broken Antenna

[daveylad]

Anybody any ideas if a snapped boat radio Antenna can be fixed? The tip about 4inches has broken but snapped completly off, I've tried to superglue it but wont stick and it looks like its made from some sort of carbon or fibreglass similar to rods. I wondered if anyone knows if I snapped the end off and just replaced the rubber tip onto it would it be okay the wire running through it seems okay

[ellicat]

I reckon it'll be sweet. As the height of your antenna is directly related to reception distance you will only lose a p00fteenth if it's just the tip.

You can check it beforehand by turning on your radio in the backyard and listening to the fisherman's reports this arvo lol. That's what I used to do with the VHF when I couldn't get out myself :blush: Mooloolaba boys seem to use 72 alot

[daveylad]

Thanks Ellicat, Used the radio the other day, couldn't get anything on my property I'm about 30ks in the bush,and in the hills, I Used it at Mooloolaba and contacted the VCG okay in the Bay and I logged out of there but later on while we were at Barwon Banks I wasn't able to transmit any message back to them to let them know we were staying out, caused phone calls to be made to home and everyone to panic. noticed later that the tip had broken completely off do you reckon that would stop transmissions at that range?

I even tried channel 16 and couldn't reach anyone at the time we were about 26 nautical miles off Mooloolaba hopefully its just the antenna

[jeff f]

radio antennas are pretuned to a certain length

if you snap any off the length it will alter the swr greatly decreasing the transmission range

buy a new one davey

[daveylad]

Thanks Jeff actually just been onto Linemaster marine electronics, going in there next week to have anew one fitted they can test them at the workshop, After the other night I would suggest to anyone that has a damaged antenna not to try to fix it but replace it ASAP :blush:

[ellicat]

daveylad wrote:

Thanks Ellicat, Used the radio the other day, couldn't get anything on my property I'm about 30ks in the bush,and in the hills, I Used it at Mooloolaba and contacted the VCG okay in the Bay and I logged out of there but later on while we were at Barwon Banks I wasn't able to transmit any message back to them to let them know we were staying out, caused phone calls to be made to home and everyone to panic. noticed later that the tip had broken completely off do you reckon that would stop transmissions at that range?

I even tried channel 16 and couldn't reach anyone at the time we were about 26 nautical miles off Mooloolaba hopefully its just the antenna

The reason you couldn't reach Mooloolaba is because you were too far away. VHF is reliant on line-of-site (LOS), so with the curvature of the earth the further away you are the less likely you will be able to communicate. Your range is approximately the square root of the height of your antenna (in feet) times 1.1 with answer in nautical miles (1nm = 1.85km). e.g. Height of antenna = 16 feet; range = 4.4nm

The Mooloolaba Tower Height = (guessing) 64 feet (20metres); range = 8.8nm

Range together = 13.2nm

Whilst antennas are "tuned" this is not a precise tuning and as long as you have the wires "there-abouts" you should still be able to transmit/receive. You can, in fact, string up the wire to get better reception in an emergency.

Buying a new antenna will set your mind at ease though. However it still wont get you communication with Mooloolaba from the Barwon banks unless you get a higher one or put it up a mast

[hooked_on_trout]

Just stick an old coat hanger in, yool be sweet as.

cheers

[dhess]

ellicat wrote:

daveylad wrote:

Thanks Ellicat, Used the radio the other day, couldn't get anything on my property I'm about 30ks in the bush,and in the hills, I Used it at Mooloolaba and contacted the VCG okay in the Bay and I logged out of there but later on while we were at Barwon Banks I wasn't able to transmit any message back to them to let them know we were staying out, caused phone calls to be made to home and everyone to panic. noticed later that the tip had broken completely off do you reckon that would stop transmissions at that range?

I even tried channel 16 and couldn't reach anyone at the time we were about 26 nautical miles off Mooloolaba hopefully its just the antenna

The reason you couldn't reach Mooloolaba is because you were too far away. VHF is reliant on line-of-site (LOS), so with the curvature of the earth the further away you are the less likely you will be able to communicate. Your range is approximately the square root of the height of your antenna (in feet) times 1.1 with answer in nautical miles (1nm = 1.85km). e.g. Height of antenna = 16 feet; range = 4.4nm

The Mooloolaba Tower Height = (guessing) 64 feet (20metres); range = 8.8nm

Range together = 13.2nm

Whilst antennas are "tuned" this is not a precise tuning and as long as you have the wires "there-abouts" you should still be able to transmit/receive. You can, in fact, string up the wire to get better reception in an emergency.

Buying a new antenna will set your mind at ease though. However it still wont get you communication with Mooloolaba from the Barwon banks unless you get a higher one or put it up a mast

The reality is that the Barwon Banks has perfect coverage from Mooloolaba as does the next reef system to the NNE the Hards. We fish the Banks regularly and have no issues with comms.

Most if not all of the QLD coast is covered by coastal repeater stations (e.g. DI, Cape Moreton, Point Lookout etc.) That have very high antennas and transmit at high power. You will probably have coverage out to about 100km offshore in most places.

[daveylad]

dhess wrote:

ellicat wrote:

daveylad wrote:

Thanks Ellicat, Used the radio the other day, couldn't get anything on my property I'm about 30ks in the bush,and in the hills, I Used it at Mooloolaba and contacted the VCG okay in the Bay and I logged out of there but later on while we were at Barwon Banks I wasn't able to transmit any message back to them to let them know we were staying out, caused phone calls to be made to home and everyone to panic. noticed later that the tip had broken completely off do you reckon that would stop transmissions at that range?

I even tried channel 16 and couldn't reach anyone at the time we were about 26 nautical miles off Mooloolaba hopefully its just the antenna

The reason you couldn't reach Mooloolaba is because you were too far away. VHF is reliant on line-of-site (LOS), so with the curvature of the earth the further away you are the less likely you will be able to communicate. Your range is approximately the square root of the height of your antenna (in feet) times 1.1 with answer in nautical miles (1nm = 1.85km). e.g. Height of antenna = 16 feet; range = 4.4nm

The Mooloolaba Tower Height = (guessing) 64 feet (20metres); range = 8.8nm

Range together = 13.2nm

Whilst antennas are "tuned" this is not a precise tuning and as long as you have the wires "there-abouts" you should still be able to transmit/receive. You can, in fact, string up the wire to get better reception in an emergency.

Buying a new antenna will set your mind at ease though. However it still wont get you communication with Mooloolaba from the Barwon banks unless you get a higher one or put it up a mast

The reality is that the Barwon Banks has perfect coverage from Mooloolaba as does the next reef system to the NNE the Hards. We fish the Banks regularly and have no issues with comms.

Most if not all of the QLD coast is covered by coastal repeater stations (e.g. DI, Cape Moreton, Point Lookout etc.) That have very high antennas and transmit at high power. You will probably have coverage out to about 100km offshore in most places.

Coast Guard reckons Channel 80 is the repeater station that they monitor for the Barwon Banks area I was receiving several channels all the way to Brisbane but couldn't transmit, didn't try 80 though.

[ellicat]

dhess wrote:

ellicat wrote:

daveylad wrote:

Thanks Ellicat, Used the radio the other day, couldn't get anything on my property I'm about 30ks in the bush,and in the hills, I Used it at Mooloolaba and contacted the VCG okay in the Bay and I logged out of there but later on while we were at Barwon Banks I wasn't able to transmit any message back to them to let them know we were staying out, caused phone calls to be made to home and everyone to panic. noticed later that the tip had broken completely off do you reckon that would stop transmissions at that range?

I even tried channel 16 and couldn't reach anyone at the time we were about 26 nautical miles off Mooloolaba hopefully its just the antenna

The reason you couldn't reach Mooloolaba is because you were too far away. VHF is reliant on line-of-site (LOS), so with the curvature of the earth the further away you are the less likely you will be able to communicate. Your range is approximately the square root of the height of your antenna (in feet) times 1.1 with answer in nautical miles (1nm = 1.85km). e.g. Height of antenna = 16 feet; range = 4.4nm

The Mooloolaba Tower Height = (guessing) 64 feet (20metres); range = 8.8nm

Range together = 13.2nm

Whilst antennas are "tuned" this is not a precise tuning and as long as you have the wires "there-abouts" you should still be able to transmit/receive. You can, in fact, string up the wire to get better reception in an emergency.

Buying a new antenna will set your mind at ease though. However it still wont get you communication with Mooloolaba from the Barwon banks unless you get a higher one or put it up a mast

The reality is that the Barwon Banks has perfect coverage from Mooloolaba as does the next reef system to the NNE the Hards. We fish the Banks regularly and have no issues with comms.

Most if not all of the QLD coast is covered by coastal repeater stations (e.g. DI, Cape Moreton, Point Lookout etc.) That have very high antennas and transmit at high power. You will probably have coverage out to about 100km offshore in most places.

Dom, is that transmission as well as receiving all the way to Mooloolaba ? When I've been out there we have not been able to transmit (or receive) to/from mates boats that were maybe 10km away at times.

Davey, Are you coming to State of Origin ? What are you going to do with the old antenna ? Do you still have the tip ? I wouldn't mind having it if you are just going to toss it. The old style mount busted on my VHF antenna, so I've replaced it with the new screw in style but only have the 27MHz antenna at the moment.

[ellicat]

http://www.catfleet21.org/rigging/June.htm

[daveylad]

Davey, Are you coming to State of Origin ? What are you going to do with the old antenna ? Do you still have the tip ? I wouldn't mind having it if you are just going to toss it. The old style mount busted on my VHF antenna, so I've replaced it with the new screw in style but only have the 27MHz antenna at the moment.

Azza and I are talking about it its just that hes busy, you know all that tropical fishing with a bit of work thrown in between we've all seen the photographs so theres no denying it :blush: :fishing: Probably know as it gets closer, hopefully will get some more fishing in down Brisbane area soon if Tugger has an6y spare spots available then I'll get the antenna to you, its an 8foot I'm going to a factory in the week to get them tested so I may have 2 of them if you want them

[ellicat]

Cheers Davey. I only need one. It's only for playing with at home. The 27Meg does me for where I take the Force fishing.

Azza is right up with kreel for "get back to work" envy lol :laugh:

[dhess]

ellicat wrote:

Dom, is that transmission as well as receiving all the way to Mooloolaba ? When I've been out there we have not been able to transmit (or receive) to/from mates boats that were maybe 10km away at times.

Thats odd because we regularly fish two boats off Mooloolaba or Rainbow Beach and easily communicate 10-15km away. No probs reaching the coast guard either but don't remember exactly where we were at the time. Could be something wrong with your mates radio or antenna.

Going by the formulas from the link you posted:

Assuming both boats antennas are 6dB gain and 3.5m (11.5ft) above the water. (mine is)

sq root 11.5 x 1.15 = 3.4 miles = approx. 5.5km x 2 = 11km range between two vessels.

Odd that transmission power isn't included in the calculation either?!?

If you do the same calculation and consider the the antenna at the coast guard is proabably at least 10m high and has a much higher gain that will change the equation dramatically.

my boat:

sq root 11.5 ft x 1.15 = 3.4miles = 5.5km

+

repeater cape moreton:

sq root 330ft x 1.52(assuming 9dB gain probably higher) = 45km probably a lot more.

Here is a coverage map.
/>http://www.msq.qld.gov.au/~/media/msqfiles/home/about-us/msq-headlines/pdf_distress_network_coverage.pdf

[daveylad]

dhess wrote:

ellicat wrote:

Dom, is that transmission as well as receiving all the way to Mooloolaba ? When I've been out there we have not been able to transmit (or receive) to/from mates boats that were maybe 10km away at times.

Thats odd because we regularly fish two boats off Mooloolaba or Rainbow Beach and easily communicate 10-15km away. No probs reaching the coast guard either but don't remember exactly where we were at the time. Could be something wrong with your mates radio or antenna.

Going by the formulas from the link you posted:

Assuming both boats antennas are 6dB gain and 3.5m (11.5ft) above the water. (mine is)

sq root 11.5 x 1.15 = 3.4 miles = approx. 5.5km x 2 = 11km range between two vessels.

Odd that transmission power isn't included in the calculation either?!?

If you do the same calculation and consider the the antenna at the coast guard is proabably at least 10m high and has a much higher gain that will change the equation dramatically.

my boat:

sq root 11.5 ft x 1.15 = 3.4miles = 5.5km

+

repeater cape moreton:

sq root 330ft x 1.52(assuming 9dB gain probably higher) = 45km probably a lot more.

Here is a coverage map.
/>http://www.msq.qld.gov.au/~/media/msqfiles/home/about-us/msq-headlines/pdf_distress_network_coverage.pdf

WHY IS IT SO (PROF JULIUS SUMNER MILLER)

[ellicat]

Power is more to do with signal clarity than distance, that's why they have high antennas.

I assume you mean 100metres = 330 feet. No doubt the repeaters are set upon a hill somewhere lol.

Interesting topic.

[dhess]

Yep on top of the lighthouse at Cape Moreton.

[tugger]

vhf radios get coverage further than line of site your 27meg is more prone to that and the lower the frequency the less times it bounces off the upper atmosphere and therefor can the signal can travel further. it also depends on the atmosphere of the day as my 27 meg can transmit and recieve people from moreton island while i'm fishing on the palmbeach reef. what i saw with daveylads radio was it didn't have a squelch dial only a button witch seems a bit odd and would need to read through the instruction manual for that curly 1. at times we could here moloaba coast gaurd while we were on the barwon banks while i was fishing with davey and would be interested to see if the arial length is the problem or the tuning of the set it could be

mark

[daveylad]

with daveylads radio was it didn't have a squelch dial only a button (tugger)

Mark, Its a squelch button that you press and then you adjust the squeclh level by pressing the up and down arrows, to release just press the button again. Mate It was my lack of knolege with Marine radios I'd read the manual but didnt soak in enough of it and didnt realise that the increase in squlch decreases the reception Transmit power. The radio is a GX600D VHF Marine DSC RADIO Designed to operate in the 156-163 MHz Marine band

[daveylad]

Just to finalise this thread I bought a new antenna, GME also had to buy a new mount because the old one was obsolete, anyway I can now pick up anything, sad but true I can sit in my yard 30ks away from the coast and pick up lucky buggers fishing, The antenna had been previously broken and fixed with some shrink tape, only a few inches on the tip but it made that much difference. My tip to anyone REPLACE it its not worth the hassle and problems it casues let alone safety.