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#2
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tnom:
Yep, I always worry about terminology... It will allow you to tune the antenna/coax from a 5:1 to a 1:1 and run your transceiver into it--WITHOUT BURNING OUT THE FINALS. The fact that, that is better than replacing finals on a daily basis may not appeal to some--they can chose to NOT use one and burn out their finals, daily, if they chose... Better yet, he can drop into the radio shop on board a truck stop, explain he does not have time, or the permission of the truck owners to start revamping their antennas and coax--I am sure the tech will see it as a no-brainer--RUN A MATCH BOX! Hey, it is america, you can take your choice... John wrote in message ... On Sat, 30 Jul 2005 22:56:21 -0700, Frank Gilliland wrote: On Sat, 30 Jul 2005 23:54:05 -0400, wrote in : If you move the radio from location to location just check the reading. If it's 2:1 or lower don't worry about it. Thanks, I have an SWR meter from radio shack that I've used in the past. I know how to use it. My problem is that I'll be in a different truck everyday and wont be able to set the SWR the way I want to. On Monday I'm gonna call the cb shop that I saw online and ask them about the SWR match box. Below is a cut and paste of this product. Let me know if this will set the SWR without having to mess with the antenna's. "Don't "Live with" High SWR Readings! This Matcher will tune your SWR very low, simply insert inline between radio & Antenna. Has 2 Adjustment knobs. Perfect for Radios with wide channel coverage, indoor antennas, non-tunable mobile antennas, or for using 10 thru 12 meters off 1 antenna. Handles 80w pep. Requires either an SWR meter built into radio, or an optional SWR meter between Radio & Matcher." This is a line flattener. ....oh brother, more voodoo CB terminology. http://www.rockwellcollins.com/ecat/gs/LF-2040.html http://www.listserve.com/archives/co.../msg00270.html http://www.listserve.com/archives/co.../msg00270.html http://www.co.missoula.mt.us/acs/radios/HF-8040.htm http://www.valcom.ca/Guelph/products...-30_photo.html Yup. Sure looks like the term "Line Flattener" is "more voodoo CB terminology" |
#3
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On Sun, 31 Jul 2005 08:36:55 -0700, "John Smith"
wrote in : tnom: Yep, I always worry about terminology... It will allow you to tune the antenna/coax from a 5:1 to a 1:1 and run your transceiver into it--WITHOUT BURNING OUT THE FINALS. Guess what, John: Most of the finals used in CB radios today (and for the past 20+ years) can withstand SWR of 30:1 indefinitely. And that includes the power transistors used in amps, too. The fact that, that is better than replacing finals on a daily basis may not appeal to some--they can chose to NOT use one and burn out their finals, daily, if they chose... Resorting to scare tactics? Gee, I don't use a matchbox and the final in my rig is just fine. In fact, I've -never- blown a final except for once when the coax connector on the radio end was shorted, but I don't think a matchbox would have fixed that problem..... do you? Better yet, he can drop into the radio shop on board a truck stop, explain he does not have time, or the permission of the truck owners to start revamping their antennas and coax-- Why stop there? Tell him the -truth-, John: If he doesn't run a matchbox he'll have to hire an engineer at $200/hr to locate the optimum location on the truck for the antenna, reinstall the whole system, tune it up with his $20k HP comm analyzer, etc..... Judas Priest, it's just a CB radio! Just plug it in and talk! I am sure the tech will see it as a no-brainer--RUN A MATCH BOX! Once again there's that phrase most favored by those who can't make a logical argument: "It's a no-brainer". Well, since the CB was first established over 45 years ago the overwhelming majority of CBers have run their rigs -WITHOUT- a matchbox and they worked just fine. Sorry, it's not a "no-brainer", but it's about as close as you can get. And if -you- can't figure it out then apparently a "no-brainer" is beyond your level of comprehension. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#4
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Frank:
With so many guys like you around, it may seem confusing... All he needs do is check with a tech... End of story... John "Frank Gilliland" wrote in message ... On Sun, 31 Jul 2005 08:36:55 -0700, "John Smith" wrote in : tnom: Yep, I always worry about terminology... It will allow you to tune the antenna/coax from a 5:1 to a 1:1 and run your transceiver into it--WITHOUT BURNING OUT THE FINALS. Guess what, John: Most of the finals used in CB radios today (and for the past 20+ years) can withstand SWR of 30:1 indefinitely. And that includes the power transistors used in amps, too. The fact that, that is better than replacing finals on a daily basis may not appeal to some--they can chose to NOT use one and burn out their finals, daily, if they chose... Resorting to scare tactics? Gee, I don't use a matchbox and the final in my rig is just fine. In fact, I've -never- blown a final except for once when the coax connector on the radio end was shorted, but I don't think a matchbox would have fixed that problem..... do you? Better yet, he can drop into the radio shop on board a truck stop, explain he does not have time, or the permission of the truck owners to start revamping their antennas and coax-- Why stop there? Tell him the -truth-, John: If he doesn't run a matchbox he'll have to hire an engineer at $200/hr to locate the optimum location on the truck for the antenna, reinstall the whole system, tune it up with his $20k HP comm analyzer, etc..... Judas Priest, it's just a CB radio! Just plug it in and talk! I am sure the tech will see it as a no-brainer--RUN A MATCH BOX! Once again there's that phrase most favored by those who can't make a logical argument: "It's a no-brainer". Well, since the CB was first established over 45 years ago the overwhelming majority of CBers have run their rigs -WITHOUT- a matchbox and they worked just fine. Sorry, it's not a "no-brainer", but it's about as close as you can get. And if -you- can't figure it out then apparently a "no-brainer" is beyond your level of comprehension. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#5
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On Sun, 31 Jul 2005 13:52:44 -0700, "John Smith"
wrote in : Frank: With so many guys like you around, it may seem confusing... All he needs do is check with a tech... He did, and as a tech I gave him my advice. I also gave him my advice as an EE. The advice is the same -- don't waste your time and money on gimmicks, just plug it in and start talking. End of story... I doubt it. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#6
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Frank:
If you were EVER a poor tech, you were a bad one, I know you are a damn liar! When he asked a real tech they are going to tell him he would be an idiot to key down on mere 5:1 and hope to not damage his radio in relative short order. When he asks a tech, he will also know for certain NEVER to bother with your advice again... How many other peoples radios have you burnt up with your poor advice, I just wonder... John "Frank Gilliland" wrote in message ... On Sun, 31 Jul 2005 13:52:44 -0700, "John Smith" wrote in : Frank: With so many guys like you around, it may seem confusing... All he needs do is check with a tech... He did, and as a tech I gave him my advice. I also gave him my advice as an EE. The advice is the same -- don't waste your time and money on gimmicks, just plug it in and start talking. End of story... I doubt it. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#7
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On Sun, 31 Jul 2005 14:11:23 -0700, "John Smith"
wrote in : Frank: If you were EVER a poor tech, you were a bad one, I know you are a damn liar! Oh gee, another sooth-sayer. What else does your crystal ball tell you? When he asked a real tech they are going to tell him he would be an idiot to key down on mere 5:1 and hope to not damage his radio in relative short order. I didn't see any part of his posts where he said his SWR was 5:1. Is that something you divined from your crystal ball? When he asks a tech, he will also know for certain NEVER to bother with your advice again... How many other peoples radios have you burnt up with your poor advice, I just wonder... I have absolutely no doubt that you wonder about a lot of things. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#8
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"Frank Gilliland" wrote in message ... On Sun, 31 Jul 2005 08:36:55 -0700, "John Smith" wrote in : tnom: Yep, I always worry about terminology... It will allow you to tune the antenna/coax from a 5:1 to a 1:1 and run your transceiver into it--WITHOUT BURNING OUT THE FINALS. Guess what, John: Most of the finals used in CB radios today (and for the past 20+ years) can withstand SWR of 30:1 indefinitely. And that includes the power transistors used in amps, too. Frank, to be fair, you must now finish this statement. Even at 3 watts, some of these tiny radios and chassis don't have enough mass to dissipate the heat that will be created by the miss-match. Sure, you can add a larger sink and forced air cooling, but stock, they won't take it. And it's never a bad idea to check the heat sink and mica insulator and replace the grease with Arctic Silver 5 or some comparable superior thermal compound. I lost an MRF477 due to improper installation by the manufacturer. The screw had been stripped and was not making proper contact with the heat sink, and that was with a reasonable SWR. |
#9
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On Mon, 01 Aug 2005 22:49:22 GMT, "U-Know-Who"
wrote in : "Frank Gilliland" wrote in message .. . On Sun, 31 Jul 2005 08:36:55 -0700, "John Smith" wrote in : tnom: Yep, I always worry about terminology... It will allow you to tune the antenna/coax from a 5:1 to a 1:1 and run your transceiver into it--WITHOUT BURNING OUT THE FINALS. Guess what, John: Most of the finals used in CB radios today (and for the past 20+ years) can withstand SWR of 30:1 indefinitely. And that includes the power transistors used in amps, too. Frank, to be fair, you must now finish this statement. Even at 3 watts, some of these tiny radios and chassis don't have enough mass to dissipate the heat that will be created by the miss-match. Sure, you can add a larger sink and forced air cooling, but stock, they won't take it. I have yet to see a CB radio that couldn't handle a 3:1 SWR (unless it was improperly installed, as you mention below). And I know that those plastic Cobra 19's and those micro-Midlands can be keyed at a normal duty cycle without -anything- hooked up to the antenna jack. Some of the older radios are a bit fussy, especially those with the 2SC799. But those are becoming quite rare -- probably for just that reason. The 2SC2078 and other modern CB finals are solid transistors that are pretty darn hard to blow, with or -without- a heatsink (the TO-220 case dissipates quite a bit of heat all by itself). And it's never a bad idea to check the heat sink and mica insulator and replace the grease with Arctic Silver 5 or some comparable superior thermal compound. I lost an MRF477 due to improper installation by the manufacturer. The screw had been stripped and was not making proper contact with the heat sink, and that was with a reasonable SWR. I have seen a few Unidens with those thick, grey, rubber heat-sink insulators -- worthless crap like that shouldn't have even been installed at the factory. Another problem I've seen is amp junkies (audio and radio) who replace their own transistors and use -WAY- too much heat sink grease. They were never taught that it's only meant to fill the air gaps where there's no direct contact -- IOW, just a little dab'll do ya. But I will qualify my statement to say that the RF transistors are rated for continuous 30:1 SWR -only- when they have a sufficient heatsink. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#10
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"Frank Gilliland" wrote in message ... On Mon, 01 Aug 2005 22:49:22 GMT, "U-Know-Who" wrote in : "Frank Gilliland" wrote in message . .. On Sun, 31 Jul 2005 08:36:55 -0700, "John Smith" wrote in : tnom: Yep, I always worry about terminology... It will allow you to tune the antenna/coax from a 5:1 to a 1:1 and run your transceiver into it--WITHOUT BURNING OUT THE FINALS. Guess what, John: Most of the finals used in CB radios today (and for the past 20+ years) can withstand SWR of 30:1 indefinitely. And that includes the power transistors used in amps, too. Frank, to be fair, you must now finish this statement. Even at 3 watts, some of these tiny radios and chassis don't have enough mass to dissipate the heat that will be created by the miss-match. Sure, you can add a larger sink and forced air cooling, but stock, they won't take it. I have yet to see a CB radio that couldn't handle a 3:1 SWR (unless it was improperly installed, as you mention below). And I know that those plastic Cobra 19's and those micro-Midlands can be keyed at a normal duty cycle without -anything- hooked up to the antenna jack. Some of the older radios are a bit fussy, especially those with the 2SC799. But those are becoming quite rare -- probably for just that reason. The 2SC2078 and other modern CB finals are solid transistors that are pretty darn hard to blow, with or -without- a heatsink (the TO-220 case dissipates quite a bit of heat all by itself). And it's never a bad idea to check the heat sink and mica insulator and replace the grease with Arctic Silver 5 or some comparable superior thermal compound. I lost an MRF477 due to improper installation by the manufacturer. The screw had been stripped and was not making proper contact with the heat sink, and that was with a reasonable SWR. I have seen a few Unidens with those thick, grey, rubber heat-sink insulators -- worthless crap like that shouldn't have even been installed at the factory. Another problem I've seen is amp junkies (audio and radio) who replace their own transistors and use -WAY- too much heat sink grease. They were never taught that it's only meant to fill the air gaps where there's no direct contact -- IOW, just a little dab'll do ya. Ain't that the truth! It's not magic, and like you said, it's only to fill the microscopic gaps. And to be honest, you can do a lot more by lapping the surfaces to make sure both surfaces are as flat as possible. This applies to all types of heat sink mating surfaces. |
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