Ferrites

[seabird51]

Hello to Rob Mark and any other wizzards out there:
You may recall that my SSB caused the AP to go wild in the prior TP. I have isolated wires such as the big lead from the SSB to the tuner that had the AP cables coiled and strapped to it. I put aluminun tape around the pvc conduit holding the SSB lead. this cured the problem with 6 megs and prolonged the stability at 8 megs. Next I put about 10 ferrites on the cables and further improved 8 megs but not a total cure. 4 and 12 megs are fine. So back to Amadon for another 10 ferrites. Any suggestions about placing them.
Nice to have this site back up. We are still looking forward to 2008 SHTP.
Have missed all of you.
Lou

[sleddog]

Lou,

I understand that the SSB system uses an automatic antenna tuner and that
there is a coaxial cable connecting the SSB transceiver to the tuner. It's probably a good idea to separate the autopilot cables from the coaxial cable. But it's likely that the bigger source of the problem is that the signal radiated from the backstay is being "received" by the electrical cables that connect between various parts of the autopilot.

My radio guru suggests placing ferrite chokes at both ends of each electrical cable that connects between various parts of the autopilot, including the d.c.
power cable to the autopilot. If you place a ferrite choke around the d.c. power cable, be sure to run both the plus and minus (power and ground) wires, together, through the same ferrite choke. If the ferrite chokes do not fix the problem, the next step is to make sure that all of the cables connecting the various parts of the autopilot are "shielded" cables and that the "shield" is connected to ground at one end of the cable. Although the shield is often connected to ground at both ends of each cable, the shield sometimes (often) will work better if it is grounded at only one end of the cable.

~sleddog

[BobJ]

I bought "RFI Kit #2" from radioworks.com for $55. I installed their compact T-4-500 line isolator in the tuner end of the cable to the radio and used the six 1/4" ferritte cores elsewhere where they were most needed. I also kept as much physical separation between the tuner cable and autopilot cables as possible on my little boat. The tuner cable ran forward on the port side, and all the autopilot cables were on the startboard side. At no point did I allow them to run parallel.

I didn't exactly know what I was doing but had no problems.

Bob J.

[seabird51]

Thanks for the replies. Getting the kit into the tuner will be a last resort because the tuner is so deep in the aft area. Separating the cables, aluminun shielding and some ferrites has definitely decreased the interference, but no total cure.
I am heading south in the AM to set up the Iridium which will get me deep behind the electric panel. While there I will put some ferrites on the power leads to the AP and on cables behind the SSB. The SSB is very close to the panel and not easily movable.
Tune in later.
Lou

[cr1]

Being a total novice on SSB, I wonder first of all if I'm posting this in the right place...
Here's my question: Being on a budget, I can't afford SSB. I was thinking of carrying a SSB receiver to receive the other boats' positions during check in and than somehow e-mail my position to the boat or race committee. I think I need SSB to do that? What about Sat phone? I'm planning on renting one.


Thanks in advance,
Rich

[seabird51]

Rich
I am not sure of how the check-ins will be managed this trip. I believe that SSB is not required but I suspect most of the check-ins will still be via SSB. You could of course listen on a SW receiver but could not ask for repeats etc.
Sat phnoe (Iridium) is an option by voice or email if you carry a laptop. GMN has system for the email that is very fast so saves airtime which can build up fa$t!!!. I doubt that you want to incur airtime charges while someone reads all the postions to you twice daily.
Lou

[jbarthelmass]

Lou,

I'm unfamiliar - who or what is GMN?

I'm planning using a satphone for check in as well

Thanks!

John

[cr1]

Hi all,
Not plowing old ground with me. I lke the idea of buying a used SSB, antenna and tuner. I've heard horror stories of installations without ground planes installed. I have a 1976 26' that has no ground plane. What are some thoughts on installation in this configuration? Maybe one of the considerations is that I don't have to get out too far, just to that chase boat, right?

Thanks in advance,
Rich
====

[seabird51]

Hello Rich, Bob and Jonn,

I will try to answer what I can.

GMN is Global Marine Net and they sell sat phones and air time. They have special software that is very fast and saves air time. ie I downloaded a 4 day Pacific GRIB in less than 2 min. That took about 10 min with my old Iridium direct system. If you batch a bunch of text emails and send at once you save more airtime. It is pretty slick! They also have Mac version that I am now using.
http://www.globalmarinenet.net/

Do not underestimate the GRIBs, I sailed in 2002 with just a Furuno radiofax and had that and email GRIBs in 2006. If I had to choose one for summer in the Pacific, racing, I would rather give up the fax. I think that is the sentiment of most who have GRIBs available and those that did not relly enjoyed the info we disseminated on the SSB at check-in. Also you can get the Wx Fax maps over the SSB with a laptop so I would not buy a Furuno at this point.

I agree with Bob about SSB's and the vulnerability of a lapttop, esp on a smaller boat out there. There is no "chase boat" just some racers who function as comm boats.

I have a vintage M700 SSB from 1986 that works fine except it will never do email. I suspect you could get one very reasonably. I sent mine up to ICOm in Seattle and had it checked and they replaced 2 parts for $150. I met Gordon West in SD and he said the old M-700 is a fantastic radio and the only one that puts out a full 150 watts. That is probably why it upsets the autopilot. (another work in progress)
The ground plane is not rocket science, just alot of copper tape in the hull.

A bit off the this track I recommend carrying a handheld epirb (ACR PLB) in your pocket. Once you get into warmer water with a pfd you stand a good chance of getting saved should you get separated from your boat. Not withstanding the local predators whose food chain you may join.

Stay with the boat
Lou

[cr1]

Rich, here is the link to this topic on our old board:

http://p4.forumforfree.com/viewtopic...193&mforum=sss


(I'd post a link to the "Should SSB's be required" thread but I would get keel-hauled.)

Thanks for the quick response...