Testing a new VHF

[stephennoble]

I have just fitted a new VHF Radio. The boat already had an aerial and cable but I dont know if it is working. Once wired in it all fired up correctly but I have not yet input the MMSI details. The boat is at the very top of Chichester harbour and we did not hear any traffic, it was blowing a hoolie so did not expect anyone to be out. I tried a radio check with solent coastguard but no reply. Either we are too far away to be heard, the aerial is faulty or something else. Any thoughts on this issue and what to check, do next? I did notice the battery voltage drop a bit on transmit, and the battery is fully charged.

 

[Billjratt]

The battery drop may indicate that the radio is working OK on high power, although it should only draw about 5 amps (do you have an ammeter?) or, maybe it depends where you are measuring the voltage in relation to the radio and battery. I take it you don't have a handheld on board, or a neighbour who can test. What about the 'maritime safety broadcasts'?

 

[stephennoble]

Thanks for the reply. We dont have an ammeter so unable to check that. I do have a hand held but it was at home! but it won't be next time! Good idea to wait for a MSB. What I did wonder is; if there is a way of checking an aerial without just doing a radio check, ie can you use a multimeter or something else?:encouragement:

 

[earlybird]

What I did wonder is; if there is a way of checking an aerial without just doing a radio check, ie can you use a multimeter or something else?:encouragement:

A multimeter isn't any use. A SWR meter is what you need, not infallible but a very good guide.
It's a fairly specialist bit of kit though, but someone might be able to lend you one. If not, easiest to listen on Ch.16 for CG. which will give you some idea.
A transmission test at reasonable range should follow. Up here CG doesn't seem to mind "radio check please" but it might be different in Chichester!

 

[Jim@sea]

I am fitting a new radio but having to use the old cable which goes from the radio to where it come out of the deck where it joins the new cable going up the mast. So I happened to be in a Radio Shack shop and they had a SWR Meter at £25, Not that I have tried it yet but for peace of mind you could get one.

 

[VicMallows]

Solent Coastguard should normally hear you OK from anywhere in Chichester Harbour, but they may miss you because of other traffic that YOU cannot hear. At this time of year Ch16 can be silent for hours .....more likely to be traffic on VTS (Ch12). Try calling up Chichester Marina on Ch80 for a radio-check ... they won't mind.

 

[VicMallows]

A multimeter isn't any use.

It can be. Open-circuit is always a fault (on any VHF antenna I have come across). Some antennas show a very low resistance which is indistinguishable from an unintended short, so tells you nothing. Current V-Tronix (sp?) show a specific resistance (10k) which gives a pretty good indication that the antenna is correctly connected.

 

[zambant]

Or try calling Solent Coastguard on Ch 67 - their preferred channel for routine traffic.
Marina is a good idea
Good luck
John

 

[nigelmercier]

... I happened to be in a Radio Shack shop and they had a SWR Meter at £25...

For marine frequencies?

 

[mickywillis]

V-Tronix Hawk gives a resistance reading of 10 K ohm's according to their manual.
Checked my new one at the weekend with a very accurate DVM and sure enough 10K.
Heard transmissions out on the water last Friday using aerial, so looks like mines OK!

 

[VicS]

I happened to be in a Radio Shack shop and they had a SWR Meter at £25, .

For marine frequencies?

I think you will find that its is for CB radio not Marine VHF frequencies,.

This one

 

[earlybird]

A CB VSWR can provide useful information at the marine band frequencies if nothing better is available. I bought one years ago for a £fiver at a Tandy closing down sale, it will show up a "bad" antenna.
I also have a home-made one, based on a design for ~150MHZ, given to me by a "Ham" friend. They're basically very simple. (Meters I mean, not Hams).
I don't really use either to measure actual radiated power, esp. the Tandy one but they provide a very clear indication of ratios.
I tend to test my aerial at the start of the season, particularly if the mast has been down.

 

[Fantasie 19]

I have just fitted a new VHF Radio. The boat already had an aerial and cable but I dont know if it is working. Once wired in it all fired up correctly but I have not yet input the MMSI details. The boat is at the very top of Chichester harbour and we did not hear any traffic, it was blowing a hoolie so did not expect anyone to be out. I tried a radio check with solent coastguard but no reply. Either we are too far away to be heard, the aerial is faulty or something else. Any thoughts on this issue and what to check, do next? I did notice the battery voltage drop a bit on transmit, and the battery is fully charged.

Can you borrow another aerial and test?

 

[PhillM]

Can you borrow another aerial and test?

Or buy and emergency antenna and use that. Not a bad thing to have on board anyway.

Force4 are knocking them out under £35 ]

http://www.force4.co.uk/department/brands/banten/banten-emergency-vhf-antenna.html

 

[oldvarnish]

Also, if you're near an NCI Coastwatch lookout, they are happy to give radio checks on VHF65

 

[old_salt]

I have just fitted a new VHF Radio. The boat already had an aerial and cable but I dont know if it is working. Once wired in it all fired up correctly but I have not yet input the MMSI details. The boat is at the very top of Chichester harbour and we did not hear any traffic, it was blowing a hoolie so did not expect anyone to be out. I tried a radio check with solent coastguard but no reply. Either we are too far away to be heard, the aerial is faulty or something else. Any thoughts on this issue and what to check, do next? I did notice the battery voltage drop a bit on transmit, and the battery is fully charged.

Is there anyone within sight of you. You could get them to check your radio output call them up on 16 and they could send to you, you can then test other boat to boat channels.
In other words just call up and have a chat with them job done.
It's the way we always do it with someone we know and can see them for a visual response as you check areal/ mic connections and others, thumbs up/down.
Yes OK it's not checking a distance but it can all be done on low power.

 

[stephennoble]

Can you borrow another aerial and test?

Great Idea as I have an emergency aerial, did not think of that or many of the other thoughts that have been suggested here.

 

[Jim@sea]

For marine frequencies?

Perhaps its wrongly described, I thought it was a Signal Strength Meter and if I connected it and pressed the transmit button on the radio it should show how many watts it is transmitting at, and if it dosent it will be a waste of £25.

 

[oldvarnish]

Perhaps its wrongly described, I thought it was a Signal Strength Meter and if I connected it and pressed the transmit button on the radio it should show how many watts it is transmitting at, and if it dosent it will be a waste of £25.

This will show you what it will and won't do.

https://www.youtube.com/watch?v=jRWKZskxcs0

Note that it says suitable for CB and Ham bands - that doesn't include marine

 

[st599]

Perhaps its wrongly described, I thought it was a Signal Strength Meter and if I connected it and pressed the transmit button on the radio it should show how many watts it is transmitting at, and if it dosent it will be a waste of £25.

Nope, it shows the ratio between peak and null voltage in a standing wave caused by reflections in the cable.

If the antenna is faulty, the power isn't converted to RF radiation. It has to go somewhere so is reflects back down the cable causing a standing wave.