tfox at knology.net
Fri Sep 1 22:22:09 CDT 2006
I just put together a SoftRock version 5.0 board, along with the 40 and 20 meter modules. Mel Seyle (a friend of K8MMO, and an AMRAD member) and I have been firing each other up about these. This is a very small boardset that has a LP filter, crystal LO, direct-conversion-like converter (not really a mixer, a CMOS switch). It feeds the resulting "audio" into your sound card, which then does all the rest of the processing (filter/demodulator, etc) in software.
The SoftRock project uses software for windows, called "Rocky", or you can use the Flex-Radio SDR-1000 software, which has built-n support. There is also Linux software around, but I haven't played with it yet.
I purchased the Soft Rock kits earlier this year, but with the move, I didn't get around to putting them together. I think they are now selling version 6. The cost is cheap. around $27.00 I think.
This is cool. You can play with various SDR software packages for very cheap HW costs. I have been listening to 40 and 20 meters on it versus my Icom 720, and it's pretty surprising how well it works. You need a sound card that can do stereo, line in (most laptops have problems in this area).
I ended up hooking up one of my DDS modules to it as the LO (instead of the crystal oscillator), and I can tune around fairly well. I used the newer module that has an AD9835 (50MHz clock).
I see people playing with the SoftRock receivers for LF, MF, HF, even the final demod for microwave systems.
Highly recommended for cheap fun.
Some web sites:
Original SoftRock 40 (40 meters) site: http://amqrp.org/kits/softrock40/index.html
SoftRock version 5.0: http://amqrp.org/kits/softrock40/version5.html
SoftRock 5.0 for LF NDBs from Japan: http://www.geocities.jp/qrper72/srv5spurious.html
Rocky SDR software (which I like): http://www.dxatlas.com/Rocky/
SoftRock demod as Microwave Spec Anal??: http://www.ntms.org/files/Soft_Rock_5_RevA.pdf
SoftRock Yahoo group: http://groups.yahoo.com/group/softrock40
There are many others playing with the SoftRock and with other SDRs. Alberto in Italy has one, I believe. TAPR is making a multi-board SDR system, but it seems to have a lot of hardware for an SDR project. The Flex Radio (which Hal has) is a leading acndidate.
I would like to purchase a Flex Radio SDR-1000, but it is not over a kilo-buck, which eliminates it from this retired-ham's purchase list. Instead, I am warming up the old soldering iron. I would like to lay out and build a basic SDR tranceiver hardware system, but as usual, making PC boards is the limitation. I don't mind paying some, but the typical costs are high.
Would others in AMRAD be interested in helping design and test the basics of hardware for an SDR transceiver? This would be a multi-band transceiver, probably low-power (but capable of driving off-the-shelf HF amplifier boards). I' m thinking of a converter very similar to the SDR-1000, as Gerald picked out good components. I want just enough hardware to support the software. For software, we can use the Flex Radio stuff, Rocky, or other packages under Windows or Linux.
We can also use this as a baseline package to do our protocol & signal analysis.
PS: I like the idea of an AMRAD-based Linux release. If it focuses on ham radio, it will fill a niche that needs filling. I can help test. If an image of the AMRAD version can be put on the web, I can download it. I downloaded several 650MB CD images yestarday and today, it only took about half an hour each.
From the AMRAD coastal carolina bureau,
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