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#1
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Hi Kevin,
If you have to cut bits off the coax to get the SWR down, your aerial isn't resonant on the frequency being used. The coax is acting like part of the aerial. Get the aerial resonant and it doesn't matter what length of coax you use as the SWR will not change. "Keven Matthews" wrote in message ... I recently moved my shack from an upstairs room to downstairs, much closer to the garden and antennas. All the antennas previously had a long run of coax to the old shack. The obvious thing was to have a nice new short run of coax to my HF vertical which is now only 15' away. So I cut the coax and since then the antenna is no longer resonant on 40 Metres. Also this week I was putting up a new HF wire antenna, it was getting dark and raining by the time I was hoisting it up but so I could just have a listen that night a grabbed an old (15 years) large coiled up of quantity RG213 coax complete with rotten oxydized pl259 plugs on each end which had just sat on the garage wall for years. I just slung the coil down and plugged in at each end. The plugs looked so rotten it was shameful but it pitch dark by then! However The SWR was pretty good across the band. Regardless I started my evening doing a tidy job with some of that nice 5DFB japanese coax all ready for the following day. Guess what ? I put on the nice new cable and plugs and the antenna is no longer anywhere near resonant on 80M. So why am I getting a better result with a long length of still coiled cable sitting on my patio rather that a much shorter brand new piece. Please could some one explain to me if the coax length does matter, it has certainly never been a problem for me in the past on VHF and Six but I am new to HF frequencies. If you do need to have a certain size run, what can you do with the cable if you phisically dont need it ? Many Thanks & 73 for 2004 Keven G7UUD |
#2
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Arrrg! Your making my stomach hurt reading this misinformation...
(They told me all I had to do to become a ham was to memorize these questions.) "Mike" wrote in message ... Hi Kevin, If you have to cut bits off the coax to get the SWR down, your aerial isn't resonant on the frequency being used. The coax is acting like part of the aerial. Get the aerial resonant and it doesn't matter what length of coax you use as the SWR will not change. |
#3
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w4jle wrote:
Arrrg! Your making my stomach hurt reading this misinformation... Well, let's add a few words to make his statement correct. Get the aerial resonant, with a 50+j0 ohm feedpoint impedance, and it doesn't matter what length of coax you use as the SWR will not change. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#4
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Now you are getting technical, beyond the understanding of most of today's
hams. (I looked everywhere on my SWR's meter and couldn't find a J knob and isn't a 50 to 0 SWR kinda high) "Cecil Moore" wrote in message ... w4jle wrote: Arrrg! Your making my stomach hurt reading this misinformation... Well, let's add a few words to make his statement correct. Get the aerial resonant, with a 50+j0 ohm feedpoint impedance, and it doesn't matter what length of coax you use as the SWR will not change. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#5
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w4jle wrote:
(They told me all I had to do to become a ham was to memorize these questions.) SNIP That's absolutely TRUE if all you want is to "...become a ham..." However, if you want to install and operate an efficient short wave radio station you need to learn quite a bit! DD, W1MCE |
#6
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Well said Sir!
Even the "appliance operators" of old had to know how the appliance worked. Were I the FCC, your first transmitter and receiver would be built from scratch and a minimum of 25 CW contacts confirmed before the use of a purchased rig would be allowed. Next no one would be permitted to apply for extra class without 5 years experience and 250 confirmed contacts.Also participation in a public service capacity, (i.e. traffic net, weather warning net, charity races etc) and have elemered 5 new hams. I have a friend that has an extra and has never been on the air. He took the exams at a hamfest just to see if he could pass them. He said he studied the question pools for a couple of days on-line. He spent 20 years in the Navy as a Chief Radioman, so the code was a joke for him. "Dave Shrader" wrote in message news:XnFJb.49405$I07.151812@attbi_s53... w4jle wrote: (They told me all I had to do to become a ham was to memorize these questions.) SNIP That's absolutely TRUE if all you want is to "...become a ham..." However, if you want to install and operate an efficient short wave radio station you need to learn quite a bit! DD, W1MCE |
#7
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![]() "w4jle" W4JLE(remove this to wrote in message ... Well said Sir! Even the "appliance operators" of old had to know how the appliance worked. Were I the FCC, your first transmitter and receiver would be built from scratch and a minimum of 25 CW contacts confirmed before the use of a purchased rig would be allowed. Careful, one of the local Ham "Channelmasters" will dub you a CBPlusser for using the term "contact". It's a pet peeve of his. Harold Burton KD5SAK |
#8
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Just like I had some "newby" attempt to chastise me on a 2 meter repeater
for using "handle". He told me that that word was only used on 11 meters. I had to admit, I did use it on 11 meters when it was a ham band. But thanks for the lesson Good Buddy! "Harold Burton" wrote in message ... "w4jle" W4JLE(remove this to wrote in message ... Well said Sir! Even the "appliance operators" of old had to know how the appliance worked. Were I the FCC, your first transmitter and receiver would be built from scratch and a minimum of 25 CW contacts confirmed before the use of a purchased rig would be allowed. Careful, one of the local Ham "Channelmasters" will dub you a CBPlusser for using the term "contact". It's a pet peeve of his. Harold Burton KD5SAK |
#9
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Handle was used on the HF ham bands before most of the readers were born.
Steve K;9;D;C;I "w4jle" W4JLE(remove this to wrote in message ... Just like I had some "newby" attempt to chastise me on a 2 meter repeater for using "handle". He told me that that word was only used on 11 meters. I had to admit, I did use it on 11 meters when it was a ham band. But thanks for the lesson Good Buddy! |
#10
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Harold Burton wrote:
SNIP Careful, one of the local Ham "Channelmasters" will dub you a CBPlusser for using the term "contact". It's a pet peeve of his. Harold Burton KD5SAK It may be a 'pet peeve' but what do you call: "T40E 599 TU de W1MCE" For me it's a contact! It is not a QSO. It is not a Rag Chew. It's the minimum requirement for a DXCC type CONTACT. BTW: is it Harold Burton or HALLIBURTON?? Hmmm ... ??? |
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