SSB Seminar - request for ideas for presentation

[brianb]

Hello All,

I have been asked to pull together the SSB portion of the communication seminar. I was planning to focus on SSB installation and methods to make sure it all works reliably. I was going to set up a working station as a means of working through material that focuses on getting a radio up and running.

I won't be spending time on sail mail, I believe Bob has someone lined up already.

What questions might you who are doing an install have ?

Thanks,

Brian
Redsky

 

[Wylieguy]

SSB Installation

I'm installing a SSB/Ham HF radio on my Wyliecat 30 for the PacCup (maybe SSS TransPac in 2012?). Here's my dilemma: (1) No backstay or shrouds (2) No possibility of anything above stanchion level aft of the mast -which is 5 feet from the bow (3) No metal thru hulls - only 2 plastic speedo/depth holes (4) No metal anything inside the hull. I'm very interested in creative solutions! I'll be at the SSB seminar for sure!
Pat Broderic "NANCY"

 

[John Hayward]

Hi Pat,

The antenna part is quite easy on the WylieCat 30. The mast is carbon fiber with no other wires close and therefore not a radiator, so just run a piece of wire (any gauge that doesn't break is fine, insulated is fine, but shielded is NOT) up on a spare halyard when you want to send/receive and run it down when your done. Alternatively you could tape it to the mast or silicone it if you wanted it up permanently. For the grounding, you could take a piece of copper foil and put a weight on the end and drop it over the stern when you wanted to send/receive. Both of these would be a bit of a pain when you wanted to use the radio, but on the positive side would require no modifications to the hull or deck and corrosion and other common problems would be very visible. And, yes this would work. Tossing a piece of copper foil over the side at the dock attached to the existing grounding sytem and checking signal strength, and SWR with and without is a common method of trouble shooting permanent installations.

Good Luck!

John
Dream Chaser

 

[jfoster]

Hi Pat,

The antenna part is quite easy on the WylieCat 30. The mast is carbon fiber with no other wires close and therefore not a radiator, so just run a piece of wire (any gauge that doesn't break is fine, insulated is fine, but shielded is NOT) up on a spare halyard when you want to send/receive and run it down when your done. Alternatively you could tape it to the mast or silicone it if you wanted it up permanently. For the grounding, you could take a piece of copper foil and put a weight on the end and drop it over the stern when you wanted to send/receive. Both of these would be a bit of a pain when you wanted to use the radio, but on the positive side would require no modifications to the hull or deck and corrosion and other common problems would be very visible. And, yes this would work. Tossing a piece of copper foil over the side at the dock attached to the existing grounding sytem and checking signal strength, and SWR with and without is a common method of trouble shooting permanent installations.

Good Luck!

John
Dream Chaser

The best antenna I know of, so far, for a cat rigged boat is the rope antenna. http://www.ropeantenna.com/

John
Blueberry

 

[glythcott]

SSB Installation

I will be installing a SSB on an Express 27. I am wondering about a ground plane. I do not want to put plates outside my hull. My keel bolts are readily accessible, but my keel is fully encapsulated. Can I use my keel bolts? If not, what are my choices? I don't want a marginal setup. If I'm going to carry the damn thing, I want it to work well.

 

[Culebra]

Grounding, reducing interference

Same for me... While I've read differing opinions on how to achieve a good ground, it seems everyone agrees that having a good ground is the most important part of the setup. At present, the plan for Culebra (Olson 34) is probably less than ideal, but is it likely to be enough, and is it a decent plan? (right, install it and find out)... The current plan is to use a single copper strap (of the recommended width and thickness) to tie together the engine, the small stainless fuel tank and, using a keel bolt, the glassed-in keel. There isn't any other significant metal surface area in the boat, I don't want or plan to add any other copper screen or sheeting, and I have no metal thru hulls. An externally installed plate is a nonstarter for me (extra drag, throughbolts in the hull, no thanks).

Other important topics would be adequate use of ferrites, isolators, etc. to reduce interference with other instruments. How to ensure good connections to the copper strap (use tapped holes with machine screws? untapped hole with screw and nut? other?). Proper installation of the tuner, its location, how to connect it to ground, and if different, how to connect the radio and other instrumentation to ground.

Thanks, Paul

 

[BobJ]

George and Paul, once the deck is finished you can look at my grounding setup. It's not real "polished" but it seemed to work fine. My keel is not encapsulated and one copper strap goes to a keel bolt. Paul, I just folded the strap over a couple of times to add thickness and then drilled a hole through it. I wire-brushed everything and used a second SS nut to "sandwich" the copper strap on the top of the bolt.

I found the keel strap was insufficient however, so I added a second strap going to the engine.

To see a polished setup get ahold of Chris Humann. His Dana 24 has encapsulated keel ballast but by tying in engine, tanks, etc. he was able to get a great grounding setup. His boat is in Berkeley.

Keep the comments coming for Brian - I know he's already put a lot of thought into his presentation.

 

[brianb]

SSB install, Olson 34 and Exp 27

Hello Paul and Glythcott,

I have done installs on both boats (I own an Olson 34). The keel bolt connection works well. On the express we tied to the keel bolts and ran a single strip of copper foil most of the length of the bilge. This was on Elise, and she had a really strong signal all the way to Hawaii, I know this because on monitored the checkins from my home in the South Bay.

The Olson I have connected to the keel bolts as well as the engine block, make sure you don't connect to the wrong side of the engine mounts as they are isolated with a rubber insulator. That set up works great and I used in several Pac Cups and Long Pacs, never missed a check in, even with running a mere 5 watts power output.

A connection to keel can be done several ways. Add a stainless nut. Use a stainless hose clamp and clamp a spade lug beneath it. In a large keel bolt you can drill and tap a hole for an 8/32 screw and secure a spade lug under that.

For RF currents the flow is all on teh surface of the conductor, hence copper foil is popular as it has large surface area. Also, coax braid or other copper/tin braid make acceptable ground runs. The larger the diameter the more surface area. Copper foil has more area but a bit tougher to deal with and expensive.

As Bob mentions the more metal the better. You can tie in your life lines and stancions but in my experience that has not been necessary.

The ulitmate solution is an aluminum hull ! Those boats have stunning signals out there. Carbon likely would do as well.

Brian

 

[brianb]

Nothing above stanchion level aft of mast ?

I'm installing a SSB/Ham HF radio on my Wyliecat 30 for the PacCup (maybe SSS TransPac in 2012?). Here's my dilemma: (1) No backstay or shrouds (2) No possibility of anything above stanchion level aft of the mast -which is 5 feet from the bow (3) No metal thru hulls - only 2 plastic speedo/depth holes (4) No metal anything inside the hull. I'm very interested in creative solutions! I'll be at the SSB seminar for sure!
Pat Broderic "NANCY"

Hi Pat,

Can a whip be installed on the hull at stern if it slopes back over the water some ? Is the issue the boom length striking anything mounted at stern ?

Brian

 

[Ergo]

I used a 17' SSB whip antenna in 2004 and it worked well. I mounted it perpendicular to the deck at the stern. I don't think it would be a problem to angle it back.

Bill Merrick

 

[Wylieguy]

Wyliecat transom probs.

Brian & Bill, The boom isn't the problem; the main sheet is - especially during a jibe. When the boom's in the full "run" position, there's about 35' of sheet. During a jibe, this line whips across the aft end of the boat. It's impossible to sheet in during the jibe - it's almost a "you gotta see it" sort of thing. Matter of fact, you're invited to join me for the SYC (1/3), GGYC (1/9),or CYC (1/16/17) to see in person. A Ham on the East Coast has suggested an 8.5 foot CB antenna on the bow. I may try that. But it will still need a counter-poise, and that's the big problem in a boat with no engine or thru hulls. Thanks, Pat

 

[jfoster]

SNIP A Ham on the East Coast has suggested an 8.5 foot CB antenna on the bow. I may try that. But it will still need a counter-poise, and that's the big problem in a boat with no engine or thru hulls. Thanks, Pat

Hey Pat, the best antenna choice for a Wliecat is the rope antenna http://www.ropeantenna.com/
(a wire fed up through the core of a halyard) using a spare halyard on the front of the mast.

The ground to use will be the forward most keel bolt That big steel fin with the massive metal bulb on the bottom ought to be way more coupling to sea water than an engine and a through hull.

There is a lot of "contempt prior to investigation" in the concept of just using your Wyliecat keel as the ground plane. Try it anyway, please. If it is not adequate, the look at adding a Dynaplate as well.

John Foster
Blueberry, Nonsuch 22 Sail #48

 

[brianb]

sloping the antenna - an advantage

I used a 17' SSB whip antenna in 2004 and it worked well. I mounted it perpendicular to the deck at the stern. I don't think it would be a problem to angle it back.

Bill Merrick

Hi Bill,

Actually sloping the antenna should be advantageous for fleet check in with boats within 300 miles or so. For distances beyond that, say for sail mail when one is several days out, a more vertical antenna may be slightly better.

Brian

 

[BobJ]

Pat, this may also be one of those offshore "adjustments" we make in our sailing technique/habits.

You won't be gybing that often and due to surfing, you will probably have a preventer rigged anyway. BTW, I'm guessing the preventers on your boat would go from the tip of the wishbone to the tip of the bow to get as much angle as possible.

Gybing won't be the same as what you're used to - it may take you a half-hour to get around to gybing once the thought crosses your mind! There's usually plenty of time to remove the preventer, pull the slack out of the mainsheet, and then pull some in while you are bringing the boat around.

Once you get down the track and into squall land, you might sail a couple of degrees higher during the night to lessen the risk of an unintentional gybe. Racing solo, I would also switch the autopilot to wind vane mode if I was taking a nap. When a squall hits the wind will veer 15 degrees or so, enough to gybe the boat if the autopilot is in compass (normal) mode.

Revised gybing technique and a carefully-placed and robust antenna mount should solve the problem.

 

[jfoster]

Pat, this may also be one of those offshore "adjustments" we make in our sailing technique/habits.....SNIP......Revised gybing technique and a carefully-placed and robust antenna mount should solve the problem.

Hi Bob:
Gybing in heavy wind in a cat rigged boat is quite likely to rip off any objects protruding above or towards the stern from the shelter of the push pit rails.

You can't sheet in fast enough to prevent this, though grabbing a hand full of the multiple parts of the main sheet, pulling them in and hurling them towards the new leeward side will occasionally help to prevent the "rip off" from happening.

Mounting an antenna on the pull pit at the bow, instead of the push pit at the stern avoids such "rip off" hazards. Same applies to radar radome mounting. Ripping a Life Sling bag off the push pit, during a gybe, is knowledge gained in much the same way you learn not to try to carry a pussy cat by the tail.

John Foster
Blueberry, Nonsuch 22, sail #48

 

[Culebra]

Not so elegant

Here's a thought... although, I'll preface it by saying it's not an elegant solution. If the antenna is meant to be temporary (for the race only), it could be sort of portable, too: one could make a mount on the stern so that, with enough slack in the cable, a whip antenna could be quickly lowered to the side deck and later raised again into position. Then either lower it before gybing, or instead, raise it before each check-in.

 

[brianb]

Bow Antenna - sounds good

Hi Pat,
John's idea sounds good. We rigged a 34' sport boat and a SC 27 for the Pac Cup with kevlar backstays by sliding a #16 wire under the backstay cover. The keel bolts were used as the connection to the water. Communication was great. So running a spare halyard up front with a wire internal to the line would do the job.

A 8' CB whip is really short for 4 MHz, you will have lots of losses in the tuner in that setup. I would highly recommend doubling the antenna length. Thats not to say you wouldn't transmit a signal, but just it might be very hard to be heard.