Marine HAM

[dkenny64]

CptCrunchie, if you'd like I can measure the height of the aft stay isolator off the deck. I also own an Irwin 43.. my aft stay is isolated.. -dkenny64

[S/V Illusion]

Originally Posted by CptCrunchie

I just got off the phone with my heart tech guy. He had a brilliant suggestion.

For the $4000 budget I've set for the SSB, plus the modifications to the boat, and the ongoing issue of being in the danger zone, he suggested I look into a satellite phone. He says sat phones use a completely different frequency that will not effect my CRT-D.

My immediate reaction was the expense and the coverage. But wow! Those have come way down!

https://satellitephonestore.com/cata...-phone-kit-322

If I buy the 1 year @ $1,057, it's a 1200 minute package that includes the phone. This would give us 100 minutes a month, for 4 years based on our SSB budget!

No muss, no fuss, no dangerous antenna to stand too close to, ....and I will sleep well at night!

I had no idea the cost had dropped that much! And the coverage........!!! Wow!

As you likely are not in close proximity to the antenna while talking into a microphone connected to the radio with a 2 foot cable, how can the RF field affect you? There are simple RF field calculations to clarify where the ‘exposure field’ is isolated and it sounds like whoever is giving you advice here may be unaware of the actual radiation field.

[Paul L]

Originally Posted by S/V Illusion

As you likely are not in close proximity to the antenna while talking into a microphone connected to the radio with a 2 foot cable, how can the RF field affect you? There are simple RF field calculations to clarify where the ‘exposure field’ is isolated and it sounds like whoever is giving you advice here may be unaware of the actual radiation field.

The unwanted RF from SSBs is apparent in a lot of devices that are within the cabin, ie not near the antenna. Examples include USB devices attached to computers, cabin LEDs, pactor modems themselves, other radios.

[Paul L]

Originally Posted by CptCrunchie

Good idea. Any suggestions? Is a police scanner the same thing? I have one, just never used it.

I don't have any recent experience with receivers only. There are a number of threads on CF discussing it if you want to try your luck at searching.

[S/V Illusion]

Originally Posted by Paul L

The unwanted RF from SSBs is apparent in a lot of devices that are within the cabin, ie not near the antenna. Examples include USB devices attached to computers, cabin LEDs, pactor modems themselves, other radios.

In virtually every instance, you are referring to conducted RF, not radiated RF. None of which is relevant in the scenario the OP describes.

[Paul L]

Originally Posted by S/V Illusion

In virtually every instance, you are referring to conducted RF, not radiated RF. None of which is relevant in the scenario the OP describes.

Perhaps, but the results of being wrong in this case are far higher than just flashing lights or disconnected pactor modems. It is a life critical device that the vendor is cautioning the user about.

[Brian.D]

Here is a compatibility chart for the device the OP has. It should be noted that anything to do with RF is rated by power, not frequency. At least not that I can see. By the chart, basically anything that produces an electromagnetic field is harmful. This includes, but not listed as, satphones. A satphone can be categorized as a cellular device.

https://bsci-prod2-origin.adobecqms....lity_Guide.pdf

[Paul L]

Originally Posted by Brian.D

Here is a compatibility chart for the device the OP has. It should be noted that anything to do with RF is rated by power, not frequency. At least not that I can see. By the chart, basically anything that produces an electromagnetic field is harmful. This includes, but not listed as, satphones. A satphone can be categorized as a cellulare device.

https://bsci-prod2-origin.adobecqms....lity_Guide.pdf

Looks like 2m, 6ft, for a 100watt unit.

[CptCrunchie]

Originally Posted by Brian.D

Here is a compatibility chart for the device the OP has. It should be noted that anything to do with RF is rated by power, not frequency. At least not that I can see. By the chart, basically anything that produces an electromagnetic field is harmful. This includes, but not listed as, satphones. A satphone can be categorized as a cellular device.

https://bsci-prod2-origin.adobecqms....lity_Guide.pdf

The ISatPhone2 manual states:

Wireless phones may adversely affect the operation of some implanted cardiac pacemakers and other medically implanted equipment. Pacemaker patients should be aware that the use of an IsatPhone 2 in close proximity to a pacemaker might cause the device to malfunction. If a minimum distance of 15cm (6") is kept between an IsatPhone 2 and a pacemaker, the risk of interference is limited. If you have any reason to suspect interference is occurring, immediately switch off your IsatPhone 2.

This is pretty much what my tech told me about my cellphone. He said to never keep it in my left breast pocket, and talk on it with either hands free or on my right ear. And if I want to carry it in my shirt pocket - which I do - I buy shirts with right breast pockets.

To verify this info, I just called Boston Scientific and talked to two of their techs - Diane and Chad - and they confirmed this. It's the same as a cell phone.

Then they gave me some very helpful advice about my unit, something that goes against what I believed would happen.

If I get too close to a magnet, or the antenna of a sat phone, it won't re-write the programming, nor will it delete it. Instead, the device will receive information it thinks is coming from my body, and this could cause it to malfunction. At worse, it will shock me. (I know what that is like, because they test fired it when they installed it while I was under a local, and believe me, I'm sure I peeled the paint in the room.) However, as soon as I move away, the device will return to its normal functioning.

As to the SSB/HAM, exposure to a 150W signal within 10' of RF could trigger a malfunction. But the biggest difference between the sat phone and a SSB is the inconsistency of the signal strength. Apparently, (and I'm not an engineer nor electronics expert) a SSB can have the output adjusted, where a sat phone is consistent.

So, a sat phone is actually better suited for me, and I don't have to modify the boat! That works for me!

[Cordelia]

Might consider reaching out to sea-tech.com for assistance.

[nmccubbin]

We have had the ICOM 718 for years. With a sligt mod is runs all marine bands

Also ICOM tuner, which integrates nicely with the radio. Previously had an SGC tuner which quit. I see no difference in performance between the SGC and ICOM tuners.

Concur with others recommending a backstay antenna with the tuner VERY close to it.
We have tried many antennae over the years. None were significantly better than the backstay, so no reason to have them

[carlwk3c]

Originally Posted by CptCrunchie

I'm looking to add a marine HAM radio to the boat for our SoPac adventures. The boat is a 43' Irwin with a 58' mast DWL.

I really like the iCom 802 radio but have no clue how to set one up, what I need, nor how to connect it to weather fax, text/SailNet, or a maritime operator. I have a General license, but have never set up a system, let alone one on a boat. I also have an iPad, iPhone and an iMac.

I want to be able to send email, connect to weather, and do some voice. Above all, I want KISS for as little cost as possible.

Things I know:

I want to use the back stay as an antenna, and understand the use of isolators and grounding planes.

Things I don't know:

Tuners!

Antenna lengths.

How to connect everything together.

Whatever I do, it cannot interfere with the CRT-D computer running my heart. Tech says I just need to stay 10' from the antenna when transmitting, and from where the radio will be, I have a good 25'. The other concern is getting a shock.

I have an Icom M802 and AT140 tuner on our Crealock 34. Not using the backstay yet as it has no insulators, but ran a heavy insulated wire up on a halyard with a spare halyard and a small split block climber’s pulley running on the backstay.
First contact from Salinas, Puerto Rico (on the 40m ham band - 7.25MHz) was a Russian ham about 300 mi S of Moscow.
The tuner and backstay are 10-12’ behind the nav station.
I have an ICD. No problems.

[carlwk3c]

Originally Posted by roverhi

Have an opened up ICOM 718 with a SGC tuner, backstay antenna, and copper foil running under the deck as a ground plane. ICOM, for one, makes good tuners for their ham radios but tune off a signal from the radio not the rf output of the antenna. I went with the SGC tuner because it uses the rf output so is compatible with all radios. Easy to set up, find a place as close to the antenna as you can get for the tuner as the antenna and rf transmissions actually start at the tuner so the shortest run to the actual antenna is critical, run a coax cable from tuner to wherever you install the radio. Hook the radio to ground plane. That is not a ground as in the dc electric sense. Some people install an external below the water line plate, others run a wire to a convenient through hull or buy a bundle of wires device, or use copper foil strip that I run from tuner to the bow. That should get you transmitting. Email and downloading weather is easiest with a Pactor III modem.

I bought all but the SGC tuner used. Radio was $425, back stay insulators $150 each, Pactor II modem upgraded to Pactor III $400. The SGC tuner new was $400 with no deals that I could find. Don't remember what the copper cost but it was 3" heavier gauge in a roll. The KISS 'bundle of wires' ground is $150. Probably the cheapest you are going to be able to get the radio up for voice transmit is a little over a boat unit and definitly get it done for under two boat units. The SGC tuner was expensive with the ICOM tuners nearly half as costly. Same goes for the Pactor modems. The latest version will set you back a boat unit though my used one worked just fine.

The ICOM 718 radio was/is the perfect radio for me, easy to operate, great communication all the way from the mainland to Hawaii, and relatively cheap. An ICOM 802 radio will cost more than my whole system did. The StaLok back stay insulators are expensive. Might look at an external wire run up the backstay as a substitute at very little cost. If you buy everything new cost would escalate to possibly over 4 boat units.

The issue with using a ham rig modified to transmit on marine frequencies are twofold.
1) it’s illlegal, except in dire emergency, because the radio is not type approved foruse in the maritime radio service
2) it won’t have DSC, and most ships and shore stations are not listening for voice calls, so without DSC to open their squelch, they won’t hear your call.

[carlwk3c]

Originally Posted by CptCrunchie

I have a budget of 4 boat units, so your info is very encouraging.

Is there such a thing as a masthead mounted HAM antenna? Since I'll be taking the mast down shortly, it would definitely be a good way to keep the RF away from my device.

Also, what is a good length of either a cable up the backstay or the backstay itself? I have no issue with going the isolator and mechanical fittings route, but I would want the bottom isolator to be at least 10' off the deck, which is roughly 3.5' above the rear arch I'm installing for solar panels.

If on the backstay, the tuner would be under the MSR berth. If on top of the mast .......hmmmmm....... That would be roughly 5' from the nav table/radio.

The tuner is typically mounted below deck back near the backstay. High voltage insulated wire, like that used to feed electric fence continuity under ground across fence gates, with really thick, tough insulation, is typically used to feed from the tuner up to the bottom of the insulated portion of the backstay to prevent shocks. However, as others have stated, the antenna really begins at the high voltage terminal coming out of the tuner. In other words, that feed wire radiates as part of the antenna. It’s just highly insulated to prevent RF burns/shock from accidental contact.