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#11
posted to rec.boats.cruising,rec.boats,rec.boats.electronics
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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. |
#12
posted to rec.boats.cruising,rec.boats,rec.boats.electronics
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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. |
#13
posted to rec.boats.cruising,rec.boats,rec.boats.electronics
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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. |
#14
posted to rec.boats.cruising,rec.boats,rec.boats.electronics
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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. |
#15
posted to rec.boats.cruising
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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. |
#16
posted to rec.boats.cruising
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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 |
#17
posted to rec.boats.cruising
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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! |
#18
posted to rec.boats.cruising
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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; |
#19
posted to rec.boats.cruising
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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 @ |
#20
posted to rec.boats.cruising,rec.boats,rec.boats.electronics
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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. |
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