SSB Radio Installation / Icom 802 ?

[jwrhind]

Hi

I'm in process of buying my first yacht (secondhand) and considering installation of a SSB radio. I want one that I can use on amateur bands and occasionally on marine bands if I need to.

1. I understand that as a UK registered yacht, I cannot install an Amateur transceiver modified to cover the marine bands for reasons of type approval. Is this correct?

2. I would need to modify the backstay to add insulators. Is the best approach to assemble a new insulated backstay and then replace the existing one.

3. How easy is it to reprogram an Icom 802 for amateur bands transmit?

4. What's the best place to get an RF earth for the ATU (I expect that the radio does not need an RF earth). I envisage two options - using the keel or installing a seperate plate. I'm uncertain that the keel is earthed anyway and would appreciate comments re the effect of such installation on corrosion.

Thanks
John

 

[Birdseye]

The questions you ask suggest you dont have a ham license. If that is correct, you will find the ham community very unhelpful, so its best to get one. Not difficult and doesnt require morse these days.

Following on from that, a ham set all-banded to use on marine frequencies undoubtedly wouldnt be type approved which is required whether you are UK registered or SSR or not at all... If you werent bothered about a license, this wouldnt concern you. Personally it wouldnt concern me either - and I have a ham license.

A modded ham set would not have DSC facilities. To be honest I am not sure what real use SSB radio is as an emergency facitility these days. I suspect most people use satellite kit for that, bearing in mind that SSB is really for deep sea useand wont necessarily work short distance because of propagation

You can get an aerial tuner from any ham shop. People like Waters and Stanton. Google them . What you want is one for an unbalanced end fed aerial.

I made up a new backstay - after all, the top and bottom terminals are where ageing will have occurred, so why put old wine into new bottles. If I were doing the job again, I would simply raise the aerial to the mast head on a halliard when I wanted it. In practise I found I never used the radio when sailing so why risk the extra joins.

Earthing is an issue I never bottomed. I had a bronze plate but found no difference between using that, the keel bolts, the guardrails and finally nothing at all. Never understood why, but I could still raise Siberia and S America from Europe with no earth at all.

But first of all ask yourself why you want it at all. I used mine for chatting to other hams (who wont speak to you without a license) and for the maritime mobile nets for weather. The NASA weatherman is an easire solution to that problem.

 

[Guest]

Post deleted by danfoley

 

[jwrhind]

Hi Birdseye

I've had a UK ham licence for some years but have not been "active" since around the mid 1980s so am out of touch. I was thinking that I could possibly get back in to the hobby, as well as providing an additional means of communication for safety. I'm not interested in having HF DSC, but it would be useful for email, weather data, etc.

I found an article a few months ago that "suggested" that a modded ham set for marine bands would be allowed elsewhere, but not on a UK vessel.

I have no day-to-day need of marine HF and so a ham set is a good cost effective solution. And until the backstay needs to be replaced, a wire on a halyard would be a good idea and the SGC tuners look good on paper.

Cheers
JR

 

[Matrosen]

Re: Thin Wire Antenna?

I used plastic covered steel clothes line! It's riggged from the top of the main mast to the top of the mizzen with home made nylon insulators, then down to the aft deck where it changes to coax to the ssb. It was done in a hurry as a temp and very, very cheap solution to get us from the south of France to the south of Spain, but five years later it is still there and working!

 

[Birdseye]

Re: Thin Wire Antenna?

Within reason the wire diameter doesnt matter. I use automotive multistrand plastic coated copper wire for my home aerial without obvious problem and it has lasted years.
You can get small egg type insulators from a ham shop but I simply put some flexible plastic tube over the wire, formed it into a loop at the end and used that.

 

[jwrhind]

Re: Thin Wire Antenna?

" is the diameter of the wire totally irrelevant? "

The wire diameter does matter but the most important factor is the length of wire. It's some time since I was involved in antennas but here's some general guidance.

At wire diameters less than about 2.5mm, the resistance increases significantly and so this is a sensible minimum. Above about 15mm there's little advantage. Copper has lower resistance than steel or aluminium and so is the preferred material.

A good solution is a steel central conductor for strength and surrounded by copper conductors to form a multstrand wire. This offers a good combination of strength and weight, since each copper conductor can be of small diameter as long as the total section area is maintained.

Running an aerial in proximity to standing rigging will impact performance and that's probably a reason that people use the backstay -afterall it's free apart from the insulators! On the other hand, a wire on a halyard is quick. cheap, and easy to repair.

JR

Disclaimer - Author's personal opinions.

 

[William_H]

Re: Thin Wire Antenna?

A few comments re antenna. Stainless steel wire has more resistance than copper perhaps a tenth of an ohm for a backstay so not really a problem. The clearance from other paralell conductors is the important part hence the use of the backstay with insulators. Thiose little ceramic egg insulators are good but not that strong. I had some in the cap shroud of a 23 foot heavy catamaran and the eggs failed in compression with porcellain going in all directions. This was using 3/16 or maybe one size bigger rigging wire.
My best suggestion to John however is to forget the radio on the boat the sailing will keep you quite busy and amused certainly intially. I do realise this is possibly just winter dreaming. regards ole will

 

[Benbow]

Re: Thin Wire Antenna?

You can get Norseman or sta-lock - type self assembly terminals that are also insulators. They will allow you to re-use an existing backstay.