SSB Rig and Antenna Setup

[Hull152_Patrick]

One of the things I’m doing when I have time is writing up how things are setup on the boat.

We don’t have the benefit on the ketch of a nice long backstay to put an antenna into, but it seems a little off (and slightly dangerous) to me to have one leg of an uninsulated forked backstay hooked us as the antenna. The whole backstay would be radiating and it would definitely be touchable (bad), but it is HF so its not that bad. Anyway, the PO swears it worked great, I’ve never heard a thing on it but haven’t tried too hard yet.

Here’s what the hole system looks like:

Rig
Icom M710 SSB Radio modified for HAM frequencies is wired directly to the battery switch on it’s own dedicated breaker.
The Face plate is mounted above the Navstation, the main unit is mounted in the aft hanging locker.

Antenna
The antenna wire and antenna tune control cable lead under the cockpit sole to an ICOM AT-130 antenna tuner located on the forward bulkhead in the port lazerette above the water heater. The antenna tuner is wired through a line isolator to the port side backstay chain plate.
The starboard half of the backstay is also disconnected from the bonding system.
There is no isolator in either leg or the main part of the backstay.

Ground
The antenna ground is hooked to the upper mizzen shroud chain plate which is part of the common ground plane on the boat.

I’m curious those of you with SSB or HAM radios how have you setup your antennas?

Thanks,
-p

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s/v Deep Playa | Pearson 424 #152 | http://www.DeepPlaya.com

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Owners no more...
Thanks Dawn and Patrick!

[john stevenson]

Patrick,
That is certainly a different way of doing it.  From your description it sounds like the set up uses the boats bonding system as the ground for the transmitter.  Other people use the lifelines.  Bill Trayfors over on the SSCA forum recommends radials, but has installed rigs on other boats many different ways, all successful.  So there are other ways of doing it than the copper foil.  I guess it must work.

There are a couple of issues I would have with the rig your described, but I am far from an expert.

1. My line isolator is on the coax between the radio output and the tuner, as close to the radio as possible.  I don't know what you have on the antenna lead from the tuner to the chainplate, but it is not a type of line isolator with which I'm familiar.
2. On my Ketch rig the backstays are very close to the mizzen lowers and will make contact under sail.  Since the entire mizzen rig seems to be part of the signal ground it would be possible for the transmit output to get into the ground system.  I don't know that would do, but I assume nothing good.
3. Using the entire main mast rig as part of the antenna means everything will be hot when transmitting, especially when in Pactor mode.  I don't think you will get more than a mild burn if you touch the rig during a transmission, but it is something to be aware of.
4. Since there are no isolators in the main mast rig, I assume the lower and forestay chainplates are also disconnected from the bonding system.

My rig is pretty conventional.  I have an ICOM IC 802M.  The radio is mounted under the navigation desk.  The radio output is connected to a T-4 line isolator, also under the desk, then to a SG-230 tuner in the starboard cockpit locker.  The antenna lead is connected to the starboard backstay just above an isolator, which is above the intersection of the backstay and the mizzen lower.  There is another isolator at the head of the backstay and a third just below the delta plate on the port backstay leg.  So the antenna is isolated to the starboard and upper backstay.  The signal ground is two radials, one going aft from the tuner, near deck level, the other athwartship along the hull.  I have a copper foil, but it is disconnected at this time.  I get decent, but not great performance from this set up.  I use it mainly for email and a few nets (e.g., Herb).

You have probably already done this, but I would take your setup to the SSCA forum.  There are a number of radio professionals on that forum.

On Wed, Jul 22, 2009 at 12:18 AM, Patrick Walters < ([email][/email])> wrote:

One of the things I'm doing when I have time is writing up how things are setup on the boat.
 
We don't have the benefit on the ketch of a nice long backstay to put an antenna into, but it seems a little off (and slightly dangerous) to me to have one leg of an uninsulated forked backstay hooked us as the antenna. The whole backstay would be radiating and it would definitely be touchable (bad), but it is HF so its not that bad. Anyway, the PO swears it worked great, I've never heard a thing on it but haven't tried too hard yet.
 
Here's what the hole system looks like:

Rig
Icom M710 SSB Radio modified for HAM frequencies is wired directly to the battery switch on it's own dedicated breaker.
The Face plate is mounted above the Navstation, the main unit is mounted in the aft hanging locker.
 
Antenna
The antenna wire and antenna tune control cable lead under the cockpit sole to an ICOM AT-130 antenna tuner located on the forward bulkhead in the port lazerette above the water heater. The antenna tuner is wired through a line isolator to the port side backstay chain plate.
The starboard half of the backstay is also disconnected from the bonding system.
There is no isolator in either leg or the main part of the backstay.
 
Ground
The antenna ground is hooked to the upper mizzen shroud chain plate which is part of the common ground plane on the boat.

I'm curious those of you with SSB or HAM radios how have you setup your antennas?
 
Thanks,
-p

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s/v Deep Playa | Pearson 424 #152 | http://www.DeepPlaya.com

—
Regards,
John Stevenson
http://www.svsarah.com

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[Indulgence]

Patrick,

I have a similar setup as John…IC 718 with a SGC 230, with an insulated backstay as my antenna, and copper foil as a ground plane. I run neon tube power cable from my sgc 230 to the antenna (you can purchase 25′ from Hamilton Maring for 25$)

I have been very happy with the performance and have recieved good signal reports.

— On Wed, 7/22/09, John Stevenson <> wrote:

Quote:

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[Anonymous]

My antenna is a separate piece of insulated wire running from the stbd combing to the head of the main mast. This provides for a longer wire, is non-structure to the rig, and does not interfere with the sails. There is bungie cord at the deck side to an insulator (just a piece of high density plastic rod with a hole at each end) to keep the wire taunt. Insulated clothes line makes a good antenna wire and you can use crimps to make loops at each end. This of course connect to the AT-130 tuner.

Pete

Patrick Walters wrote:

P { MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } One of the things I’m doing when I have time is writing up how things are setup on the boat.

We don’t have the benefit on the ketch of a nice long backstay to put an antenna into, but it seems a little off (and slightly dangerous) to me to have one leg of an uninsulated forked backstay hooked us as the antenna. The whole backstay would be radiating and it would definitely be touchable (bad), but it is HF so its not that bad. Anyway, the PO swears it worked great, I’ve never heard a thing on it but haven’t tried too hard yet.

Here’s what the hole system looks like:

Rig
Icom M710 SSB Radio modified for HAM frequencies is wired directly to the battery switch on it’s own dedicated breaker.
The Face plate is mounted above the Navstation, the main unit is mounted in the aft hanging locker.

Antenna
The antenna wire and antenna tune control cable lead under the cockpit sole to an ICOM AT-130 antenna tuner located on the forward bulkhead in the port lazerette above the water heater. The antenna tuner is wired through a line isolator to the port side backstay chain plate.
The starboard half of the backstay is also disconnected from the bonding system.
There is no isolator in either leg or the main part of the backstay.

Ground
The antenna ground is hooked to the upper mizzen shroud chain plate which is part of the common ground plane on the boat.

I’m curious those of you with SSB or HAM radios how have you setup your antennas?

Thanks,
-p

---

s/v Deep Playa | Pearson 424 #152 | http://www.DeepPlaya.com

Post generated from Pearson424 Forum using Mail2Forum

[RichCarter]

Patrick
The description you’ve provided for your antenna installation sounds wrong. Although its possible to tune your entire rig at specific frequencies, it won’t work for most frequencies and its dangerous. The proper way to adapt a standing rig to act as an antenna is to install insulators. Insulators are very expensive, but its the only safe way to go. For a sloop, these are installed at the top and bottom of the backstay so that the active section is out of reach. For a ketch, the antenna section is normally the wire that runs between the two sticks. In both cases, the wire section can be a little shorter or longer than ideal. Normally, a good antenna tuner can adapt it by changing the electrical length as seen by the transceiver. If the wire section is a bad multiple of the frequency you are attempting to use, the tuner may be unable to adjust. I have this problem with the 40meter band.

One problem with using the rig for an antenna is that if you lose your rig, you lose your radio. Adding a second antenna is a good idea. This allows you to switch over in an emergency. It can also be used in the case when the band you want to use can’t be tuned up because of a resonance problem with the length of your rigging. There are a number of backup antenna solutions available. The most simple is a kite with a long wire. A more flexible solution is to add a small HF mobile antenna such as a hamstick. The hamstick is a whip antenna that can be mounted on your pushpit. You switch whips for each band. The whips are inexpensive. They come in two pieces so that when disassembled they stow easilly. You could also get an outbacker antenna. This is a fiberglass antenna that has individual taps for each band. They come in several models, one of which is setup for the marine bands. These are moderatly priced. There are also various screwdriver antennas that are easier to use because they can be adjusted to almost any band without tools, but they are expensive.

I recommend a set of hamsticks as backup for anyone going offshore. These are inexpensive and reliable. No antenna tuner is needed. You need a short section of feed line from your nav-staion out to the pushpit and a mounting bracket. An RF switch makes it convenient to switch from your antenna tuner to your backup antenna, but its not required. The switch goes where the feed line connects to the back of your radio. Three hamsticks are all that’s needed, 80m, 40m, and 20m. They only cost about $25 each. You can get a whole set if you want. These of course work on the amateur bands. If I were in an emergency, I think I’d call for help on the amateur bands first. There is a better chance of making a contact.

Here’s a book that’s free and discusses mobile and marine installations. Hope this helps

http://www.sgcworld.com/Publications/Books/hfguidebook.pdf

Regards,
Rich KE1EV
BlackSheep

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