cling film?


John Fell
 

Ah yes ,
A mini olde style Fylingdales Radome would work .You may find /p operation would bring more attention than you would like and if it was windy ........

Good to see the next generation working through the systems Engineering we had to do on narrowband 10GHz back in the late 1980s ,Such Fun .
73
John
G0API

On Sun, 24 Jan 2021 at 16:34, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Hi Ben,
Polystyrene boxes and cling film are OK for temp /P .
Keep up the good work .
73
John
G0API


Thanks John. 

Should do a little better this year, didn't start in this field until April last year so should get 3 months of extra points, hi.
Thinking on keeping rain off the radiator, a balloon would be good, blown up to cover but not touch the elements but can't get it on, hi. 

Need like a sphere, in two halves, bottom has coax though it first, connected, then bottom and top halves joined together to keep the rain off the radiator, hi. 

All good fun!

Ben 


militaryoperator
 

Hi Ben,
Polystyrene boxes and cling film are OK for temp /P .
Keep up the good work .
73
John
G0API


Thanks John. 

Should do a little better this year, didn't start in this field until April last year so should get 3 months of extra points, hi.
Thinking on keeping rain off the radiator, a balloon would be good, blown up to cover but not touch the elements but can't get it on, hi. 

Need like a sphere, in two halves, bottom has coax though it first, connected, then bottom and top halves joined together to keep the rain off the radiator, hi. 

All good fun!

Ben 


ian hope (2E0IJH)
 

Totally off topic, but I burst into laughter when saw cling film as title, as had been watching the re-runs of London's Burning on drama, If anyone remembers  Cling Film was one of fire fighters
 
Ian
M5IJH

 
 
Sent: Sunday, January 24, 2021 at 11:16 AM
From: "Andy G4JNT" <andy.g4jnt@...>
To: "UK Microwaves groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] cling film?
A different sort of use, but I used to use cling film and silicone grease along with a tie wrap to hold it in place,  to protect the end of a run of EW90 guide when the dish wasn't connected to it.
 
Andy
 
 
On Sun, 24 Jan 2021 at 11:14, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
As my uw antennas are all temporary, ie I put then up and down only when needed, akin to portable op's but from the home qth, I noticed after the last 23cm use which was in the rain here, got soaked inside but that's another problem, that there was water shorting or very nearly shorting the folded dipole to the boom. 
 
I guess those with permanent setups way up high have other techniques for wx or such.
 
Has anyone with portable experience, non so far here, tried say cling film over the radiator or a plastic bag etc? 
 
My 23 and 13 are standard Yagi folded dipole type, I'm ok on 9, its a flat panel in an outside protective cover and my 10Ghz ex mil dipole on wg feed did have a plastic cover over it, presumably to stop the ingress of water to the wg but it was cracked so I removed it. A small piece of cling film over the end would stop any ingress I'm guessing. 
 
Anyway, thoughts?
 
Ben.G4BXD
 

 

 


alwyn.seeds1
 

Dear Ben,

My stacked 23 cm Wimos detune significantly in the rain- return loss falls from 15dB to 11dB (corrected for feeder loss). Have known this to trip the PA in torrential rain, before I added a circulator.

I have some professional shrouded Yagis that I might replace the Wimos with; these use heavy plastic shrouds and and are massively constructed, but gain at 23cm is lower.

That said, you’re not losing a lot of signal with a 10dB return loss at the feedpoint.

Regards,

Alwyn G8DOH
  
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


John Fell
 

Hi Ben,
Polystyrene boxes and cling film are OK for temp /P .
Problem at 1.3GHz and above are large rain drops gathering close to the feed entry which will do their dielectric thing and reduce signals .Hard to wipe off up a mast ....
Longer term radomes can use thin PTFE sheet secured across Horn/feed mouths .Ideal mounted so water slides of and cannot puddle .Use RTV silicone adhesive to retain in place .Check the installation daily from ground to ensure birds have not  pecked through the sheet .A small drainage hole at the lowest point will help to eliminate and condensate .
I am a big fan of spray on or dipped Silicone conformal coating - works VERY WELL.

It is a good idea to have an idea of "average" conditions , so a daily check can be made using the system.Sun noise is a good near calibrated source or Cold Sky /ground on the higher uwave bands .

Keep up the good work .

73
John
G0API

On Sun, 24 Jan 2021 at 11:14, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
As my uw antennas are all temporary, ie I put then up and down only when needed, akin to portable op's but from the home qth, I noticed after the last 23cm use which was in the rain here, got soaked inside but that's another problem, that there was water shorting or very nearly shorting the folded dipole to the boom. 

I guess those with permanent setups way up high have other techniques for wx or such.

Has anyone with portable experience, non so far here, tried say cling film over the radiator or a plastic bag etc? 

My 23 and 13 are standard Yagi folded dipole type, I'm ok on 9, its a flat panel in an outside protective cover and my 10Ghz ex mil dipole on wg feed did have a plastic cover over it, presumably to stop the ingress of water to the wg but it was cracked so I removed it. A small piece of cling film over the end would stop any ingress I'm guessing. 

Anyway, thoughts?

Ben.G4BXD


Andy G4JNT
 

A different sort of use, but I used to use cling film and silicone grease along with a tie wrap to hold it in place,  to protect the end of a run of EW90 guide when the dish wasn't connected to it.



On Sun, 24 Jan 2021 at 11:14, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
As my uw antennas are all temporary, ie I put then up and down only when needed, akin to portable op's but from the home qth, I noticed after the last 23cm use which was in the rain here, got soaked inside but that's another problem, that there was water shorting or very nearly shorting the folded dipole to the boom. 

I guess those with permanent setups way up high have other techniques for wx or such.

Has anyone with portable experience, non so far here, tried say cling film over the radiator or a plastic bag etc? 

My 23 and 13 are standard Yagi folded dipole type, I'm ok on 9, its a flat panel in an outside protective cover and my 10Ghz ex mil dipole on wg feed did have a plastic cover over it, presumably to stop the ingress of water to the wg but it was cracked so I removed it. A small piece of cling film over the end would stop any ingress I'm guessing. 

Anyway, thoughts?

Ben.G4BXD


militaryoperator
 

As my uw antennas are all temporary, ie I put then up and down only when needed, akin to portable op's but from the home qth, I noticed after the last 23cm use which was in the rain here, got soaked inside but that's another problem, that there was water shorting or very nearly shorting the folded dipole to the boom. 

I guess those with permanent setups way up high have other techniques for wx or such.

Has anyone with portable experience, non so far here, tried say cling film over the radiator or a plastic bag etc? 

My 23 and 13 are standard Yagi folded dipole type, I'm ok on 9, its a flat panel in an outside protective cover and my 10Ghz ex mil dipole on wg feed did have a plastic cover over it, presumably to stop the ingress of water to the wg but it was cracked so I removed it. A small piece of cling film over the end would stop any ingress I'm guessing. 

Anyway, thoughts?

Ben.G4BXD