New VHF Aeriel

Sans Bateau

Sans Bateau

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So you walk into the chandlers to buy a new VHF Aeriel, there are about 4 - 5 different ones. Except that some have a built in hawk, what is the difference between one or the other

Is it just a case of the more you spend the better it is????? /forums/images/graemlins/confused.gif
 
It is a question of paying your money etc. Obviously the combined aerial and wind indicator types are going to be more expensive. but they are useful if you don't have a lot of space at mast top and there might be problems accommodating wind speed indicator, a proper Windex and an aerial, even with a stand off bracket.

I would judge the quality by the fixings and the connectors. Some are pretty naff and may not last long in such an exposed situation.

On our trip down to the Med, our "whippy" V-Tronix aerial got bust ( the connector on the base broke off). The Spanish don't seem to go in for the slimline steel jobs and we were forced to buy a more substantial, longer fibreglass type. It was too heayweight for the original plastic standoff bracket, so I had to spend some time up top fixing the proper angle bracket on the mast side, which makes for a much stronger installation. However, it was worth it, reception was vastly improved and we were picking up stations we had never heard before.
Back to your original question, I would say the answer should be that you buy the best you can afford. I think VHF rates as a safety item, in which case penny pinching is not recommended.
 
An issue I noted over the weekend is that quite a few aerials are supplied with the most basic coax cable (including the common wind/VHF combo) and the fittings cannot easily cope with an upgrading of the coax to the grade recommended for reasonable run lengths (up to 20 m). I spent quite a time on Sunday doing just that. You may be tempted to do a quick search on e-bay for a shop run by salty john of this parish (no connection) who offers what appears to be a good aerial with decent cable and fittings
 
Good point, as it is most likely to be the coax that has degraded, I was thinking of leaving the aeriel and just change the cable, but as you point out if, for instance, the coax is moulded into the aeriel base, I can't.
 
With me it wasn't that the coax was moulded in, its just that the RG8X coax that I was installing has a slightly larger diameter both externally and with respect to the internal layers - getting the new cable into the fittings was the challenge.
 
The Metz antenna which SaltyJohn sells is very highly regarded - I will be buying one shortly. But you need to be aware that unlike the cheaper units it has a standard pl259-so239 connection at its base - not crimped-in coax. So, as has been said you can use high quality coax, BUT you must make sure you make a good join - if you are not experienced at attaching a pl259 to coax get it done by someone who does it every day. Suppliers of coax will do this for you for a small cost. You could do this for just one end (the top!) then run the coax down the mast and do the other end yourself - that is less critical because you can easiy inspect/replace a bad connection at the radio end and it will not be exposed to weather.

Also make sure you seal-up the connection at the masthead with sikaflex or similar, it is not weatherproof alone. (I don't know if the antenna includes some kind of 'boot' to weatherproof it.)
 
[ QUOTE ]
Also make sure you seal-up the connection at the masthead with sikaflex or similar, it is not weatherproof alone. (I don't know if the antenna includes some kind of 'boot' to weatherproof it.)


[/ QUOTE ] I would like to emphasise how essential it is to waterproof the connection. PL259's are NOT waterproof and if you do get an antenna with such a socket, you need to make sure the join is completely weatherproof. Water leaking down into the coax is a sure fire way of losing outgoing AND incoming signal.
 
I use self amalgamating tape to waterproof the PL259 connection; some go to greater lengths, some do nothing. Here's a good discussion on the subject:
http://www.eham.net/articles/17553

The Metz on my ketch had been there 6 years when I finally got the mast down and removed the antenna. The joint and cable were still perfect.
 
Hi Guys

Sorry to drag this up again, but it crossed my mind about joining coax....

Is there any beniefit (or indeed the opposite) to be had in using BNC/TNC fittings for this? Would the the signal loss be any different?

Thanks
 
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