Effect of Weather on reception

Started by daveg4otu, April 28, 2009, 06:23:48 PM

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daveg4otu

Only a few days into use  here but have noticed this evening - with a band of very heavy (thundery)showers out to the N and East  of this location(Torquay) that  reception in those directions is  between awful and  poor - the number of  received signals being down at times to only one or two- and with signals dropping in and out.

Just wonder what other users experience of this  is - I know UHF sigs can be very weather sensitive.
5 Miles N of BHD at 50.28.28 N/3.30.43W...400ft amsl.

Hampshire, Devon, Dorset and Isle of Wight  Airfields Websites.....
http://devonairfields.tripod.com/index.htm

malc41

We get the same here. We overlook the river Trent, and storms/rain follows the river up towards the humber.

The frequencies being used are very short wavelength, thus can be distorted by rain etc
15 Miles East of EGNJ

CoastGuardJon

Quote from: malc41 on April 28, 2009, 06:49:15 PMThe frequencies being used are very short wavelength, thus can be distorted by rain etc

27cm wavelength, and yes, just the same effects - during the recent fine weather with HP hanging around, some very good results.
ANRB :  AOR AR8000 : Icom R-7000 : Icom IC-R9000 : JRC NRD-545 : OptoElectronics Digital Scout and OptoLinx Interface; Realistic Pro-2005 : UBC 800XLT - listed in alphabetical order, not cost, preference, performance or entertainment value!

WAL 2T

Rain attenuation isn't generally a significant factor at 1GHz (it starts becoming a big problem above 10GHz as you move closer to the water absorption line) and rain scattering will hit you at around 3-5GHz. Perhaps on weak, bursty signals it would have an effect on contacts at the edge of your coverage ranges.
Chris

Under the EGGP 27 Centreline & 15nm from EGCC

daveg4otu



Thanks for comments....

BTW- I'm not talking about  your ordinary shower of rain - Rather the kind of rain I'm talking about is  the  cats & dogs (plus frogs) kind!
5 Miles N of BHD at 50.28.28 N/3.30.43W...400ft amsl.

Hampshire, Devon, Dorset and Isle of Wight  Airfields Websites.....
http://devonairfields.tripod.com/index.htm

WAL 2T

There's a good section on Rain attenuation in Introduction to Propagation (Seybold) including the ITU rain attenuation model to play around with, scientific calculators in hand... and a strong coffee in the other


Chris

Under the EGGP 27 Centreline & 15nm from EGCC

CoastGuardJon

Hi WAL 2T, whether it's rain attenuation or what I don't know, but thick low cloud definitely makes a significant difference to my reception.
ANRB :  AOR AR8000 : Icom R-7000 : Icom IC-R9000 : JRC NRD-545 : OptoElectronics Digital Scout and OptoLinx Interface; Realistic Pro-2005 : UBC 800XLT - listed in alphabetical order, not cost, preference, performance or entertainment value!

HadNav

Cloud below a planes height will affect radar. Thats when I hear strange throttle ups and downs when the planes can't be observed visually or are just plane noisy!

HadNav

Water vapour attenuates radar frequencies also sat tv.