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Old 20-01-2013, 22:10   #61
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Re: Installing an ICOM IC-M802

"The only ground I have found that is simple to install and seems to always have a good reflected power reading on all bands is the KISS-SSB ground."

This is a meaningless statement. A low SWR reading has absolutely no bearing on an antennas operating efficiency. A dummy load will also show a 1:1 swr on your meter but is highly inefficient as a radio antenna. As a ham radio operator of 30+ years, I personally am sceptical about the performance of the KISS-SSB ground system at least compared to a decent dynaplate arrangement.

In my opinion the KISS-SSB people are taking advantage of the low technical competence of most marine radio installers and the inability of marine radio users to test the relative performance of their HF radio systems. I also believe that KISS-SSB make some misleading statements in their advertising of the KISS-SSB product.

In short, an HF radio system will still receive and get out without any grounding system at all, particularly on the higher frequencies - but - the system is probably operating at 10% efficiency. Installing the KISS-SSB system may lift operating efficiency up to say 50% which may seem adequate for some users but is still well below optimal operating efficiency.

It seems silly to spend thousands of dollars on HF radio equipment only to have it functioning at a low level of efficiency. Installing a dynaplate can be a painful exercise but don't be fooled into thinking that you are not losing something by substituting the KISS-SSB system

Cheers
Paul - vk4ma
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Old 21-01-2013, 01:23   #62
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Re: Installing an ICOM IC-M802

Quote:
Originally Posted by vk4ma View Post
"The only ground I have found that is simple to install and seems to always have a good reflected power reading on all bands is the KISS-SSB ground."

This is a meaningless statement. A low SWR reading has absolutely no bearing on an antennas operating efficiency. A dummy load will also show a 1:1 swr on your meter but is highly inefficient as a radio antenna. As a ham radio operator of 30+ years, I personally am sceptical about the performance of the KISS-SSB ground system at least compared to a decent dynaplate arrangement.

In my opinion the KISS-SSB people are taking advantage of the low technical competence of most marine radio installers and the inability of marine radio users to test the relative performance of their HF radio systems. I also believe that KISS-SSB make some misleading statements in their advertising of the KISS-SSB product.

In short, an HF radio system will still receive and get out without any grounding system at all, particularly on the higher frequencies - but - the system is probably operating at 10% efficiency. Installing the KISS-SSB system may lift operating efficiency up to say 50% which may seem adequate for some users but is still well below optimal operating efficiency.

It seems silly to spend thousands of dollars on HF radio equipment only to have it functioning at a low level of efficiency. Installing a dynaplate can be a painful exercise but don't be fooled into thinking that you are not losing something by substituting the KISS-SSB system

Cheers
Paul - vk4ma
I have heard a lot of good things from a lot of knowledgeable people about the KISS grounding system, including our own resident HF radio guru, Bill Trayfors.

I have also heard that dynaplates don't actually work the way they are supposed.

Note I say "I have heard" which means I don't really know what I'm talking about. I have no technical knowledge whatsoever, but I am also struggling with these issues as I am installing an M802 in my boat as well.

So in your opinion if a KISS system is not optimal, what is? What about an 8 ton non-encapsulated lead keel? The keel bolts are accessible and the keel is in contact with sea water (if that matters), albeit through a (usually flaking) layer of antifoul.
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Old 21-01-2013, 01:35   #63
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Re: Installing an ICOM IC-M802

Quote:
Originally Posted by Dockhead View Post
I have heard a lot of good things from a lot of knowledgeable people about the KISS grounding system, including our own resident HF radio guru, Bill Trayfors.

I have also heard that dynaplates don't actually work the way they are supposed.

Note I say "I have heard" which means I don't really know what I'm talking about. I have no technical knowledge whatsoever, but I am also struggling with these issues as I am installing an M802 in my boat as well.

So in your opinion if a KISS system is not optimal, what is? What about an 8 ton non-encapsulated lead keel? The keel bolts are accessible and the keel is in contact with sea water (if that matters), albeit through a (usually flaking) layer of antifoul.
I'm sure Paul will have his own opinion here but in the meantime, I'll chime in. I reckon the antifouled non-encapsulated lead keel is a good(ish) HF ground. It is a little deep in the water which is not ideal, its better to have the ground closer to the surface but not so close that it is exposed in a seaway. The antifoul is not a problem as the keel is capacitor coupled to the seawater.

Best ground IMO is a steel hull

I wait to hear from those who don't like the dynaplate although to be fair, some just say it isn't any better using a bronze thruhull so why go to the extra trouble to fit one. Paul obviously likes them and I have found mine to work OK!
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Old 21-01-2013, 03:02   #64
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Re: Installing an ICOM IC-M802

Hi the purpose of a 'ground' is to provide a return current path for a vertical monopole antenna and is not needed at all for a dipole. RF will not penetrate very far at all under the surface of the sea so an efficient ground must either connect to the sea surface or be above it. Two 5+m wires from the ATU are enough for an efficient current return in a fiberglass or wood hull, or via a capacitor from a metal hull (which only the part above the water is functioning). The ground wires need not be 1/4 wave because the ATU tunes the entire vertical/ground system. As VK4MA said SWR is meaningless as to efficiency. Also the effect of surrounding wires, rigging etc. does not significantly affect the radiation pattern - 1 or 2 dB of directivity is not noticeable at all.

Bob N6BK HS0ZIA
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Old 21-01-2013, 04:08   #65
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Re: Installing an ICOM IC-M802

With next to no "knowledge", but some experience of bad transmission, these are my observations. I had a dynaplate in my Sabre, and installed a second one because I had dreadful transmission problems, there was no improvement but since I was out of the Crribbean and into the Med I gave up! I then changed boat and the system on the LH is to have 6" copper strip end to end on both sides of the boat about 12" below waterline, and the same Icom 802 produces fine results. Shame is that I dont currently have need of SSB. I did hear that copper mesh glassed in was good, but as I said, I am just a humble user, not an expert!
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Old 21-01-2013, 05:13   #66
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Re: Installing an ICOM IC-M802

Quote:
Originally Posted by Shamancat View Post
........... As VK4MA said SWR is meaningless as to efficiency. ..........
In the interests of accuracy, this statement is not entirely correct. Perhaps it could better stated could be a low (<2) VSWR does not give a guarantee of efficiency. The point being that a high VSWR is a very useful indication that one has antenna system problems.
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Old 21-01-2013, 05:26   #67
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Re: Installing an ICOM IC-M802

Quote:
Originally Posted by Shamancat View Post
Hi the purpose of a 'ground' is to provide a return current path for a vertical monopole antenna and is not needed at all for a dipole. RF will not penetrate very far at all under the surface of the sea so an efficient ground must either connect to the sea surface or be above it. Two 5+m wires from the ATU are enough for an efficient current return in a fiberglass or wood hull, or via a capacitor from a metal hull (which only the part above the water is functioning). The ground wires need not be 1/4 wave because the ATU tunes the entire vertical/ground system. As VK4MA said SWR is meaningless as to efficiency. Also the effect of surrounding wires, rigging etc. does not significantly affect the radiation pattern - 1 or 2 dB of directivity is not noticeable at all.

Bob N6BK HS0ZIA
That would mean that the keel would be no good at all, wouldn't it?

Nor a through-hull far below the waterline?
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Old 21-01-2013, 05:54   #68
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Re: Installing an ICOM IC-M802

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That would mean that the keel would be no good at all, wouldn't it?

Nor a through-hull far below the waterline?
That is correct.
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Old 21-01-2013, 05:55   #69
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Re: Installing an ICOM IC-M802

Paul,

As a Ham for 30 years, I am surprised you have not learned about radial grounding systems. As a result it may be inappropriate for you to accuse a vendor of ripping off people.

The only thing that surprises me about the KISS ground is that it still works after being folded into a tube. Even the Icom manual suggests the use of a radial grounding system.

My boat came with copper strapped to everything on the boat. I made a radial ground and it seems to work great with very similar readings to KISS.

I suspect that a Dynaplate may in fact produce a stronger ground wave, but I have never seen any test that would prove that. So if we assume it is stronger, putting a hole in your boat and putting usp with corrosion to reach out up to 150 miles on 2MHz is not really worth it to me personally.

However when we are talking about a sky wave, the best thing we can do is transfer maximum power to the antenna. If the antenna and ground system matches up (low SWR) then the sky wave component should be as strong as it will get.

I have HF, UHF, and Microwave experience and while my first impression of KISS was the same as yours, my open mind and tests on about 40 boats the past year have changed my mind. Actually the worst installation I found was a Cat with a Dynaplate. To me that does not mean Dynaplates are bad now, it was in fact the configuration. The SWR was so high the transmitter shut down and that is a problem.

By the way since we are comparing credentials, I have approximately 5 years of formal technical training, plus 4 years of collage to be an electrical engineer, and have over 40 years in communications with the marking point being when I got my 1st class radio telephone license with a radar endorsement. In an earlier life I was chief engineer for a TV station and I am a qualified Navy MARS operator. I took and passed all three Ham tests in one sitting without even studding for the Advanced test.

I learned a long time ago to have an open mind with regard to HF coms as HF coms is mostly magic anyway. Communications propagation changes by the minute during periods of the day regardless what ground you install.

73s
TL Sparks
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Quote:
Originally Posted by vk4ma View Post
"The only ground I have found that is simple to install and seems to always have a good reflected power reading on all bands is the KISS-SSB ground."

This is a meaningless statement. A low SWR reading has absolutely no bearing on an antennas operating efficiency. A dummy load will also show a 1:1 swr on your meter but is highly inefficient as a radio antenna. As a ham radio operator of 30+ years, I personally am sceptical about the performance of the KISS-SSB ground system at least compared to a decent dynaplate arrangement.

In my opinion the KISS-SSB people are taking advantage of the low technical competence of most marine radio installers and the inability of marine radio users to test the relative performance of their HF radio systems. I also believe that KISS-SSB make some misleading statements in their advertising of the KISS-SSB product.

In short, an HF radio system will still receive and get out without any grounding system at all, particularly on the higher frequencies - but - the system is probably operating at 10% efficiency. Installing the KISS-SSB system may lift operating efficiency up to say 50% which may seem adequate for some users but is still well below optimal operating efficiency.

It seems silly to spend thousands of dollars on HF radio equipment only to have it functioning at a low level of efficiency. Installing a dynaplate can be a painful exercise but don't be fooled into thinking that you are not losing something by substituting the KISS-SSB system

Cheers
Paul - vk4ma
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Old 21-01-2013, 06:06   #70
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Re: Installing an ICOM IC-M802

Actually Bob the purpose of the ground is to provide a reflected 1/4 wave for the 1/4 wave antenna. Since our antenna is never a true 1/4 wave, we need the antenna tuner to ad coils to lengthen the equivalent antenna and capacitors to shorten the antenna at higher frequencies. The radiation form the antenna element is what is hitting the ionosphere and providing the distance communication. Given the right conditions we could talk long distances with very little power.

73s
TL Sparks

Quote:
Originally Posted by Shamancat View Post
Hi the purpose of a 'ground' is to provide a return current path for a vertical monopole antenna and is not needed at all for a dipole. RF will not penetrate very far at all under the surface of the sea so an efficient ground must either connect to the sea surface or be above it. Two 5+m wires from the ATU are enough for an efficient current return in a fiberglass or wood hull, or via a capacitor from a metal hull (which only the part above the water is functioning). The ground wires need not be 1/4 wave because the ATU tunes the entire vertical/ground system. As VK4MA said SWR is meaningless as to efficiency. Also the effect of surrounding wires, rigging etc. does not significantly affect the radiation pattern - 1 or 2 dB of directivity is not noticeable at all.

Bob N6BK HS0ZIA
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Old 21-01-2013, 06:08   #71
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Re: Installing an ICOM IC-M802

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Originally Posted by TLSparks View Post
Paul,


I suspect that a Dynaplate may in fact produce a stronger ground wave, but I have never seen any test that would prove that. So if we assume it is stronger, putting a hole in your boat and putting usp with corrosion to reach out up to 150 miles on 2MHz is not really worth it to me personally.

However when we are talking about a sky wave, the best thing we can do is transfer maximum power to the antenna. If the antenna and ground system matches up (low SWR) then the sky wave component should be as strong as it will get.
Sky and ground wave are equally improved by increased antenna radiation. Low SWR does not ensure that, only high radiation efficiency. A vertical antenna with a poor return current ground and 1:1 SWR is most certainly not as strong as it will get, all your qualifications notwithstanding.
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Old 21-01-2013, 06:16   #72
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Re: Installing an ICOM IC-M802

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So if we assume it [dynaplate] is stronger, putting a hole in your boat and putting usp with corrosion to reach out up to 150 miles on 2MHz is not really worth it to me personally.

Apologies to the OP for talking again about my own situation. But putting a hole in my boat for a radio ground is not an option. My boat has a fully cored hull -- so the only holes which will ever be in it, in my ownership, are the ones it was born with.

This is the same situation as many larger higher-end boats like Swans and Hallberg-Rassys, so I'm not the only one in this boat (so to speak).

Sure is a lot of conflicting advice. If the keel is out, looks like I have a choice of throughhull or KISS. Or both, I guess. But my throughhulls are pretty deep -- deep hull form.
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Old 21-01-2013, 06:28   #73
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Re: Installing an ICOM IC-M802

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Originally Posted by TLSparks View Post
Actually Bob the purpose of the ground is to provide a reflected 1/4 wave for the 1/4 wave antenna. Since our antenna is never a true 1/4 wave, we need the antenna tuner to ad coils to lengthen the equivalent antenna and capacitors to shorten the antenna at higher frequencies. The radiation form the antenna element is what is hitting the ionosphere and providing the distance communication. Given the right conditions we could talk long distances with very little power.

73s
TL Sparks
Actually Sparks you are confusing the near field reactive ground with the far field reflective ground (provided by the sea). The tuner merely supplies capacitive or inductive reactance as required to achieve a conjugate match (low SWR) and has nothing whatever to do with return current collection required by a monopole antenna or its efficiency as a radiator.
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Old 21-01-2013, 06:28   #74
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Re: Installing an ICOM IC-M802

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........

Sure is a lot of conflicting advice. If the keel is out, looks like I have a choice of throughhull or KISS. Or both, I guess. But my throughhulls are pretty deep -- deep hull form.
Suck it and see, nothing lost if the keel or thruhull doesn't work so well; just add a KISS counterpoise later.

One thing that all (almost all) the experts agree on is that HF antennas / propagation is more of an art than anything else. Sure there is some science but.......
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Old 21-01-2013, 07:06   #75
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Re: Installing an ICOM IC-M802

Obviously I would agree it is all about antenna radiation and not SWR.

However, it would not be possible to get a 1:1 SWR with a poor ground for a typical boat installation. Possibly with a manual tuner faking the match at a shore facility, but not with a typical 802 and an AT140, regardless of the grounding system. Given a typical installation, the better the SWR the more the antenna system gets.

Boats with high SWR do not put out ground or sky waves.

I use the SWR as an overall health of the installation. If the SWR is high, it is usually corrosion on the antenna or the grounding system.

73s
TL Sparks
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Quote:
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Sky and ground wave are equally improved by increased antenna radiation. Low SWR does not ensure that, only high radiation efficiency. A vertical antenna with a poor return current ground and 1:1 SWR is most certainly not as strong as it will get, all your qualifications notwithstanding.
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