Radio Installation

[Rob Jones]

Was wondering if anybody could give me some advice regarding the wiring on my Hummingbird radio.

I have replaced the old antenna with a Vitronix RIB Raider.

The cabling @ the antenna end was corroded and the end thingy fell off.

The new antenna has a 6m cable included, my question is this - what is the best way to fit the new antenna. Would I change the whole cable on the boat? which will entail some fiddly feeding and pulling, or replace the end thingy, if the latter what is the end thingy and where would I get one from?

The new cable seems to have a brass type end - the other is just cut coaxial, which I presume I would add the radio connector.

All advice appreciated

[Nos4r2]

From a safety point of view, change the cable seeing as you've got one. You know the one time it'll stop working is when you're in the shit.

[Hightower]

Look for a local amature radio shop or CB shop (if they still exist) you can buy a couple of PL259 plugs and a female connector. This will join up your coax, then you'll have to think about waterprooing it all. Chop a piece of 1" conduit about 10" long slide this over the connector and fill the ends with silkoflex.

Go here: http://www.nevada.co.uk/

[daveh]

Definitely change the cable it is usually the source of poor range and reception. It's really not that hard; just attach a thin mousing line - the thin reels of dyneema are pretty good then pull it all through. You might appreciate it one day.

[stepheneyre]

hi
i would replace the whole lot just tape the old and new wire together(end to end) and pull through gentley
replacing the wire gives the best waterproof and you know it works
thanks
stephen eyre
sheffield.

[Mike C]

Its always best to have one length of cable from the transmitter to the aerial if you can. Any join, even if its a proper plug can corrode. That will cause a mismatch and increase the SWR (Standing Wave Ratio). Basically the amount of signal that gets reflected back into the transmitter instead of radiating out of the aerial! There is always some reflected power but the more you have the less far your signal will go…. And if its too bad you can blow up the transmitter…. Especially the Hummingbird – could be wrong but I don’t think that has much in the way of high SWR protection.

As for waterproofing. The RIB Raider has a fairly good waterproofy connection that goes into it. I just smear a little silicone grease and I’ve had no trouble with that aerial. The PL259 that goes into the transmitter isn’t waterproof but if that’s inside the console then more grease will probably do there. That’s all I have, but I take Hightower’s point

If the cable isn’t long enough to go from TX to Arial then it may be wise to visit an Amateaur Radio shop as Hightower said. Get plenty cable and ask then to wire up the PL259 on one end for you if they will. To my mind they are more difficult to wire than the Vitronix end which just push fits. Then mouse the bare end through your ducting. If it’s wired shorted (at either end) then bye bye Hummingbird.

(Vitronix used to do a longer length cable version once – maybe you could call them and do a swap?)

Happy transmitting!

Mike C (G4OTQ in my Ham Radio days)

[Hightower]

Very sound advise Mike .

[steedthrust]

Oops

[steedthrust]

Is it okay to shorten a VHF aerial cable? Am worried it may 'tuned' to a certain length.


Also is it okay to shorten a GPS cable?


Cheers

[Rob Jones]

Frustrating morning as I need to get the boat fixed up and I only have today to do it. Of course wake up today and its snowing.

I am getting to grips with the cabling situation - the thingy on the end is a brass hollow nose bullet - which can be pulled off the new wire, which I have done, The pl259 part is the silver screw connection that goes into the radio, but it turns out mine has been threaded so the original still fits but the new does not have enough length to grip the remaining 3 threads.

I have decided a new radio is in order - to that end I pulled the bullet part of and attached it to the old co-axial.

Will now attempt to determine the range by getting my daughter to run with my handheld whilst I sit on a snow covered boat waiting for her chitter chatter.

Thanks All.