VHF Radio advice

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roggie

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Advice wanted and I'm told you are all very helpful...

I've a narrowboat moored on the Slough Arm and last January joined St Pancras CC on their annual trip down the Thames to the Royal Docks - very enjoyable it was too. Didn't have a VHF radio but as in convoy didn't need one... did use a 2 way with another boat just in case. Decided to buy a VHF and book onto a course for next time - given that its usage will not be too often I went to ebay rather than a new radio... so

Purchased a second hand seafarer vhf radio and a new 1m Fibreglass Marine Radio Antenna + Cable 3db Gain 156-162Mhz Boat VHF Fixed (separately). Radio powers up from a stand alone 110a marine battery - all displays fine static coming over loud and clear... plus in the aerial with 5 metre cable and the static doesn't change in tone at all - squelch seems to work (how to tell?). Tested amps drawn when on tx in hi power and clamp meter shows around 25a. I did try (in SE London) to plug into car lighter plug but no difference. Next steps is to drive nearer to river to eliminate bad reception. I would have thought that it could receive something even with a coat hanger let alone a 1m aerial.. nothing obvious adrift internally as far as I can see. I found a copy of the manual online (badged as a GX121OS Horizon Explorer).

Any thoughts on ways forward - the seller removed this from a boat they brought and thought it worked..

Regards,

Roger
 
" clamp meter shows around 25a."

hi roger assume you mean ampmeter ? and 25 watts.

You really really need to listen on of the busier Thames channels such as those used by London VTS,preferably on lower reaches of Thames which are usually quite busy.
It is not usual to hear sod all at such times as LW but for it to get busy around HW.
There is probably nothing wrong as you may have just been out of range or simply no traffic when you were listening,
Try listening on 12/14/68/72 , others can suggest further channels.
 
I trust and hope you haven't pressed the Transmit button without an aerial attached this can burn the set out. Old Git gives excellent advice on which channels to listen out on in the Thames area. You will not receive anything without a pukka VHF aerial. I am not familiar with that unit but it may be that it is an American one. If this be the case I regret to tell you that it may not work well as there are slight variances of frequencies to ours. I'm certain someone here will be able to give you better advice on this matter.
 
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You could be very "naughty" and call London VTS for a radio check
Or wait until more boats are out and about and do the same on CH16

(Using reserved channels for non essential traffic is deemed bad practice - hence naughty...)
 
Don't try to transmit without the vhf aerial connected, you'll damage your radio.
Check your aerial connections, you may have a shorted connector.
 
byron said:
. . . . . You will not receive anything without a pukka VHF aerial.
Click to expand...

The above is not specifically true as any piece of wire can be used for receive only. ;)

byron said:
. . . . . I am not familiar with that unit but it may be that it is an American one. If this be the case I regret to tell you that it may not work well as there are slight variances of frequencies to ours. I'm certain someone here will be able to give you better advice on this matter.
Click to expand...

Sadly, the GX121OS Horizon Explorer is not licensable in the UK as Byron has pointed out, a large number of the frequencies used are reversed. If Ofcom were to find you using it, you could be taken to court and fined and the equipment confiscated (that used to be part of my job). If you think they cannot find you, then transmitting on incorrect frequencies can be traced very easily as, all over London and the UK generally, we have remote frequency monitoring receivers which although are primarily for bandwidth occupancy monitoring can be and are used on occasion to locate offenders and pirate FM broadcast transmitters, especially if someone has complained about illegal signals.



.
 
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lenseman said:
The above is not specifically true as any piece of wire can be used for receive only. ;)



Sadly, the GX121OS Horizon Explorer is not licensable in the UK as Byron has pointed out, a large number of the frequencies used are reversed. If Ofcom were to find you using it, you could be taken to court and fined and the equipment confiscated (that used to be part of my job). If you think they cannot find you, then transmitting on incorrect frequencies can be traced very easily as, all over London and the UK generally, we have remote frequency monitoring receivers which although are primarily for bandwidth occupancy monitoring can be and are used on occasion to locate offenders and pirate FM broadcast transmitters, especially if someone has complained about illegal signals.



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Click to expand...

I think the original poster has the UK version, a Seafarer. If I am not mistaken he was referring to the user manual he found on the Internet which is for the USA badged version called the Horizon. Therefore I do not think you have to worry about the Frequencies. Anyway a USA spec. one tends to have the same Frequencies, just a different mode of operation (Split, Duplex, Simplex) so there is little chance of transmitting out of band and upsetting other users, just the chance of upsetting Marine band users, which at the technical level is the same as a USA ship visting the UK (of course at the policy level its illegal)
 
Thanks for all the advice - will take radio near to the Thames this weekend. Its a Seafarer and the manual was the horizon. Agreed that a radio is pretty important hence getting around to buying one. The Port of London issues a safety bulletin at http://www.pla.co.uk/pdfs/maritime/Safety_Bulletin_Issue_1_Sept_2012.pdf about the sinking narrowboat - fortunately we don't have a hole near the waterline (well not as large as Mini Moo). A friend of mine took some video of the SPCC boats going past the Thames Barrier - we are last http://www.youtube.com/watch?v=8PAN3B_muME&feature=share&list=UUk6XXDpUU8aqvh2PNRIB8Qw
 
VHF signals are easily blocked by any physical obstructions so you need a reasonable line of sight in order to communicate with another station.
Perhaps if you could find another boat moored near yours with a fixed or portable VHF you could ask for assistance with a radio check.


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Checking with a known good VHF on another vessel or a hand held is probably the most sensible . Otherwise you dont know if anyone is transmitting in the area . .


The clarify the issue over US vs International channel frequencies :

Some of the channels which are two frequency ( duplex) channels in the international set are single frequency ( simplex ) channels in the US. They use the International ship station frequency for both stations.

These are 07, 18, 19, 21,22, 23, 65, 66, 78, 79, 80, 83 and 88



You should not see anything like 25amps on transmit ... 6 amps according to the spec
 
Thanks for the advice. I parked up right by the Thames in Greenwich this afternoon for about 30 minutes - received nothing on channel 16 or any of the other channels I tried - just static. There was a reasonable number of boats moving as well. My boat is moored out near Iver on the Slough Arm of the GU so can't really check as suggested. I'll try to contact someone I know who has a radio but won't be for a while....
 
Dear All,

Again thanks for the advice. I brought another VHF radio and straight away picked up broadcasts on Channel 14 from VTS on the Thames - this from my back room. I'll next wait till there is a fair amount of chatter and try both radios to make sure it isn't me. Then I'll liaise with the seller as to best next steps - looks like its the radio rather than antenna/signal strength.

Next steps in the course and license - we are planning to go down the Thames (through central London) with other boats so will be able to monitor channels. In response to a few offline comments - narrowboats are not that bad on the Thames, you only are allowed out in reasonable wind and can see large boat and move the boat so you hit the wash head on rather than side on, even the catamaran taxi boats seem to slow down when they pass you. If you take obvious precautions (keep front doors closed) and make sure no large holes just above the waterline you should be OK, oh and top up the diesel so you don't get the rubbish slopping around rather than staying in the bottom of the tank like on canals. We did notice our domestic water wasn't as clean as normal but it had sorted itself out once back on canals and it had settled. Time for more Milton I think.

So give us a wave if you are near the Thames in central London Good Frriday afternoon.
 
Our 48 foot narrow boat is called Salar - after Salar the Salmon (which I must read one day) by Henry Williamson (Tarka the Otter fame). St Pancras cruising club http://www.stpancrascc.co.uk/ organise a Easter cruise to the Fox at Hanwell and given that we should be exploring the River Lea last week in March this linked well with a return to our home mooring on he Slough Arm in Iver. I'll also be keeping a eye on the Basingstoke Deepcut locks opening as I quite fancy a trip down there in June/July. To be honest I prefer canals to rivers, brought Salar down from Reading to Brentford last March (last week - great weather - doubt we will be that lucky this year - and parts of the Trent the year before. My wife doesn't mind steering on the Thames but isn't too keen on canals - I guess she likes the open spaces.
 
Given that we will be leaving Limehouse at approx 12 noon - say 2 hours before high tide, and those coming the other way getting to Richmond lock 2 hours before HT, we should meet up around Putney - thats a guess. I'll try to make sure I fly the Cutweb Internet boating club burgee. http://www.cutweb.org.uk/ Might not go for the bowler hat and wastecoat.... At least I should be able to listen on the radio - but which channel?:)
 
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