I am thinking about buying a VHF radio for my McGregor Venture 23. I am not sure whether to buy a handheld or console model. I would prefer a console model, but do not want to pull the boat out of the water to install an antenna on the top of the mast. Can the mast itself be used as an antenna? The mast does not a have an electrical path to the water and the boat is not in saltwater; therefore the mast is not grounded.
- Status
- Not open for further replies.
M
Mark
Depends
It depends on where you will be sailing and if there are repeater stations around. For example here in Albany on the South coast of Western Australia we have our antenna mounted on the stern rail. With the one single repeater located on a smallish hill it means that we have a range of about 200 mile along the caost and out to sea about 50 mile. So a stern mount works perfectly. Putting the atenna on the mast will give you a little more coverage but then again some of that "extra" power is lost in the length of coax. And besides jsut how far out do you intend to sail? I would try mounting the antenna on the stern of the yacht and test before spending a lot of time and money putting it up the top of the mast.
It depends on where you will be sailing and if there are repeater stations around. For example here in Albany on the South coast of Western Australia we have our antenna mounted on the stern rail. With the one single repeater located on a smallish hill it means that we have a range of about 200 mile along the caost and out to sea about 50 mile. So a stern mount works perfectly. Putting the atenna on the mast will give you a little more coverage but then again some of that "extra" power is lost in the length of coax. And besides jsut how far out do you intend to sail? I would try mounting the antenna on the stern of the yacht and test before spending a lot of time and money putting it up the top of the mast.
B
Bayard Gross
Probably not
I will speculate from your location that you are sailing in lakes and as such may not reguire the additional range and power afforded by a "console" unit that draws power off the 12 volt battery. I think a good handheld in the $150 to $200 range will provide adequite performance for your needs. Further, as you have a twenty three foot boat, I think you use an outboard for power which may or may not have an alternator to charge a 12 volt battery. If it does not, then a fancy console radio with 25 watts of transmit power and great range from a mast antenna will be useless if your battery is not charged up. I also think it is wise to use AA batteries in a handheld because if the batteries fail, you can very easily store back-up batteries that can also be used for flashlights, laterns, back up navigational lights, etc. The rechargable battery packs seem nice but you will need two and what happens if one is at home being charged and the one you are using runs out of power? Hence, stick to quick to replace AA batteries.
I will speculate from your location that you are sailing in lakes and as such may not reguire the additional range and power afforded by a "console" unit that draws power off the 12 volt battery. I think a good handheld in the $150 to $200 range will provide adequite performance for your needs. Further, as you have a twenty three foot boat, I think you use an outboard for power which may or may not have an alternator to charge a 12 volt battery. If it does not, then a fancy console radio with 25 watts of transmit power and great range from a mast antenna will be useless if your battery is not charged up. I also think it is wise to use AA batteries in a handheld because if the batteries fail, you can very easily store back-up batteries that can also be used for flashlights, laterns, back up navigational lights, etc. The rechargable battery packs seem nice but you will need two and what happens if one is at home being charged and the one you are using runs out of power? Hence, stick to quick to replace AA batteries.
T
Tom s/v GAIA
NO!! The mast CAN'T be used as an antenna
As to the question about a hand held, the 2 gentlemen before me have covered that very well. Myself, I like the extra power, but carry a hand held as a just-in-case. Sail safe. Tom s/v GAIA
As to the question about a hand held, the 2 gentlemen before me have covered that very well. Myself, I like the extra power, but carry a hand held as a just-in-case. Sail safe. Tom s/v GAIA
E
Echo Gulf
Think Mast Head
Go with the mast head mounted antenna and console radio. In an emergency it's nice to know you can reach out and touch someone. Mounting the antenna on the stern is a very bad idea, marine radio signals are line of sight (meaning that they can be easily blocked by obstructions). I speak from experience when I say it is next to impossible to transmit to a vessel less than a mile ahead when the main and jib are set. Good Luck, Echo Gulf
Go with the mast head mounted antenna and console radio. In an emergency it's nice to know you can reach out and touch someone. Mounting the antenna on the stern is a very bad idea, marine radio signals are line of sight (meaning that they can be easily blocked by obstructions). I speak from experience when I say it is next to impossible to transmit to a vessel less than a mile ahead when the main and jib are set. Good Luck, Echo Gulf
J
Joe Ford
Are you serious?
Echo Gulf, Are you telling us that vhf radio waves will not penetrate sail cloth? That's definitely a weak signal. I am a coastal/catalina island type cruiser. I have used an 8 ft stern mounted antennae for years with a 5/25 watt console and have had no problems with coverage 15 miles and more ship to ship. Much further to shore based transmitters. My 1/5 watt handheld works well at over five miles. My suggestion, get a $40 stern mount. If you're behind a mountain the mast's extra 20 feet won't help much.
Echo Gulf, Are you telling us that vhf radio waves will not penetrate sail cloth? That's definitely a weak signal. I am a coastal/catalina island type cruiser. I have used an 8 ft stern mounted antennae for years with a 5/25 watt console and have had no problems with coverage 15 miles and more ship to ship. Much further to shore based transmitters. My 1/5 watt handheld works well at over five miles. My suggestion, get a $40 stern mount. If you're behind a mountain the mast's extra 20 feet won't help much.
S
Steve C.
Combo Idea
If you do not plan on taking long trips, ie coastal cruising, I would suggest a good handheld vhf and a masthead antenna. Because of the line of sight, the higher masthead mount would give you the extended range you may be looking for with a 5 watt handheld. The masthead mounting could even be used as an optional antenna. Back in forth in a lake, or similarly sized sailing area, you probably don't need it, but it's nice to have there. Bite the bullet, drop the mast and be sure to check the gain (dB) rating on any antenna you use. Higher gain = longer range. Higher antenna (height) = greater transmission range. Solution = longer antenna with higher gain. Clear as mud? One last suggestion. Get a handheld GPS. Runs on batteries, does the obvious and tells you how fast and in what direction you're travelling, without drilling holes. Not to mention they are great backup equipment. With both the handheld VHF and the handheld GPS, end of the day, they go in my bag and into the house. Good luck.
If you do not plan on taking long trips, ie coastal cruising, I would suggest a good handheld vhf and a masthead antenna. Because of the line of sight, the higher masthead mount would give you the extended range you may be looking for with a 5 watt handheld. The masthead mounting could even be used as an optional antenna. Back in forth in a lake, or similarly sized sailing area, you probably don't need it, but it's nice to have there. Bite the bullet, drop the mast and be sure to check the gain (dB) rating on any antenna you use. Higher gain = longer range. Higher antenna (height) = greater transmission range. Solution = longer antenna with higher gain. Clear as mud? One last suggestion. Get a handheld GPS. Runs on batteries, does the obvious and tells you how fast and in what direction you're travelling, without drilling holes. Not to mention they are great backup equipment. With both the handheld VHF and the handheld GPS, end of the day, they go in my bag and into the house. Good luck.
D
Don Alexander
Test Results
Dan, I have done the tests. Results as follows:- Hand Held - Hand Held Range approx 3 miles. Hand Held - Base Station (on hill) Range approx 15m. Masthead - Masthead Range approx 25m. Masthead - Base Station Range approx 50m. VHF does not require an earthed ground for the antenna as do other HF & MF aerials. The self capacitance of the person, or the shielding wire of the screened co ax feeder does this for you.
Dan, I have done the tests. Results as follows:- Hand Held - Hand Held Range approx 3 miles. Hand Held - Base Station (on hill) Range approx 15m. Masthead - Masthead Range approx 25m. Masthead - Base Station Range approx 50m. VHF does not require an earthed ground for the antenna as do other HF & MF aerials. The self capacitance of the person, or the shielding wire of the screened co ax feeder does this for you.
G
Gord May
Dipping Distance = Range
Since VHF Radio is line-of-site; it's axiomatic that range is equal to the "Dipping Distance" or combined distance to horizon of both transmitting and recieving antennas. Dipping Distance is calculated; Distance (nM) = 1.144(Sq. Root x Height in Feet Send)+ 1.144(Root Ht. Recieve) Note: includes correction for refraction (1.17 x 0.977) Assuming a generous height of 13 Feet for a rail-mounted antenna, and a 45 Ft masthead mtd. antenna: Range = Root 13 + Root 45 Range = 3.6 + 6.7 = 10.3 nM This is the theoretical maximum range over which these 2 radios can communicate. If they were both using mast-head mounted antennas, they'd have a maximum communicable range of 13.4 nM. ((a 30% increase; but only 3.1 nM range extension). I've used both mast-head and rail-mounted antennas, with (more or less) equal satisfaction, in MY normal communications mode (I always have BOTH available). Others might nead all the range they can get. If you know your application(s) & do the numbers; you can decide if the time, effort, and expense of a mast-head mounting is worth it to YOU. Regards, Gord
Since VHF Radio is line-of-site; it's axiomatic that range is equal to the "Dipping Distance" or combined distance to horizon of both transmitting and recieving antennas. Dipping Distance is calculated; Distance (nM) = 1.144(Sq. Root x Height in Feet Send)+ 1.144(Root Ht. Recieve) Note: includes correction for refraction (1.17 x 0.977) Assuming a generous height of 13 Feet for a rail-mounted antenna, and a 45 Ft masthead mtd. antenna: Range = Root 13 + Root 45 Range = 3.6 + 6.7 = 10.3 nM This is the theoretical maximum range over which these 2 radios can communicate. If they were both using mast-head mounted antennas, they'd have a maximum communicable range of 13.4 nM. ((a 30% increase; but only 3.1 nM range extension). I've used both mast-head and rail-mounted antennas, with (more or less) equal satisfaction, in MY normal communications mode (I always have BOTH available). Others might nead all the range they can get. If you know your application(s) & do the numbers; you can decide if the time, effort, and expense of a mast-head mounting is worth it to YOU. Regards, Gord
D
Dan McGuire
Thanks
The response to my question was great. Hardly any of the answers actually addressed my question which was whether the mast could be used as an antenna, if it was not grounded. But the answers were all interesting and informative. Bottom line-I will probably get a handheld; there is not that much of an increase in range and it should be adequate for the lake. Thanks.
The response to my question was great. Hardly any of the answers actually addressed my question which was whether the mast could be used as an antenna, if it was not grounded. But the answers were all interesting and informative. Bottom line-I will probably get a handheld; there is not that much of an increase in range and it should be adequate for the lake. Thanks.
G
Gord May
Tom answered emphatically
You CANNOT use your mast as an antenna. He's absolutely correct, of course. Gord
You CANNOT use your mast as an antenna. He's absolutely correct, of course. Gord
E
ed bauer
antenna
Dan The standard formular for a vertical radiator is 5/8 wave lenght divided by the frequency.You'r vhf radio is around 156 mhz.so @5/8 w/l the antenna lenght would be around 3.7 ft.You'r mast is not tuned to this freq.You could try a match at the base of the mast ie inductive/capacitive but i would not bother
Dan The standard formular for a vertical radiator is 5/8 wave lenght divided by the frequency.You'r vhf radio is around 156 mhz.so @5/8 w/l the antenna lenght would be around 3.7 ft.You'r mast is not tuned to this freq.You could try a match at the base of the mast ie inductive/capacitive but i would not bother
T
T J Furstenau
A Mast Disadvantage
Now, let me preface this by saying that my antennae is at the masthead. One thing I haven't seen mentioned is the fact that one of the emergencies that a sailor can run into is a dismasting. Now when a radio is truly needed, there is no antennae where it is needed. This is just a reminder that with a masthead antennae, one should also get a seperate emergency antennae. As I learned in Boy Scouts, "Be Prepared". T J
Now, let me preface this by saying that my antennae is at the masthead. One thing I haven't seen mentioned is the fact that one of the emergencies that a sailor can run into is a dismasting. Now when a radio is truly needed, there is no antennae where it is needed. This is just a reminder that with a masthead antennae, one should also get a seperate emergency antennae. As I learned in Boy Scouts, "Be Prepared". T J
E
Echo Gulf
To Joe Ford,
The cone of silence (as we call it), has been experienced by us on several occassions. It seems as if the sails, mast shrouds etc. cause a narrow area of poor radio transmission immediately in front of the boat. Our equipment is very similar to yours and has been serviced to ensure peak performance. The most dramatic occurrence happened while we were travelling south through the Straights of Georgia, our comms with another boat less than a mile ahead of us was unreadable at best, but yet we were able to speak with friends in Desolation Sound at least 20 miles distant but behind us, as if they were next door. Furher invesigation back at our own marina revealed that all the other boats with stern mounted attennas have the same story (we all had 8ft fibreglass whips). Several of us got together and equiped out boats with masthead antennas resolving this issue. I don't believe, with my very limited knowledge of the subject, that the cause is related to a weak signal as much as to the type of signal (vhf/fm). As was mentioned, a dismasting would sever communications. I have acquired small magnetic mount attenna that is easy to store away, for use in an emergency. Echo Gulf
The cone of silence (as we call it), has been experienced by us on several occassions. It seems as if the sails, mast shrouds etc. cause a narrow area of poor radio transmission immediately in front of the boat. Our equipment is very similar to yours and has been serviced to ensure peak performance. The most dramatic occurrence happened while we were travelling south through the Straights of Georgia, our comms with another boat less than a mile ahead of us was unreadable at best, but yet we were able to speak with friends in Desolation Sound at least 20 miles distant but behind us, as if they were next door. Furher invesigation back at our own marina revealed that all the other boats with stern mounted attennas have the same story (we all had 8ft fibreglass whips). Several of us got together and equiped out boats with masthead antennas resolving this issue. I don't believe, with my very limited knowledge of the subject, that the cause is related to a weak signal as much as to the type of signal (vhf/fm). As was mentioned, a dismasting would sever communications. I have acquired small magnetic mount attenna that is easy to store away, for use in an emergency. Echo Gulf
J
Joe Ford
That's really interesting, Echo...
... I will ask around about that phenomenon. As a matter of curiousity, did you try turning the boat to see if transmission quality improved, so you weren't broadcasting through the "cone"? I'm also wondering how the vhf waves react when the radio is near mounainous shores or other obstructions. For the record, I have the installation of a mast whip antenna on my project list, but for increased range, not for any problems with a cone effect. I will combine that project with others that involve dropping the mast. I am enjoying this thread. You learn something new every day.
... I will ask around about that phenomenon. As a matter of curiousity, did you try turning the boat to see if transmission quality improved, so you weren't broadcasting through the "cone"? I'm also wondering how the vhf waves react when the radio is near mounainous shores or other obstructions. For the record, I have the installation of a mast whip antenna on my project list, but for increased range, not for any problems with a cone effect. I will combine that project with others that involve dropping the mast. I am enjoying this thread. You learn something new every day.
- Status
- Not open for further replies.