rtony
New Member
We are putting an AIS aerial on our mast. I have read that this should not be too close to the VHF radio aerial. Is this just because of interference when sending a radio message or could damage actually be done to the AIS engine?
AIS Aeriel
- Thread starter rtony
- Start date
fireball
Well-Known Member
If it is too close then when you hit transmit on the VHF you could be sending 25w straight down into the AIS engine - it may not like such a LOUD noise ....
Vertical seperation is fine ...
Vertical seperation is fine ...
William_H
Well-Known Member
Best bet is an AIS antenna on the stern rail where it can be used as an emergency VHF com antenna if mast comes down. olewill
wooslehunter
Well-Known Member
Agree - you should get enough range even if the AIS antenna is mounted on the pushpit. Some people like to watch what's going on miles away but IMO that just confuses matters.
If you think about it, a pushpit antenna can also double up as an emergency antenna should the stick fall down. If the AIS & VHF boxes are mounted close, then it's just a case of swapping the plugs over. If not, then make up an adaptor cable to take one to the other. PL259 is OK but I prefer BNC connectors.
If you think about it, a pushpit antenna can also double up as an emergency antenna should the stick fall down. If the AIS & VHF boxes are mounted close, then it's just a case of swapping the plugs over. If not, then make up an adaptor cable to take one to the other. PL259 is OK but I prefer BNC connectors.
Salty John
Well-Known Member
But, your AIS engine is a BNC connector and all radios are PL259. The adapter you need is a BNC/SO239 that allows a PL259 to be attached to an AIS engine. Remove the adapter and you can plug the AIS aerial into your radio.
Graham_Wright
Well-Known Member
[ QUOTE ]
If you think about it, a pushpit antenna can also double up as an emergency antenna should the stick fall down.
[/ QUOTE ]
Unfortunately, it also doubles as a grab handle when going ashore. How much would performance be affected if it pointed downwards?
Salty John???
If you think about it, a pushpit antenna can also double up as an emergency antenna should the stick fall down.
[/ QUOTE ]
Unfortunately, it also doubles as a grab handle when going ashore. How much would performance be affected if it pointed downwards?
Salty John???
Salty John
Well-Known Member
Being 'upside down' doesn't effect the performance per se because the radiation pattern is symmetrical. But, of course, it will be located lower than a vertically mounted aerial, and there may also be some interference from the rail and its other inhabitants.
A 'tool-less' rail mount bracket will allow you to turn the aerial to point downwards when not in use, or even remove it completely and stow it below.
A 'tool-less' rail mount bracket will allow you to turn the aerial to point downwards when not in use, or even remove it completely and stow it below.