VHF radio installation and use questions
Submitted by Paul N on Fri, 2016-08-05 08:52
Im relocating the antenna for my vhf and 27meg radios to mount on top of the hafdtop . Due to rod holders and outriggers there is not a lot of space left up there . I was wondering how close to each other I can mount the two antennas . If they are only a foot apart will this cause interfeance ?
Also I have only used the VHF to log on and off on chanel 73 in metro waters ,is there a boat to boat chat chenel that can be used . The only other time i have used it has been at gamex in exmouth and they seem to use 17 as a chat chanel but i think its not the same here.
I have googled it but im still not sure about chanel usage .
Thanks for any help
Cheers
Paul
Rob H
Posts: 5745
Date Joined: 18/01/12
I would say it would only a
I would say it would only a problem if you tried to transmit on both at the same time.
Otherwise the aerial is passive as far as I know?
Channel 16 is the emergency and contact channel.
It is perfectly acceptable, legal and proper practice to use 16 (which you should be monitoring continuously) to contact your mate or anyone then request a change to a working channel.
You must use proper etiquet though, not "Boris ta John change ta 73 cockhead"
Dont laugh it happens ALL the time
Give a man a mask, and he'll show you his true face...
The older you get the more you realize that no one has a f++king clue what they're doing.
Everyone's just winging it.
Paul N
Posts: 480
Date Joined: 09/11/06
Thanks Rob
Was thinking the same thing about transmitting at the same time.
didn't know it was ok to contact someone on 16 and then switch to another channel for general chat .
Are there reserved channels for a chat ? or channels that shouldn't be used (other than 16 ).
Don't worry, Fully aware of etiquette
Rob H
Posts: 5745
Date Joined: 18/01/12
From memory (and dont quote
From memory (and dont quote me!) it is 16 and 67 that are emergency channels.
Individual areas such as Port Authorities, VMR will have VHF working channels such as 71, 72, 73, 10 etc and there are also repeaters up and down the coast which use specific channels such as Moresby ranges 82, Rat Island 81 etc
While technically a radio operator should know all these channels the reality is that other than the obvious ones, you dont need to worry too much about that, just listen on a channel for a few minutes or just use it and they will soon come on and tell you its their working channel, just apologize and pick another or ask them to suggest one.
Absolutely, 16 is THE contact and emergency channel. If you see a vessel coming straight at you or need to get hold of another boat or ya mate, 16 is for initial contact.
More often nowadays they use a private channel VHF or UHF for tug operations etc which you wont even be able to get on and its only the adhoc commercial work that will grab a channel and use it for a few hours days or weeks.
Give a man a mask, and he'll show you his true face...
The older you get the more you realize that no one has a f++king clue what they're doing.
Everyone's just winging it.
resurgence
Posts: 573
Date Joined: 23/04/14
Other commonly used channels
68 is normally used for vessel to vessel chatter. 81 is the repeater at Rottnest. 82 is the repeater at Pinjarra. The sea rescue groups around Perth metro area use 73.
sunshine
Posts: 2555
Date Joined: 03/03/09
Close antennas even on different frequencies
Will cause what is called a null in the antenna's wave pattern so rather than being truly omnidirectional it isn't quite as strong in the direction of the second antenna.....it won't be that significant ....the further apart the better and the higher the position on the boat the better. Believe a firm called Benelec actually make a dual band whip suitable for ally hulls (requires the hull as a ground plane) .....never seen one used but they are professionally wound so might be an option
Starbug
Posts: 563
Date Joined: 27/08/09
A foot appart? Way too
A foot appart? Way too close.
Anything this close will cause the antenna to be detuned. Lower radiated power, high SWR, nulls in your reception/transmission pattern, overheating of your radios PA and premature failure...... All are possible and none are desirable. If you have no room dump the 27mhz. One well installed radio and antena is better than two poorly installed units.
Go get a VHF licence or at least read and understand the channel uses and what to avoid using.
Multiband antennas require splitters to attach both radios. Splitters cause significant insertion losses.
barneyboy
Posts: 1392
Date Joined: 08/01/09
If you are going to use ch 16
remember you silence period for 3 minutes at a time every hour on the hour and every 1/2 hour, 24/7..
It would be piss weak if you didn't.
As for your antennas, you could just leave 1 down and use the other and alternate?
FEEEISH ONNN!!!
Dougo
Posts: 23
Date Joined: 12/08/14
Silence period deleted
Barney Boy, the silence period to which you refer has been dropped for some time now
Cheers
dodgy
Posts: 4563
Date Joined: 01/02/10
It being mandatory was
It being mandatory was dropped 3 or 4 years ago. Still recommended though.
Does anyone know where the love of god goes, when the waves turn the minutes to hours?