Issue with Icom M802 Installation

[mcerdos]

Hi,

I recently installed an iCom m802 SSB.

First, the good stuff. I am certain the grounding plate I am using is isolated from anything else on the vessel. I have a bronze plate on the rudder. The unit was installed on its own circuit with a full +/- run directly to the battery via an exclusive double pole breaker. There is no common ground.

Now the not so good: I am experiencing interference problems. The coax cable from the base unit to the AT 140 antenna tuner runs to the aft locker via a conduit that houses AIS/GPS cables and a couple of Ethernet cables for the computer network. When I transmit on the SSB, the AIS crashes and the computer network is having problems (the router will reset). There are common connections to these devises. I used RG8X from recommended by my West Marine and crimp on PL259 connectors for this run.

What could cause this interference?

Any help will be greatly appreciated!!!

[wa2enm]

Recheck all PL259 connections. A short between the shield and the center conductor could load RF onto the shield and make a new antenna that spews RF on who knows what freqs.

[mcerdos]

Originally Posted by wa2enm

Recheck all PL259 connections. A short between the shield and the center conductor could load RF onto the shield and make a new antenna that spews RF on who knows what freqs.

Thanks! I will do this. I think I will replace the crimp on connecters with the solder kind. I will have a little more control.

Would this be enough to cause the electronics close to the cable to freak out?

[svinshallah]

You might also try the Radio Works T4 line isolator installed right at the AT-140. It blocks any RF on the shield from being conducted towards the 802.

[lonesoldier0408]

Any chance of cross connection or too close proximity of antenna. Faulty antenna isolation ie; crushed over tightened Teflon washer at antenna base, improperly located nylon washer. Just some things to look at and review.

[btrayfors]

The coax between the M-802 main unit and the AT-140 should be located as far from other electronics wiring as possible. In addition, it is a very good idea to install an RF choke (such as was mentioned above) in the coax line close to the AT-140, and to install ferrites at both ends of both the coax and the control cable.

It is also a good idea to use very well shielded coax, like RG-214 which has two layers of shielding or LMR-400 which has one layer of foil and one layer of traditional shielding.

Remember, any current flowing through a conductor creates an electro-magnetic field around that conductor. The stronger the current, the stronger the electro-magnetic field.

Bill
WA6CCA

[funk-an-bord.de]

1. The coax between the M-802 main unit and the AT-140 should be located as far from other electronics wiring as possible.
2. .. install an RF choke (such as was mentioned above) in the coax line close to the AT-140, and to install ferrites at both ends of both the coax and the control cable.
3. If you are limited to the diameter of 5 mm then the H155 cable has a good shield: .. one layer of foil and one layer of traditional shielding.
4. If you can not isolate mecanicaly the HF cable and the other (AIS/Ethernet)
there is a shield HEGEMIP from hellermanntyton.
Its difficult to get, and does not help against the magnetic component
A tube of cupper or iron may give a better shielding.
Wilhelm,
AC1WA

[d4raffy]

Apologies for the slight thread drift ..but its on a similar line ... as a new owner of an 801E, AT141 & KISS..about to install. Couple of quick install questions ...

1. I am sure i have read that there maybe problems between SSB components and the Autopilot - is this the case ? - my AT141 and Antenna wire will be about 50cm - 1m from my S2G computer and rudder reference ?

2. Does the KISS have to rest / touch the hull closest to the water. I understand it works by capacitance - but I want to secure it with some clips which will elevate it some what of the hull - does the distance mater ?

Thanks for any friendly advice ...

[btrayfors]

Originally Posted by d4raffy

Apologies for the slight thread drift ..but its on a similar line ... as a new owner of an 801E, AT141 & KISS..about to install. Couple of quick install questions ...

1. I am sure i have read that there maybe problems between SSB components and the Autopilot - is this the case ? - my AT141 and Antenna wire will be about 50cm - 1m from my S2G computer and rudder reference ?

2. Does the KISS have to rest / touch the hull closest to the water. I understand it works by capacitance - but I want to secure it with some clips which will elevate it some what of the hull - does the distance mater ?

Thanks for any friendly advice ...

The KISS is a radial ground system which does not require any physical or capacitative contact with seawater.

Radials work very well with no ground reference. Matter of fact, in many tests and thousands of installations ashore it has been found that elevated radials are superior in performance to those running along the ground or buried underground.

Bill
WA6CCA

[mcerdos]

Originally Posted by btrayfors

The coax between the M-802 main unit and the AT-140 should be located as far from other electronics wiring as possible. In addition, it is a very good idea to install an RF choke (such as was mentioned above) in the coax line close to the AT-140, and to install ferrites at both ends of both the coax and the control cable.

It is also a good idea to use very well shielded coax, like RG-214 which has two layers of shielding or LMR-400 which has one layer of foil and one layer of traditional shielding.

Remember, any current flowing through a conductor creates an electro-magnetic field around that conductor. The stronger the current, the stronger the electro-magnetic field.

Bill
WA6CCA

Bill,

I have made a couple of changes to my set up. I redid the connectors and ohmed them for any shorts. I am certain my connectors are good. Also, instead of running a wire from the antenna tuner to the grounding counterpoise copper strip, I added a piece of flat copper webbing from the tuner to copper counterpoise stripe. I read this in an iCom publication. It still doesn't resolve my problem of interference (although it is better). I am thinking perhaps the RG8X coax I used wasn't sufficient enough to shield the signal being sent to the antenna tuner. I figure there must be a coax that will shield me since radios are used on planes and any interference would result in a bad day. Do you know of a coax that will be sure to give me an absolute 100% shielding?

Please not that I do not have the option of running the cable away from other cables as it has to pass through a water tight bulkhead where all other antenna cables come together to get toe the lazarette.

[btrayfors]

The coax types I mentioned above -- RG-214 and LMR-400 -- both have excellent shielding. Nothing practical is going to give you 100%.

The RF choke and ferrites I also mentioned above are standard practice and will greatly reduce spurious emissions from the coax.

Any reason you can't simply drill another 1/2" hole through that watertight bulkhead to pass the coax? There are watertight pass-throughs which would probably work OK, as would sealant.

If you absolutely must run the coax adjacent to other wires, there's not much more you can do. But, if the wires only come together at that bulkhead, you might get lucky and hope that's at a low-current point in the coax :-)

Bill
WA6CCA

[TLSparks]

Good morning,
No the KISS-SSB does not have to be close to the hull and it is not a capacitive coupling to the sea. It is a radial type ground and as such is kind of like a second antenna making up the second half of a 1/2 wave antenna.

Originally Posted by d4raffy

Apologies for the slight thread drift ..but its on a similar line ... as a new owner of an 801E, AT141 & KISS..about to install. Couple of quick install questions ...

1. I am sure i have read that there maybe problems between SSB components and the Autopilot - is this the case ? - my AT141 and Antenna wire will be about 50cm - 1m from my S2G computer and rudder reference ?

2. Does the KISS have to rest / touch the hull closest to the water. I understand it works by capacitance - but I want to secure it with some clips which will elevate it some what of the hull - does the distance mater ?

Thanks for any friendly advice ...

[TLSparks]

Hi Mark,
I have read through most of the responses here and it is all good advice. However, one thing that seems to be left out is what you are using for an antenna. With these issues, I assume it is a isolated back stay or a Gam and not a vertical? On some boats folks have no back stay and use a shorter stay.

There is some difference of opinion on where an RF Isolator should be installed. To help your issue it may be OK at the tuner, but Icom, the RF Isolator manufactures, and I recommend it to be close to the transceiver.

With a back stay type antenna you get a significant amount of radiation into the boat. If you are using a short stay the radiation can be even more as the angle of the antenna to the boat is less. As a result it also goes into the coax and the control cable. I have solved many SWR issues here in Mexico by simply switching the RF Isolator to the back of the transmitter and placing 2 or 3 ferrite cores at the tuner. For that matter you are better off with 5 snap on cores at the transceiver which is what is inside the RF Isolator and eliminate the additional connection.

As far as your issues with the other electronics, all the wires going to and coming from the electronics are antennas picking up the signal radiating into the boat. I remember one boat in La Paz that had a woofer that beat when doing email. The only way to possibly help the situation is using snap on ferrite cores on all wires leading to and from the effected equipment. Be sure and get good cores from a Ham outlet and not radio shack cores. If you can loop a wire through the core it increases it effectiveness at the square of the turns. e.g. 1 turn - 1 core, 2 turns = 4 cores, and 3 turns = 9 cores. So a larger core with more turns close to the electronics can sometimes work best.

By the way a couple of cores on the woofer solved that problem.

Regards
Terry
AD7XL

Originally Posted by mcerdos

Hi,

I recently installed an iCom m802 SSB.

First, the good stuff. I am certain the grounding plate I am using is isolated from anything else on the vessel. I have a bronze plate on the rudder. The unit was installed on its own circuit with a full +/- run directly to the battery via an exclusive double pole breaker. There is no common ground.

Now the not so good: I am experiencing interference problems. The coax cable from the base unit to the AT 140 antenna tuner runs to the aft locker via a conduit that houses AIS/GPS cables and a couple of Ethernet cables for the computer network. When I transmit on the SSB, the AIS crashes and the computer network is having problems (the router will reset). There are common connections to these devises. I used RG8X from recommended by my West Marine and crimp on PL259 connectors for this run.

What could cause this interference?

Any help will be greatly appreciated!!!

[mcerdos]

A quick update on this....

I opened a ticket with ICOM. I was very disappointed with their SLOW and lack of content response:

"The RF interference you describe can be quite common aboard sailing vessels because of the limited "real estate" and the close proximity of other electronics. The radio cannot be altered to minimize it's RF output, so you will need to address each system that is being affected. This will mean using ferrite beads on all of the wires for each system and it also may mean shielding areas that are affected and grounding the shields to the ship's ground. As is everything aboard a vessel, it always seems to be a challenge. "

In other words, we can't offer any help but we think you need to address issues with all other electronic devices that didn't exist prior to the installation of the M802. Thanks for nothing!

I have a HAM friend that is helping me now. He believes the RG8X coax I used for the 40' run from the navigation station to the lazarette should be ample and not radiate enough RFI to impact other electronics. Next week he is giving me a crash course on a BIRD meter and some steps to narrow down the problem. I will also install a RF choke and ferrites. Although, I wish to minimize the RFI as much as possible prior to the installation filters.

At this point, I think what we expect to find is a) a problem with the iCom AT140 Antenna Tuner or b) that the manufacturer pre-installed counterpoise is insufficient. If B is the issue, the next step will be to install the KISS SSB Grounding System.

More to come soon...

Still very open to all ideas and suggestions.

[TLSparks]

Hi Mark
It is unfortunate that Icom is so slow. They tell me they are short handed.

However what they told you is basically what I said as well. I am retired, but have worked on over 200 boats here in Mexico while cruising. I have chased down all kinds of issues. I suspect there is nothing wrong with the Icom gear. However, if you have a back stay it radiates a portion of the energy into your boat. The radiation patern is basically a circle around the wire, propagating away from the wire at 90 degrees. So if you look up at your antenna, is the signal propagating into the boat? If so you can only stop that from getting into other electronics using Snap On Ferrite Cores on each and every wire of the effected equipment. In fact sometimes you need multiple cores if the radiation field is strong like when a short stay is used.

24 foot vertical antennas radiate much less into the boat, but do not seem to work as well as a back stay.

A Kiss-SSB RF ground will probably radiate even more into the boat than your present RF ground.

Regards
Terry
AD7XL

Originally Posted by mcerdos

A quick update on this....

I opened a ticket with ICOM. I was very disappointed with their SLOW and lack of content response:

"The RF interference you describe can be quite common aboard sailing vessels because of the limited "real estate" and the close proximity of other electronics. The radio cannot be altered to minimize it's RF output, so you will need to address each system that is being affected. This will mean using ferrite beads on all of the wires for each system and it also may mean shielding areas that are affected and grounding the shields to the ship's ground. As is everything aboard a vessel, it always seems to be a challenge. "

In other words, we can't offer any help but we think you need to address issues with all other electronic devices that didn't exist prior to the installation of the M802. Thanks for nothing!

I have a HAM friend that is helping me now. He believes the RG8X coax I used for the 40' run from the navigation station to the lazarette should be ample and not radiate enough RFI to impact other electronics. Next week he is giving me a crash course on a BIRD meter and some steps to narrow down the problem. I will also install a RF choke and ferrites. Although, I wish to minimize the RFI as much as possible prior to the installation filters.

At this point, I think what we expect to find is a) a problem with the iCom AT140 Antenna Tuner or b) that the manufacturer pre-installed counterpoise is insufficient. If B is the issue, the next step will be to install the KISS SSB Grounding System.

More to come soon...

Still very open to all ideas and suggestions.