Click here if you are having trouble logging into the forums
Privacy Policy |
Please read our Terms
of Service | Signup and
Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User
cyberhedz
sage
Reged: 07/29/08
Posts: 221
Loc: 38.16N, 76.28W
|
|
Hey folks, I'm thinking about possible getting into radio astronomy and was curious about a few things. first, yagi or dish antenna? second, software, i know i'm not nasa, but how close to imaging radio emissions can an amateur get within reason?
My starter equipment MTM CATV reciever, hooked into PC, using either a 30" sat TV dish, or like a 10 element yagi. I'm pretty good at building my own stuff and love electronics, so this seemed liek a new hobby to try out.
your thoughts?
--------------------
Sam
-CPC 1100, stock for now-
-Celestron 15X70 skymaster binocs-
-Celestron 2x barlow-
-Hyperion 13mm, 24mm-
Baader O-III filter
wishlist:
-Antares 1.6x barlow-
-Baader UHC,Skyglow & moon-
-lumicon or baader H-beta-
-DGM Optics NPB filter-
-Hyperion 3.5, 5, 8, 17, 21, Aspheric 31 & 36-
-Meade 5000 or WO 40mm super wide, maybe some lower powers, have to find some first  -
-Antares Sentinel 80mm Semi-APO-
|
StarmanDan
professor emeritus
Reged: 08/27/07
Posts: 626
Loc: China Spring, Texas
|
|
I'm also starting with the MTM CATV tuner. I'm going to start with a simple yagi as it will be easier to make. I plan on starting simple by going for radio meteors fist then I might work my way up to a radio Jove. I'd be interested in seeing what you get with your setup.
--------------------
"Starman" Dan Doyle
Texas Astronomical Society of Dallas
Central Texas Astronomical Society
8" LX200GPS w/ST80 guidescope, Canon 350D+DSI Pro
150mm f/8 Sky Watcher Refractor
10" f/4.5 Homemade Dob
RV-6 Criterion Dynascope
http://darcstar.wordpress.com
|
walt r
Post Laureate
Reged: 02/13/07
Posts: 3524
Loc: Doylestown, PA
|
|
Check through the posts in this forum. There are many links for more info in those posts as well as some discussions on equipment (receivers and antennas).
--------------------
Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
|
cyberhedz
sage
Reged: 07/29/08
Posts: 221
Loc: 38.16N, 76.28W
|
|
no offense, but those links suck in the sticky. anyone have some better place to check out? or at least just verify my setup
--------------------
Sam
-CPC 1100, stock for now-
-Celestron 15X70 skymaster binocs-
-Celestron 2x barlow-
-Hyperion 13mm, 24mm-
Baader O-III filter
wishlist:
-Antares 1.6x barlow-
-Baader UHC,Skyglow & moon-
-lumicon or baader H-beta-
-DGM Optics NPB filter-
-Hyperion 3.5, 5, 8, 17, 21, Aspheric 31 & 36-
-Meade 5000 or WO 40mm super wide, maybe some lower powers, have to find some first -
-Antares Sentinel 80mm Semi-APO-
|
walt r
Post Laureate
Reged: 02/13/07
Posts: 3524
Loc: Doylestown, PA
|
|
Well, I wasn't refering to the links in the "sticky" but to links in threads in this forum over the past year or so. Try some of these (found by looking page by page).
thread
thread
thread
thread
These are just from this year and only go back 8 pages.
--------------------
Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
|
galacticphoto
super member
Reged: 11/12/09
Posts: 119
Loc: Huntsville, AL and Atlanta, Ga
|
|
I've spent a few minutes considering exactly this topic several time, but keep coming to the same conclusion. I hope someone can point to a mistake in my thought process.
I typically image at 1 to 2.5"/pix, and find that most "interesting" subjects for "imaging" are 10s of arcsec to 10s of arcminutes. Typically the more interesting subjects, from an imaging perspective, show features down to as fine as one can go (arcminutes at least).
The beamwidth of an antenna is proportional to lambda/Ae (lambda = wavelength, Ae is effective aperture). In order to get to 30', which won't offer much resolution, one needs to go with something like a 10m dish (yagi stacks loose too much in the feed, killing the G/T), and operating at something like 2 1/2 GHz. If one wants 3', try increasing the frequency X10 (and associated tolerancing problems).
It seems that RF imaging is only for those with really big antennas (high G/T) that operate at really high frequencies (like upper microwave, or millimeter wave).
Robert
--------------------
--------------------
Mewlon250 or SPX250 on MI-250
TMB92SS or ED80 on CGE
H9+FLI wheel or Skynyx 2-0+Truetech wheel
Canon 10X42IS for two-eye visual
Nikon D2Xs + Nikkor glass for "real" photography
www.galacticphotography.com
|
walt r
Post Laureate
Reged: 02/13/07
Posts: 3524
Loc: Doylestown, PA
|
|
That is correct Robert. If you look around for more picture of radio telescopes from the 1950's 60's you'll see large fields covered with smaller dipole antennas. These were combined into a larger 'phased' array to increase the resolution. But since the frequencies were only in the 100's of MHz the resolution was still low.
Another way to think about this is compare the wavelengths of radio and visible light.
--------------------
Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
|
|
1 registered and 0 anonymous users are browsing this forum.
Moderator: RLTYS
Print Thread
|
Forum Permissions
You cannot start new topics
You cannot reply to topics
HTML is disabled
UBBCode is enabled
|
Thread views: 291
|
|
|
|
|
|
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
