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#1
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On Thursday, December 18, 2014 2:13:00 PM UTC-6, Channel Jumper wrote:
One other thing - as Columbo would say, the SWR meter does not indicate resonance, it only tells you what the feed line tells it. By changing the length of the coax you can make the antenna appear as being resonant or non resonant, even though the antenna may or may not be a perfect 50 ohm load. If changing the length of the coax makes large changes in the SWR, that just shows you have poor decoupling from the antenna to the feed line. Need a balun or choke, or a better balun or choke than what is being used. What you state is largely a CB radio wives tale, due to most of them not properly decoupling the antenna from the line. With proper decoupling, the length of the coax will have little bearing on the SWR seen at the rig. It will be the same as what is seen at the antenna input, minus any decrease in SWR due to coax loss. IE: very high coax loss can make anything look good at the rig. |
#2
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![]() Quote:
The reason I use the term CB radio is because most people gets their start on the Chicken Band and you don't have to have a lot of intelligence to use something that only takes place on less then 1 MC of bandwidth. You can practically cut a piece of wire to a resonant length and throw it up in a tree and not even use a piece of coax and talk on all 40 channels on a CB radio without a tuner. When you become a ham and you want to talk everywhere, you must learn a little about feed lines and antenna's and what works and what does not and what a antenna tuner really does and what it cannot do. The most hilarious people to me are the ones that uses non resonant antenna's, an amplifier and a antenna tuner and just because their signal is loud and strong they think that they can overcome being resonant. They end up talking to other LIDS with the same situation and the only people they can hear are those that are the loudest! I have owned a G5RV that I bought at a hamfest 4 years ago that was only out of the bag once, and even then only for one week. The first time I tried to operate on 40m with it 20' off the ground, which was as high as I could get it on poles placed on my lot - everyone on 40m told me to get the heck off the G5RV, which was incentive enough to find something better and quit fooling around with junk! As far as me not being a ham - you have your opinions and I have mine! 10-4 Rodger Dodger, I'm gone!
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No Kings, no queens, no jacks, no long talking washer women... |
#4
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On Fri, 19 Dec 2014 16:38:58 +0000, Channel Jumper
wrote: If you transmit a dead carrier and you don't say anything you are in fact violating the Part 97! As long as you identify yourself at the end of the transmission (and every 10 minutes), and not interfering with anyone, methinks it's legal. There's no lower limit on the speed of a CW transmission. Let's do the math for the MINIMUM Morse code speed: http://www.w8ji.com/cw_bandwidth_described.htm 1 / (0.002 WPM * 0.83 baud/wpm) = 602 seconds (10 mins) So, if I were experimenting with ultra narrow band long range Morse code or data transmission, that requires that I send very slowly, my MINIMUM speed would be 0.002 words per minute before one needs to identify. Disclaimer: I am not an attorney. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#5
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![]() "Channel Jumper" wrote in message ... Sorry Jeff, but you just shot yourself in the foot! If you transmit a dead carrier and you don't say anything you are in fact violating the Part 97! All you people did was reaffirm what I had already said. The sad fact is that we give out licenses like lolly pops at a barber shop with no real instruction involved and once a person gets a license they automatically think that they don't need to know the rules or anything that they learned to pass the exam to get the license. Had we had real Elmer's when we gave out those licenses, we wouldn't have 90% of the garbage we hear today on the HF radio! As far as amplifiers goes, yes I can see someone using a amplifier on 160 meters in the summertime, but the rest of the time, all they are doing is broadcasting - not really serving any purpose. If the OP bought a commercial OCFD in the first place - he wouldn't have these problems. The people that made comments about their OCFD out performing a center cut dipole for X frequency doesn't understand how a OCFD works. If you have a 80m OCFD and you use it on 10 meters, it acts like a 8 wavelength long 10m dipole. You actually get a realization of GAIN from the OCFD when you use it on 40 or 20 or 10m... Unfortunately in my book to realize gain you must give up something in one direction to improve your signal in another. So the term GAIN really isn't relevant here. Instead of using the term GAIN I should say improvement, because improvement would be a more relative term. Yes, I got my ham license out of the same Cracker Jack box that I got my First Class Phone license out of around 1972. The OCF I have is home built, but the blaun was bought. It does not take too much to add about 40 feet of wire to one side and 80 feet to the other side. The testing I did was on 80 meters around 2 or 3 in the afteroon. The band was almost dead, Not a signal within 50 khz of either side of where I was testing. I did ID and ask if the frequency was in useseveral times during the test. Ham radio is partly for testing and experminenting. That is what I was doing for about the 10 minuits total. You can look in the books and theory and everything else, but unless you put up several antennas and compair them in the same area like I have , it is all just a guess. The ground, trees,and atmosphere are almost impossiable to modle on a computer for every location. The OCF I was compairing was to an 80 meter dipole on 80 meters only, not other bands. Without being able to rotate an anenna, you have to take what you get as far as where the main lobe of the signal goes. Most of the ones that complain about amplifiers not being needed are the ones that don't have one,but wish they did. I seldom run one,but at times it does make a big differance in making good contacts and not. Same as with a beam. People with poor antennas say they can work all they can hear,but they do not realise they are not hearing much either. I don't knock people with poor antennas. At one time I did not have a very good antenna system either. Lived on a small lot without any trees and the best I could do was a dipole up about 20 feet. Still had fun with what I had. The name is real and the call is KU4PT, unlike some that post on here witout a real name or showing a call. --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com |
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