Condition, Soft (Annealed) Temper
Specifications Met
American Society for Testing and Materials (ASTM)
ASTM Specification
ASTM B152
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Old 27-12-2009, 01:29   #15
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Constructing Counter- poise

Hi John,
If one visualizes a trampoline - then what we need to do is give the vertical antenna a copperclad trampoline to bounce the transmission off into space.
The important requirement is to ensure that the base of the antenna is higher than the counterpoise (not by much)
Ideally, if your engine room's headlining (ceiling) measures more than 8' x 4', a very simple design and construction method could be used to install the counterpoise:-
Go to your local Lowes Untitled Document and buy a 8' x 4' x 1/4" plywood sheet - $17.88.
Next :- apply as described earlier, the copper foil to one side of the plywood with some adhesive that will glue the 2 different materials.
Once that job completed - drill a hole through the copper and ply at a point where a radio grounding wire can be terminated from the tuner.
Then insert a countersunk machine screw, a nut & washer; to take the wire.
Next turn over the ply sheet and paint it with an appropriate colour and type of paint for an engine room.
Next - fix the new copperclad headlining to the existing.
Next - connect up the counterpoise to the tuner.

Richard
PS - if the engine room's ceiling is too small - go to plan B.
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