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my SWR reading
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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----- |
my SWR reading
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----- |
my SWR reading
"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----- |
my SWR reading
"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. |
my SWR reading
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 |
my SWR reading
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 |
my SWR reading
"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. |
my SWR reading
"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 |
my SWR reading
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 |
my SWR reading
Try transmitting up and down the band to see where your lowest swr is.
Then you can shorten or lengthen the antenna a bit to get a low swr in the 28.4 mhz range. If you can't quite get it to 1:1, coiling the coax at the feedpoint, 4 or 5 turns about 6 inches in diameter can get you pretty close to 1:1. 2:1 isn't bad, but you're probably not getting full power output if your rig is solid state. ================================= When SWR is 2:1 the reflected power is only 11% of the tx output power, which will hardly be noticeable at the receiving end . Even when SWR would be 3:1 only 25% of the transmitter power would be reflected , still resulting in only a fraction of an S-point at the receiving end. But a low SWR will make the solid state PA of your radio feel happier ! Frank GM0CSZ / KN6WH |
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