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#31
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See my comment to Larry, above -- triple expansion steam is great.
Both of us are machinery nuts -- Dee talks her way onto all sorts of vessels just to see the engine room. We looked at a lot of tugboats in our search for Fintry, and saw a lot of wonderful machines. Finally concluded, though, that tugboats were all engine room and no space for anything else. Who needs 2,000hp in an 80' displacement hull unless you're going to tow something. Otherwise it's just a mechanism for converting diesel into bow wave. -- Jim Woodward www.mvFintry.com .. "Glenn Ashmore" wrote in message news:9esrb.12620$62.6334@lakeread04... I think the Cat is the wrong direction for your personality. I sense that you are a gadget freak like me. Here is the repower option for certain engine nervana. :-) http://www.thesandpebbles.com/san_pa...blo_engine.htm Jim Woodward wrote: Thanks. As I say on site, the Lister is a real conundrum. I love the thing. It will run forever, even on three cylinders. Absolutely rock solid dependable. It has three ways of cooling (three pumps have to fail to shut it down) and two ways of providing lube oil pressure, can run either wet or dry sump. It has a nice sound. It has temp gauges on every cylinder -- full instrumentation both below and in the wheelhouse. I have an exhaust valve sitting on my desk -- 3.5" diameter x 10" tall. It's a wonder. To start it, you go down in the engine room, turn on the lube oil (remote dry sump), the seawater main, and the 24v to the starter, spin a wheel on the front to decompress, bar the flywheel over a couple of times to make sure everything's free, and push a button on the "Motormatic" box. Relays start clicking, the prelube pump (24v) starts, and oil pressure comes up. When oil pressure hits 50psi, the starter engages. After a quarter turn or so, you spin off the decompress and it starts. The prelube pump stops. You turn off the 24v to the starter and let it warm up for a few minutes. You can shut it down from the wheelhouse, but you have to go down and shut off the lube oil. Now, this is a wonderful sequence, particularly the Motormatic (in this age of computer everything), but can you imagine trying to sell it as a yacht over here in fifteen years? It has a number of little open catch basins for fuel that leaks off. It's hard mounted to huge engine beds, so the whole boat vibrates when it's running -- four huge pistons, and while you can practically count the strokes, they're very present. The official RN manual says that you shouldn't run the boat between 7.5 and 10 knots, only faster or slower (top is 10.3), because of various resonances. Parts are beginning to be a problem (new starter $4,000). And, as also shown graphically on the site, it's huge (see http://www.mvfintry.com/pix/erplan800.png) -- the Cat 3406 is no little thing, but look at the difference. While the engine room is 20 feet square, I've got a lot to go in it and removing the Lister helps. And so forth. I'm sad, though. I'll miss it, except when trying to sleep. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#32
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Jim,
Wow, what a vessel! Our strategy for these size vessels (and this has only been tested in the lab so I consider it to be pre-beta) is that our wireless navigation servers can be connected together via ethernet cable to get through bulkheads that a wireless signal will not travel. In fact you can connect some of the NMEA devices to 1 wireless nav server and others to the 2nd wireless nav server and any wireless client that connects to either nav server get's all of the nmea data. It remains to be seen how many people will actually want something like this though. For larger vessels where 802.11 signal range presents an issue, we are planning to add wireless mesh networking to the navigation server so you won't need to run any wires to extend the range. This is another configuration that we're working on but will probably only have practical applications in the commercial shipping space or on very large yachts. Cheers, Todd -- Marine Wireless http://www.marinewireless.us "Jim Woodward" jameslwoodward at attbi dot com wrote in message ... Larry and Todd: It's not quite so simple -- take a look at http://www.mvfintry.com/pix/portland800.jpg. There are two w/t compartments on the main deck and six below, all possibly with data, as well as tanks. The wheelhouse can also be separated by a w/t door. (Remember that in The Perfect Storm movie, Andrea Gail flooded from the wheelhouse. What really happened, we'll never know.) Maybe you guys are right -- that wireless would work fine -- certainly there are a lot of openings in the bulkheads, although they're all small (2" tops) and sealed with intumescent caulk to keep fire and flood in one place if they happen -- AC, DC, H&C potable water, sal****er fire main, black and gray water, compressed air, diesel, and all the information wires. Question then, given that running wire is really easy, because we'll have the conduit for phone, burglar, fire alarm, audio, etc. anyway (sure, maybe all of these can be wireless also, but there are some security issues, etc.), am I better off with wired or wireless? If Larry's right and 802.11 will really reject everything that it might meet, is it a more robust installation to go wireless? This assumes that all of the primary stuff on the bridge is wired -- we're talking about personal computers (in the broader sense of the words) and a couple of non-critical remote readouts here. None of this will go in until we get her on this side of the pond next summer (God willing). I'd be delighted to try it sometime after then.... -- Jim Woodward www.mvFintry.com |
#33
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On Sun, 9 Nov 2003 10:23:23 -0500, "Jim Woodward" jameslwoodward at
attbi dot com wrote: If you ever get a chance, go aboard one of the Liberty ships, or any of the old triple expansion steamers -- the third cylinder is enormous..... If you ever get to England, go look at some of the fantastic triple expansion steam engines in museums still working. There are many of them with big webpages to whet your appetite. Simply amazing engines. I've been in the John Brown's engine room. It came to Charleston and I took the tour to support it. She was booked up on the trip up the Cooper, so I trailed her in my jetboat.... Larry W4CSC "Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!" |
#34
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On Sun, 9 Nov 2003 10:31:21 -0500, "Jim Woodward" jameslwoodward at
attbi dot com wrote: Who needs 2,000hp in an 80' displacement hull unless you're going to tow something. Otherwise it's just a mechanism for converting diesel into bow wave. I think the same thing every time I see a pleasure trawler with over 125hp or twin engines. What are they going to do, plow up the bottom? We see Super Nordic Tugs on the ICW plowing their way to Florida on their big twin diesels using enormous quantities of diesel as they plow their way through Charleston. Doesn't look like they're any faster than the ones burning far less fuel from a 120 Lehman at a liesurely pace.... How silly. If they're in a hurry, there are jet planes!...... Larry W4CSC "Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!" |
#35
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"Larry W4CSC" wrote in message
... On Sun, 9 Nov 2003 10:08:42 +0100, "Meindert Sprang" wrote: That is nonsense. It all depends on proper PCB design. I HAVE measured it, for crying out loud! Gee, the manufacturers that HAVE to pass FCC specs on radiation don't know that. They spend lots of money coating cases, using metal cabinets, and other shielding. You should go into consulting. Organ manufacturers would love to put out digital organs and keyboards without having to coat the whole thing in tin foil and expensive shielded boxes with foil shielded data lines to pass the FCC tests. Of course it all depends on the application. Certain areas just need complete shielding where extremely low limits are required. All I am saying is that to get something like NMEA equipment quiet and unsusceptible to HF and VHF at reasonable levels like specified in IEC and FCC standards applicable to that kind of equipment, it is not necessary to have everything shielded. And I believe a lot of equipment present on the market prove this statement. And judging from your previous posts here in this group, the interference problems you have had are caused by certain NMEA equipment that is definately not FCC approved. Check the multiplexer and expander you so much prefer: no FCC approval and well known to produce interference. Whoa, sport! Your attack on me was about 4800 baud NMEA and it RADIATES LIKE HELL into the HF on every boat I know of because of the way you manufacturers treat the interconnects, dangling the 4800 baud pulses out there in unshielded space. Quit sidestepping the issue. I am not sidestepping the issue. I just happen to have good experience with NMEA, without any interference on HF. Unshielded 4800 baud data has no place around a submicrovolt HF receiver within a few feet of its receiving antenna.... Like I said befo with properly filtered outputs, which is just mandatory if you want to get something through the IEC of FCC tests, there will be no problem. I mean, it is stupid to have NMEA drivers capable of running at 10Mbaud if you only have to drive 4800 baud. So with the properly dimensioned drivers and RC networks, the slew-rate of the output datasignal is brought back so such a low figure, that there are no significant harmonics present over a few 100 kHz. AS with consumer electronics, until the regulators step in to force the manufacturers to conform to some sort of radiation standard, nothing will change. I don't understand what your implying here. Navigation electronics without specific IEC945 approval falls in the same category as consumer electronics and is therefore subject to the same EMC limits. So there ARE regulations enforced. But we seem to keep on disagreeing on this subject. So lets end this discussion. Best, Meindert |
#36
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On Sun, 9 Nov 2003 23:25:24 +0100, "Meindert Sprang"
wrote: And judging from your previous posts here in this group, the interference problems you have had are caused by certain NMEA equipment that is definately not FCC approved. Check the multiplexer and expander you so much prefer: no FCC approval and well known to produce interference. I was waiting for this. I've bypass the Noland and it still tears up MF-HF. If I run just the Garmin and nothing else you can hear it. Any one of the instruments in the boat radiates into the Icom M802 quite badly. The more you turn on, the more noise there is..... Oh, yeah, the Noland, too!....(c; Larry W4CSC "Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!" |
#37
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"Larry W4CSC" wrote in message
... On Sun, 9 Nov 2003 23:25:24 +0100, "Meindert Sprang" wrote: And judging from your previous posts here in this group, the interference problems you have had are caused by certain NMEA equipment that is definately not FCC approved. Check the multiplexer and expander you so much prefer: no FCC approval and well known to produce interference. I was waiting for this. I've bypass the Noland and it still tears up MF-HF. If I run just the Garmin and nothing else you can hear it. Any one of the instruments in the boat radiates into the Icom M802 quite badly. The more you turn on, the more noise there is..... Any chance of using ferrite ringcores on the NMEA lines to surpress it ? Meindert |
#38
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On Mon, 10 Nov 2003 07:56:03 +0100, "Meindert Sprang"
wrote: Any chance of using ferrite ringcores on the NMEA lines to surpress it ? Meindert Not as long as the unbalanced lines are all exposed like they are. Every cable from every instrument uses a Belden foil-shielded pair. But the radiation is going to happen, anyway, because the output of some of the instruments is unbalanced, inserting a radiating ground inside the faraday shield. Most instruments, you have to abandon the shield (screen connection for you UK readers) at the point where the instrument's unshielded power cable with its dangling data lead hangs out. There's no way to complete the shielding to the instrument. Maybe Icom is right. Make all the NMEA connections via a coax connector, unbalanced. M802 uses a BNC, in total abandonment of any NMEA balanced concept. The shield of the coax to that BNC MUST be connected to NMEA B (-) to get data on the radio's DSC display. So, I figured RF from the transmitter's case follows this odd ground down into the network shield and screws it all up. But that didn't pan out because the network does the same thing with the cable to the Icom disconnected. Lucky for me that during short SSB transmissions, the system components just ignore the trashed data, so the users don't see there's no NMEA data for the 20 seconds the SSB is talking. I think this is the reason more people don't mention or notice it. The displays just freeze until you stop talking or take a breath when the SSB output power drops to a very low level and data stream resumes. Oddly enough, I don't notice this malady on the Seatalk unbalanced, unshielded part of the system. This may be because its cables are much shorter and all the Seatalk instruments are very close together. (RL70CRC Plus, Smart Heading Sensor, WAAS-GPS). Even the GPS receiver built into its antenna has a very short cable because I found a great little unused place right on top of the helm to port of the crank handle for the main sheet traveler to put both Garmin and Raymarine GPS antennas. Coverage through the fiberglass hardtop on the cockpit is excellent and noone uses the antenna for a grabhandle like they did when the antennas were initially on top of the hardtop. It's cable to the Seatalk plastic box with European screw terminals is only about 10" long. None of the Seatalk wires are over 24", making them much too short to fit an 8 Mhz wavelength. Seatalk radiates, too, even on these short cables. If I shut down the whole NMEA network and just run the RL70CRC Plus, WAAS-GPS and Smart Heading Sensor with the NMEA cables unplugged from the RL70, I can still hear data noise from the Seatalk across the HF bands. Someone knows about this because none of the Seatalk harmonics is on a marine HF channel. I only have a few in the ham bands. It's just too bad there isn't a STANDARD everyone was FORCED to follow that would completely eliminate this easily-fixed interference. USB and RS-232C and RS-422 running at home don't tear up my ham station sitting right next to the computer. I just can't believe marine electronics cannot be built for these lofty prices that doesn't interfere, either. Ferrites won't stop the plastic boxes and unshielded cables with square waves in them from radiating unless you rounded off the edges, which would trash the data timing. The computers in the plastic boxes also radiate. Doesn't take much to trash a submicrovolt receiver and open its squelch. We used to have an Adler-Barbour 12V electronic-controlled cold plate that just ATE, of all frequencies, Channel 16 with its incessant pulsing, opening the squelch of all the VHF receivers with a maddeningly repetitive pulsing shuusssh of the closing squelch.....It only trashed 16, the channel you listen to most. Drove all the helmsmen crazy until we figured out what it was and shut it down. It's someone else's problem now. This fridge runs off a 1-cyl engine compressor. Larry W4CSC "Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!" |
#39
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"Larry W4CSC" wrote in message
... On Mon, 10 Nov 2003 07:56:03 +0100, "Meindert Sprang" wrote: Any chance of using ferrite ringcores on the NMEA lines to surpress it ? Meindert Not as long as the unbalanced lines are all exposed like they are. Every cable from every instrument uses a Belden foil-shielded pair. But the radiation is going to happen, anyway, because the output of some of the instruments is unbalanced, inserting a radiating ground inside the faraday shield. Most instruments, you have to abandon the shield (screen connection for you UK readers) at the point where the instrument's unshielded power cable with its dangling data lead hangs out. There's no way to complete the shielding to the instrument. But you only connect the shielding on the transmitting side of the cable, right? Never connect shielding on both sides unless it is part of the data connection. It is always better to have signal and return in a pair, shielded by a screen that is connected on the TX side. Maybe Icom is right. Make all the NMEA connections via a coax connector, unbalanced. M802 uses a BNC, in total abandonment of any NMEA balanced concept. The shield of the coax to that BNC MUST be connected to NMEA B (-) to get data on the radio's DSC display. Hold on! That cannot be right. If the NMEA source you connect to the M802 has a NMEA A (+) and a NMEA B (-) line, it is a balanced output where both wires are 'live'. If you connect that to the BNC of the M802, which is unbalanced (BNC is grounded), you'll effectively short circuit the NMEA B to ground. In such a case, you only connect the NMEA A to the input and the ground of the NMEA talker to the ground of the listener. you should leave the NMEA B unconnected. So, I figured RF from the transmitter's case follows this odd ground down into the network shield and screws it all up. But that didn't pan out because the network does the same thing with the cable to the Icom disconnected. Lucky for me that during short SSB transmissions, the system components just ignore the trashed data, so the users don't see there's no NMEA data for the 20 seconds the SSB is talking. I think this is the reason more people don't mention or notice it. The displays just freeze until you stop talking or take a breath when the SSB output power drops to a very low level and data stream resumes. Normally this kind of interference could be solved by looping the NMEA wires through ringcores, effectively breaking the antenna formed by the wires. Oddly enough, I don't notice this malady on the Seatalk unbalanced, unshielded part of the system. This may be because its cables are much shorter and all the Seatalk instruments are very close together. (RL70CRC Plus, Smart Heading Sensor, WAAS-GPS). Even the GPS receiver built into its antenna has a very short cable because I found a great little unused place right on top of the helm to port of the crank handle for the main sheet traveler to put both Garmin and Raymarine GPS antennas. Coverage through the fiberglass hardtop on the cockpit is excellent and noone uses the antenna for a grabhandle like they did when the antennas were initially on top of the hardtop. It's cable to the Seatalk plastic box with European screw terminals is only about 10" long. None of the Seatalk wires are over 24", making them much too short to fit an 8 Mhz wavelength. Indeed. And if the NMEA wires are longer, you can 'break' them by using ringcores. Ferrites won't stop the plastic boxes and unshielded cables with square waves in them from radiating unless you rounded off the edges, which would trash the data timing. No problem to round off the edges. I have for instance, put RC networks on the NMEA outputs. You can see the round-offs but a UART samples the signal on several (mostly 16) positions within one bit time. So slow slopes on the signal are no problem. It's not egde-driven but level driven. Meindert |
#40
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On Mon, 10 Nov 2003 15:01:06 +0100, "Meindert Sprang"
wrote: "Larry W4CSC" wrote in message ... On Mon, 10 Nov 2003 07:56:03 +0100, "Meindert Sprang" wrote: Any chance of using ferrite ringcores on the NMEA lines to surpress it ? Meindert Not as long as the unbalanced lines are all exposed like they are. Every cable from every instrument uses a Belden foil-shielded pair. But the radiation is going to happen, anyway, because the output of some of the instruments is unbalanced, inserting a radiating ground inside the faraday shield. Most instruments, you have to abandon the shield (screen connection for you UK readers) at the point where the instrument's unshielded power cable with its dangling data lead hangs out. There's no way to complete the shielding to the instrument. But you only connect the shielding on the transmitting side of the cable, right? Never connect shielding on both sides unless it is part of the data connection. It is always better to have signal and return in a pair, shielded by a screen that is connected on the TX side. It's all connected as a Faraday shield on one end only. Sure wish it were foil coax in a sealed environment, dammit. This open crap around screws eats my shorts. Maybe Icom is right. Make all the NMEA connections via a coax connector, unbalanced. M802 uses a BNC, in total abandonment of any NMEA balanced concept. The shield of the coax to that BNC MUST be connected to NMEA B (-) to get data on the radio's DSC display. Hold on! That cannot be right. If the NMEA source you connect to the M802 has a NMEA A (+) and a NMEA B (-) line, it is a balanced output where both wires are 'live'. If you connect that to the BNC of the M802, which is unbalanced (BNC is grounded), you'll effectively short circuit the NMEA B to ground. In such a case, you only connect the NMEA A to the input and the ground of the NMEA talker to the ground of the listener. you should leave the NMEA B unconnected. Won't work unless you connect the coax shield of the BNC connector (radio ground) to the NMEA -. This is EXACTLY what I'm talking about! MANY of the instruments you buy has NO BALANCED NMEA lines! The RL70CRC NMEA inputs are balanced lines....The Garmin are not. The Icom is not. NMEA (-) B input to the VHF is grounded hard inside the box. It's input is unbalanced, too. Yeoman's input and output is unbalanced, as is the B&G Network instruments. None of these have a real NMEA (-) and will NOT read data hooked from NMEA + to screen/shield/ground, from the multiplexer or any balanced NMEA transmitter source hooked up independently. You can't connect it if IT AIN'T THERE!.... So, I figured RF from the transmitter's case follows this odd ground down into the network shield and screws it all up. But that didn't pan out because the network does the same thing with the cable to the Icom disconnected. Lucky for me that during short SSB transmissions, the system components just ignore the trashed data, so the users don't see there's no NMEA data for the 20 seconds the SSB is talking. I think this is the reason more people don't mention or notice it. The displays just freeze until you stop talking or take a breath when the SSB output power drops to a very low level and data stream resumes. Normally this kind of interference could be solved by looping the NMEA wires through ringcores, effectively breaking the antenna formed by the wires. Oddly enough, I don't notice this malady on the Seatalk unbalanced, unshielded part of the system. This may be because its cables are much shorter and all the Seatalk instruments are very close together. (RL70CRC Plus, Smart Heading Sensor, WAAS-GPS). Even the GPS receiver built into its antenna has a very short cable because I found a great little unused place right on top of the helm to port of the crank handle for the main sheet traveler to put both Garmin and Raymarine GPS antennas. Coverage through the fiberglass hardtop on the cockpit is excellent and noone uses the antenna for a grabhandle like they did when the antennas were initially on top of the hardtop. It's cable to the Seatalk plastic box with European screw terminals is only about 10" long. None of the Seatalk wires are over 24", making them much too short to fit an 8 Mhz wavelength. Indeed. And if the NMEA wires are longer, you can 'break' them by using ringcores. Oh, boy, let's patch it......screw that. Let's fix the manufacturing problems and STANDARDIZE! Ferrites won't stop the plastic boxes and unshielded cables with square waves in them from radiating unless you rounded off the edges, which would trash the data timing. No problem to round off the edges. I have for instance, put RC networks on the NMEA outputs. You can see the round-offs but a UART samples the signal on several (mostly 16) positions within one bit time. So slow slopes on the signal are no problem. It's not egde-driven but level driven. Meindert I gave up trying to make it quiet. I got it lowered a bit in strength, but it's still buzzing away like a cheap SCR light control all over the place........ If there's a REAL emergency I HAVE to hear, I'll just shut it down and use the radio in PEACE. Larry W4CSC "Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!" |
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