Sidebar Sidebar
  • You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

output power for sat uplinks??

C

Chatter

Member
Oct 28, 2009
33
0
16
chambersburg pa
ive been fooling around on the amsat and satscape sites trying to get comfortable with sat tracking. when im ready, what kind of output power should i start with to make contact? i dont wanna end up using over kill
 

What radio are you going to use? If you're doing it with an HT, set it to 5 watts. Did you watch the video I made on how to do this?
 
i saw the video you made on sat coms w/ your hand held. is that an ht? thats where i heared of satscape. pretty cool stuff man! ill be using the vx-8r when it gets here, should be wednesday or thursday. i still have to save up for that antenna though. 5 watts is the max for vhf on that radio isnt it?
 
Yeah, 5 watts on VHF is the max for most HT's. It's enough to hit the satellite, especially if you're using a yagi. You can home-brew one for about $25 or so if you want to do that while you're saving for the Arrow version. The homebrew one won't be portable, but it will still be handheld. I made one for 1.2Ghz...only took a few hours. The measuring of all the elements was the most time consuming part.
 
I'm not sure I understand your question? You TX on the Uplink frequency and RX on the downlink. When the satellite starts it's pass, start listening on the higher frequency and change it to the lower frequencies as it moves by and it starts to fade out on each one. After you do it once, you'll see what I mean. You don't need to shift the TX frequency on 2 meter uplinks.
 
i understand the doppler shift freq change, but by saying you do not need to shift tx, do you mean rxing on a seperate freq than txing.? oh ok, 2 meters tx and rx on the same freq.what about 440 MHz?
 
You TX on 2m and RX on 440 Mhz. You can either do this by programming an odd split or using both VFO's
 
i guess i could have asked that differently. what i meant was, i saw multiple uplink freqs and multilpe downlink freqs. which rx freqs do you listen to from which tx freqs?
 
OK, I understand now. Satscape lists all of the frequencies that the bird uses, but it doesn't tell you what they're for, or when they're active. You need to keep an eye on the frequency schedule for the bird you want to work on AMSAT - The Radio Amateur Satellite Corporation. Here is the page for AO-51: AMSAT - The Echo Project Page The one you want is the Analog uplink and Analog downlink. On that satellite, 145.920 Mhz is always active for uplink and 435.300 Mhz for downlink. You can also look at the Satellite Maps link on the navbar above which shows you real time mini maps of all of the common birds as well as the regular frequencies used. That page is good for a quick snapshot...you'll still need to use satscape (or something similar) to get the exact pass times.
 
I'll jump in here and so hi I'm new around here and have only been a ham for around a year. just wondering if i could get the directions for that homebrewed sat antenna??
the 2m/440
 
Here's a thread where I made the 1.2Ghz version. The PDF that is attached to the first post in the thread has the instructions. Perhaps I should make a new thread with just the instructions attached. If you go through that thread you can see some attached pics of a 2m/440 one for satellite usage. If you make one, make sure and show us your finished product and describe what you did :0

http://www.worldwidedx.com/home-brew-mods/35899-homebrew-1-2-ghz-10-element-yagi-antenna.html
 

dxChat
Help Users
  • No one is chatting at the moment.


      Top Bottom
      Back