Which Pactor & whip antenna on aluminum arch

Originally Posted by btrayfors

As to whether or not it's worth the extra bucks to buy the usb or the Pro version, it may well be. These have computer control of your radio...a VERY handy feature...and the usb version doesn't take up the single serial port on older laptops, and it works with the new laptops which no longer have a serial port.

I do like the techie features of the pro and others, if I only had time to play, i'd buy one . I do like bluetooth options with the USB version. With so many gadgets on board wiring them all together is a PITA. I do have a bluetooth GPS and it is quite handy interfacing with the chart software on the computer.

[Dream Maker]

Thanks everyone for your input. I got a call today from the Shakespeare tech support rep.

He told me that I can mount the whip antenna on the transom beside the aluminum arch. He did say that there is a possiblity of resonating the arch. This could be a problem if people are near the arch when we are using the radio and they touch it. They could get a nasty RF burn.

I understand that this is the same issue if I use the toe rail as the ground.

The tech rep said that it could be helped if I put a spacer between the antenna and the arch when I put the extra support needed at the 4 - 5' level.

He said that the resonating of the arch wouldn't help or hurt the antenna.

Sounds like if we use a whip antenna with our arch and tie into the toe rail for the grounding, we will have a lot of potential for RF burns. Perhaps not a great idea?

He also said I can use a 17' whip antenna with 6' of cable between the antenna and the tuner. The radio will think it has a 23' antenna.

When I asked if the antenna would be noisy in the wind. He said he hadn't had that question before but that the antennas are fairly rigid and shouldn't be noisy.

One further question-- I was told by a rep selling Icom radios that I could use my aluminum water tank as a ground. My tank is totally behind built in cabinets except for where the shut off valve comes out. Can I put the connection between the radio and the water tank onto the bolt that connects the water tank to the bulkhead?
Will this be a good enough ground?

If anyone has any comments on this information, I'm all ears.

Thanks again

Cathy

[Sunspot Baby]

Notice the RF burn comment from Shakespear. Good reception is important, safety is more so.

The ICOM 802 with the dedicated tuner is such a fine rig that it would probably work without a ground. Your aluminum water tank is a fairly good ground and is probably close enough to the water in which you float to be excellent.

I run an 802 with mediocre ground plane and send and receive to distant stations when I can hear others, with high tech rigs, in my area failing.

Mine is probably a minority opinion among the radio techies, but your choice of a whip antenna is potentially more limiting to your ability to send and receive email than anything except traffic on the frequency and propagation.

I say again, why are you avoiding an insolated backstay as an antenna?

George

[Radio University]

The M802 and AT140 CAN NOT be used with out a ground! All SSB's need to have a ground plane.

Do not use the water tank for ground. Chances are it is bonded. If this is the case, you will be creating ground loops and can affect tuning. Plus you have current flowing through the ground system of the tuner.

No matter what ground system you use ( I recommed using ground plates, others recommed using radials and some even use toe rails. ALL WILL WORK IF DONE PROPERLY) you MUST have a ground and do not connect it to somethings that is bonded.

On my website, I have a document the includes all part numbers and suppliers for the ICOM M802 DIY Self Install Kit. Click on BLOGS on the top of my website.

[Dream Maker]

To answer the question from George about why I am not considering an isolated back stay.

I would prefer not to cut a perfectly good back stay as I don't like the idea of more potential places for a rig to fail. I would also like to keep the price down if possible.

SSB installs are quite pricy. Based on my reading, I understand that a whip antenna or separate ss lifeline rigged as an antenna on a separate halyard will work just as good for a fraction of the price.

I am leaning more towards the separate lifeline antenna after learning that the whip antenna combined with my arch leads to the potential for RF burns.

Thanks again for all the input.

[Dream Maker]

Please forgive the perhaps naïve question. Although I have been sailing for manyyears, this is my first boat.

How would I know if my water tank is bonded and water could happen if I use it as the ground for my SSB?

Thanks

[btrayfors]

Cathy,

I think you are 'leaning' in the right direction. As one of the primary proponents of the 'alternate backstay' antenna, I can tell you they work absolutely as well as the regular insulated ones. In addition, they are semi-permanent, so are easy to drop if you need to service them, shorten them, etc.

RE: RF burns, these are extremely rare on a boat. Every experienced ham I know (been one for almost 40 years) has seen an RF 'burn' at some point, usually in the form of a 'hot microphone'. You get a tingle, and know something's wrong right away.

In theory, you can get an rf burn from any antenna or pseudo-ground system (radials, toerails, lifelines, etc.). For this to actually happen, two things have to be going on at exactly the same time: (1) you have to be actually transmitting, not just listening; and (2) you have to make physical contact with a part of the antenna or ground system at a point where high voltage is present. In other words, you have to be actually grabbing the antenna or pseudo-ground at the right place.

This is why, to be 'prudent' in the commercial sense and to avoid potential liability, the recommended way to install an antenna and ground system is to connect with the backstay way above deck level where it's unlikely to be grabbed, and to use wide copper strapping to carry RF to the seawater, either by direct coupling to a thru-hull or ground plates. These practices do, in fact, work OK.

However, alternate install types will work just as well or better, and while there is a small (tiny?) chance of someone sometime getting an 'rf burn' that is extremely unlikely. Particularly, it is unlikely if the radio operator is watchful and if all members of the crew are aware of the potential (but unlikely) problem.

On my boat I use an alternate backstay system, and my tuner uses the toerails and lifeline/pushpit/pulpit complex for a pseudo-RF ground. It works like gangbusters, and has done so for the past 18 years. No RF burns, no other problems.

Good luck in whatever you choose to do.

By the way, James is absolutely right....in NO circumstances should you try to use the 802 and its tuner without a ground system. This is true of any tuner as well....you must have a ground system, even a simple one, both to achieve the communication goals you have and to avoid damaging the tuner and/or radio.

How simple? Just last night a ham friend and I were checking out an SG-230 tuner for a friend to put on eBay. We pulled a random wire up into a tree, attached it to the tuner, attached two 1/4 wave radials (for the 40m and 20m amateur bands) and, voila, instant tuning and good communication. This is the second time I've done this in the same way with the same model tuner. It's just as easy on a boat!

Bill

[btrayfors]

Cathy,

James already answered your question re: water tanks and grounding. Here's a bit of amplification on his remarks.

1. Many boats follow the accepted practice of tying in all large metal items (tanks, engine, thru hulls, etc.) together as part of the DC ground system (i.e., the ground system used for your 12V electrical complex). This ensures that all metals are at the same ground potential, and minimizes problems from electrolysis. So, it's quite possible that your aluminum tank is tied into the DC ground system as well. This would be via a wire or a metal strap to the boat's DC common ground.

2. It is generally recommended that the RF gounding system for a radio NOT be connected to the DC grounding system, since this could induce unwanted "ground loops", affect tuning, and could result in some interference between onboard DC equipment and the SSB radio equipment (both ways).

Bill

[Dream Maker]

Thanks again in advance for comments. The input we have received from this forum has been very useful.

We have been looking at our options for a Ham/SSB radio. We know that
the Icom M802 is the newest
standard and the most expensive. We would appreciate any comments on Icom 718. We met another long term cruiser with it and they like it.

We know that it is not a true "marine radio". However, it is listed in Icom's marine products brochureand is a third of the price of an IC 802. We can get it opened up for all channels. Is there something that we are missing? Why would we pay three times the amount for an IC802? Space is not an issue and we don't need more than 100 memory channels.

For the DSC capabilities, we have this on our VHF radio and we carry an EPIRB so the emergency button is not a feature that we need.

For an antenna, we had planned to use the alternate back stay approach using a stainless steel life line. Yesterday, we learned of a commercial product called a "rope antenna" for $165. Any comments on one versus the other?

Thanks
Cathy

[CaptMarti]

Originally Posted by Dream Maker

Which Pactor modem should I buy to go with either an Icom M802 or M710?

Also, I am considering a whip antenna. I have an aluminum arch on the transom. I am told that I should not brace the antenna against it or put it near the arch. Any comments?

Thanks in advance.

If you don't use the backstay as your antenna and want to use a whip, you'll need a 23 foot whip antenna and mounting this on a sailboat can be problematic. You should not mount it on top of your arch as a previous post had suggested.

The least expensive radio modem is the PTCIIex. It needs RS232 serial to USB adapters but there are many good ones on the market now and it is not hard to find them. The IIex is physically smaller than the PTCIIUSB and so it's a little easier to find a spot for it at the Nav station.

Pactor is an operating system...similar to Microsoft's XP or VIsta. Pactor III is the latest and the fastest with a net operating speed of 2800bps. Not fast but definitely tried and true. You'll have to work on your island time if you're used to DSL speeds.

I use the M802 and find it is the easiest dual Marine SSB and ham radio to operate. Changing frequencies is a breeze using the dials. When you get the M802, don't forget to buy the marine ssb receiving antenna as well. You;ll need this for the DSC function of the radio. The M802 is the only ssb radio for recreational vessels in the US that has DSC. It is a terrific safety feature as well.

Good luck and let me know if you need any additional help!
Capt Marti

[hellosailor]

Cathy-
I would add in passing that one reason you get many different suggestions rather than one "right way" is because every sailboat is different. Even two "identical" sisterships will be different in terms of the electrical characteristics of their rigging, which in turn affects how they will perform as or with radio antennas.
The ARRL (American Radio Relay League), a national organization for ham radio, has recently published a book just for "Marine Amateur Radio" which can be considered the same as SSB in terms of installation and performance issues. ARRLWeb: ARRL Product Catalog and look way down the page for more information.

This is a field where no one can guarantee you "the best" performance on the first try. You may or may not be able to get away with less than extensive grounding, or a counterpoise (which is not quite the same thing). You may or may not have issues with the arch, with RFI, and so on. It's not a turnkey thing, if you really want it to work well. You need to look at the options, consider time and budget, then do some testing and tweaking and if you find one option to be much better than another (by actually communicating with other boats via radio) then sometimes you will change things.

On Pactor...whatever or however you want to call them, Pactor modems are the market leaders for sending email via HF radio. And Pactor-3 is way faster than the older versions. By the time you look at all the time and effort you'll be investing in "radio"...the extra cost for Pactor-3 is insignificant.

[mark_morwood]

I came across this as an alternative to cutting your backstay. I have not tried it but may well when I install a HF radio on my cat. I had been looking at a long whip, but this looks simpler and better.

Rope Antennas, Single Side Band antennas for Sail boats, powerboats, SSB antennas

Mark.

[hellosailor]

Mark-

Aside from the pretty color? Why would anyone buy a "rope antenna", which is just an inexpensive longwire antenna in an expensive braided "rope" jacket? Easier, faster, and cheaper to just hoist a longwire antenna, isn't it?

[colemj]

Originally Posted by CaptMarti

I You should not mount it on top of your arch as a previous post had suggested.
Capt Marti

Why not? I have a 28' whip mounted on the top of my arch. The entire arch, lifelines and bonding below (copper foil laminated into the hulls along with copper strap radials) act as counterpoise. The coupler is mounted on the arch immediatly below the antenna, which only requires a short 12" run of wire from the coupler to the antenna.

This seems to work very well. What are the drawbacks I am missing?

http://farm1.static.flickr.com/104/2...27b85968_b.jpg

The picture in the link shows the top of my arch. On the left (to the observer) is the antenna and coupler (white box). on the right is another coupler with a long wire antenna hooked to a ham radio (antenna coiled and stowed behind the solar panel, so difficult to see).

This photo shows the boat and antenna in perspective.
http://farm1.static.flickr.com/98/26...6888d42a_b.jpg

Since I am interested in maximum performance and not against making changes to my setup, what am I giving up by mounting an antenna on top of the arch? (keep in mind that I don't have a backstay to use and am not interested in single band dipole antennas).

Mark