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#1
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Hash: SHA1 Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? I appreciate any opinions. Jim -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFHHmVGQuDJiZ/QrH0RAnRNAJ9NcIJ58EeREFNwztYV7nkCSbb+hACcDveD LHfGOxSNluOb7JXvTpx3OLY= =EEQ7 -----END PGP SIGNATURE----- |
#2
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if the radio is happily putting out its rated power then don't touch it,
keep operating! remember, too low an swr can kill you! "James Barrett" wrote in message ... -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? I appreciate any opinions. Jim -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFHHmVGQuDJiZ/QrH0RAnRNAJ9NcIJ58EeREFNwztYV7nkCSbb+hACcDveD LHfGOxSNluOb7JXvTpx3OLY= =EEQ7 -----END PGP SIGNATURE----- |
#3
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![]() "James Barrett" wrote in message ... -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? I appreciate any opinions. Jim What are you feeding your dipole with? Coax or ladder line ?I found that if you use 450 ohm ladder line for your feed the length of the feed line can cause you problems . What kind of rig are you using ? BTW welcome to the group ! 73 Will _._ ._ ..._ _ ..._ .. _.. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFHHmVGQuDJiZ/QrH0RAnRNAJ9NcIJ58EeREFNwztYV7nkCSbb+hACcDveD LHfGOxSNluOb7JXvTpx3OLY= =EEQ7 -----END PGP SIGNATURE----- |
#4
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ahso#1 wrote:
What are you feeding your dipole with? Coax or ladder line ?I found that if you use 450 ohm ladder line for your feed the length of the feed line can cause you problems. Not if your ladder-line is a multiply of 1/2 wavelengths at the frequency of operation. -- 73, Cecil http://www.w5dxp.com |
#5
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![]() "James Barrett" wrote in message ... -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? I appreciate any opinions. Jim Go up and down in frequency a few hundred KC and see what the swr is in several places. Depending on the feedline and length it should probably be lower at some frequency near 28.4. |
#6
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James Barrett wrote:
Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? That's marginally OK. What is the SWR at 28 MHz.? What is the SWR at 29 MHz? -- 73, Cecil http://www.w5dxp.com |
#7
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![]() "James Barrett" wrote in message ... Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? I appreciate any opinions. Jim If you can hear - and be heard and the band is open - then you're ok. If you can't hear or get heard - raise the antenna and try again. Good swr does not automatically mean a good antenna. |
#8
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![]() "James Barrett" wrote in message ... -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? I appreciate any opinions. Jim It's probably too long, but check it at 28 & 29 Mhz. If the SWR at 28 is better, it is too long; if the SWR at 29 is better, it is too short. Assuming you are using 50 Ohm coax, no reason you can't get it below 1.5:1. Tam |
#9
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On Tue, 23 Oct 2007 17:19:02 -0400, James Barrett wrote:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? I appreciate any opinions. Jim Nobody else has asked this magic question yet.... How high off of the ground is your dipole? --Teh |
#10
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James Barrett wrote:
Hi, I just got my new (used) HF rig, and I strung up a half wave dipole for 10 meters using 28.4 mhz in my calculations. Several hours later I am getting an SWR reading of 2:1 at 28.4mhz. Is that pretty good or should I try to do better? I appreciate any opinions. Jim Jim, whatever the in and outs as discussed in this thread, if you cut and resonate at 28.4, have the dipole at a decent height, feed it with 50 ohm coax you should get better than 2:1. Do you know what the actual resonant frequency of the dipole + feeder is? As an example I have a ten metre dipole in my loft, some 25 feet above ground. It resonates at 28.44 at the end of approx 10 metres of 50 ohm coax, the SWR is 1.4:1 . The bandwidth at 2:1 is 28.25 -28.63. At 2.5:1 it is 28.160-28.760. This is before the ATU, after the ATU the TX sees from 1:1 to 1.4:1 over the whole of ten metres. See http://www.radiowymsey.org/FanDipole/FanDipole.html Charlie. -- M0WYM www.radiowymsey.org |
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