FAQ's for new ski boaters..

[Gerrit]

I do not think so, as far as I am aware they are both have legally limits of 25w output, for more than that you should get a SSB radio

On standard radio's 29mhz is limited to 5watt and vhf to 25watt. The wave length of 29 is much longer that vhf, if they were to use the same modulation the 29 will work further. BUT they dont use the same modulation, vhf uses FM modulation were as 29mhz uses AM. With AM you cant use high output like 25watt or more of the vhf, all you will get is interference from higher output on 29mhz.

Bottom line is that VHF WILL go further and you will have much clearer comms. 29mhz is old technology witch should have been canned a VERY LONG time ago.

The next thing we will be using is digital modulation on vhf, a bit pricey at the moment but we will be able to talk back to port 100's of nm's away.

If i can give you guys advise, fit your radio yourself and then take it to a RF tekkie to lay your cable and the connector. Let them test the VSWR to be well within limits and you will have comms for a long time.

[Searaider]

Very interesting Gerrit,thanks
At the moment I'm trying to hook up my GPS to my VHF (DSC)

[Gerrit]

Very interesting Gerrit,thanks
At the moment I'm trying to hook up my GPS to my VHF (DSC)

RTFM 

[benniejordaan]

29mhz is old technology witch should have been canned a VERY LONG time ago.

I can't agree with you more on this one! Last time it was discussed, the comment was that there isn't enough VHF channels available in SA to dedicate some to ski boat opps. I'm not too sure about this although we wouldn't want them to use the working channels. Bearing mind on the KZN coast there are many independent ski boat clubs unlike in the cape.

Any comments on this???

[Gerrit]

I can't agree with you more on this one! Last time it was discussed, the comment was that there isn't enough VHF channels available in SA to dedicate some to ski boat opps. I'm not too sure about this although we wouldn't want them to use the working channels. Bearing mind on the KZN coast there are many independent ski boat clubs unlike in the cape.

Any comments on this???

Yes and No, there is a limit to the usable spectrum, especially the marine band.

The channels used for marine is a international standard. It means that all container ships, fishing trawlers, cruise liners etc will be using these channels.  Keeping in mind that VHF is so powerful it would create a lot of traffic on the radio's.

Let say all the clubs are using the channels allocated for talking, you will get a boat asking permission to return to shore at site A, site B will be within range, both will respond or the wrong operator will respond and you could end up with big problems. This could be overcome by using proper radio procedures, unfortunately not all the boats know this or they just don't care. The talking channels would very soon be overcrowded by guys talking to buddies, boats getting permission to launch or to return.

Keeping in mind that the marine radio we use is in essence a VHF radio. My suggestion would be for the clubs to apply for their own frequency from ICASA. This will enable them to program their and their member's radio on that specific frequency. They will then be able to use that band by them self with out anybody else using it. All the emergency and weather channels will still be available on the radio's.

With the coming of Cell phone a lot of VHF spectrum became available, Icasa regulating this spectrum it could work. The same frequencies can be used by different clubs 300-400km apart.

But then again VHF works in Cape Town, not sure how many clubs and boats there is in relation to KZN.

[benniejordaan]

Thanks Gerrit,
So it really is up to the clubs to take the initiative. And then ofcource the problem of "re-programming" and especially that of old installations. Many of us use both VHF and 29 Meg.

[Gerrit]

Thanks Gerrit,
So it really is up to the clubs to take the initiative. And then ofcource the problem of "re-programming" and especially that of old installations. Many of us use both VHF and 29 Meg.

Re programming the old radios will be easier than the new ones, there is a lot of old hands that will program the old installations eyes closed. The new ones i am not so sure how it will work. But then again in todays day and age, a simple email to the distributor/manufacturer will sort you out.

As you said allocating spectrum for marine use will not work, but if the clubs apply for their own spectrum there would be no problems as long as ICASA regulate it.

[Tsutsuma]

In Maputo we have three Official Ski Boat Clubs -
Clube Naval &
Maputo Marina &
Clube Maritimo.
We all only use VHF.
In the old days we had a Ski Boat CB radio system and were on 27.085mhz
That was then stopped in the1990,s
Clube Maritimo is on International VHF channel 62
WE have a Repeater Station on the Inhaca Island Light House
with it,s own UPS Back up system.
Clube Naval & The Marina is on International VHF channel 22.
NB : When you buy a new VHF in South Africa - it 99% of the time is on USA System.
        This has the effect that you will not have channel 62 - it jumps from 61 to 63.
        To correct this you need to press the up & down channel buttons at the same time and hold it there until
        your VHF radio swithes over from USA on the LCD to Int "International"
        Your VHF has to be in the "ON" position to do this.
On the anttenea we have found that a 6DB gain works the best.
I have a boosted "Whip" type because the 6DB rigged fiberglass models would later crack and break due
to the fact that my boat is small - I run very far to my fishing spots and my anttenea is mounted on the top of my T top.
The "Whip" is more flexable and just right for my boat.
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[John F]

Clube Naval & The Marina is on International VHF channel 22.

Last time I checked (3 weeks ago), Clube Naval used VHF Ch. 20.
Within a radius of +/- 3 nm miles, it's better to use VHF Ch. 10.