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VHF Radio Range Problem
I suspect that my Marine VHF radio is a little lacking in range, even on the
25W setting. It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Tips and hints welcome. Cheers, John |
I had the same problem on my Pearson 303. I was told that the antenta wire
going up the mast had chaffed through and was shorting out. I replaced the wire and now it works fine. It is the original radio from 1985 on the boat. "MazingTree" wrote in message .uk... I suspect that my Marine VHF radio is a little lacking in range, even on the 25W setting. It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Tips and hints welcome. Cheers, John |
Ah that's encouraging. Another reply in UK.rec.sailing (didn't see the
electronics group!) concurs with this thought. I think I shall replace the antenna and aerial, unless I can get the Vtronix Antenna apart to replace just the cable. Sounds worth doing first anyway. John "Richard" wrote in message ... I had the same problem on my Pearson 303. I was told that the antenta wire going up the mast had chaffed through and was shorting out. I replaced the wire and now it works fine. It is the original radio from 1985 on the boat. "MazingTree" wrote in message .uk... I suspect that my Marine VHF radio is a little lacking in range, even on the 25W setting. It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Tips and hints welcome. Cheers, John |
In article ,
"MazingTree" wrote: I suspect that my Marine VHF radio is a little lacking in range, even on the 25W setting. It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Tips and hints welcome. Cheers, John I would suspect the antenna and or coax cable in your case. Sounds like a simple case of old tired coax, or detuned, ort failing antenna. Here in the North Pacific, we usually are getting 50+ miles boat to boat with 25 Watts and 10db antennas on 0ver 300 ton Coastal Freighters, with some paths reaching out to 90+ miles. Of course your milage may vary, as to Actual Tx Power, and Receiver Sensitivity, and Antenna losses. Bruce in alaska -- add a 2 before @ |
If your boat is fiberglass or wood, make certain you have a ground plane for
the antenna. The earth connection of your transceiver needs to connect to large matt or screen on the hull which is connected electrically with the water. Some boat builders bond the screen into the deck. As a check, borrow a VHF base station antenna and see if it performs correctly. If it does, you have found your problem. Now fixing it, is another matter. Steve "MazingTree" wrote in message .uk... I suspect that my Marine VHF radio is a little lacking in range, even on the 25W setting. It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Tips and hints welcome. Cheers, John |
Used my VHF for a 1300 nm contact today.
krj Steve Lusardi wrote: If your boat is fiberglass or wood, make certain you have a ground plane for the antenna. The earth connection of your transceiver needs to connect to large matt or screen on the hull which is connected electrically with the water. Some boat builders bond the screen into the deck. As a check, borrow a VHF base station antenna and see if it performs correctly. If it does, you have found your problem. Now fixing it, is another matter. Steve "MazingTree" wrote in message .uk... I suspect that my Marine VHF radio is a little lacking in range, even on the 25W setting. It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Tips and hints welcome. Cheers, John |
"MazingTree" wrote in
.uk: It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Ok, let's splurge and drop by Waste Marine for a Shakespeare VHF power/SWR meter. It's a little white meter with a switch and adjustment control on the front and two coax connectors, one on each side. $30. You'll need a short coax jumper to go from the meter's transmitter connector to the VHF transceiver. If you also buy two right-angle PL-259/SO-239 connectors to make the coax jacks come out the back of it, instead of the side, you can make a neat permanent installation of the meter on the panel next to the radio so you KNOW it's actually transmitting and that the antenna is OK at any time you don't get an answer. Use is simple. To check the antenna out, put the meter switch in the SET position, key the transmitter on some channel in the middle of the band (NOT CHANNEL 16!) and rotate the little adjustment control until the meter is at the SET mark at full scale. Now, switch to SWR position and read the SWR scale on the meter, while still holding the transmitter keyed. A perfect antenna, which rarely exists, will show no movement of the needle off the 1 on the SWR scale, indicating no reflected power back from the antenna. All the power is going out on the air. Any reading on SWR below 2:1 (the 2 on the SWR scale) is fine. 2:1 means you're losing 10% of your power back from the antenna. At the antenna it's worse than that but noone can really tell the difference out on the horizon between 25W and 15W. If the SWR is higher than 2:1, especially if it goes way up off the SWR scale, which only goes halfway up at 3:1, the antenna or the cable is TOAST...probably from a lightning hit or broken coaxial cable. Worst case....SWR sucks over 3:1....what now?...... Now we get out the bosun's chair and have the galley slaves haul us, and our SWR meter, up the mast to the antenna. Move the jumper coax cable from the transmitter jack to the antenna jack as up at the top it will be jumpering the meter to the antenna. Unplug the coax cable off the antenna, after the galley slaves secure the line to a cleat, please, and connect it to the transmitter jack on our meter. Connect the open end of the jumper coax to the antenna. Move a galley slave to the radio and have him/her turn it on. Repeat the SWR set and measurement procedure above. If you have to significantly move the SET control from the position you had it at the transceiver end of the coax....or.....if you get little or no reading at all....the coax is TOAST. Replace it and start measuring again. Ok, what if we get good power level up the coax? Switch to SWR position and read the SWR under the antenna, now. It would normally be a little higher than what you'd measure at the transceiver on a good antenna because the reflected power that makes the SWR position run is attenuated by the cable when we measured it back at the radio. That'd be normal. Again, the SWR here should be less than 2:1. If it's high, the antenna is toast! Go to your favorite marine "discount" dealer and order a Metz Manta 6 VHF antenna, not that piece of plastic crap with COAX RUNNING OUT OF THE PLASTIC they'll invariably try to pawn off on your. The Metz is guaranteed for life. They'll send you a new one if you ever tear up this one. It's the best antenna for sailboat masts....damned near indestructable. it comes with a right-angle stainless bracket to mount it to the mast if your current one isn't compatible. http://www.metzcommunication.com/manta6.htm You won't need the handrail mount. Mounted on the handrail sucks. ALTITUDE IS OUR FRIEND ON VHF! Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. Daytime, normal weather....50' mast to 50' mast...probably 15 miles...a little over the visual horizon from the top of the mast. VHF is line-of- sight to the radio horizon. Mathematically it's: http://continuouswave.com/whaler/reference/VHF.html As you can see from that, the major concern is "path loss" and antenna height. The 3dB Metz gives you double whatever power is at the end of the cable atop the mast in Effective Radiated Power (ERP) The 6dB antenna is too tall to make sense up there...easily destroyed plastic. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Before we spend hundreds on a new radio, let's get the antenna checked out with the cheap meter, first. If the SWR is reasonable, under 2:1, when you test it at the radio, THEN we'll flip the switch to POWER mode and read the handy little wattmeter, which is "fairly accurate" at LOW SWR READINGS, being most accurate at 1:1 with no reflected power. Check the 25W high power and 1 watt low power in this meter mode. As the SWR increases, this reading increases, so don't get way excited if it reads 30 watts at 2:1 SWR. It was calibrated into a perfect dummy load at the factory. Now, of course, if you're reading ZERO and can't get the meter to SET in SWR mode....then we've got a bad transmitter. Your choice to repair or replace. If it's old, dump it. They stopped making my beloved M-59 the jetboat jumping waves couldn't destroy...dammit. Lionheart has an M-602 on the mainmast Metz and an M-59 on the mizzen lower down. Captain Geoffrey likes the way the M-602 matches the M-802 HF panel...(c; There's no difference in the range of the big expensive 602 and the old M-59 I can tell. M-59 has new clothes. They call it the M-302, now. If you don't need the extra toys of the M-402, like remote Commander mic, etc., it has the same radio operation. Any Icom is fine. M-127s, the Radio Of The Year back in 2000 and before, is a great radio. They're still available, but discontinued, now. Gotta keep cranking up those model numbers, you know! As the range webpage shows, 10 miles is pretty fair, boat 2 boat on VHF. The investment in the little SWR/Power meter will help you find out the true health of the radio/antenna/cable combo....Everyone should buy one. |
"Steve Lusardi" wrote in
: If your boat is fiberglass or wood, make certain you have a ground plane for the antenna. The earth connection of your transceiver needs to connect to large matt or screen on the hull which is connected electrically with the water. Some boat builders bond the screen into the deck. As a check, borrow a VHF base station antenna and see if it performs correctly. If it does, you have found your problem. Now fixing it, is another matter. Steve The end-fed halfwave antennas, such as the Metz Manta-6 do not require any ground or groundplane at all. The antenna rod, itself, is a total 1/2 wavelength dipole, but fed from the bottom end. No ground is necessary. http://www.metzcommunication.com/manta6.htm Guaranteed for life.... |
The Antenna system is a Vtronix Great Hawk, the one with the Wind indicator
built into it. Since I first posted, I have spoken with their technical man, and he was very helpful, and explained that it's fitted with a special solderless connection to enable the cable to be unscrewed and checked. from my description to him, it sounds like the aerial has been up the mast for a long time though, so I may swap the antenna anyway, whilst I am up the mast. He says it is possible after a very extended period of time for the antenna to become faulty due corrosion and possibly water ingress. John wrote in message ... On 2005-06-06 said: I had the same problem on my Pearson 303. I was told that the antenna wire going up the mast had chaffed through and was shorting out. I replaced the wire and now it works fine. It is the original radio from 1985 on the boat. THat was my first thought. Check your feedline and the antenna, make sure the feedline is good and your antenna system not corroded or otherwise less than optimum. IF your antenna on the mast with 25 watts can't outperform your portable then you've got a problem somewhere. I note you didn't say waht kind of antenna you were using with the portable. However I'd do some real servicing to the antenna system before I rushed out and bought a new transceiver. Richard Webb, amateur radio callsign nf5b active on the Maritime Mobile service network, 14.300 mhz REplace anything before the @ symbol with elspider for real email -- agood captain is one who is hoisting his first drink in a bar when the storm hits. |
Yes I am sure you are correct, according to the Vtronix Hawk information,
this is an end fed dipole, and so needs no ground. John "Larry W4CSC" wrote in message ... "Steve Lusardi" wrote in : If your boat is fiberglass or wood, make certain you have a ground plane for the antenna. The earth connection of your transceiver needs to connect to large matt or screen on the hull which is connected electrically with the water. Some boat builders bond the screen into the deck. As a check, borrow a VHF base station antenna and see if it performs correctly. If it does, you have found your problem. Now fixing it, is another matter. Steve The end-fed halfwave antennas, such as the Metz Manta-6 do not require any ground or groundplane at all. The antenna rod, itself, is a total 1/2 wavelength dipole, but fed from the bottom end. No ground is necessary. http://www.metzcommunication.com/manta6.htm Guaranteed for life.... |
Excellent post - Thanks. I think I follow it all, and it makes logical
sense. I had searched for some time for a Meter to mesaure output power, but must have been using the wrong terminology because I couldn't find anything. My Antenna, is a Vtronix Great Hawk, which appear to be very popular over here in the UK, and appears well made, with a special solderless cable fitting, and appears to be well engineered. It also houses the windex, so I may stick with this type. Price is similar to the Metz it would appear. I wonder if you SWR meter can be purchased from the UK. I'm off to find out now! thanks, John "Larry W4CSC" wrote in message ... "MazingTree" wrote in .uk: It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Ok, let's splurge and drop by Waste Marine for a Shakespeare VHF power/SWR meter. It's a little white meter with a switch and adjustment control on the front and two coax connectors, one on each side. $30. You'll need a short coax jumper to go from the meter's transmitter connector to the VHF transceiver. If you also buy two right-angle PL-259/SO-239 connectors to make the coax jacks come out the back of it, instead of the side, you can make a neat permanent installation of the meter on the panel next to the radio so you KNOW it's actually transmitting and that the antenna is OK at any time you don't get an answer. Use is simple. To check the antenna out, put the meter switch in the SET position, key the transmitter on some channel in the middle of the band (NOT CHANNEL 16!) and rotate the little adjustment control until the meter is at the SET mark at full scale. Now, switch to SWR position and read the SWR scale on the meter, while still holding the transmitter keyed. A perfect antenna, which rarely exists, will show no movement of the needle off the 1 on the SWR scale, indicating no reflected power back from the antenna. All the power is going out on the air. Any reading on SWR below 2:1 (the 2 on the SWR scale) is fine. 2:1 means you're losing 10% of your power back from the antenna. At the antenna it's worse than that but noone can really tell the difference out on the horizon between 25W and 15W. If the SWR is higher than 2:1, especially if it goes way up off the SWR scale, which only goes halfway up at 3:1, the antenna or the cable is TOAST...probably from a lightning hit or broken coaxial cable. Worst case....SWR sucks over 3:1....what now?...... Now we get out the bosun's chair and have the galley slaves haul us, and our SWR meter, up the mast to the antenna. Move the jumper coax cable from the transmitter jack to the antenna jack as up at the top it will be jumpering the meter to the antenna. Unplug the coax cable off the antenna, after the galley slaves secure the line to a cleat, please, and connect it to the transmitter jack on our meter. Connect the open end of the jumper coax to the antenna. Move a galley slave to the radio and have him/her turn it on. Repeat the SWR set and measurement procedure above. If you have to significantly move the SET control from the position you had it at the transceiver end of the coax....or.....if you get little or no reading at all....the coax is TOAST. Replace it and start measuring again. Ok, what if we get good power level up the coax? Switch to SWR position and read the SWR under the antenna, now. It would normally be a little higher than what you'd measure at the transceiver on a good antenna because the reflected power that makes the SWR position run is attenuated by the cable when we measured it back at the radio. That'd be normal. Again, the SWR here should be less than 2:1. If it's high, the antenna is toast! Go to your favorite marine "discount" dealer and order a Metz Manta 6 VHF antenna, not that piece of plastic crap with COAX RUNNING OUT OF THE PLASTIC they'll invariably try to pawn off on your. The Metz is guaranteed for life. They'll send you a new one if you ever tear up this one. It's the best antenna for sailboat masts....damned near indestructable. it comes with a right-angle stainless bracket to mount it to the mast if your current one isn't compatible. http://www.metzcommunication.com/manta6.htm You won't need the handrail mount. Mounted on the handrail sucks. ALTITUDE IS OUR FRIEND ON VHF! Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. Daytime, normal weather....50' mast to 50' mast...probably 15 miles...a little over the visual horizon from the top of the mast. VHF is line-of- sight to the radio horizon. Mathematically it's: http://continuouswave.com/whaler/reference/VHF.html As you can see from that, the major concern is "path loss" and antenna height. The 3dB Metz gives you double whatever power is at the end of the cable atop the mast in Effective Radiated Power (ERP) The 6dB antenna is too tall to make sense up there...easily destroyed plastic. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Before we spend hundreds on a new radio, let's get the antenna checked out with the cheap meter, first. If the SWR is reasonable, under 2:1, when you test it at the radio, THEN we'll flip the switch to POWER mode and read the handy little wattmeter, which is "fairly accurate" at LOW SWR READINGS, being most accurate at 1:1 with no reflected power. Check the 25W high power and 1 watt low power in this meter mode. As the SWR increases, this reading increases, so don't get way excited if it reads 30 watts at 2:1 SWR. It was calibrated into a perfect dummy load at the factory. Now, of course, if you're reading ZERO and can't get the meter to SET in SWR mode....then we've got a bad transmitter. Your choice to repair or replace. If it's old, dump it. They stopped making my beloved M-59 the jetboat jumping waves couldn't destroy...dammit. Lionheart has an M-602 on the mainmast Metz and an M-59 on the mizzen lower down. Captain Geoffrey likes the way the M-602 matches the M-802 HF panel...(c; There's no difference in the range of the big expensive 602 and the old M-59 I can tell. M-59 has new clothes. They call it the M-302, now. If you don't need the extra toys of the M-402, like remote Commander mic, etc., it has the same radio operation. Any Icom is fine. M-127s, the Radio Of The Year back in 2000 and before, is a great radio. They're still available, but discontinued, now. Gotta keep cranking up those model numbers, you know! As the range webpage shows, 10 miles is pretty fair, boat 2 boat on VHF. The investment in the little SWR/Power meter will help you find out the true health of the radio/antenna/cable combo....Everyone should buy one. |
Larry,
Would have the URL for Waste Marine, I can't see this listed in Google? I wonder if you have a typo, it seems an odd name for a company selling marine equipment :-) Cheers, John "Larry W4CSC" wrote in message ... "MazingTree" wrote in .uk: It's an older style Navico, I only get about a 10 mile range out at sea, Yacht to yacht, although I can just reach the Coast Guard from around the Eddystone (about 15 miles to the coast) This woulnd't seem so bad, except my brand new ICOM M31 portable gives exactly the same range, both tramistting and receiving, and that's using it down at deck level, and at only 5W output! whereas my Main boat VHF has an aerial on the top of the mast. Ok, let's splurge and drop by Waste Marine for a Shakespeare VHF power/SWR meter. It's a little white meter with a switch and adjustment control on the front and two coax connectors, one on each side. $30. You'll need a short coax jumper to go from the meter's transmitter connector to the VHF transceiver. If you also buy two right-angle PL-259/SO-239 connectors to make the coax jacks come out the back of it, instead of the side, you can make a neat permanent installation of the meter on the panel next to the radio so you KNOW it's actually transmitting and that the antenna is OK at any time you don't get an answer. Use is simple. To check the antenna out, put the meter switch in the SET position, key the transmitter on some channel in the middle of the band (NOT CHANNEL 16!) and rotate the little adjustment control until the meter is at the SET mark at full scale. Now, switch to SWR position and read the SWR scale on the meter, while still holding the transmitter keyed. A perfect antenna, which rarely exists, will show no movement of the needle off the 1 on the SWR scale, indicating no reflected power back from the antenna. All the power is going out on the air. Any reading on SWR below 2:1 (the 2 on the SWR scale) is fine. 2:1 means you're losing 10% of your power back from the antenna. At the antenna it's worse than that but noone can really tell the difference out on the horizon between 25W and 15W. If the SWR is higher than 2:1, especially if it goes way up off the SWR scale, which only goes halfway up at 3:1, the antenna or the cable is TOAST...probably from a lightning hit or broken coaxial cable. Worst case....SWR sucks over 3:1....what now?...... Now we get out the bosun's chair and have the galley slaves haul us, and our SWR meter, up the mast to the antenna. Move the jumper coax cable from the transmitter jack to the antenna jack as up at the top it will be jumpering the meter to the antenna. Unplug the coax cable off the antenna, after the galley slaves secure the line to a cleat, please, and connect it to the transmitter jack on our meter. Connect the open end of the jumper coax to the antenna. Move a galley slave to the radio and have him/her turn it on. Repeat the SWR set and measurement procedure above. If you have to significantly move the SET control from the position you had it at the transceiver end of the coax....or.....if you get little or no reading at all....the coax is TOAST. Replace it and start measuring again. Ok, what if we get good power level up the coax? Switch to SWR position and read the SWR under the antenna, now. It would normally be a little higher than what you'd measure at the transceiver on a good antenna because the reflected power that makes the SWR position run is attenuated by the cable when we measured it back at the radio. That'd be normal. Again, the SWR here should be less than 2:1. If it's high, the antenna is toast! Go to your favorite marine "discount" dealer and order a Metz Manta 6 VHF antenna, not that piece of plastic crap with COAX RUNNING OUT OF THE PLASTIC they'll invariably try to pawn off on your. The Metz is guaranteed for life. They'll send you a new one if you ever tear up this one. It's the best antenna for sailboat masts....damned near indestructable. it comes with a right-angle stainless bracket to mount it to the mast if your current one isn't compatible. http://www.metzcommunication.com/manta6.htm You won't need the handrail mount. Mounted on the handrail sucks. ALTITUDE IS OUR FRIEND ON VHF! Does anyone have any thoughts about what range I can expect yacht to yacht on a 32 footer sailing boat with mast head antenna with 25 Watts. Daytime, normal weather....50' mast to 50' mast...probably 15 miles...a little over the visual horizon from the top of the mast. VHF is line-of- sight to the radio horizon. Mathematically it's: http://continuouswave.com/whaler/reference/VHF.html As you can see from that, the major concern is "path loss" and antenna height. The 3dB Metz gives you double whatever power is at the end of the cable atop the mast in Effective Radiated Power (ERP) The 6dB antenna is too tall to make sense up there...easily destroyed plastic. I am considering purchasing the ICOM M421, do you think this is the best bet, or could the aerial be faulty. I have checked all the deck level connections and these seem OK. Before we spend hundreds on a new radio, let's get the antenna checked out with the cheap meter, first. If the SWR is reasonable, under 2:1, when you test it at the radio, THEN we'll flip the switch to POWER mode and read the handy little wattmeter, which is "fairly accurate" at LOW SWR READINGS, being most accurate at 1:1 with no reflected power. Check the 25W high power and 1 watt low power in this meter mode. As the SWR increases, this reading increases, so don't get way excited if it reads 30 watts at 2:1 SWR. It was calibrated into a perfect dummy load at the factory. Now, of course, if you're reading ZERO and can't get the meter to SET in SWR mode....then we've got a bad transmitter. Your choice to repair or replace. If it's old, dump it. They stopped making my beloved M-59 the jetboat jumping waves couldn't destroy...dammit. Lionheart has an M-602 on the mainmast Metz and an M-59 on the mizzen lower down. Captain Geoffrey likes the way the M-602 matches the M-802 HF panel...(c; There's no difference in the range of the big expensive 602 and the old M-59 I can tell. M-59 has new clothes. They call it the M-302, now. If you don't need the extra toys of the M-402, like remote Commander mic, etc., it has the same radio operation. Any Icom is fine. M-127s, the Radio Of The Year back in 2000 and before, is a great radio. They're still available, but discontinued, now. Gotta keep cranking up those model numbers, you know! As the range webpage shows, 10 miles is pretty fair, boat 2 boat on VHF. The investment in the little SWR/Power meter will help you find out the true health of the radio/antenna/cable combo....Everyone should buy one. |
MazingTree wrote:
Larry, Would have the URL for Waste Marine, I can't see this listed in Google? I wonder if you have a typo, it seems an odd name for a company selling marine equipment :-) Cheers, John Hi John, Waste Marine is a common pun on a very big company in the USA with _many_ stores called West Marine. Their website can be found at http://www.westmarine.com/ Of course, on our side of the Atlantic we've never heard of the bloody outfit... Vriendelijke groeten, Kees |
MazingTree wrote:
I wonder if you SWR meter can be purchased from the UK. I'm off to find out now! John, Type "swr meter vhf site:uk" and up they pop. Most of them seem radio ham oriented, but I was quickly able to find one that's GBP 29.95, which sounds reasonable. -- Kees |
Kees Verruijt wrote:
MazingTree wrote: I wonder if you SWR meter can be purchased from the UK. I'm off to find out now! John, Type "swr meter vhf site:uk" and up they pop. Most of them seem radio ham oriented, but I was quickly able to find one that's GBP 29.95, which sounds reasonable. -- Kees Oops, that should have read ''Type "swr meter vhf site:uk" into Google'' of course... -- Kees |
"MazingTree" wrote in
. uk: I wonder if you SWR meter can be purchased from the UK. I'm off to find out now! thanks, John Sorry I didn't notice you were in the UK, John. If you know any ham radio operators, they'll know, too, where to purchase a similar VHF SWR meter. |
Kees Verruijt wrote in
ll.nl: Type "swr meter vhf site:uk" and up they pop. Most of them seem radio ham oriented, but I was quickly able to find one that's GBP 29.95, which sounds reasonable. Just make sure they are for the 156 Mhz range in their specs. Many ham radio SWR meters are only for frequencies below 30 Mhz...the HF band. |
"MazingTree" wrote in
.uk: Would have the URL for Waste Marine, I can't see this listed in Google? I wonder if you have a typo, it seems an odd name for a company selling marine equipment :-) Shakespeare manufactures marine antennas in the US. Go to Google and search for: Shakespeare ART-2 Antenna Radio Tester There are lots of dealers. I looked at Shakespeare's website and see they have a new model out, the ART-3, but have never seen one. The ART-2 has been out for many years. It's all you need. http://www.google.com/search?hl=en&q=Shakespeare+ART- 2+Antenna+Radio+Tester&btnG=Google+Search The PDF catalog is at: http://www.shakespeare-marine.com/catalog/fullline.pdf Click on "Radio Accessories" in the control panel of the Adobe Acrobat Reader. It's the 2nd unit down on the left. |
Kees Verruijt wrote in
ll.nl: Of course, on our side of the Atlantic we've never heard of the bloody outfit... Sorry for causing the confusion. You haven't missed anything having never been in an overpriced West Marine store. |
"MazingTree" wrote in
o.uk: solderless connection to enable the cable to be unscrewed and checked I don't like it. Solderless usually means corroded within 5 miles of the sea. |
Larry W4CSC wrote:
Kees Verruijt wrote in ll.nl: Of course, on our side of the Atlantic we've never heard of the bloody outfit... Sorry for causing the confusion. You haven't missed anything having never been in an overpriced West Marine store. In proper Dutch, "Watersport Mafia," is what we call the combined marine stores over here in the Netherlands. I suspect this translates _real_ easy into English ;-) -- Kees |
In article ,
"Steve Lusardi" wrote: If your boat is fiberglass or wood, make certain you have a ground plane for the antenna. The earth connection of your transceiver needs to connect to large matt or screen on the hull which is connected electrically with the water. Some boat builders bond the screen into the deck. As a check, borrow a VHF base station antenna and see if it performs correctly. If it does, you have found your problem. Now fixing it, is another matter. Steve The construction of the hull of the vessel has absolutly "No Bearing" on the preformance of a VHF Marine Antenna, that is on a mast, or elevated more than 3 feet off the deck. Any advice to the contrary is just plain BS. Any installation of "Screen" in the deck of a vessel for Grouding Purposes is also plainly BS, and is basically a useless undertaking. Again, any advice to the contrary is uninformed, especially for Vhf Antennas, and even for MF/HF Antennas. If you would like to dispute the above, feel free to give us your source of this great "Radio Wisdom". We can all use a good laugh and smile session. Me who really would enjoy, someone defending the above statments with REAL Science, and Real Physics...... |
In article ,
krj wrote: Used my VHF for a 1300 nm contact today. krj Can you say "Troposhperic Ducting", with a straight face??? Me |
Me wrote:
In article , krj wrote: Used my VHF for a 1300 nm contact today. krj Can you say "Troposhperic Ducting", with a straight face??? Me Can you say satellite communications? krj |
Many thanks for the comprehensive replies here,
Checking them out now! I have also spotted something called and AV-40 Avair, which also looks like it might do the trick, and seems available over here. John "Larry W4CSC" wrote in message ... "MazingTree" wrote in .uk: Would have the URL for Waste Marine, I can't see this listed in Google? I wonder if you have a typo, it seems an odd name for a company selling marine equipment :-) Shakespeare manufactures marine antennas in the US. Go to Google and search for: Shakespeare ART-2 Antenna Radio Tester There are lots of dealers. I looked at Shakespeare's website and see they have a new model out, the ART-3, but have never seen one. The ART-2 has been out for many years. It's all you need. http://www.google.com/search?hl=en&q=Shakespeare+ART- 2+Antenna+Radio+Tester&btnG=Google+Search The PDF catalog is at: http://www.shakespeare-marine.com/catalog/fullline.pdf Click on "Radio Accessories" in the control panel of the Adobe Acrobat Reader. It's the 2nd unit down on the left. |
"krj" wrote in message . .. Me wrote: In article , krj wrote: Used my VHF for a 1300 nm contact today. krj Can you say "Troposhperic Ducting", with a straight face??? Me Can you say satellite communications? krj Twenty years ago I used a 2 meter ham handheld running 1 watt to talk from Portland, OR to China...it was via repeaters in the pacific NW intertie and then commercial (Boeing Aviation?) satellite link from Seattle to China and back out on a ham repeater. I must admit it surprised me greatly at first, but then I figured out what was going on. Troposcatter? Ionized meteor trails? Tropoducting? Aurora bounce? All of the these can result in long distance VHF marine communications but none last for long or occur very often. Tropscatter should remind Bruce in AK of the old White Alice systems up there. 73 Doug K7ABX |
|
"Doug" wrote in
nk.net: Twenty years ago I used a 2 meter ham handheld running 1 watt to talk from Portland, OR to China...it was via repeaters in the pacific NW intertie and then commercial (Boeing Aviation?) satellite link from Seattle to China and back out on a ham repeater. I must admit it surprised me greatly at first, but then I figured out what was going on. I was talking to a guy riding the train into Helsinki, Finland, through their local UHF repeater on top of some mountain from Charleston a few months ago....so there....(sticks tongue out, smiling) Of course, I was on Echolink on the computer VoIP for ham radio...(c; My Swiss buddy, Werner, AA4IX, is from Berner Oberland in unbelievably beautiful countryside of Thun on the Thuner See (lake). There is a repeater on top of one of the local mountains on Echolink he talks to his buddies back in HB9-land daily. Of course, an ugly American, I don't speak German. Other German friends claim Berner Oberland doesn't speak German, either...(c; |
Richard,
Actually I had a look at the Shakepear Antenna, and the Vtronix (Great Hawk) in a shop today. The Great Hawk has a quite superior solderless connection, it appears to use gold plated parts, and has two sealing O rings, and is quite clever in construction. I do take the point about a soldered connection, but although I do have a nice weller soldering iron, it would be interesting doing that at the top of the mast! If we compare that with the Shakespear antenna, although the Shakespear antenna itself certainly looks pretty robust, the connector is just a standard RF type as far as I can see, and therefore less well protected from the elements than the Great Hawk. There may be some grommet to cover it up, but I couldn't see one in the Antenna pack. A look around my Marina here in the UK, shows that Vtronix, both with wind vane and without would appear to outnumber the Shakespear probably 4 to 1. The main marine specialist here in Plymouth does not stock them, although a smaller chamndlery did. So I think on balance I still have a good quality bit of kit. Any way it's up the mast now, and done. I have a VSWR meter in the post for £29, which will also confirm my cable works fine too and the I have a perfect matching antenna - Hopefully :-) The one thing I would say here in the UK is that no-one in the Marine industry appears to let on that you can buy a cheap meter and test your own set. The best advice I got from UK electronics dealers, is that if you bring in the set, we can test it for £20, then if it's not the set, we come out and test it, but that was an opene ended price. I guess they have to make a living! I also suppose that's why I came to a newgroup. Thanks everyone for all the information. John wrote in message . .. On 2005-06-08 Larry said: "MazingTree" wrote in . co.uk: solderless connection to enable the cable to be unscrewed and checked I don't like it. Solderless usually means corroded within 5 miles of the sea. I was thinking the same thing. SOlderless connections are not robust enough for me for most applications. I don't use the solderless coax connectors anywhere in my operations. sOunds like it's time to change out that antenna for something a little more fit for the duties you expect of it. Richard Webb, amateur radio callsign nf5b active on the Maritime Mobile service network, 14.300 mhz REplace anything before the @ symbol with elspider for real email -- agood captain is one who is hoisting his first drink in a bar when the storm hits. |
On Wed, 08 Jun 2005 21:31:50 GMT, "Doug" wrote:
"krj" wrote in message ... Me wrote: In article , krj wrote: snip Tropscatter should remind Bruce in AK of the old White Alice systems up there. 73 Doug K7ABX It reminds me also. Did you happen to work on them too, Doug? The DEW-Line used Troposcatter Quad Diversity radio systems too. I loved putting that on resumes, except no one knew what it meant. I worked on both the DEW-Line and White Alice (plus flew the Barrier (WV-2) while in the USN, from Midway to Adak and return...non-stop). We used to keep AFRN on a speaker so we could tell if fading was beginning. The first time I heard the pop song "Vibrations" on AFRN, I nearly freaked...I *knew* my radios were going down, but didn't have a clue as to how or why....:) Norm B |
"engsol" wrote in message ... On Wed, 08 Jun 2005 21:31:50 GMT, "Doug" wrote: "krj" wrote in message ... Me wrote: In article , krj wrote: snip Tropscatter should remind Bruce in AK of the old White Alice systems up there. 73 Doug K7ABX It reminds me also. Did you happen to work on them too, Doug? The DEW-Line used Troposcatter Quad Diversity radio systems too. I loved putting that on resumes, except no one knew what it meant. I worked on both the DEW-Line and White Alice (plus flew the Barrier (WV-2) while in the USN, from Midway to Adak and return...non-stop). We used to keep AFRN on a speaker so we could tell if fading was beginning. The first time I heard the pop song "Vibrations" on AFRN, I nearly freaked...I *knew* my radios were going down, but didn't have a clue as to how or why....:) Norm B I didn't work on them, just used them for our military communications off Adak Island in the Aluetian chain of Alaska back in 70-72. One of the sand crabs (military term for a highly paid civilian) who worked there was a member of the ham club at the Naval Communications Station, and he arranged a "techie" tour for us, after all the security clearance paperwork exchanged hands. I was impressed by the dummy load cooled by some kind of antifreeze and pumps if my memory is correct. I was back on Adak in 84-86 and White Alice had been completely torn down and the old site was a popular "parking spot" for the local teen agers. Adak is in native Indian hands these days. 73 Doug K7ABX |
"MazingTree" wrote in
k: The one thing I would say here in the UK is that no-one in the Marine industry appears to let on that you can buy a cheap meter and test your own set. The best advice I got from UK electronics dealers, is that if you bring in the set, we can test it for £20, then if it's not the set, we come out and test it, but that was an opene ended price. I guess they have to make a living! I also suppose that's why I came to a newgroup. Same as here, but maybe we're a little more "enlightened", for some unknown reason. Just keep shipping those wonderful ales I love....thanks...(c; One thing I had to apologize for is TEA. There were two RAF pilots who had been guarding the skies over Charleston after 9/11 sitting in a restaurant I was in, drinking hot tea. I thanked them for what they were doing for us and profusely apologized for the terrible tea they were being forced to drink in our country. Had a great time talking to them after that.... |
Would that have been the AN/TRC-80? Shaw AFB used to have one setup across
the runway back in the 70s. BIG microwave dish, pointed at the horizon only a few feet off the ground. I used to tell the neighbors that thing was the reason their TV was always tore up.....NOT my ham radio station. I wasn't the one running MEGAWATTS in the neighborhood....(c; I've tried to post one to alt.binaries.pictures.sports.ocean but it's been kinda spotty of late... 73 DE W4CSC "Doug" wrote in k.net: I didn't work on them, just used them for our military communications off Adak Island in the Aluetian chain of Alaska back in 70-72. One of the sand crabs (military term for a highly paid civilian) who worked there was a member of the ham club at the Naval Communications Station, and he arranged a "techie" tour for us, after all the security clearance paperwork exchanged hands. I was impressed by the dummy load cooled by some kind of antifreeze and pumps if my memory is correct. I was back on Adak in 84-86 and White Alice had been completely torn down and the old site was a popular "parking spot" for the local teen agers. Adak is in native Indian hands these days. 73 Doug K7ABX |
In article et,
"Doug" wrote: "krj" wrote in message . .. Me wrote: In article , krj wrote: Used my VHF for a 1300 nm contact today. krj Can you say "Troposhperic Ducting", with a straight face??? Me Can you say satellite communications? krj Twenty years ago I used a 2 meter ham handheld running 1 watt to talk from Portland, OR to China...it was via repeaters in the pacific NW intertie and then commercial (Boeing Aviation?) satellite link from Seattle to China and back out on a ham repeater. I must admit it surprised me greatly at first, but then I figured out what was going on. Troposcatter? Ionized meteor trails? Tropoducting? Aurora bounce? All of the these can result in long distance VHF marine communications but none last for long or occur very often. Tropscatter should remind Bruce in AK of the old White Alice systems up there. 73 Doug K7ABX Yep, but those systems can't work today as the fequencies used then, are in the Cellular Band now. Can you imagine a 40Kw 20 Mhz wide cellular singals, with 90 Ft parabolic antennas on each end, and this was all before transistors. Bruce in alaska -- add a 2 before @ |
Larry W4CSC wrote:
"MazingTree" wrote in k: The one thing I would say here in the UK is that no-one in the Marine industry appears to let on that you can buy a cheap meter and test your own set. The best advice I got from UK electronics dealers, is that if you bring in the set, we can test it for £20, then if it's not the set, we come out and test it, but that was an opene ended price. I guess they have to make a living! I also suppose that's why I came to a newgroup. Same as here, but maybe we're a little more "enlightened", for some unknown reason. Just keep shipping those wonderful ales I love....thanks...(c; One thing I had to apologize for is TEA. There were two RAF pilots who had been guarding the skies over Charleston after 9/11 sitting in a restaurant I was in, drinking hot tea. I thanked them for what they were doing for us and profusely apologized for the terrible tea they were being forced to drink in our country. Had a great time talking to them after that.... Your teabags are great for scaring away the gulls. That bit of string is SO useful for hanging them from the boom. In the UK we think that tea bought in a teabag is usually sweepings from the blending room floor, but we still drink the stuff! Dennis. |
"Dennis Pogson" wrote in
: In the UK we think that tea bought in a teabag is usually sweepings from the blending room floor, but we still drink the stuff! Dennis. In Boston, we shoveled the good tea overboard.....remember?...(c; -- Larry You know you've had a rough night when you wake up and your outlined in chalk. |
I replaced the old antenna, which when looked at up the mast appeared to be
a quire weathered, and had some corrosion. The connector appeared very good though still, so I reckoned the cable would be OK still. The new antenna works much better and I even picked up Guernsey radio from Plymouth sound Breakwater, which has to be about 80 Miles! Not sure I would have been able to call them back mind!! Comms to friends this weekend has been what I would expect from a standard 25W VHF, so looks like it was the Antenna. Thanks for everyones help in this matter. John "MazingTree" wrote in message .uk... Many thanks for the comprehensive replies here, Checking them out now! I have also spotted something called and AV-40 Avair, which also looks like it might do the trick, and seems available over here. John "Larry W4CSC" wrote in message ... "MazingTree" wrote in .uk: Would have the URL for Waste Marine, I can't see this listed in Google? I wonder if you have a typo, it seems an odd name for a company selling marine equipment :-) Shakespeare manufactures marine antennas in the US. Go to Google and search for: Shakespeare ART-2 Antenna Radio Tester There are lots of dealers. I looked at Shakespeare's website and see they have a new model out, the ART-3, but have never seen one. The ART-2 has been out for many years. It's all you need. http://www.google.com/search?hl=en&q=Shakespeare+ART- 2+Antenna+Radio+Tester&btnG=Google+Search The PDF catalog is at: http://www.shakespeare-marine.com/catalog/fullline.pdf Click on "Radio Accessories" in the control panel of the Adobe Acrobat Reader. It's the 2nd unit down on the left. |
"MazingTree" wrote in
.uk: Thanks for everyones help in this matter. John Glad it's fixed, John. Sail safe. -- Larry You know you've had a rough night when you wake up and your outlined in chalk. |
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