This past weekend I was able to get the ICOM SSB and tuner installed on my CD 33 and connected except for the ground. The ICOM manuel is not very specific as to what to ground to. the quarter berth has a copper sheathing epoxied over much of the berth with a strap lead aft to the starboard locker. I am wondering if I could ground the radio and tuner to the cooper or should I go to something else. I see mention of people using ground plates but do not know where mine is (I assume I have one and most likely it is impossible to reach). Any thoughts?
Thanks,
Larry
lmace@gt.com
SSB ground
Moderator: Jim Walsh
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D. Stump, Hanalei
Re: Counterpoise....
Larry,
The copper sheathing is probably someones' attempt at providing a counterpoise for the SSB antenna. If you are looking for a chasis ground for the electronics, go for the normal ground of the 12 volt system. That should ultimately get to the engine ground too. Not sure if you could induce EM noise into the SSB if you ground to the counterpoise.
Dave Stump
Captain Commanding
s/v Hanalei CD-30
The copper sheathing is probably someones' attempt at providing a counterpoise for the SSB antenna. If you are looking for a chasis ground for the electronics, go for the normal ground of the 12 volt system. That should ultimately get to the engine ground too. Not sure if you could induce EM noise into the SSB if you ground to the counterpoise.
Dave Stump
Captain Commanding
s/v Hanalei CD-30
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Larry DeMers
`Re: SSB ground
Larry,
Yes, that screen would probably work quite well as a ground for your SSB. It works by way of capacitance to the water on the other side ofthe hull, so even though there is no direct or DC conection to the exterior ground through this screen, it is an effective ground at frequencies greater than a couple hundred kilohertz.
If you do have a sintered brass grounding plate mounted externally, then this would be a good ground also..unless it has been painted over, in which case it is not worth as much.
Normally, a ground grid screen is layed into the hull layup, the full length of the boat. But this is only true if it is ordered this way. Other hams and SSB users have installed a screen grid after-market, which is not as good, and a lot of work too. However, both ideas work well enough for this application, I believe.
Make your connection to the ground screen lead as short and as tight as possible. Cover all exposed metal with an insultor or wrap in self-amalgamating tape. You should measure less than .1 ohm at the connection if done right (may need a sensitive VOM meter)
Larry DeMers
s/v DeLaMer
Cape Dory 30
demers@sgi.com
Yes, that screen would probably work quite well as a ground for your SSB. It works by way of capacitance to the water on the other side ofthe hull, so even though there is no direct or DC conection to the exterior ground through this screen, it is an effective ground at frequencies greater than a couple hundred kilohertz.
If you do have a sintered brass grounding plate mounted externally, then this would be a good ground also..unless it has been painted over, in which case it is not worth as much.
Normally, a ground grid screen is layed into the hull layup, the full length of the boat. But this is only true if it is ordered this way. Other hams and SSB users have installed a screen grid after-market, which is not as good, and a lot of work too. However, both ideas work well enough for this application, I believe.
Make your connection to the ground screen lead as short and as tight as possible. Cover all exposed metal with an insultor or wrap in self-amalgamating tape. You should measure less than .1 ohm at the connection if done right (may need a sensitive VOM meter)
Larry DeMers
s/v DeLaMer
Cape Dory 30
larry mace wrote: This past weekend I was able to get the ICOM SSB and tuner installed on my CD 33 and connected except for the ground. The ICOM manuel is not very specific as to what to ground to. the quarter berth has a copper sheathing epoxied over much of the berth with a strap lead aft to the starboard locker. I am wondering if I could ground the radio and tuner to the cooper or should I go to something else. I see mention of people using ground plates but do not know where mine is (I assume I have one and most likely it is impossible to reach). Any thoughts?
Thanks,
Larry
demers@sgi.com
-
Bill
Re: Counterpoise....
Dave
Is there a formula for determining the size of the grid (I guess bigger is better) for aftermarket installation? And where does on obtain the copper mesh? Can the mesh be expoxied in place leaving two (or one) exposed lead?
I know the strapping is available from WM et al...., but dont know about the mesh.
Thanks
Bill
cd25d@rhapsodysails.com
Is there a formula for determining the size of the grid (I guess bigger is better) for aftermarket installation? And where does on obtain the copper mesh? Can the mesh be expoxied in place leaving two (or one) exposed lead?
I know the strapping is available from WM et al...., but dont know about the mesh.
Thanks
Bill
D. Stump, Hanalei wrote: Larry,
The copper sheathing is probably someones' attempt at providing a counterpoise for the SSB antenna. If you are looking for a chasis ground for the electronics, go for the normal ground of the 12 volt system. That should ultimately get to the engine ground too. Not sure if you could induce EM noise into the SSB if you ground to the counterpoise.
Dave Stump
Captain Commanding
s/v Hanalei CD-30
cd25d@rhapsodysails.com
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D. Stump, Hanalei
Re: Ya got me! ! !
Bill,
The answer to ALL your questions is, "I don't know"! I know about counterpoise antennas from playing with radio controlled models. Haven't any idea where ya get the material for installing the beast in a real boat! Maybe someone else knows and will answer.
D. Stump
Hanalei
The answer to ALL your questions is, "I don't know"! I know about counterpoise antennas from playing with radio controlled models. Haven't any idea where ya get the material for installing the beast in a real boat! Maybe someone else knows and will answer.
D. Stump
Hanalei
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Larry DeMers
Re: Ya got me! ! !
Dave and Bill,
You may be right..in that he was refering to a DC ground, rather than an RF ground. But when he mentioned an external grounding shoe, that is an RF grounding device only, and so I took that to mean that his whole question refered to this as an RF ground question.
If it's a DC ground you want, choose the closest possible connection to the negative battery post on the batteries. Choosing virtually any other place will result in more noise and a poorer ground, due to small but important losses in each connector and splice between the negative post and the attachment for your ground. The larger that voltage difference is, the more noise will be allowed into your radios rcvr.
If it is an Rf ground (counterpoise) that he meant, then attach the antenna shield to the gridwork built into the boat. Use the shortest and best connection possible. Route away from other metallic objects, as this grid will act like an antenna for a portion of it's path, until it can capacitively couple to the water on the other side of the hull. Nearby metal can absorb and reradiate some of the transmitters output power, resulting in a bit higher SWR and poorer output signal.
Dave..so you were into RC modeling too hey? Me too. I got in back in the early escapement days, and built my own 12 channel tone transmitter and tuned reed receiver..a long time ago..but then switche d to proportional and have been having fun with hydros and gliders and a 1/4 scale cessna 180 taildragger. What a great hobby! Write sometime, and tell me about what you fly..
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~~~~~Sailing Lake Superior~~~~~
demes@sgi.com
You may be right..in that he was refering to a DC ground, rather than an RF ground. But when he mentioned an external grounding shoe, that is an RF grounding device only, and so I took that to mean that his whole question refered to this as an RF ground question.
If it's a DC ground you want, choose the closest possible connection to the negative battery post on the batteries. Choosing virtually any other place will result in more noise and a poorer ground, due to small but important losses in each connector and splice between the negative post and the attachment for your ground. The larger that voltage difference is, the more noise will be allowed into your radios rcvr.
If it is an Rf ground (counterpoise) that he meant, then attach the antenna shield to the gridwork built into the boat. Use the shortest and best connection possible. Route away from other metallic objects, as this grid will act like an antenna for a portion of it's path, until it can capacitively couple to the water on the other side of the hull. Nearby metal can absorb and reradiate some of the transmitters output power, resulting in a bit higher SWR and poorer output signal.
Dave..so you were into RC modeling too hey? Me too. I got in back in the early escapement days, and built my own 12 channel tone transmitter and tuned reed receiver..a long time ago..but then switche d to proportional and have been having fun with hydros and gliders and a 1/4 scale cessna 180 taildragger. What a great hobby! Write sometime, and tell me about what you fly..
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~~~~~Sailing Lake Superior~~~~~
D. Stump, Hanalei wrote: Bill,
The answer to ALL your questions is, "I don't know"! I know about counterpoise antennas from playing with radio controlled models. Haven't any idea where ya get the material for installing the beast in a real boat! Maybe someone else knows and will answer.
D. Stump
Hanale
demes@sgi.com
-
Ken Coit
Re: Counterpoise....
Bill,
Here's the URL for a wholesaler of screening:
http://www.twpinc.com/rfi.html
They carry copper for RFI shielding and lots of other types as well. They even have a price list and ship! Tinned copper would be ideal, but I doubt anyone makes it. Encapsulating copper in epoxy ought to be a fairly permanent solution. I have no idea if copper screen is still carried by the Home Depots of the world, but they are a likely retail source. I think you want to run tinned braid from the screen so as to maximize the surface area which is important at the higher frequencies.
Good luck!
Ken Coit
Parfait CD-36 #84
ND7N
parfait@nc.rr.com
Here's the URL for a wholesaler of screening:
http://www.twpinc.com/rfi.html
They carry copper for RFI shielding and lots of other types as well. They even have a price list and ship! Tinned copper would be ideal, but I doubt anyone makes it. Encapsulating copper in epoxy ought to be a fairly permanent solution. I have no idea if copper screen is still carried by the Home Depots of the world, but they are a likely retail source. I think you want to run tinned braid from the screen so as to maximize the surface area which is important at the higher frequencies.
Good luck!
Ken Coit
Parfait CD-36 #84
ND7N
Bill wrote: Dave
Is there a formula for determining the size of the grid (I guess bigger is better) for aftermarket installation? And where does on obtain the copper mesh? Can the mesh be expoxied in place leaving two (or one) exposed lead?
I know the strapping is available from WM et al...., but dont know about the mesh.
Thanks
Bill
D. Stump, Hanalei wrote: Larry,
The copper sheathing is probably someones' attempt at providing a counterpoise for the SSB antenna. If you are looking for a chasis ground for the electronics, go for the normal ground of the 12 volt system. That should ultimately get to the engine ground too. Not sure if you could induce EM noise into the SSB if you ground to the counterpoise.
Dave Stump
Captain Commanding
s/v Hanalei CD-30
parfait@nc.rr.com
-
Jeff Barnes
Re: SSB ground
Larry:
Although I am not exactly clear as to how your copper screen is set up, heer is what I did for grounding on my CD36 (Jazman). i have the the ICOM 710 (with remote frontg panel) and the AT-130 tuner. The tuner is mounted in the lazarette, i.e. as close as possible to the base of the insulated backstay antenna. This is important so that you minimize the length of high voltage cable from the tuner. Regrding grounding, I have used copper foil which is available from West Marine. One end of the foil is attached to the ground terminal of the antenna tuner. The foil then leads to one of the connections on a bronze dynaplate. If you do not have one, one or two through hull fittings will suffice (connect with SS hose clamp arond base of fitting). I believe I used approximately 15'of foil. The foil was epoxied to the hull interior using West Systme resin for protection and to prevent oxidation.
Regrds,
Jeff
Although I am not exactly clear as to how your copper screen is set up, heer is what I did for grounding on my CD36 (Jazman). i have the the ICOM 710 (with remote frontg panel) and the AT-130 tuner. The tuner is mounted in the lazarette, i.e. as close as possible to the base of the insulated backstay antenna. This is important so that you minimize the length of high voltage cable from the tuner. Regrding grounding, I have used copper foil which is available from West Marine. One end of the foil is attached to the ground terminal of the antenna tuner. The foil then leads to one of the connections on a bronze dynaplate. If you do not have one, one or two through hull fittings will suffice (connect with SS hose clamp arond base of fitting). I believe I used approximately 15'of foil. The foil was epoxied to the hull interior using West Systme resin for protection and to prevent oxidation.
Regrds,
Jeff
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D. Stump, Hanalei
Re: 40 foot Coast Guard Utility Boat! ! !
Larry,
Years ago I flew an ASW-17 sailplane with something like a 12' wingspan, but rolled it on the high start one day and watched it disintigrate as it went down the field. Decided then and there that flying was a little to expensive, so changed to boats. Have had RC sailboats, last one an IACC class, and about three years ago I built Dumas's 40"CG Utility Boat. It is twin Screwed, twin engine, with full actual running lights and blue flasher, with a three tone adjustable siren. Two speeds forward and two reverse. Drives the other skippers crazy when I run it down between the slips with siren and lights flashing! It looks like the real thing, only smaller.
Good talking to ya....
Dave Stump
Hanalei
Years ago I flew an ASW-17 sailplane with something like a 12' wingspan, but rolled it on the high start one day and watched it disintigrate as it went down the field. Decided then and there that flying was a little to expensive, so changed to boats. Have had RC sailboats, last one an IACC class, and about three years ago I built Dumas's 40"CG Utility Boat. It is twin Screwed, twin engine, with full actual running lights and blue flasher, with a three tone adjustable siren. Two speeds forward and two reverse. Drives the other skippers crazy when I run it down between the slips with siren and lights flashing! It looks like the real thing, only smaller.
Good talking to ya....
Dave Stump
Hanalei
-
larry mace
Re: SSB ground
Jeff and others,Jeff Barnes wrote: Larry:
Although I am not exactly clear as to how your copper screen is set up, heer is what I did for grounding on my CD36 (Jazman). i have the the ICOM 710 (with remote frontg panel) and the AT-130 tuner. The tuner is mounted in the lazarette, i.e. as close as possible to the base of the insulated backstay antenna. This is important so that you minimize the length of high voltage cable from the tuner. Regrding grounding, I have used copper foil which is available from West Marine. One end of the foil is attached to the ground terminal of the antenna tuner. The foil then leads to one of the connections on a bronze dynaplate. If you do not have one, one or two through hull fittings will suffice (connect with SS hose clamp arond base of fitting). I believe I used approximately 15'of foil. The foil was epoxied to the hull interior using West Systme resin for protection and to prevent oxidation.
Regrds,
Jeff
I do not have screen but instead copper that appears to be solid. There is a 1" copper strip attached to the epoxied copper in the quarter berth that leads to a thru hull I think. I was thinking of connecting the radio via a wire to the screw in the quarter and likewise leading a wire from the tuner in the starboard locker to the same screw. Is it better to use copper foil instead of a wire in connecting to the copper plate?
Thanks,
larry
lmace@gt.com
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Jeff Barnes
Re: SSB ground
Larry:
The antenna-tuner should be connected to the copper ground plane using copper foil. There is a ground terminal on the Icom tuner for this purpose. Ideally, the 1" strap which runs from the copper in your berth should be connected to the Dynaplate (assuming you have one), but as I mentioned, 1 or 2 through hull fittings should work. Just make sure the connections are good. The radio can be grounded with a wire to the copper. Make sure the control cvabel between the radio and tuner is hooked properly. It is easy to make a mistake when your working inside the tuner.
Regards,
Jeff
The antenna-tuner should be connected to the copper ground plane using copper foil. There is a ground terminal on the Icom tuner for this purpose. Ideally, the 1" strap which runs from the copper in your berth should be connected to the Dynaplate (assuming you have one), but as I mentioned, 1 or 2 through hull fittings should work. Just make sure the connections are good. The radio can be grounded with a wire to the copper. Make sure the control cvabel between the radio and tuner is hooked properly. It is easy to make a mistake when your working inside the tuner.
Regards,
Jeff