[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: FT-847 replacement



Achim,

At 10:48 AM 12/17/2005 +0100, Achim Vollhardt wrote:
>Hi Folks,
>all very good ideas.. but to be honest, I don't believe such a radio 
>will be produced for us.

BY the MAJOR radio mfr's...I agree!

>BUT: This does not mean, we cannot do it ourself. After all, we are 
>radio amateurs. Have a look at this:
>
>http://www.qsl.net/amsat-dsp-radio/
>
>This idea is not from me nor is it new.. but it somehow died in 2001.

Probably too soon, too much...but today it is possible.

>My proposal:
>
>- collect all needs in one document (call it 'white paper')
>- split up in subsystems and define interfaces
>- distribute work to interested OMs
>
>IF there is enough interest, this could really work.. I mean, we are 
>building satellites ourself, a transceiver is not so far fetched.

This sounds like a perfect TAPR project.  They have done such before,
perhaps married with some of our Amsat designers.  I also know some eme
folks currently heavy into designing SDR receivers.

>All this project could go under Amsat coordination.. PCBs (or even 
>modules) could be distributed later via the Amsat-shops.. and all of it 
>can/will/should be open-source/GNU public license.
>
>For shortwave, something similar exists already.. try google for 
>'picastar'.. I have built one myself and I (and many other builders) are 
>very pleased, to say at least..

I would suggest one look at Matt Ettus USRP project that exists today:
http://www.ettus.com/

I am a member of SARA and the SETI-League and both organizations are
seriously examining the use of the Ettus boards for 1420 MHz radio
astronomy receivers.  It is a mere step to a transceiver.
See: http://www.qsl.net/al7eb/raseti.htm

DSP-10, SDR-14, USRP are all steps in that direction.

I think the state of the SDR art imply a dual-conversion transceiver at
this time.  So which IF should be chosen?  28-MHz? 70-MHz? or 140-MHz?
USRP can give one a basic 28-MHz SDR for $550, right now!  Or add his
daughter boards for higher frequencies.  I like the idea of a VHF/UHF
satellite dual-RX, dual-Tx SDR as basis for all satellite bands using xvtrs.

Many of the desired attributes mentioned on this thread can be done in the
computer in sw.  Perhaps imbedded DSP makes sense though.  There are so
many directions one can go with this.

This is why I said this IS the brave new world of Ham Radio!  {I am going
to archive and outline the suggestions that have been put out over the last
couple days just for my own "white paper"}

Excellent thoughts folks!

>What do you think? Is is worth a try?

YES.  I would inquire with our Amsat digital gurus, as well.  They are in
process of pursuit of builidng the SDX for Eagle and particularly the
CC-Rider project.  Mudh talent there!

73's
Ed - KL7UW  
=========================================
http://www.qsl.net/al7eb
SETI-League Argus Station - BP40IQ
RA on 1420-MHz with 2.4m dish, meridian-scan: dec=+6
=========================================
----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home