Can I fix this VHF aerial?

[Pikey Dave]

Originally Posted by Richard Selman

My drysuit is my main bit of life support equipment.....

The boat's mine

[martini]

Originally Posted by BogMonster

Cost of half a tank of fuel

[Erin]

Originally Posted by martini

Won't be so bad once you've got your new toy.

[Channel Ribs]

Originally Posted by Erin

Won't be so bad once you've got your new toy.

How many new toys does a bloke need?

Although I am reminded of these wise words, in answer to my own question...

He who dies with the most toys, wins.

[martini]

Originally Posted by malthouse

How many new toys does a bloke need?

How many are there? That's how many I need

[BogMonster]

Originally Posted by martini

I bet that hurts

[Erin]

Originally Posted by malthouse

How many new toys does a bloke need?

I'm working on the basis that you need enough toys to fill the garage, garden and shed, at which point you need to buy just one more, so that you have nowhere to put it and have the required excuse to move to a bigger place with more storage. That's the plan anyway

[martini]

Originally Posted by BogMonster

I bet that hurts

It's been covered on here more than once, I prefer not to think about it

I keep the economy reading on the smartcraft set to "litres per km" or some other meaningless figure

[BogMonster]

Originally Posted by martini

I keep the economy reading on the smartcraft set to "litres per km" or some other meaningless figure

Good plan, stupid unfathomable measurement that is, never understood it so it's got to be wrong

An ancient long-deceased aunt once said (just after my father bought an aeroplane in the late 70's) that "<tut> little boys never grow up their toys just get more expensive" - a fine motto to live by

[Richard Selman]

New aerial bought.

With the height extended by the A-frame, the coax does not reach the set. Problem with these aerials is that the coax is captive in the aerial. Would there be any major problem with extending the length by 2m or so on top of the 6m ish it comes with providing I do a decent splice or does this unbalance the aerial?

Richard

[GJ0KYZ]

Originally Posted by Richard Selman

New aerial bought.

With the height extended by the A-frame, the coax does not reach the set. Problem with these aerials is that the coax is captive in the aerial. Would there be any major problem with extending the length by 2m or so on top of the 6m ish it comes with providing I do a decent splice or does this unbalance the aerial?

Richard

You could try a BNC-BNC join or a PL259 join if need be. Don't use spit and tape else all hell will break loose. In any case, cover the join in Sekafix and make sure it stays in the console or out the elements somewhere.

[Pikey Dave]

Originally Posted by Richard Selman

New aerial bought.

With the height extended by the A-frame, the coax does not reach the set. Problem with these aerials is that the coax is captive in the aerial. Would there be any major problem with extending the length by 2m or so on top of the 6m ish it comes with providing I do a decent splice or does this unbalance the aerial?

Richard

No problem at all. I have to do the same. What did you buy in the end?

[martini]

Originally Posted by Richard Selman

New aerial bought.

With the height extended by the A-frame, the coax does not reach the set. Problem with these aerials is that the coax is captive in the aerial. Would there be any major problem with extending the length by 2m or so on top of the 6m ish it comes with providing I do a decent splice or does this unbalance the aerial?

Richard

This type of aerial has always been a pet hate of mine. Apart from the PITA of not being able to disconnect the aerial from the cable, they don't lend themselves to good performance.

The cable you have there is called RG58, it's just about the worst performing 50 ohm coax available. The reason the aerial comes with such a short length is because it's generally accepted that any longer length would have an unacceptable amount of signal loss.

For me personally, I like to get the maximum possible performance from my VHF which is why I use a good quality antenna with a connector at the base, coupled with a good quality mini-RG8 coax.

You could extend the cable you have, it won't damage your equipment or anything, but don't expect to get the kind of range your radio is actually capable of.

[GaryC]

Originally Posted by Richard Selman

New aerial bought.

With the height extended by the A-frame, the coax does not reach the set. Problem with these aerials is that the coax is captive in the aerial. Would there be any major problem with extending the length by 2m or so on top of the 6m ish it comes with providing I do a decent splice or does this unbalance the aerial?

Richard

I was always told at Transmission School (Comms) that each connected break in the cable created a 3db loss. This is the same as changing your 2.7metre ant for a 1m ant. Breaks also cause reflections again. However it is acceptable to put one in. I would put it in a IP68 box or such.

My wife bought me a 2.7 metre whip with 12m of cable and they delivered it to her office. Bit of a job getting it home though.

Gary

[BogMonster]

Originally Posted by GaryC

My wife bought me a 2.7 metre whip with 12m of cable and they delivered it to her office. Bit of a job getting it home though.

Gary

Be popular with that at rush hour on the Tube

[Richard Selman]

Martini - what aerial would I be better using?

Cheers

Richard

[martini]

Originally Posted by Richard Selman

Martini - what aerial would I be better using?

Cheers

Richard

Richard, mines made in Norway by a company called Comrod, bulletproof but expensive!

If you're thinking about taking your new one back and replacing it with something else, my advice would be to speak to Malthouse on here. He's quite knowledgable on antennas and can do you a very good deal on a new one. You might not get a reply for a couple of days though, he's meant to be on a yacht delivery at the mo.

As for the cable, the most suitable would be mini-8 (aka RG8x), very low loss for it's size, RG213 performs better but it's half inch diameter and doesn't like going round corners and through conduits! After much searching the best one I've found is made by Ancor. It has 96% braid which is better than most and reduces the signal loss. It also has a tinned centre conductor as well as tinned braid which improves corrosion resistance. It's available at various places but I buy all my cable from a US company called Genuinedealz.

Moving on to connectors There's a small UK firm called WH Westlake that do a good quality PL259 and can supply a reducer to suit the Mini-8 cable. They also do a PL259 that's specifically for mini-8 but don't buy this as it's the screw on type which is no good. Connectors really need to be soldered, if you're going to all the trouble of sourcing the right components, you don't want to spoil it by using screw-ons.

As for the soldering, there's a right way to do it and several wrong ways. Sounds extreme but if you don't feel up to it and don't know anyone who does, you could run the cable, cut to length, then post it with connectors to me. I'm happy to solder them for you FOC. In fact I'm fairly sure I've got some 259's in stock, I'd just charge you what they cost me plus postage back.

Seems like a lot of work for something you may hardly use but IMO apart from your lifejacket, your VHF is probably the most important bit of safety equipment onboard.

A very wise, old engineering tutor once told me "All things are only as strong as their weakest point." Remembering this statement has served me well throughout my career as a steel fabricator as well as many other circumstances!

[boristhebold]

My drystack broke mine for me trying to fit my boat into a different (smaller) slot ... didnt even attempt at fixing it as it wasn't worth it, replaced it at a cost of £60.

[Richard Selman]

Thanks for the offer but the cable will be run through the A-frame which is now a part of the boat......

Ok with a soldering iron and my dad's an expert (built electronic gear for a living).

Does this cover the technique?

http://www.scribd.com/doc/8511808/PL...lation-on-RG8X

What diameter is RG-8X?

Cheers

Richard

[martini]

That's the way, excellent article there

Note the comment re soldering iron size, I've got a 100w and really struggle. Bigger the better.

RG8x is 6.1mm iirc