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what size wire to use for 30amp 12v circuit ?
Is there an online chart of wire sizing for 220v, 110v and 12v wiring ?
Thank you, Courtney |
what size wire to use for 30amp 12v circuit ?
Courtney,
http://www.ancorproducts.com/ look under technical information Be aware that even these people are stuck in % voltage drop when at 12v you very often have to be concerned more with actual value and not percentage of supply. Matt Colie Courtney Thomas wrote: Is there an online chart of wire sizing for 220v, 110v and 12v wiring ? Thank you, Courtney |
what size wire to use for 30amp 12v circuit ?
The Ancor calculator Matt mentioned is about right. Things to keep in mind
are that a 25 foot length of wire is only good for 12.5 feet of distance..........out and back, right? And the type insulation is worth considering, particularly if it's going to be near any heat, oil, sunlight, etc, etc. Remember also that under emergency conditions (no alternator turning) there isn't going to be that comfortable 14.7 volts to fall back on, but something like 12.3 or 12.4 from a good, recently charged battery. Lots of high class SSB radios will start jumping frequency or channels with 11 volts at the radio, and the tuner will also be trying to retune everytime you holler "Heeeelp" in the mic. Welding cable is worth considering. Fine, cable laid wire with good tough neoprene jacketing. Terminals deserve good swedged tools, and wicking a little solder in after the swedging is super around salt water and batteries. Old Chief Lynn |
what size wire to use for 30amp 12v circuit ?
In article ,
"Lynn Coffelt" wrote: The Ancor calculator Matt mentioned is about right. Things to keep in mind are that a 25 foot length of wire is only good for 12.5 feet of distance..........out and back, right? And the type insulation is worth considering, particularly if it's going to be near any heat, oil, sunlight, etc, etc. Remember also that under emergency conditions (no alternator turning) there isn't going to be that comfortable 14.7 volts to fall back on, but something like 12.3 or 12.4 from a good, recently charged battery. Lots of high class SSB radios will start jumping frequency or channels with 11 volts at the radio, and the tuner will also be trying to retune everytime you holler "Heeeelp" in the mic. Welding cable is worth considering. Fine, cable laid wire with good tough neoprene jacketing. Terminals deserve good swedged tools, and wicking a little solder in after the swedging is super around salt water and batteries. Old Chief Lynn I agree with "Old Chief Lynn" here, if the appliance we're discussing here is an MF/HF SSB Radio. The thing that needs to be understood is that Battery Voltage at the terminals is NOT Voltage at the back of the Radio, or at the PowerAmp DC Terminals, especially at the 20 to 25 Amp draw of a 100 to 150 watt Peak Envelope Power Radio. It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. So any voltage drop associated with the wiring between the battery and the radio at the the Demand Input Current of the radio, effects the available output power. How many times have I seen a radio that receives perfectly, but dies whenever you press the PTT and modulate the Mic. LOTS. This is one of the reasons that the Powersupplys for FVSA (Fishing Vessel Safety ACT) and SOLAS requires that any batteries used for powering these MF/HF SSB Radios be on or above the same deck as the Radio, and Battery Condition be certified each year by a Discharge Test, in the case of SOLAS Required Vessels. When FVSA was out for Public Comment, there was a bit of a uproar about this requirment, as no one had that type of power system aboard, but it was made LAW anyway, and most of the fleet installed the required battery under the wheelhouse floor, right behind the wheelhouse on that deck, or on top of the wheelhouse. These locations will tend to keep the wire runs short, and any installer woirth his Salt, should and would DOUBLE the wiresize on the MF/HF SSB Radio that any table stated would be good enough. Most of the vessels I Inspected had AC PowerSupplies, or DC/DC Converters running from Ships Power of 120Vac or 32Vdc and Power leads of a foot or two, before the FVSA, and we just added an 8D battery between the two. Bruce in alaska -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
Where did you hear that myth??? Iv'e been a marine electronics tech for 30
years and have never heard that one. I know what you stated is total bs but just for drill I did a little test before leaving work today. Hooked up a variable power supply to my Icom 735 with a Bird 4381 power analyst in line (which reads PEP directly). I also verified the wattmeter readings using an o-scope. The power didn't start to drop til the voltage dropped below 10.5v and I was able to receive just fine all the way down to 9.5v. Below that the rig started to die. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. |
what size wire to use for 30amp 12v circuit ?
|
what size wire to use for 30amp 12v circuit ?
In article ,
"Eric Fairbank" wrote: Where did you hear that myth??? Iv'e been a marine electronics tech for 30 years and have never heard that one. I know what you stated is total bs but just for drill I did a little test before leaving work today. Hooked up a variable power supply to my Icom 735 with a Bird 4381 power analyst in line (which reads PEP directly). I also verified the wattmeter readings using an o-scope. The power didn't start to drop til the voltage dropped below 10.5v and I was able to receive just fine all the way down to 9.5v. Below that the rig started to die. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. Just try your experiment with ANY SGC designed and built radio. Bruce in alaska I am Old School, and an Old Fart, and I do remember back in the Old Days, before Autotuners, allowed anyone to think they were World Class Radiomen... -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
"Bruce in Alaska" wrote in message
... It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. But.... it is also a fact that any modern rig that is also allowed on commercial vessels (IEC/EN60945) will never show this behavior, otherwise they wouldn't be able to pass the the tests to comply with that standard. Meindert |
what size wire to use for 30amp 12v circuit ?
"Eric Fairbank" wrote:
Where did you hear that myth??? Iv'e been a marine electronics tech for 30 years and have never heard that one. I know what you stated is total bs but just for drill I did a little test before leaving work today. Hooked up a variable power supply to my Icom 735 with a Bird 4381 power analyst in line (which reads PEP directly). I also verified the wattmeter readings using an o-scope. The power didn't start to drop til the voltage dropped below 10.5v and I was able to receive just fine all the way down to 9.5v. Below that the rig started to die. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. Just try your experiment with ANY SGC designed and built radio. Bruce in alaska I am Old School, and an Old Fart, and I do remember back in the Old Days, before Autotuners, allowed anyone to think they were World Class Radiomen... -- Oh, my gosh, it's just killing me to sit here without jumping in! Then when I heard SGC mentioned, I knew that someone besides me had experienced "Bruce's Law". I am compelled to defend his position and scientific observations without reservation. How much midnight oil I've spent working on the DC supply system on "commercial" vessels, trying to reduce the voltage drop. Until the "code" made batterys in the pilot house almost mandatory, can't you imagine running an SGC711 from engine room batterys? Here's a typical example (it is a genuine "commercial", by the way) of a vessel still using this one time popular rig: http://www.alaskaboat.com/sn033.htm Those SGC711's were hard to coax to even 75 watts PEP with any wire less than #4 if you were more than two feet away from the battery! (OK, stretching a little here) And the built-in wire antenna tuner was a charmer, hey? But as the URL and dozens more can show, that not everyone has yet to install an Icom M802. Some earlier SEA's and Icom's with first generation digital VCO tuning were cool, too. A sneeze or laugh in the mic was as apt to change channels as anything if the antenna was fed directly from the radio, and some joker installed #10 wire for DC power! Early automatic antenna tuners were (are) cool, too. A little pitching and rolling in the North Pacific and they would lock up and refuse to even try to tune anymore. Then the transmitter's fabulous SWR power foldback circuit hit the fan and 5 to 10 watts could be used to heat up the tuner's coils and capacitors. (condensers, actually) Lots of this early stuff is still out there. By the thousands. Modern marine SSB radios certainly have improved their ability to survive poor installations, but is that any reason to go as cheap as possible with DC wiring and antenna installations? (RF ground on "Tupperware" boats is probably just as important, but I digress) Old Chief Lynn (besides, tubes help heat the pilothouse and ease aching joints) |
what size wire to use for 30amp 12v circuit ?
Lynn Coffelt wrote: "Eric Fairbank" wrote: Where did you hear that myth??? Iv'e been a marine electronics tech for 30 years and have never heard that one. I know what you stated is total bs but just for drill I did a little test before leaving work today. Hooked up a variable power supply to my Icom 735 with a Bird 4381 power analyst in line (which reads PEP directly). I also verified the wattmeter readings using an o-scope. The power didn't start to drop til the voltage dropped below 10.5v and I was able to receive just fine all the way down to 9.5v. Below that the rig started to die. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. Just try your experiment with ANY SGC designed and built radio. Bruce in alaska I am Old School, and an Old Fart, and I do remember back in the Old Days, before Autotuners, allowed anyone to think they were World Class Radiomen... -- Oh, my gosh, it's just killing me to sit here without jumping in! Then when I heard SGC mentioned, I knew that someone besides me had experienced "Bruce's Law". I am compelled to defend his position and scientific observations without reservation. How much midnight oil I've spent working on the DC supply system on "commercial" vessels, trying to reduce the voltage drop. Until the "code" made batterys in the pilot house almost mandatory, can't you imagine running an SGC711 from engine room batterys? Here's a typical example (it is a genuine "commercial", by the way) of a vessel still using this one time popular rig: http://www.alaskaboat.com/sn033.htm Those SGC711's were hard to coax to even 75 watts PEP with any wire less than #4 if you were more than two feet away from the battery! (OK, stretching a little here) And the built-in wire antenna tuner was a charmer, hey? But as the URL and dozens more can show, that not everyone has yet to install an Icom M802. Some earlier SEA's and Icom's with first generation digital VCO tuning were cool, too. A sneeze or laugh in the mic was as apt to change channels as anything if the antenna was fed directly from the radio, and some joker installed #10 wire for DC power! Early automatic antenna tuners were (are) cool, too. A little pitching and rolling in the North Pacific and they would lock up and refuse to even try to tune anymore. Then the transmitter's fabulous SWR power foldback circuit hit the fan and 5 to 10 watts could be used to heat up the tuner's coils and capacitors. (condensers, actually) Lots of this early stuff is still out there. By the thousands. Modern marine SSB radios certainly have improved their ability to survive poor installations, but is that any reason to go as cheap as possible with DC wiring and antenna installations? (RF ground on "Tupperware" boats is probably just as important, but I digress) Old Chief Lynn (besides, tubes help heat the pilothouse and ease aching joints) Let's just watch out here. I was in a junk shop a while ago and I told the proprietor what was actually hoping to find. We got talking about ships and boats. He stopped and asked if I could tell him about something in back. When retrieved, it turned out to be a marine HF - real live dinosaur (dynosoar?). I think is was Hammerlund or EF Johnson - most of the crystals had been pulled, but it still had a the 2 1625s in the final (and a little burned spot on the tank). I looked at him and said "You know - They haven't made 'em like this for a long time". (Aren't we glad!) Matt Colie - Lifelong Waterman, Licensed Mariner and Perpetual Sailor |
what size wire to use for 30amp 12v circuit ?
So, now your saying your theory only applies to certain radios? Then you shouldn't make blanket statements like you did. You mislead the average joe who reads this newsgroup. It is not common knowledge and while it may be a "fact" for "one" radio, it is certainly not a "fact" in general. I disproved your statement on the Icom 735, and today I disproved it on the SEA222, Icom-710, Icom-802, SEA235 and a Yaesu FT-897. I'm not disputing the fact that minimizing voltage drops on an HF installation is of prime importance. I just think you are way out of line making such a statement and claiming it as a commonly understood fact. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. Just try your experiment with ANY SGC designed and built radio. |
what size wire to use for 30amp 12v circuit ?
|
what size wire to use for 30amp 12v circuit ?
In article ,
"Eric Fairbank" wrote: So, now your saying your theory only applies to certain radios? Then you shouldn't make blanket statements like you did. You mislead the average joe who reads this newsgroup. It is not common knowledge and while it may be a "fact" for "one" radio, it is certainly not a "fact" in general. I disproved your statement on the Icom 735, and today I disproved it on the SEA222, Icom-710, Icom-802, SEA235 and a Yaesu FT-897. I'm not disputing the fact that minimizing voltage drops on an HF installation is of prime importance. I just think you are way out of line making such a statement and claiming it as a commonly understood fact. Eric Eric, just how did you disprove this? Using the same setup that you used in your original experiment? Well, now, why don't you try modifing your setup and put 30Ft of #14 Wire from your very stiff powersupply to the radios. Now try the putput power test again, and come back and tell us all what you find. You see Bill Forgey, the Retired Chief Engineer at SEA, and I, did all of these experiments years ago in the SEA Engineering LAB, and concluded that yes, this was the case. One of the reasons that more headroom in the HF Amplifier sections was a prime design factor in the SEA 322-330 Series Radios, but which still did not completely resolve the problem of trying to operate a 20+ amp Current draw, thru a less than steller Power Wire. Bruce in alaska -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
In article , Bruce in Alaska wrote:
In article , "Eric Fairbank" wrote: So, now your saying your theory only applies to certain radios? Then you shouldn't make blanket statements like you did. You mislead the average joe who reads this newsgroup. It is not common knowledge and while it may be a "fact" for "one" radio, it is certainly not a "fact" in general. I disproved your statement on the Icom 735, and today I disproved it on the SEA222, Icom-710, Icom-802, SEA235 and a Yaesu FT-897. I'm not disputing the fact that minimizing voltage drops on an HF installation is of prime importance. I just think you are way out of line making such a statement and claiming it as a commonly understood fact. Eric Eric, just how did you disprove this? Using the same setup that you used in your original experiment? Well, now, why don't you try modifing your setup and put 30Ft of #14 Wire from your very stiff powersupply to the radios. Now try the putput power test again, and come back and tell us all what you find. You see Bill Forgey, the Retired Chief Engineer at SEA, and I, did all of these experiments years ago in the SEA Engineering LAB, and concluded that yes, this was the case. One of the reasons that more headroom in the HF Amplifier sections was a prime design factor in the SEA 322-330 Series Radios, but which still did not completely resolve the problem of trying to operate a 20+ amp Current draw, thru a less than steller Power Wire. Car audio caps can always beef up the supply transients needed for solid state SSB and stereos. greg |
what size wire to use for 30amp 12v circuit ?
In article ,
"Lynn Coffelt" wrote: Oh, my gosh, it's just killing me to sit here without jumping in! Then when I heard SGC mentioned, I knew that someone besides me had experienced "Bruce's Law". I am compelled to defend his position and scientific observations without reservation. How much midnight oil I've spent working on the DC supply system on "commercial" vessels, trying to reduce the voltage drop. Until the "code" made batterys in the pilot house almost mandatory, can't you imagine running an SGC711 from engine room batterys? Here's a typical example (it is a genuine "commercial", by the way) of a vessel still using this one time popular rig: http://www.alaskaboat.com/sn033.htm Those SGC711's were hard to coax to even 75 watts PEP with any wire less than #4 if you were more than two feet away from the battery! (OK, stretching a little here) And the built-in wire antenna tuner was a charmer, hey? But as the URL and dozens more can show, that not everyone has yet to install an Icom M802. Some earlier SEA's and Icom's with first generation digital VCO tuning were cool, too. A sneeze or laugh in the mic was as apt to change channels as anything if the antenna was fed directly from the radio, and some joker installed #10 wire for DC power! Early automatic antenna tuners were (are) cool, too. A little pitching and rolling in the North Pacific and they would lock up and refuse to even try to tune anymore. Then the transmitter's fabulous SWR power foldback circuit hit the fan and 5 to 10 watts could be used to heat up the tuner's coils and capacitors. (condensers, actually) Lots of this early stuff is still out there. By the thousands. Modern marine SSB radios certainly have improved their ability to survive poor installations, but is that any reason to go as cheap as possible with DC wiring and antenna installations? (RF ground on "Tupperware" boats is probably just as important, but I digress) Old Chief Lynn (besides, tubes help heat the pilothouse and ease aching joints) Ah Oh, I feel a Story coming on.... StonerWatts .... A Real Tale about MF/HF Marine Radio...... Years ago, I was working for Northern Radio, as a Field Tech/Radioman and getting the Alaska State Ferries ready for their Annual SOLAS Inspections. The State wanted to replace the venerable Northern N550 MF/HF SSB Radios with something totally SolidState, and had put out the refit for BID. Well Don Stoner, and his partner PeeAir Gorrale, wanted to get their SGC711 into the US Market, so they bid the job really LOW, and got the contract to refit all the State Ferries. Their guys did the installations, and had left the vessels, for me to get them thru FCC/SOLAS Inspections. I did everything else, first and left the MF/HF Radio's for last, and when I finnally got around to doing the preinspection testing, found that all but one wouldn't meet Frequency Tolerance, and NONE of them would meet PowerOutput Requirments, using the accepted Testing Procedures, expected by the FCC Field Engineers, of the day. I got ahold of the Port Captain, and explained the problem, and since these radios were NEW and under Warrentee (sp) that it was SGC's problem to rectify, but since the Inspection was setup for the next morning, SGC better get their collective Ass in gear, or the ships would fail the Inspection and not be ready to sail on schedual. SGC was summoned and one of their Field Techs reset all the Crystal Frequencies and did his best to get the Power Output up to spec's. They worked all night on the first boat due for inspection, and when I showed up, one hour before Inspection time, the Power problem still wasn't resolved. Finally, the Tech, called his office and Don Stoner, drove out, and showed up just as Bob Zinns, the FCC Engineer, did and they came aboard together. While Bob and I went thru all the other Inspection Items, don worked on the 711. After 2 hours, Bob and I were ready to do the MF/HF Radio Inpsection, and we were presented with Don Stoner, and his very expensive Tek Storage OScope, connected across a 50 Ohm Dummy Load, and he said he would demonstrate the Power Output of the 711 with this Test Setup. Mr. Zinns looked very skeptical, and I didn't say a word, but Don proceeded with his demontration. He picked the Mic and mashed the PTT and sope the test phrase "Five, five, five", into the mic. He had the Storage Oscope set to capture the Peak Voltage Pulse of the transmission, and then showed the assembliadge the reading, and got out his calculator, and computed the PEAK Envelope Power for that, very narrow Pulse. "Yup" he said, "just exactly 152 PEP Watts". Mr Zinns asked hm to demonstrate that on a Peak Reading Bird WattMeter, and Don stated that he would not, that his demonstation was sufficent. Mr Zinns took out an 801 PinkSlip and Failed the vessels SOLAS Inspection, citing the lack of spec'd Transmit Output Power. I tested the radio, in the accepted way using a Bird Wattmeter, and found that we could get maybe 80 Watts PEP out of it with a Maximum Scream in the Mic. Everyone went home and the FCC and SGC had a WAR of Fax's and Phonecalls, between the Seattle Field Offce, FCC Headquarters, State of Alaska Ferry Systems, Port Captain, and SGC, ect. After three days of this, it was determined by the FCC's Chief Engineer, that Don Stoner's method of testing did in fact prove that the radio was in compliance, and that the FCC Field Offices would accept that method of testing, for the SGC711 only, and Issue SOLAS Certificates for the Alaska State Ferries which had SGC711 Radios fitted. The long and short of the story is: All the SGC's were stripped off all the Alaska State Ferries within 6 Months, for the simple reason that they couldn't talk to any of their regular BaseStations, on a consistant basis, as they were used to doing with the N550's previously fitted. All were replace with Icom's first generation MF/HF Radios that actually would "Whistle up" to 150PEP on a Wattmenter. Northern Radio continued to do all the FCC/SOLAS Annual Inspections, untill I left the company. The State of Alaska Communications Shop, took over the job and was still doing it when I joined the FCC a few years later, as the Southeastern Alaska Resident Field Agent and started doing the FCC/SOLAS Inspection on the Alaska Ferries as the FCC Inspector. The StonerWatts Story is still around in FCC Lore, and told in Marine Radio Shops, all around the North Pacific. Bruce in alaska just cause you can see the spike on a scope doesn't mean you can actually talk to someone...... -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
In article ,
Matt Colie wrote: Let's just watch out here. I was in a junk shop a while ago and I told the proprietor what was actually hoping to find. We got talking about ships and boats. He stopped and asked if I could tell him about something in back. When retrieved, it turned out to be a marine HF - real live dinosaur (dynosoar?). I think is was Hammerlund or EF Johnson - most of the crystals had been pulled, but it still had a the 2 1625s in the final (and a little burned spot on the tank). I looked at him and said "You know - They haven't made 'em like this for a long time". (Aren't we glad!) Matt Colie - Lifelong Waterman, Licensed Mariner and Perpetual Sailor A lot of the OLD Northern Radio Co. AM Sets had 807/1625's in them. when I started at Northern, we still were servicing those and I have very fond memorries of traveling all over the State of Alaska, hauling a RCA Tube Caddy full of 807's, 1625's, 811's and an 813 or two.... I even remember when we used 866A's in the Power supplies, as Recitifiers. Bruce in alaska -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
I'm just shaking my head here Bruce. You keep changing your story. I disagree with your original blanket statement which was not in reference to old SGC rigs or installations with 30ft of #14 wire. Jeez! Eric "Bruce in Alaska" wrote in message ... Eric, just how did you disprove this? Using the same setup that you used in your original experiment? Well, now, why don't you try modifing your setup and put 30Ft of #14 Wire from your very stiff powersupply to the radios. Now try the putput power test again, and come back and tell us all what you find. |
what size wire to use for 30amp 12v circuit ?
So, now your saying your theory only applies to certain radios? Then you shouldn't make blanket statements like you did. You mislead the average joe who reads this newsgroup. It is not common knowledge and while it may be a "fact" for "one" radio, it is certainly not a "fact" in general. I disproved your statement on the Icom 735, and today I disproved it on the SEA222, Icom-710, Icom-802, SEA235 and a Yaesu FT-897. I'm not disputing the fact that minimizing voltage drops on an HF installation is of prime importance. I just think you are way out of line making such a statement and claiming it as a commonly understood fact. Eric Eric, just how did you disprove this? Using the same setup that you used in your original experiment? Well, now, why don't you try modifing your setup and put 30Ft of #14 Wire from your very stiff powersupply to the radios. Now try the putput power test again, and come back and tell us all what you find. You see Bill Forgey, the Retired Chief Engineer at SEA, and I, did all of these experiments years ago in the SEA Engineering LAB, and concluded that yes, this was the case. One of the reasons that more headroom in the HF Amplifier sections was a prime design factor in the SEA 322-330 Series Radios, but which still did not completely resolve the problem of trying to operate a 20+ amp Current draw, thru a less than steller Power Wire. Bruce Car audio caps can always beef up the supply transients needed for solid state SSB and stereos. greg You bet! the big capacitors (condensers, really) were often used here to help SSB rigs "whistle" or "five, five, five" up near ratings. In fact the internal big filter capacitors in bench test power supplies contributed trouble pinpointing the problems bringing rigs up to snuff. When the DC power wire resistance caused momentary voltage drops in a real world installation, the Simpson 260 couldn't see what the voltage actually was during PEP peaks. Just a little needle quiver. (forget the digital VOM.... it read all over the place) When you finally sweated and groaned the old Tektronics scope (me..... Heathkit) up on the ship/boat, the cause of channel changing, low power and tuner lock-up became clear. Once in a while a quick BIG cap across the SSB power terminals just before we took Bob Z aboard would do the trick. I enjoyed your Peeair story, Bruce, I know Don must be rolling over in the grave. (I did like Don's little active (Dymek?) antenna, though, to get the WEFAX antenna up and away from the digital noise disaster in the pilot house) Old Chief Lynn |
what size wire to use for 30amp 12v circuit ?
"Lynn Coffelt" wrote in news:du5fag$v08$1
@emma.aioe.org: When you finally sweated and groaned the old Tektronics scope (me..... Heathkit) up on the ship/boat, the cause of channel changing, low power and tuner lock-up became clear. Hey, Chief! Wanna borrow my little Fluke handheld storage scope?...(c; http://www.tessco.com/products/displ...87&eventPage=1 They got a new color one with 200 Mhz bandwidth and two channels to drool over, now. Digital persistence....(c; |
what size wire to use for 30amp 12v circuit ?
Bruce in Alaska wrote in news:bruceg-
: I even remember when we used 866A's in the Power supplies, as Recitifiers. Yecch.....flashovers! Been there, done that.... Bruce, have you seen what an AM transmitter looks like, now? A 50KW AM broadcast transmitter uses POWERTAB transistors for final output stages! http://hawkins.pair.com/wabcnow/wabcn14.jpg That little board puts out 1KW with 240VDC applied... Amazing. A 50KW broadcast transmitter cooled with muffin fans....55KW from the power company...50KW to the antenna! |
what size wire to use for 30amp 12v circuit ?
On Thu, 02 Mar 2006 00:51:43 -0500, Larry wrote:
http://hawkins.pair.com/wabcnow/wabcn14.jpg That little board puts out 1KW with 240VDC applied... Do they put 50 boards in parallel? |
what size wire to use for 30amp 12v circuit ?
In article ,
Larry wrote: Bruce in Alaska wrote in news:bruceg- : I even remember when we used 866A's in the Power supplies, as Recitifiers. Yecch.....flashovers! Been there, done that.... Bruce, have you seen what an AM transmitter looks like, now? A 50KW AM broadcast transmitter uses POWERTAB transistors for final output stages! http://hawkins.pair.com/wabcnow/wabcn14.jpg That little board puts out 1KW with 240VDC applied... Amazing. A 50KW broadcast transmitter cooled with muffin fans....55KW from the power company...50KW to the antenna! No, i really haven't kept up on Broadcast Engineering, since I left that field in the late 60's, in a previous life. I understandf that some of the newer Transmitters using Class D & E Amps are very efficent and compact in the extreme, compared to what I was working with. Bruce in alaska -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
In article ,
"Lynn Coffelt" wrote: I enjoyed your Peeair story, Bruce, I know Don must be rolling over in the grave. (I did like Don's little active (Dymek?) antenna, though, to get the WEFAX antenna up and away from the digital noise disaster in the pilot house) Old Chief Lynn Yea, Don was one hell of a smart guy, and one World Class Radio Designer, for his day. I think I still have a Stoner CB around here somewhere. Lynn, would you know if Finn Christensen is still working for SGC. He was the guy who did the orginal design of the N571-575 series Poweramps, and left Northen just before it was bought by that Guy from California and moved to Redmond. He went to SGC to help PeeAir figure out how to build a SS PA for the follow on SSB Radios after the 711. I kind of lost track of him after Northen went under, and I saw him at the Bankrupcy Auction. Bruce in alaska -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
"Bruce in Alaska" wrote in message ... In article , "Lynn Coffelt" wrote: I enjoyed your Peeair story, Bruce, I know Don must be rolling over in the grave. (I did like Don's little active (Dymek?) antenna, though, to get the WEFAX antenna up and away from the digital noise disaster in the pilot house) Old Chief Lynn Yea, Don was one hell of a smart guy, and one World Class Radio Designer, for his day. I think I still have a Stoner CB around here somewhere. Lynn, would you know if Finn Christensen is still working for SGC. He was the guy who did the orginal design of the N571-575 series Poweramps, and left Northen just before it was bought by that Guy from California and moved to Redmond. He went to SGC to help PeeAir figure out how to build a SS PA for the follow on SSB Radios after the 711. I kind of lost track of him after Northen went under, and I saw him at the Bankrupcy Auction. Bruce in alaska -- No, I am not familiar with Finn. I really only know Pierre from telephone conversations. He would make a sales pitch call once in a while. And I'd have to try to be polite. There was a nice 100' Knight-Carver (or was it Carver-Knight?) here with two of the latest and greatest SGC 24 channel synthesized rigs here. Owner's full time maintainer said factory techs had installed and tuned them down in San Diego. One of them worked fairly well, but the other barely hailed vessels in the same marina. Super Tech, Old Chief Lynn was called into action. The poor performer's little square box manual tuner was at arms length in a console cavity. When I finally got the lid off the little bugger, the tuning jumpers and capacitors were still untouched in their little plastic bags. Sheesh! I'm slowly gathering dusty parts for an 866A lit power supply...... I'm without a rig right now, and never had a store boughten transmitter yet. Itching to get back on 40 CW before I forget the code. (or there are no CW operators there). (is this thread, "30amp 12v circuit", something for filament power?) Old Chief Lynn |
what size wire to use for 30amp 12v circuit ?
Wayne.B wrote in
: Do they put 50 boards in parallel? No, it actually has something like 248 boards, in parallel. There is one board that always puts out 100 watts, the only board turned on at the negative 100% modulation peak. The other boards are controlled by a long driver board mounted outside the RF shield and hooked to them with big ribbon cables. The modulation audio simply turns all but the one on and off as the audio waveform is converted to the digital data. With no modulation, half the boards produce a 50KW output carrier. As the audio waveform goes up, more boards switch in up to 100% modulation peak, then back to half and down to only the one 100W output, then back up. The output amounts to a sum of all these boards' square wave switching output. The big square wave is sent to a tuned circuit that filters out the harmonics with more low-pass filters to keep the neighbors happy. The output, of course, is an amplitude modulated sinewave that is quite smooth, considering it comes from a digitized square wave. Being actually a switching power supply at the RF carrier frequency, the boards are 95+% efficient like the power supply in your computer....making the company VERY happy as the electric bill comes down from 130KW load, the rest wasted as heat, to 55KW load with only 5KW of heat coming off with simple cooling fans. Simply amazing switcher technology, considering AM's analog roots. Harris has a pretty good lock on the market for AM transmitters, now. The boards come in 100W, 200W, 500W and 1KW power levels, I think. Binary switching them as the audio waveform is digitized makes quite small power steps hardly recognizable in the modulated output. Listen to almost any clear channel AM station in the USA and you'll be listening to a Harris DX-50 these days. Hell, WWL on 870Khz was on the air through the hurricane with theirs....near New Orleans. |
what size wire to use for 30amp 12v circuit ?
On Fri, 03 Mar 2006 12:59:23 -0500, Larry wrote:
Being actually a switching power supply at the RF carrier frequency, the boards are 95+% efficient like the power supply in your computer. Interesting, I had no idea that AM transmitter technology had gotten that sophisticated. Makes sense though. Unfortunately I can't see much applicability to the SSB world, or to reduced carrier AM. |
what size wire to use for 30amp 12v circuit ?
In article ,
Larry wrote: "Lynn Coffelt" wrote in news:du8kc5$k1$1 @emma.aioe.org: (is this thread, "30amp 12v circuit", something for filament power?) 30 amps? REAL filaments won't even glow at 30 amps!....(c; If you'd like them, I have pdf files of the '63 RCA Power Tube Guide, '52 Eimac Broadcasters Tube Catalog, and some other interesting old ebooks I've collected. They're too big to email but I can setup a virtual FTP server for ya, chief. 600KW of CW on 40 meters will reach out and touch someone...(c; 600Kw on 40 Meters has the ability to reach out and touch the operator, if he should get to close to the RF Ammeter..... Bruce in alaska -- add a 2 before @ |
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