| Author |
Message |
    
Nightlinks
Member
Username: Nightlinks
Post Number: 65
Registered: 1-2009
| | Posted on Wednesday, May 06, 2009 - 2:54 pm: | 
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Hello,
Does weather condition change swr readings? Yesterday it was raining over here in NYC and saw my swr reading at less than 1 and it's usually at 1.7 when it is not raining. I'm not sure if cold weather changes swr reading since i just got my meter.
CEF#1021
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Bruce
Senior Member
Username: Bruce
Post Number: 5046
Registered: 9-2003
| | Posted on Thursday, May 07, 2009 - 8:50 am: |
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VSWR ( SWR ) can never be less that 1:1 however YES if a CB antenna gets wet it will change it somewhat.
The old hallos and squailos on 6 and 2 meters were VERY easly detuned by water with some going to 3:1 when wet.
Any reading under 1.5:1 the loss is very small under 4%.
On 6 since 66
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Nightlinks
Member
Username: Nightlinks
Post Number: 67
Registered: 1-2009
| | Posted on Thursday, May 07, 2009 - 7:26 pm: |
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Thanks Bruce,
CEF#1021
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Tech237
Moderator
Username: Tech237
Post Number: 1156
Registered: 4-2004
| | Posted on Friday, May 08, 2009 - 11:38 am: |
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Bruce is correct, most antennas will change a little as weather conditions change. However if you see a large change, say 1.5:1 going to 2.5:1, then I'd start looking for things like cracks in insulation on both the antenna and the coax.
Over the years, I have noticed that fibreglass covered (radomed) antennas are less prone to VSWR shifts in bad weather than more exposed ones, and that coax is less prone than open wire feeder.
Simon
Tech237
N7AUS
.
I thought he said, "there was no rust for the wicked, and I own an MGB"
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Flying_cloud
Junior Member
Username: Flying_cloud
Post Number: 24
Registered: 4-2009
| | Posted on Friday, May 08, 2009 - 9:35 pm: |
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one thing I noticed with my wilson 5000 mobile is when driving the wind moving the antenna will cause the swr raito to change but when stopped it will return to 1.3:1 just thought you would like to know this little bit of info |
