Vhf antenna replaced

[Dan Gurney]

Morning all,*

Looking for opinions particularly from Menai/Anglesey mob.

I replaced my broken Glomex antenna with a Metz whip as suggested on here.

So I did a couple of radio checks with Holyhead coastguard this past weekend. From in the strait (just off Ty Calch) and on full power the response was “broken and barely readable”. I tried again by the outer mark off Caernarfon Bar and the response was “good, readable”. Now I never used to routinely do radio checks before so I don’t know if this is ‘normal’, but I can’t help feeling it isn’t.

The Metz has a plug connecting it to the cable whereas the Glomex was ‘hardwired’ to the end of the cable. The Metz is also considerably shorter than the Glomex, but with it’s mount etc, the tip *is probably only 50cm or so below where the tip of the Glomex would be.

Thoughts?

[spartacus]

Did you solder the cable connectors?

[Dan Gurney]

I tried, totalled a plug, then got someone else who knows what they're doing to do it for me.

[SteveHall]

Mine wasn't the best until it was soldered up at both ends...

I do find though with VHF its so patchy regardless of antenna or unit - I have been sat next to people who haven't picked things up but i have - and then drift a little further and its opposite.

Let me know how you get on Dan.

[jwalker]

Just a few thoughts, did you check the gain of your new antenna against the old one to have a valid comparison, 5ft above the water is a bad height for an antenna - if it's in this range try and get it higher, connections must be good - check the installation with an SWR meter - one designed for CB radio will be fairly inexpensive and, contrary to popular myth, will work well enough.

[Dan Gurney]

Tbh, I didn't check the gain. Looking at the Glomex website it seems most are 3db except really long ones. 3db is what the Metz is. The base of the Ariel is about 6ft off the water . Which puts the tip at 9 or 10. Can't really get it much higher without installing a mast!

[office888]

Keep in mind, with a higher dBi, it flattens the TX wave out which can make it difficult for clear communications in rough seas. Your receive will be amazing thanks to the longer radiating whip, but RX and TX are two different animals.

The Metz has a more "donut like" pattern. Yes, there's more wasted power heading both up and down, but it'll make it easier to communicate with a SAR Helo or in rough seas.

[SteveHall]

Dan - Did you ever get to the bottom of this? Mine seems to be losing performance recently?

[Dan Gurney]

I didn't tbh mate. It seems to work OK out over the bar but in the strait it's poor. Holyhead CG says I'm weak but readable in the strait but I've had a couple of occasions when they haven't responded to my test.

Not sure what I'm going to do next tbh.

[SteveHall]

I have had issues where i am in line of sight and my hand held is getting it loud and clear and my fixed unit is barely readable - my issue seems to be Rx - I dont do that much chattering so not 100% sure on Tx - but I haven't had any complaints.

I have spoken to Navico about my unit, and also Salty John about the Metz - They have both given me things to try and test but I still am not much better either.

Salty John is sending me some other bits to try, failing that I will try a new cable and plugs (£20), and if that hasn't improved anything then it will be a new antenna (£60+) failing that new VHF(£???)

One thing I did get asked about was LED nav lights, as apparently they can cause issues (when powered on) - I am not posh enough for them though...

[Firefly]

Steve, I am a bit late getting in on this thread but I can try to help. What coax and connectors are you using and how long is the coax from VHF to antenna?

If you are sure your antenna is correctly installed and that your VHF has no issues, I would recommend having a new, high quality, low loss antenna coax manufactured using crimped connectors instead of solder ones. It sounds to me like you have a problem with the installation and the coax would be my first port of call; pardon the pun

[ShinyShoe]

Originally Posted by SteveHall

One thing I did get asked about was LED nav lights, as apparently they can cause issues (when powered on) - I am not posh enough for them though...

Some of the WAFI people report issues with USB Charges that use a buck convertor. LEDs may do the same.

[Pikey Dave]

Originally Posted by ShinyShoe

Some of the WAFI people report issues with USB Charges that use a buck convertor. LEDs may do the same.

I have ( or had) a Griffin USB charger, the bullet type that fits into the cig lighter, for my satnav. It screwed up the radio reception royally.
Dan, you need to get an assistant in another boat with a proven radio & do some testing in the Strait. As others have said, eliminate the obvious (poor cabling/connections) & then eliminate boat borne interference from engine/sounder/ etc. I wouldn't imagine that the Strait is the best place for comms anyway due to the hills.

[SteveHall]

Originally Posted by Firefly

Steve, I am a bit late getting in on this thread but I can try to help. What coax and connectors are you using and how long is the coax from VHF to antenna?

If you are sure your antenna is correctly installed and that your VHF has no issues, I would recommend having a new, high quality, low loss antenna coax manufactured using crimped connectors instead of solder ones. It sounds to me like you have a problem with the installation and the coax would be my first port of call; pardon the pun

I am using the stuff provided by Salty John -
"Top quality marine RG8X cable with two silver plated PL259 connectors - one fitted and one supplied loose."

My issue with a cable that is already done with crimped ends is I wont be able to get it though the gland on the a-frame (unless I make the hole bigger)

[Pikey Dave]

Originally Posted by SteveHall

I am using the stuff provided by Salty John -

"Top quality marine RG8X cable with two silver plated PL259 connectors - one fitted and one supplied loose."



My issue with a cable that is already done with crimped ends is I wont be able to get it though the gland on the a-frame (unless I make the hole bigger)

Do you know anyone who installs satellite systems/audio etc? Run the cabling & ask them to crimp the other end on for you. You can buy the crimping pliers cheap enough, although solder is best imo.
I'd be tempted to run the cable (if it's not too late) from antenna to VHF, so that the crimped end is external at the antenna end.
Fwiw, I prefer plug & socket connections over "hard wired" connections as in the Glomex, much easier for fault finding.
Something else to try, disconnect the cable at both ends & check continuity & insulation of the core & braid.

[SteveHall]

I have left the pre made end at the antenna end - as I thought that is going to get the most weather, and the other end has been made with solder.

I have tested the cable for shorts, and its all good - but think I will replace it as its the cheapest part.

Its strange as it worked well at the start and has slowly felt to degrade over time.

[Pikey Dave]

Originally Posted by SteveHall

I have left the pre made end at the antenna end - as I thought that is going to get the most weather, and the other end has been made with solder.

I have tested the cable for shorts, and its all good - but think I will replace it as its the cheapest part.

Its strange as it worked well at the start and has slowly felt to degrade over time.

That to me would point to a progressive fault rather than a sudden failure, I'd be looking for water ingress/bad connection at the exposed end.

[Xk59D]

I had similar issues on my last boat, replaced cables, metz antenna and turned out was the vhf losing power over time, new one cured obviously.

[SteveHall]

Already checked and they all look clean and dry...

My thought is some kind of damage to the cable that has let water in over time.

[jeffstevens763@g]

when my garmin stopped working i bought a temp antenna to fault find turned out the radio was shot kept the temp antenna as a back up.