sv Elysium

Cruising thrugh Life

 

Many cruise to disconnect, yet others feel the need to travel the wild blue and stay grounded. How can we do combine both objectives?

We have four weather sources offshore:

  • perhaps the best is looking outside !!!,

  • the Sony all band receiver hooked to laptop gets us weatherfaxes (They are good some places like the UK and not so good other places like Argentina) and we can listen to Herb in the Atlantic and other weather nets.

  • an iridium phone (which Beth needs to send in her magazine articles) gets us GRIB files, a technology which has really replaced weatherfaxes and text forecasts by e-mail from Saildocs,

  • an inmarsat C which produce free text weather (NAVTEXT style) twice a day, and also provides a redundent epird type emergency signal. On our long southern ocean passage we also had a shore based router sending us weather over Sat C. The Sat C is viewed today as obsolete, but we like it.

In bad weather we really use the Sat C as it's bullet proof and does not require much messing around. I tend to get seasick early in a passage if I try to mess with the radio to get faxes.

Most crusing boats do have an SSB, and can get e-mail text weather (same text as the sat C) and GRIBs that way (Sailmail or Airmail).

When we are sitting in harbour looking for a weather window, we mostly go to cyber cafes to look up all the tond of weather maps/sat photos/forecasts available on the net, but we will also use wifi or a cell phone if they are available.

Regards,
Evans

The SGC Smartuner gets energy into an antenna, but the design of an antenna is what controls what happens to the RF energy from there. For some antennas, the antenna is simply not complete without a radial system, or at least a counterpoise. Other types of antennas need no RF ground system at all. Most reference books on antennas provide solid guidance on radials and counterpoises, but only for antennas cut to a specific frequency. When using an SGC Smartuner, the rules have to change because the Smartuner operates across the full range of HF frequencies.

Radials and Counterpoises have two basic purposes:

1. To improve the RF ground conductivity for the ground current return path. Unless you live in a salt-water swamp, your ground conductivity makes a very poor path for the return of ground currents. This increases the ground losses and reduces the efficiency of an antenna that needs a good RF ground.

2. To provide a counterbalance for the feed point of the antenna to reduce RF radiation back to the radio room.

The Smartuner changes the rules because there is no single frequency that you will be operating on, so all of the thumb rules for ¼ and ½ wavelength radials don’t apply. It is possible to be either a purist or a pragmatist in deciding what radials to put in place. We’re going to be pragmatic about it and say, “Here are the thumb rules that work with a Smartuner:”

1. If the antenna is balanced, you don’t need an RF Ground. Dipoles and Loops are the most common forms of balanced antennas in use. With a properly installed antenna fed by a Smartuner at the feed point, no RF ground is necessary.
2. If the antenna is unbalanced, a radial system or counterpoise is necessary for operation. The radial our counterpoise system is connected to the Smartuner RF Ground.
3. Base fed vertical antennas must have a good RF Ground system for efficiency. Vertical antennas can have radials mounted on or below the surface of the actual ground. If the radial system is mounted above the ground, it is technically a counterpoise and takes the place of the actual ground. An equally good ground can be created by mounting well-bonded chicken wire or other grid material to form the ground plane near the antenna.
4. Vertical antennas mounted high in the air will need to have a radial system mounted just below the antenna (a ground plane antenna) and connected directly to the Smartuner RF Ground. The ground plane on the antenna will shield anything mounted below it from RF, so a good place to mount the Smartuner for a raised vertical antenna is below the ground plane.
5. More radial wires are generally better. As the number gets larger, they improve the RF Ground less and less, to the point where there is no difference when adding one more radial to a system that already has 120 installed. Minimum systems of as few as 4 wires can provide an acceptable ground and increase the antenna’s efficiency by a significant amount. Generally, 6-8 radials is the minimum that should be used.

Figure 1 - Ground Radial System
Picture Courtesy of www.arraysolutions.com

6. Radial wires should be as long as the antenna wire if possible. If you must use shorter wires, keep them as long as possible and use extra radial wires.
7. Antennas that use a vertical section as part of the radiator, such as the Inverted-L antenna, need to have a ground radial system just like a vertical antenna.
8. Horizontal, unbalanced antennas, such as a long wire or random wire, need an RF Ground wire that should be 10-15% longer than the antenna wire itself. This is often called a counterpoise. The RF ground wire in this case can be laid out in many ways, just so long as it does not cross over itself to form a loop. Indoors, such wires are often run under carpets or along walls, out of windows, or anywhere else convenient. This wire will often have large RF voltages on it, so it should be kept away from people or insulated to prevent contact.
9. Avoid connecting to a polluted ground. Building or Plant grounds can have a lot of other energy flowing through them that can get into your very sensitive receiver. RF Noise can come from many sources, particularly in industrial areas, and it can be present within the ground. Avoiding this energy is one of the main reasons for creating your own ground system.

While the Smartuner will provide a good match with a poor RF ground system and you will be able to transmit, your antenna efficiency will be low and you will be subject to RF problems that can make operation miserable at the very least. Getting the greatest efficiency out of your antenna system needs a proper RF ground unless you’re using a balanced antenna system.

BTW this is just not theory on my part i have now completed 2 circumnavigations. So i have had a good opportunity to put all this theory to the test. I have been fortunate enough to be able to play radio in most continents and i now have a good feel based on experience how the propagation plays out. I am not just a email and net user of ham radio when cruising i make it habit to be on the air virtually contstanly. When i was standing watch i always had the receiver running somewhere on HF. Am I a HF addict abolutely yes. I have also helped numerous people in my club activities diagnose and install HF radios and antennas well in excess of a 150 installations all for free out of love. Everything i talk about in here i have put into practise. My background is in engineering, now mostly in avionics and in defence project management. I do very little engineering work now. However in the past that was my main brief working on RF systems from DC to 50 ghz. Over the last few years i have been very fortunate to work on a very modern and upgraded HF communications system jointly developed in the USA and Australia. So i have had a great introduction to state of the art hf techniques. That is not to say that we as hams as whole are behind the times. But what i have learnt and even the military has learnt is that using knowledge and planning you can make HF a very reliable medium. In fact a lot of the things that we discuss in here have also been used professionally. As an example using techniques we discuss here has resulted in output power of military transmitters typical dropping to about 4 or 5 kilowatts verus running upto 10kw to 50 even 100 kilowatts. This all comes from better HF planning and antenna selection. I like to always think of it a science rather than voodoo.

If you have a HAM license and use 14 mhz for most of the popular maritime nets cut it for about 42 feet. This will give great efficiency on 14mhz and below. If you heading offshore for a long period of time you wil use 14 mhz and 12 mhz a lot. The difference in signal strength between a high angle to long backstay and a optimum length one is close to 10 db. So shortening back to gain this 10 db is worthwile considering that it would take 1 kilowatt of power to get back the 10 db on transmit. Even if you did use a amplifier your hearing is down 10 db at the optimum take off angle.

So thats how i derived at my suggestion for the maximum length of 42 feet. But for others and confirming what you said about longest is best, i support your suggestion if was only coastal cruising or heading into the caribean islands. Its mostly short skip and high angles will work.

I run Nobletec on my ibook with a Keyspan USB adaptor to the GPS. Works better than most of my friends PC's.

For weather fax I use a Mac program MAC MULTIMODE with great results. (http://www.blackcatsystems.com/software/multimode.html) I just use the Radio speakers and the built in laptop mic to get the picture (I can plug it in to the mic too, but why bother)

We ran Windows XP and Virtual PC all this summer while cruising. This allowed the use of Airmail software and the Sailmail system for email from remote spots in British Columbia.

I tried weatherfax software under Windows, but my 600mhz iBook wasn't fast enough. I'll give Mac Multimode a try. Thanks for the tip!
Hi Dick

With a laptop and a SSB/HF radio: http://www.wefax.de/ This is the world's most detailed WeFAX website.

If you use a macintosh: SSB/HF + "multimode" ( WeFax, CW, Sitor, TTY, Helschreiber, etc.) .... plus with a special antenna you can direct download the weather satelite data.

With a laptop and proper software or a dedicated WeFax you can simply download from the 'shortwave' spectrum as many countries broadcast such info.

The BEST text for your own personal weather forecasting (after reading all those downloaded WeFax charts, etc.) is Dashew's "Mariners Weather Handbook"

Hi-- the answer is a 6-66 antenna.

1. Bend a 66 inch piece of 3/8 soft copper tubing into a perfect circle
except leave a 6 inch gap. Flatten the ends and connect them with a
scrap piece of fiberglass batten.
2. Get a 300 ohm (pigtail type) to 75 ohm coax tranformer (Rad Shack).
3 Split the the twin lead down the middle for 6 inches forming a "Y".
4. Attach this to the ends of the circle of tubing.

You now have a 6-66 omnidirectional antenna!

You can make a support frame out of two pieces of 1/2 inch poly pipe
using "T" connectors thru which the tubing goes, in an "X" form. Add two
more "T"s in the center of each half of the X, aiming one up and one
down. Add two verticals of convenient length one up towards the sky
the other down towards the earth. This whole mess now looks like
a child's "Jack", as in bounce the ball and pick up the jacks.
Haul up with the main halyard sliding along the back stay. Lead the
coax and a safety down haul to the conpanionway or a convenient hatch.
Also works if attached to the overhead in the main cabin but signal is
not as strong particularly with a wet salty deck!
And they say a picture is worth 1000 words! Don't see why!

Out at sea the cheapest solution is Sailmail using SSB Radio. It's text only plus you can download GRB weather info and it does have some limits but at $250 / year it's the cheapest you'll find. Sat phones would be the easiest to use but at a considerable cost increase. If you expect to use sat phone it's a good idea to pre buy blocks of minutes.

Jon

We get our weather from basically 3 sources -- Buoyweather (we get a daily 7 day text table showing 6 hour intervals for wind speed & direction & wave & wave interval -- via Winlink e-mail) & also the Caribbean text forecast on Winlink; Wunderground Weather -- we have an internet connection via the cell phone that works at anchor where there's a cell tower, we just look up Roatan & check the weather, just like if we were in the States. The third source for us for weather is the NW Caribbean net on 8.188 at 8 AM our time in the mornings. We keep an excel spreadsheet comparing the three different forecasts to the actual & believe it or not, so far the Wunderground Roatan weather is winning -- limited data.

Near a cell tower, we have 4 sources, away from a cell tower, we still have 3, NOAA, Buoyweather & the NW Caribbean Net! We take weather seriously!

try these I have not used, just found out about them myself.

http://www.gpsnavx.com/MacENC/index.php?page=Downloads

Another MAC site
http://macgpspro.com/html/newhtml/macgpspro/features.html


http://www.gpsy.com/

So are you getting the WX Satellites direct? (Miles)

We have been using Virtual PC with Windows XP and Airmail for a couple years. Last summer, I did some tests using the free Fax software written by Jim Corenman (?Getfax?) with some success. The reception was really bad where I was testing but I think it would have worked fine offshore.

My recollection is we're using a Keyspan high speed serial/USB adapter to our Pactor modem. The Pactor controls the Icom M-802 SSB. It all works slick. I know it seems like a kludge to use Virtual PC, but for the few apps I run in Windows, it is a good solution. A fast Powerbook helps.

Let me know if you want to see this package work sometime. - Charlie

The 11.5 meter length is a good compromise length meeting the needs of high frequency communications between and 10 and 30 mhz as well as being suitable for coastal communications between 2 and 10 mhz. Antennas of this length are common on naval vessels for this very reason. Since even most long backstays are short at 2 and 4 mhz the differences in efficiency will not mount to much.

The 11.5 meter length is a good compromise length meeting the needs of high frequency communications between and 10 and 30 mhz as well as being suitable for coastal communications between 2 and 10 mhz. Antennas of this length are common on naval vessels for this very reason. Since even most long backstays are short at 2 and 4 mhz the differences in efficiency will not mount to much

As Rich said, the web site has a free program, download English version from http://wefax.de/html/hauptteil_wxsat.htm

Although it's a satellite program, it will decode HF fax as well.

Simply connect HF radio earphone/speaker-out to the mike-in on the lap top, get the wire from any electronic store. Remember to tune receiver 1.9kHz lower than the frequency listed. You may need to adjust the "tilt", read help file on how to do it.

The world wide frequency list is available at http://www.nws.noaa.gov/om/marine/rfax.pdf

Another useful propagation prediction program runs with Airmail software, download from http://www.airmail2000.com then follow instructions from http://www.siriuscyber.net/ham/#propagation to install the propagation program. Then you enter lat/lon of transmitting station (from atlas, internet etc) & your lat/lon together with the frequency & it will tell you the best time of day to receive.

Another program I really like is jvcomm, site is http://www.jvcomm.de/index_e.html You can download trial version & have a play with it.

From my home in Sydney, Australia, I have received faxes from as far as Hawaii, San Fran, Japan & Europe.

Have fun.
Joe P

For a Mac G4 and higher I'd recommend MacENC - http://www.macenc.com/ for use with ENC charting AND for raster charts. MAC ENC can switch back and forth between both modes. VERY fast and very intuitive software. Supports GRIBs, etc. You can download a 'demo' from the above URL. The full cost is only $99 for a 'complete' download.

You can download all the USA Raster and BBS charts for free from: http://nauticalcharts.noaa.gov/mcd/enc/index.htm & http://nauticalcharts.noaa.gov/mcd/Raster/Index.htm

A good net forum for Mac related navigation software (by mostly the MacENC, etc. stuff as its rapidly become THE mac nav. software package):
http://www.macsailing.net/bbs

-------------------------------
Likewise - the BEST WeFAX/NAVTEX/TTY/CW software for a mac is "multimode" downloadable from the "BlackCatSystems" website ... a demo version is also there.
-------------------------------

I had a USB/serial port converter box between my computer (which only has USB ports) and my PACTOR modum (which only has RS-232 ports on it). Many times when I transmitted the converter box would shut-off & torpedo my transmission. I fixed the problem by deep-six'ing the cheapo Belkin converter box & bought a high quality Edgeport converter. I even paid a few bucks extra and got the model in the aluminum casing for better shielding. Never had a problem since!

Airmail: No, everything works fine. I use a PTCIIUSB over a Bluetooth connection. I had to patch in the Bootcamp drivers for Wifi and Bluetooth to get the Bluetooth working, but this was no biggie

My research has indicated that the best laptop battery supplies/chargers are made by Lind Electronics. They can make a laptop adapter that works (both runs laptop and charges battery) at supply voltages as low as 10.5 volts.

I powered the Dell straight from a dedicated breaker at our nav station panel. It was simple and worked beautifully. Unfortunately, Apple doesn't make ANY 12v power cords. Their 'airline adapter' won't work from a 12 volt supply. It turns out that the Macbook's input voltage is 16.5v and airline seats supply around 15v which is why it'll run the computer but won't charge the battery. The adapter is basically just a patch cord and doesn't convert any voltage.

I thought about doing the inverter thing as we have a little pocket Xantrax onboard but I went with an adjustable DC/DC converter from Powerstream that bumps the 12v supply to the 16.5v that the Mac needs. I had to buy the airline adapter to get the 'magsafe' connector for the laptop input (that ONLY Apple makes and is why they charge $60 (!) for it.) I wired it to the converter and although it works fine it's definately more expensive.

I've got the MacENC chartplotter program and a BU-353 USB GPS receiver which allows positioning. My next project is to pull wiring to my ancient GPS at the helm so I can do trip planning on the computer and upload waypoints and routes to it (Yeeees, I have the paper charts so don't start )Posted: Thu Mar 15, 2007 9:55 pm

Alison, you might find you hear different views on how Sailmail & Winlink differ, depending on where the respective users have been cruising and what their email and wx download needs have been.

The performance of your radio installation and the technology you will be relying on are identical. The difference in the number of shore stations (to which you connect when up/downloading) is less significant than it might seem, since so many of the Winlink stations are in N America and so, for folks cruising outside N America waters, perhaps not relevant. So one option you have is to compare your own cruising plans with the location of each system's stations. E.g. if heading for Europe, Winlink is a far more accessible system as it offers 4 or 5 shore stations (called PMBO's), depending on how you count them, to Sailmail's one station in Belgium.

Another major difference is that the Winlink user has a 30 min time limit with *each* shore station each day. Many shore station operators will extend this limit if e.g. you are on passage and need more downloading time. So for many popular cruising areas with access to multiple Winlink stations and given the finite amount of up/downloading a given crew needs, Winlink connect time is essentially unlimited. This is why it is viable to up/download small graphics (pic from the anchorage) using Winlink while wx (e.g. wind & wave charts) and other graphics up/downloads are not possible when using Sailmail.

The major benefits of the Sailmail system as I see it are that it operates as a commercial system (even tho' it is non-profit), it is under contract to provide the services for which it charges, and in that regard is a more reliable source of radio communication than the typical Winlink amatuer radio hobbyist who operates a PMBO. If the local PMBO operator decides to go on vacation, has neighbors who force him to lower his antenna height, suffers chronic service interruption from his broadband supplier, or doesn't have the money to rebuild his antenna system after a hurricane sweeps through - I've seen all these events occur with PMBO stations while we've been out cruising - that station may simply, suddenly not be available to Winlink users.

We've exclusively used Winlink while both in the Caribbean and Europe and have never been skunked, not even once, when needing to up/download wx and email data each day. But I wouldn't hesitate to add a Sailmail account if we moved to areas where it made sense to do so. I would hate to have my hands tied and *only* be able to use Sailmail if planning extensive cruising.


Cost is indeed one difference between Winlink (free) and Sailmail ($250 / yr). Sailmail has some pretty tight limits on the amount of email you can send and receive, and restricts the type and size of attachments. Winlink generally allows larger amounts of email and attachments.

Some on-line resources:

  • Marine SSB Single Sideband Simplified ~ by Gordon West (Courtesy of Icom)
    Icom America - Marine Radios - SSB Single Sideband Simplified

  • HF Users Guide ~ SGC
    http://www.sgcworld.com/Publications...fguidebook.pdf

  • General HF Technical Notes ~ SGC
    Technical

  • HF Propagation tutorial ~ by Bob Brown
    HF Propagation tutorial

  • HF Communications tutorials for download:
    About HF SSB Communications
    __________________

I tried to get some help from local Wifi services on getting a long range connection on a Mac. After a number of calls and disscussions with a lot of head scratching from those 'in the know' I decided to tackle the problem on my own. With some research on the net I came up with my own combination of external USB wifi interface (Alfa) and a high gain antenna (from Ebay). Total cost about 170.00. At present I'm connected to a hotel a little more than 1/2 mile away from the anchorage. The system will also work on a PC as the software for the interface has both on the disk.


What I have found is that my handy little PDA Ique 3600 from Garmin answers MY need for chart reference in the cockpit and where I want it which is usually forward under the dodger.

The two steps to regaining Telnet access to WL2K and your e-mail are:
1. Delete the existing configurations.
2. Enter the new Telnet configuration parameters.

The new configuration parameters are:

Remote Call Sign: WL2KW
Remote Host: washington.winlink.org
Port: 8772
Timeout in Seconds: 120
Password: cmstelnet

Remote Call Sign: WL2Ks
Remote Host: sandiego.winlink.org
Port: 8772
Timeout in Seconds:120
Password: cmstelnet

Remote Call Sign: WL2KH
Remote Host: halifax.winlink.org
Port: 8772
Timeout in Seconds:120
Password: cmstelnet

Remote Call Sign: WL2KP
Remote Host: perth.winlink.org
Port: 8772
Timeout in Seconds:120
Password: cmstelnet

The source for these configuration parameters is:
WL2K help file AIRM_TELNET

Note: These changes apply only to the WL2K Network. Access to the Sailmail Network remains unchanged

Weather..
http://www.macwx.com/

Weather Fax.. http://www.blackcatsystems.com/software/multimodeOSX.html

Tides and Currents.. http://www.versiontracker.com/dyn/moreinfo/macosx/14649

Email.. http://www.globalmarinenet.net/email.htm

All images and content copyright of David A. Kall