Go Back   IceInSpace > General Astronomy > Radio Astronomy and Spectroscopy

Reply
 
Thread Tools Rate Thread
  #1  
Old 20-06-2018, 05:50 PM
pbrowne (Peter)
Registered User

pbrowne is offline
 
Join Date: Mar 2016
Location: Perth
Posts: 7
Hydrogen Line observation - Interference from trees

I am setting up a 2.4 metre parabola pointing straight up to observe the 21cm hydrogen line at 1420MHz with meridian drift scans.



I'm planning to place the dish on a steel pole embedded in the ground and protruding 2 metres from the ground surface.


There is a tree some metres away that has a few branches well overhead of the antenna. It's a Eucalyptus tree, so not heavy with green leaves.


Question: Should I be concerned about interference from a few overhanging branches (say about 15 metres above the dish)?



My understanding is that shorter lines in the cm range should be less affected by interference (e.g weather), but I'm not sure about trees.
Reply With Quote
  #2  
Old 21-06-2018, 07:46 PM
billdan's Avatar
billdan (Bill)
Registered User

billdan is offline
 
Join Date: Mar 2012
Location: Narangba, SE QLD
Posts: 1,551
My UHF digital TV operates at 500-800Mhz and I have perfect signal/pictures with the antenna looking through the trees. The transmitter is 45Kms away.

So you should be OK, I think.
Reply With Quote
  #3  
Old 22-06-2018, 06:42 AM
bojan's Avatar
bojan
amateur

bojan is offline
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 6,932
You might be OK with couple of branches...

However, when I experimented with my 21cm receiver, nearby hedge was very good thermal radiator, signal was significantly stronger than MW when I pointed antenna in hedge direction.

Last edited by bojan; 22-06-2018 at 06:59 AM.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 05:09 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Testar
Advertisement