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4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
I tried to find any specification throgh the local dealer, and he did
not even get an answer at Sea Ray in the States (neither yes nor no, essentially along the lines of we do not supply it so we do not know): I would like to have a 4'/22kg Radar antenna on a Sea Ray 315 Sundancer Sport Spoiler, Molded Fiberglass (Seamless) w/Overhead Lighting. Is this workable, as I do not seem to get an answer from SeaRay? Or is there a lower weight limit so I would have to forego the advantages of a big enough antenna? TIA Marc -- Switzerland/Europe http://www.heusser.com remove CHEERS and from MERCIAL to get valid e-mail |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
Marc Heusser alid
wrote in : I tried to find any specification throgh the local dealer, and he did not even get an answer at Sea Ray in the States (neither yes nor no, essentially along the lines of we do not supply it so we do not know): I would like to have a 4'/22kg Radar antenna on a Sea Ray 315 Sundancer Sport Spoiler, Molded Fiberglass (Seamless) w/Overhead Lighting. Is this workable, as I do not seem to get an answer from SeaRay? Or is there a lower weight limit so I would have to forego the advantages of a big enough antenna? TIA Marc Marc, let's take a look at reality on radar...... Radar cannot see further than the horizon. The horizon depends on how far UP the antenna is mounted. From your SR31, we're up just above the flybridge. How far can YOU see with binoculars...6 miles? 5? Check it out. If we had a 500KW military surface search radar on your arch, it could "see" targets 6 miles away....maybe 8 or 9 if they are TALL targets like lighthouses, radio towers, etc. So, what's the point? You're not as tall as a containership, who can use a more powerful radar. So, why waste money on HIS radar transceiver?? From up there, how about the 4KW radome? Loading on both the arch and your electrical system are lots less, also your wallet. 4KW has no trouble making a target at 8 miles. Ours is only 2KW on the sailboat, but we don't have it high up because if you put the antenna up high you CANNOT SEE THAT DAMNED BOUY YOU ARE ABOUT TO RUN OVER IN THE FOG because the high antenna is shooting right over the top of it. Ours is up 35' on the mizzenmast, probably higher than your arch. It can see the dock 3 slips away, plenty of return from that bouy in the fog. I know the big swinging radar horn impresses the other sailors and looks cool like you're an aircraft carrier....but why?....(c; Besides, you're not going 400 knots like a jet. If you can see targets 2 miles away you have MINUTES to turn away...not seconds. That's far enough for collision avoidance isn't it? Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
"Larry" wrote in message ... Marc Heusser alid wrote in : I tried to find any specification throgh the local dealer, and he did not even get an answer at Sea Ray in the States (neither yes nor no, essentially along the lines of we do not supply it so we do not know): I would like to have a 4'/22kg Radar antenna on a Sea Ray 315 Sundancer Sport Spoiler, Molded Fiberglass (Seamless) w/Overhead Lighting. Is this workable, as I do not seem to get an answer from SeaRay? Or is there a lower weight limit so I would have to forego the advantages of a big enough antenna? TIA Marc Marc, let's take a look at reality on radar...... Radar cannot see further than the horizon. The horizon depends on how far UP the antenna is mounted. From your SR31, we're up just above the flybridge. How far can YOU see with binoculars...6 miles? 5? Check it out. If we had a 500KW military surface search radar on your arch, it could "see" targets 6 miles away....maybe 8 or 9 if they are TALL targets like lighthouses, radio towers, etc. So, what's the point? snip.... Though you might not see targets farther, with a larger antenna you would have a better resolution, and that would be a good thing, don't you think? snip.... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
Harbin Osteen wrote:
"Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. You should have paid attention in school. Last time we were in Mexico, we spoke "schoolbook" Spanish for the first few days, and then managed to pick up on Mexican Spanish enough to feel at ease. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
In article ,
Larry wrote: .... Radar cannot see further than the horizon. The horizon depends on how far UP the antenna is mounted. I know - MSEE and lots of experience in this band in military service. I am more interested in the mechanics of SR arches than electronics. From your SR31, we're up just above the flybridge. How far can YOU see with binoculars...6 miles? 5? Check it out. If we had a 500KW military surface search radar on your arch, it could "see" targets 6 miles away....maybe 8 or 9 if they are TALL targets like lighthouses, radio towers, etc. So, what's the point? In a word: Resolution. A radome antenna has 4 to 6 degrees horizontal beam width, a 4' slot antenna less has 1.8 degrees. Makes all the difference in tight places like rivers. Like seeing one or two ships. Or a small ship or sea clutter. I would go as far as saying that horizontal resolution is the only specification to worry about. What has not been captured by the antenna is never going to show up on the display. You're not as tall as a containership, who can use a more powerful radar. So, why waste money on HIS radar transceiver?? From up there, how about the 4KW radome? Loading on both the arch and your electrical system are lots less, also your wallet. 4KW has no trouble making a target at 8 miles. I AM talking about 4 kW, no more. What did you expect? .... I know the big swinging radar horn impresses the other sailors and looks cool like you're an aircraft carrier....but why?....(c; I have no TV antenna, a 6" VHF antenna only, and no satellite dish compensated for the movements ... sorry, no need to impress. I'd rather be sailing anyway but it is not possible. Besides, you're not going 400 knots like a jet. If you can see targets 2 miles away you have MINUTES to turn away...not seconds. That's far enough for collision avoidance isn't it? As I said above: It's all about resolution. Like seeing a small boat without lights when going 25 knots in darkness. Do you know what the actual permissible mechanical load would be on my arch? TIA Marc -- Switzerland/Europe http://www.heusser.com remove CHEERS and from MERCIAL to get valid e-mail |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
"HK" wrote in message ... Harbin Osteen wrote: "Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. But you understand English.........right? My grandparents (both sides) learned English when they came over. They also came over legally, as did millions of other immigrants. Folks with your type of thinking have ruined America and the future quality of life for my children, grandchildren.........etc......... I feel sorry for them based on the world they will be living in. Thanks Harry. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
JimH wrote:
"HK" wrote in message ... Harbin Osteen wrote: "Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. But you understand English.........right? My grandparents (both sides) learned English when they came over. They also came over legally, as did millions of other immigrants. Folks with your type of thinking have ruined America and the future quality of life for my children, grandchildren.........etc......... I feel sorry for them based on the world they will be living in. Thanks Harry. I've been visiting Florida for decades, starting in the 1960s. The first time we went to Miami, I practiced my high school Spanish down there. People speaking Spanish is nothing new. There are just more folks doing that now. When we lived in Florida, and it was North Florida, we spoke English and Spanish, and English mixed with Spanish. Americans are intellectually lazy. An awful lot of those born here with "anglo" parents can barely speak or write plain high-school level English. No wonder they can't pick up a little Spanish, eh? Your boy Bush has done nothing to close the leakage at the borders for the past seven years. He's your boy...why isn't he doing what you want? |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
"Harbin Osteen" wrote in
: Though you might not see targets farther, with a larger antenna you would have a better resolution, and that would be a good thing, don't you think? That is true. If you have a huge antenna, you can see whether it's one ship or 8 ships close together. That might be important for missile launching, but does it really matter in a boat? INstead of 3 tiny targets on the tiny screen...you get one big blob you can't miss on the cheap antenna. Too much resolution isn't a good thing on a small boat whos antenna is rolling and pitching so awful in the swells. Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
"HK" wrote in message ... JimH wrote: "HK" wrote in message ... Harbin Osteen wrote: "Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. But you understand English.........right? My grandparents (both sides) learned English when they came over. They also came over legally, as did millions of other immigrants. Folks with your type of thinking have ruined America and the future quality of life for my children, grandchildren.........etc......... I feel sorry for them based on the world they will be living in. Thanks Harry. I've been visiting Florida for decades, starting in the 1960s. The first time we went to Miami, I practiced my high school Spanish down there. People speaking Spanish is nothing new. There are just more folks doing that now. When we lived in Florida, and it was North Florida, we spoke English and Spanish, and English mixed with Spanish. Americans are intellectually lazy Ahh.....so Americans need to learn Spanish...eh? Like I said in another thread, you continue to amaze me. ;-) |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
Marc Heusser alid
wrote in : In a word: Resolution. A radome antenna has 4 to 6 degrees horizontal beam width, a 4' slot antenna less has 1.8 degrees. Makes all the difference in tight places like rivers. Like seeing one or two ships. Or a small ship or sea clutter. I would go as far as saying that horizontal resolution is the only specification to worry about. What has not been captured by the antenna is never going to show up on the display. Ok, let's talk about the low vs high resolution antennas.... Low is simple, it has a huge beamwidth, relatively speaking. When the boat is rolled over and the antenna towards the target is pointing, mostly, into the sea, its wide vertical antenna pattern is more likely to see "something" out 4 miles on this rotation. Because the target is "in the beam" for a much longer length of time, as the beam rotates around during this rolling/pitching motion of the boat, the receiver is more likely to see the target for that brief instant the antenna isn't pointed at the moon or Davy Jones' Locker, than it would be if the beam were "really narrow" where, even if the antenna were mounted on a oil rig and not pitching and rolling on a Sea Ray...31' or not. Every rotation of a really narrow beam antenna only leaves the target illuminated with RF and looking through that really narrow "slot" with the receiver for a much shorter instance. Try it. Touch your middle finger to your thumb making a big hole to look through. Stand rigid on the rolling/pitching deck without trying to keep your "sight" on the "target" way off in your vision. The target shows up in the big hole all the time you're looking through it....and would return our radar RF to the receiver looking through that hole so we'd get a return on the screen. Now, roll your forefinger up as tight as you can in the crook of your thumb, making a small hole to simulate looking at the same target through this massive, high resolution, antenna array. Point this hole at the target, but stand rigid not trying to follow the target around with the pitching and rolling of the boat. You can hardly see the target any more as it rolls in and out of the hole. The only time the receiver will see the target is when its rotating by the target synchronizes with the boat being somewhat level, which happens less and less often as the hole gets smaller. Actually, the hole, the window the radar looks through is a narrow vertical slot, narrow horizontally but, we hope with all that rolling/pitching, WIDE vertically. But, you get the idea of what I'm talking about. Another low vs high phenomenon that's pretty easy to grasp is in waves and troughs. The low-res antenna, the big hole, paints the target far longer than the high-res, narrow beam antenna. Being wide, it has a far better chance of seeing "something" if the waves are high because it paints the target LONGER on each rotation. The very short painting the high res big antenna does, has less chance of seeing the target around the coincidental wave. All this is why surface search radars on big ships, even Navy/CG ships, is a relatively small, large aperture antenna, not some huge, high-gain array with really high resolution....which is the targeting antenna for the missiles/gunnery. There's still that CLOSE IN target, the one you are about to run over.... It's ALWAYS much better to paint all the targets in that 1/8th mile range, no matter whether it's the return from a 40hp Yamaha outboard, the only radar reflector on his plastic fishing boat, or the little nun bouys in the channel. The CLOSE IN targets really need to make a blob in the rainstorm and fog....to hell with containerships 12 miles away. That's why it's VERY important to keep the antenna LOW, not shooting over the targets just so you can see that containership and brag about it to "her". Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
JimH wrote:
"HK" wrote in message ... JimH wrote: "HK" wrote in message ... Harbin Osteen wrote: "Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. But you understand English.........right? My grandparents (both sides) learned English when they came over. They also came over legally, as did millions of other immigrants. Folks with your type of thinking have ruined America and the future quality of life for my children, grandchildren.........etc......... I feel sorry for them based on the world they will be living in. Thanks Harry. I've been visiting Florida for decades, starting in the 1960s. The first time we went to Miami, I practiced my high school Spanish down there. People speaking Spanish is nothing new. There are just more folks doing that now. When we lived in Florida, and it was North Florida, we spoke English and Spanish, and English mixed with Spanish. Americans are intellectually lazy Ahh.....so Americans need to learn Spanish...eh? Like I said in another thread, you continue to amaze me. ;-) Why not? Americans should learn English and one other language in public school. We'd be in much better shape as a nation if more "anglo" Americans spoke Spanish, Arabic, Korean, Chinese, whatever. But of course millions of "anglo" Americans can barely speak English. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
"HK" wrote in message . .. JimH wrote: "HK" wrote in message ... JimH wrote: "HK" wrote in message ... Harbin Osteen wrote: "Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. But you understand English.........right? My grandparents (both sides) learned English when they came over. They also came over legally, as did millions of other immigrants. Folks with your type of thinking have ruined America and the future quality of life for my children, grandchildren.........etc......... I feel sorry for them based on the world they will be living in. Thanks Harry. I've been visiting Florida for decades, starting in the 1960s. The first time we went to Miami, I practiced my high school Spanish down there. People speaking Spanish is nothing new. There are just more folks doing that now. When we lived in Florida, and it was North Florida, we spoke English and Spanish, and English mixed with Spanish. Americans are intellectually lazy Ahh.....so Americans need to learn Spanish...eh? Like I said in another thread, you continue to amaze me. ;-) Why not? Shakes head in disbelief You and your ilk are indeed the reason this Country are going down the tubes. Nice going Harry. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
HK wrote:
Harbin Osteen wrote: "Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. You should have paid attention in school. Last time we were in Mexico, we spoke "schoolbook" Spanish for the first few days, and then managed to pick up on Mexican Spanish enough to feel at ease. What's your point? Your response has nothing to do with the sig. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
HK wrote:
JimH wrote: "HK" wrote in message ... JimH wrote: "HK" wrote in message ... Harbin Osteen wrote: "Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. But you understand English.........right? My grandparents (both sides) learned English when they came over. They also came over legally, as did millions of other immigrants. Folks with your type of thinking have ruined America and the future quality of life for my children, grandchildren.........etc......... I feel sorry for them based on the world they will be living in. Thanks Harry. I've been visiting Florida for decades, starting in the 1960s. The first time we went to Miami, I practiced my high school Spanish down there. People speaking Spanish is nothing new. There are just more folks doing that now. When we lived in Florida, and it was North Florida, we spoke English and Spanish, and English mixed with Spanish. Americans are intellectually lazy Ahh.....so Americans need to learn Spanish...eh? Like I said in another thread, you continue to amaze me. ;-) Why not? Americans should learn English and one other language in public school. We'd be in much better shape as a nation if more "anglo" Americans spoke Spanish, Arabic, Korean, Chinese, whatever. But of course millions of "anglo" Americans can barely speak English. And here are two unrelated issues melted into one by Harry "fake lobsterboat" Krause of Ullico fame. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
Harbin Osteen wrote:
Though you might not see targets farther, with a larger antenna you would have a better resolution, and that would be a good thing, don't you think? Basically it boils down to: The higher the frequency of the beam, the higher the frequency of the PRF (Pulse Repetition Frequency) and the shorter your pulse length the better your resolution. Antenna size only affects the signal strength the receiver sees, for the most part. Which is assuming it's built for the proper frequency. I was on an ancient AD (Destroyer Tender, built during WWII, USS Arcadia) and had a helluva discussion with a WO who was doing the CIC thing when we entered the Chesapeake Bay and why the old radar wouldn't enable me to determine where the bogey I was tracking went into and out of a glob of traffic. Also he was sure I should be able to pickup dolphins since the radar beam went over the edge of the ship, made a 90 degree down angle turn, another 90 degree angle turn at the surface, and shot out over the surface. To was repeated for the echo. This on a ship where the repeater would drop out because the AC volts supplied dropped below 90. Bill, who was a ETN2 in the old days and has forgotten most of this kind of stuff. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
On Tue, 17 Jul 2007 16:51:11 -0800, Steve Thrasher
wrote: ..... Basically it boils down to: The higher the frequency of the beam, the higher the frequency of the PRF (Pulse Repetition Frequency) and the shorter your pulse length the better your resolution. Antenna size only affects the signal strength the receiver sees, for the most part. Which is assuming it's built for the proper frequency. .... Bill, who was a ETN2 in the old days and has forgotten most of this kind of stuff. Hmmm...not quite. Here's another try: The higher the frequency, the smaller the antenna needed to shape the beam. A wider antenna gives a narrower horizontal beam. Pulse repetition frequency limits max range but helps angular depiction on a plan position indicator. Narrow transmit pulse helps resolution, hinders max range. Bigger antenna aperture increases max receive range. Your turn! :-) Brian W |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
Steve Thrasher wrote in news:469d6401$1
@news.acsalaska.net: Basically it boils down to: The higher the frequency of the beam, the higher the frequency of the PRF (Pulse Repetition Frequency) and the shorter your pulse length the better your resolution. Antenna size only affects the signal strength the receiver sees, for the most part. Which is assuming it's built for the proper frequency. What you say IS true when trying to differentiate targets IN LINE with the radar beam. However, it is the resolution caused by BEAM WIDTH that allows you to differentiate targets PARALLEL to the sweep of the beam. Let's look at two obviously extreme cases......on two antennas. Antenna 1 has a horizontal beamwidth of 25 degrees, rediculously wide. There are 3 ships visible traveling a course sort of parallel to ours but only 100 yard apart following each other about 5 miles away. They're travelling in our direction and to starboard of us. Our antenna rotates clockwise, painting the front ship first. As the wide beam starts bouncing off the front ship, a return shows at the 5 mile range ring on the first sweep. But, due to the rediculously wide beam of our wide antenna, the beam starts bouncing off the 2nd ship long before it has stopped bouncing off the first ship, so the radar display now shows a single long target, not two ships. Because the wide beam is now painting the stern trailing ship behind ship 2, ship 3, long before the beam stops bouncing off ship 2, even though it has stopped bouncing off ship 1, the display shows one LONG ship....not 3 small ships traveling one behind the other in single file. No matter what the PRF or pulse width or frequency of the RF, it will show as one ship unless we can stop painting ship 1 before it paints ship 2 and stop painting ship 2 before it paints ship 3. Pulse width will make the long blob narrower, the narrower the pulse, but no pulse, no matter how narrow, will cure this resolution problem EXCEPT a very narrow, focused beam with very little to no side lobes. Side lobes painting the ships MUST return signals BELOW the radar receiver's sensitivity setting or the original problem returns. Way too many radar operators NEVER turn down receiver sensitivity enough to see there are 3 ships, not one, maybe until the blob on the screen becomes really rediculously long. They always operate sensitivity up to the sea return threshold. Antenna 2 has a 1 degree beamwidth from its much better design, which, unfortunately, makes it HUGE in comparison. That's why the big radar antennas are SO WIDE spinning around atop the big ships. The wider the slot or reflector, the narrower their beamwidth horizontally, where it counts. This antenna starts painting ship 1, comes to the stern and stops painting ship 1 a few milliseconds before it starts painting ship 2. It will show up the 3 ships as 3 ships, not one big blob, because of its horizontal beamwidth, which has nothing to do with PRF, pulse width or RF frequency. But, do pleasure boats need to see 3 distinct targets at 5 miles? We're not going to target ship 2 for the potato gun, are we? We only need to see there's something out there and which way it's moving in relation to our collision course with it. The watch will see it's 3 ships without spending another $8000 on a big, wide open antenna array that makes the boat rock with its mass and momentum....overkill. Doesn't that make better sense? Larry -- AN/SPS-21, the old Raytheon Pathfinder. Sensitivity was awful. When I pulled the waveguide off her, it FLUSHED! FLOODING THE DECK! Leaky joints aloft....(c; The bottom joint needed a drain!...hee hee. Nothing's more fun than 4 guys lifting the antenna off the rotary joint in the middle of the Atlantic so the 5th guy can CHANGE THE DAMNED V- BELT, which broke in the storm! I got the T-shirt! |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
Steve Thrasher wrote in news:469d6401$1
@news.acsalaska.net: I was on an ancient AD (Destroyer Tender, built during WWII, USS Arcadia) and had a helluva discussion with a WO who was doing the CIC thing when we entered the Chesapeake Bay and why the old radar wouldn't enable me to determine where the bogey I was tracking went into and out of a glob of traffic. Also he was sure I should be able to pickup dolphins since the radar beam went over the edge of the ship, made a 90 degree down angle turn, another 90 degree angle turn at the surface, and shot out over the surface. To was repeated for the echo. This on a ship where the repeater would drop out because the AC volts supplied dropped below 90. Bill, who was a ETN2 in the old days and has forgotten most of this kind of stuff. Hi, Bill! Nice to meet another tender sailor! Yours would have been an SPS-21 Pathfinder, too! We also had AN/SPS-6 air search until Navy got tired of paying to fix it and we turned its nice gyro mount into a fantastic TV antenna rotator. Larry ET1 (ET-1598 Cal Tech) USS Everglades (AD-24) Started in WW2 but not completed until 1952 for Korean War. I was aboard her from 1966-1969 Pier Papa, Charleston. Two Med cruises, Cruises to JAX to do Yellowstone's work for them. Radio 2 had TBK, TBL, TCS, RBA, RBB, RBO....all mine. Callsign was Glitter Delta or my ham call at the time WB4THE/MM2 running phone patch traffic for the crew to K4OKD back home. KW7, KW37, AN/URC-32, R-390A....real comm equipment of the day. Can you still hear the 37 beeping taking hits?....(c; |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
In article ,
Steve Thrasher wrote: Basically it boils down to: The higher the frequency of the beam, the higher the frequency of the PRF (Pulse Repetition Frequency) and the shorter your pulse length the better your resolution. Antenna size only affects the signal strength the receiver sees, for the most part. Which is assuming it's built for the proper frequency. Bzzzt, Wrong answer, would you like to try again for what is behind Door #2?????? It is a good thing you have all that Military Experiencee, but it really doesn't translate into Commercial Marine Radar Experience. These two senerios are Apples and Oranges, as they use similar Technology, but are doing Totally Different Jobs andd providing Totally Different Data to the Operator. In Commercial Marine Radars the Antenna Horozontal and Vertical Beamwidth ARE very significant factors in the Resolution of Targets on the PPI type displays used. These two Specs set the Basic Operating ability of the system to differrentiate between targets, at the same distance, but sperated by small Azimuth Angles. The PRR (Pulse Repetition Rate) sets the Maximum Range, along with Pulse Length, and in Commercial Marine Radar is usually Fixed in two or three settings, determined by the Range Switch Setting. The "Frequency of the Beam" in Commecrial Marine Radars is FIXED, by the Spec'd Magnitron and in the USA, only Xband and SBand, are Licensable under CFR 47 Part 80. Since Sband Radars are very LARGE, you only find them on Vessels, usually over 1600 Tons or bigger, with 95% of the Commercial Marine Radars opeerating at 10Ghz in the XBand. If one wants to discuss the relative merits of PPR, PL, as opposed to Antenna Gain, Vertical and Horozontal Beamwidths in the designing of Commercial Marine Radars, Great, but 99% of the folks reading these posts, don't understand the language, and don't have a clue about the concepts used in the design of the Equipment that they buy, and install on their Vessels. They just look at, if the Radar shows them what's out around them, and hope they aren't missing something coming their way. Bruce in alaska a Longtime Marine RadioMan, but now just an Old Fart...... -- add a 2 before @ |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
I did not write this.
-- SeeYaa:) Harbin Osteen KG6URO When American Citizens with dual citizenship pledges allegiance to the flag, to which flag do they pledge allegiance too? This is YOUR Futu http://www.youtube.com/watch?v=n7WJeqxuOfQ - "HK" wrote in message ... Harbin Osteen wrote: "Larry" wrote in message ... Larry -- While in Mexico, I didn't have to press 1 for Spanish. While in Iran, I didn't have to press 1 for Farsi, either. While in Florida, I had to press 2 for English. It just isn't fair. Poor baby. Some of us speak and read more than one language. You should have paid attention in school. Last time we were in Mexico, we spoke "schoolbook" Spanish for the first few days, and then managed to pick up on Mexican Spanish enough to feel at ease. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
Bruce in Alaska wrote:
Bzzzt, Wrong answer, would you like to try again for what is behind Door #2?????? Sure lots of things were wrong, I did say I'd forgotten most of this stuff. :-) Probably for good reason I might add, didn't put any beans on my table. But, the answer to what was being bandied about sort of boils down to why the dish used for satellite service in Florida is a different size than the one used in Alaska, ignoring all the boring stuff about pitch/yaw and things like that. |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
|
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch - ok
In article ,
Marc Heusser alid wrote: I tried to find any specification throgh the local dealer, and he did not even get an answer at Sea Ray in the States (neither yes nor no, essentially along the lines of we do not supply it so we do not know): I would like to have a 4'/22kg Radar antenna on a Sea Ray 315 Sundancer Sport Spoiler, Molded Fiberglass (Seamless) w/Overhead Lighting. OP he I finally got an answer from SeaRay (my dealer asked a technician there, so orally only, not in writing): Yes, it should be ok to mount 22kg on the Spoiler. Thanks for all your info on radars :-) Marc -- Switzerland/Europe http://www.heusser.com remove CHEERS and from MERCIAL to get valid e-mail |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
My son in law has a Sea Ray 36... He has a 4 foot rotating bar antenna
on his arch.. No problems I am aware of... denny |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch - ok
On Thu, 19 Jul 2007 11:47:10 +0200, Marc Heusser
alid wrote: Yes, it should be ok to mount 22kg on the Spoiler. Just as an FYI, on a boat it is known as a "radar arch". |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
In article . com,
Denny wrote: My son in law has a Sea Ray 36... He has a 4 foot rotating bar antenna on his arch.. No problems I am aware of... denny Thank you - good to know. Marc -- Switzerland/Europe http://www.heusser.com remove CHEERS and from MERCIAL to get valid e-mail |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch?
In article ,
Larry wrote: Bruce in Alaska wrote in news:bruceg- : Bruce in alaska a Longtime Marine RadioMan, but now just an Old Fart...... - Bruce's radar still operates on a bedspring antenna on VHF....(c; Now THAT's OLD! Larry I actually DID work on one of those VHF Radars, as very young tech. It was at a Military Museum, and I replaced the Dynamotor that suppiled the HV for the Transmitter. I got the Dynamotor from a unit that was "Scrapped in Place" half way up the Mountain at Alitak, Alaska on the southern tip of Kodiak Island. It was installed during WWII, to do Sea Search for the Japanese Navy approching Kodiak Island. I was able to lug the Dynamotor, down off the mountain, on one of my trips to the top, to service a Remote Base Marine VHF site I had installed at the summit. It is amazing how far 25 Watts of VHF will go when the Antenna is at 3500 Ft. That Site was designed to work a Tropo Path, 235 Miles long, to an associated Salmon Processor at Chignik, Alaska. Really worked good most of the summer, untill a weather front would come thru and dissrupt the Temprature Inversion Layer between the two locations. Then it would go out, and it took a couple of days, to rebuild the Inversion Layer, before the path would return. Now days, it is all done by SatPhones, and Cellular. Oh well, MF/HF is just about DEAD, as well, in the Maritime Community. Good thing I am reTIRED..... Bruce in alaska -- add a 2 before @ |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch - ok
In article ,
Wayne.B wrote: On Thu, 19 Jul 2007 11:47:10 +0200, Marc Heusser alid wrote: Yes, it should be ok to mount 22kg on the Spoiler. Just as an FYI, on a boat it is known as a "radar arch". That is what I thought too - Sea Ray calls them Sport Spoiler ;-) Marc -- Switzerland/Europe http://www.heusser.com remove CHEERS and from MERCIAL to get valid e-mail |
4'/22kg Radar Antenna on Sea Ray 315 Sundancer Arch - ok
On Fri, 20 Jul 2007 21:02:29 +0200, Marc Heusser
alid wrote: That is what I thought too - Sea Ray calls them Sport Spoiler ;-) That's some marketing jerk that barely knows which end goes forward. |
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