Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old March 1st 09, 07:06 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2008
Posts: 133
Default OT inquiring about information on satellite modems


I bought a Comstream CM 701 Modem thru eBay. It has an input card but I
cant find information on what frequency the card is designed to accept.
The IF input card is marked 5MB Modem.
If there is anyone reading this and is willing to point me to where I can
find information on the Comstream horizontal card (plig-in), I'd sure
appreciate knowing where I can find it.

Jerry KD6JDJ


  #2   Report Post  
Old March 1st 09, 10:46 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Feb 2009
Posts: 10
Default OT inquiring about information on satellite modems

On Sun, 01 Mar 2009 06:06:13 +0000, Jerry wrote:

I bought a Comstream CM 701 Modem thru eBay. It has an input card but
I cant find information on what frequency the card is designed to
accept. The IF input card is marked 5MB Modem.
If there is anyone reading this and is willing to point me to where I
can
find information on the Comstream horizontal card (plig-in), I'd sure
appreciate knowing where I can find it.

Jerry KD6JDJ


Look he

http://www.1megastar.com/cm701man.pdf



--
73's
Ken Slimmer, WA0SBU

  #3   Report Post  
Old March 2nd 09, 12:48 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2008
Posts: 133
Default OT inquiring about information on satellite modems


"Ken Slimmer" wrote in message
...
On Sun, 01 Mar 2009 06:06:13 +0000, Jerry wrote:

I bought a Comstream CM 701 Modem thru eBay. It has an input card but
I cant find information on what frequency the card is designed to
accept. The IF input card is marked 5MB Modem.
If there is anyone reading this and is willing to point me to where I
can
find information on the Comstream horizontal card (plig-in), I'd sure
appreciate knowing where I can find it.

Jerry KD6JDJ


Look he

http://www.1megastar.com/cm701man.pdf



--
73's
Ken Slimmer, WA0SBU


Hi Ken

Thanks for the reference. I read it (again). Actually, I scanned it.
The information in that manual is difficult for me to understand. Still, I
gain a little more understanding about this"BPSK" system each time I reread
the documents.
My original goal was to assemble an antenna with the needed amplifiers and
demodulators so I can see NOAA's Earth images on the computer monitor.
When I began this project I thought the demodulator would be easy to 'hook
up'. That was a big mistake. The BPSK demodulation is like a seperate
science.

It appears that I need to find a proper card for this CM 701. I find no
reference to the "5MB Modem card in the CM701 I now have.

Jerry KD6JDJ



  #4   Report Post  
Old March 2nd 09, 09:47 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Feb 2009
Posts: 10
Default OT inquiring about information on satellite modems

On Sun, 01 Mar 2009 23:48:34 +0000, Jerry wrote:


Hi Ken

Thanks for the reference. I read it (again). Actually, I scanned
it.
The information in that manual is difficult for me to understand.
Still, I gain a little more understanding about this"BPSK" system each
time I reread the documents.
My original goal was to assemble an antenna with the needed amplifiers
and
demodulators so I can see NOAA's Earth images on the computer monitor.
When I began this project I thought the demodulator would be easy to
'hook up'. That was a big mistake. The BPSK demodulation is like a
seperate science.

It appears that I need to find a proper card for this CM 701. I find
no
reference to the "5MB Modem card in the CM701 I now have.

Jerry KD6JDJ



Jerry;
Sounds like a fun project, too bad I don't have one to play with.
  #5   Report Post  
Old March 3rd 09, 11:37 PM
Junior Member
 
First recorded activity by RadioBanter: Mar 2009
Posts: 1
Default

Quote:
Originally Posted by Ken Slimmer View Post
On Sun, 01 Mar 2009 23:48:34 +0000, Jerry wrote:


Hi Ken

Thanks for the reference. I read it (again). Actually, I scanned
it.
The information in that manual is difficult for me to understand.
Still, I gain a little more understanding about this"BPSK" system each
time I reread the documents.
My original goal was to assemble an antenna with the needed amplifiers
and
demodulators so I can see NOAA's Earth images on the computer monitor.
When I began this project I thought the demodulator would be easy to
'hook up'. That was a big mistake. The BPSK demodulation is like a
seperate science.

It appears that I need to find a proper card for this CM 701. I find
no
reference to the "5MB Modem card in the CM701 I now have.

Jerry KD6JDJ



Jerry;
Sounds like a fun project, too bad I don't have one to play with.

The Comstream CM701 modem normally uses a Comstream proprietary encoding mode and uses BPSK or QPSK to stream data. The IF is 70 MHz which is rarely used anymore. About the only thing that will decode the stream is an ABR200/202 receiver. I am afraid for the purposes you are desiring, the CM701 is going to be of little value. I have worked with them for years on SCPC program distribution networks for radio stations.

NOAA downlinks are on a variety of frequencies, but mostly on 137 MHz or 1681 MHz (or thereabouts).

Sorry,
Michael
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
wtb Ramsey Packet modems Sam Taylor Swap 0 August 30th 06 08:23 PM
cable modems? PDRUNEN Antenna 1 January 16th 05 07:18 AM
old modems [email protected] Homebrew 1 December 28th 04 01:38 AM
FS: GRAPES Packet modems Jim, N2VX Swap 0 July 27th 03 01:27 PM
FS: GRAPES Packet modems Jim, N2VX Swap 0 July 23rd 03 01:11 PM


All times are GMT +1. The time now is 01:00 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017