Indian Software Defined Amateur Radio Transceiver launched

why wait? I'm interested primarily for the reciever, it's not like it's hard to build or buy a rf sensing t/r switch, use your 718 for tx and listen on the sdr.

the 100w pa will likely be far higher in price than it's worth, building a solid state pa isn't overly difficult, the only hitch I can see is finding out exactly how they will export band switching for filtering. Any cheesy chicken bander amp can be rebuilt (ranging from adding a few components to gutting it and starting over using the nice pretty shell/heatsink) to include switched filtering and proper bias control.
ideas for pa design and filter network are readily available via google or check out ameritrons site for a full schematic on the als500.

 

I guess, to some, who think there's some form of accountability while taking one's dirt nap, as you put it, it would matter.

At least the car that I own wasn't bought with bucks derived from sweat shop labor.

 

I was more talking about... Status Symbols. To me at least, it came across you were disgruntled for not having the same level of "bling" as the kids put it.

Andrew

 

Let Us Know What You Think!

I'm glad the Indian amateur community's experimenting with SDR, but I would have liked to see some innovation beyond what is basically the discontinued 1 watt SDR Flex-Radio offered several years ago by Flex and the PowerSDR software under development by the same company.

Hey, if someone gets one of these boards, be sure and come back and post in the talk and opinons section. Let us know how you like it, and write a review if you can.

To me it's still too much money, at $479 plus shipping for a single 1 watt board, without enclosure and accessories, but I'd still like to hear your thoughts if you get one.

73 de K3VR

Brian

 

The software is the radio, so most development will come in software.

Secondly, Flex radio aren't really the ones doing all of the development:

Right from the Flex radio systems' front page:

 

I don't know how much software dev they're doing, but I know that PowerSDR 2.x is being worked on. I have no idea how much is in house and how much is open source.

I'm 99% sure I'm going to be getting a Flex 5000A soon... is there any software other than PowerSDR that people are running on it? Any other open source software?

 

The basis and foundation for PowerSDR is open source work that was contributed by others. FFTW and DTTSP, essentially. So a lot of the code base is open source that Flex did not develop themselves.

Just like Red Hat did not invent Linux, Flex Radio Systems did not invent SDR.

You might be able to use Rocky (free, but not open source), and there's also GNU radio, which is reported to work with Flex Radio systems' hardware.

 

Yep, I figured it was a mix, and I'm pretty familiar with the open source model and history. I was running an ISP on some early version of FreeBSD, then migrated it to Redhat 4.2 back in the day.

From what it looks like, anyone could build just about any hardware, they just have to write compatible drivers for the software to interface with, right? And anyone can write software to the drivers the hardware manufacturers are providing...

This could get real interesting. Probably gonna go order my Flex 5000A now.

 

Cool. I'm running Ubuntu on my desktop and have about 80 servers running RHEL, FreeBSD and Ubuntu server.

Frankly, I like Ubuntu server the best. It's debian based and pretty stable.

Correct. All you need is something to generate In phase and quadrature (I/Q) signals. Maybe some control circuitry for the bandpass filters and that's it.

I'm waiting on the mercury board from TAPR/HPSDR. It's direct sampling, 0-65MHz. Much better than any sound card SDR.

 

Damnit man! Just when I thought I had this figured out. How much for a similar HPSDR setup to match the Flex 5000A, and when's the Mercury board supposed to come out?

 

They say soon. There are boards/kits in alpha, but I don't believe they've released it just yet.

I wouldn't bank on using HPSDR as your main transceiver just yet. It's an experimental project, and not really produced for "appliance operation."

However, if you're interested in it, the website is http://www.hpsdr.org

I am primarily interested in it for experimentation, not to replace my main station radio.

 

I've been reading on there, and it seems like you could get a box going for not too much money. I think you're probably right. I should stick with the Flex as the main rig, then experiment to my heart's content on the HPSDR stuff.

What I can't find is a good explanation of what pieces it takes to get a functional radio. Most of the modules seem straightforward, but it seems like many of them duplicate some or all of the functions of some of the others.

Looks like at a minimum you need an Atlas backplane, some type of enclosure (which one?), a power supply (ATX? How big?), then some sort of receiver at a minimum.

I would love to see some example configurations with various modules (or really, an example accompanying each module's main page), to see where they're heading with this stuff.

 

There are a couple of routes you can go with HPSDR, you can even use your Flex with it.

At minimum for "sound card SDR":

- Atlas backplane
- Ozy control board
- Janus A/D module
- some sort of power supply (PC power supply)
- Frontend (Softrock, flex radio)
- reasonably fast computer (3GHz preferred)
- modified PowerSDR

This is not what you want, but this is where the project has reached so far.

However, it gets interesting, and this is what you'll need for direct sampling SDR:

- Atlas backplane
- Mercury DDC (receiver)
- Penelope DUCk exciter (transmitter)
- Ozy control board
- reasonably fast computer
- modified PowerSDR

 

That was part of what I was wondering... one option is IF out of the Flex and in to a module, but that doesn't give me direct sampling without a conversion, and the conversion is only going to be as good as the relevant frontend module in the Flex pre-IF.

Thanks for the two configurations, that actually answers one of the questions I had. It seemed like if you were going with the direct sampling, you had no need for the Janus module.


Is there a way to use the Flex as the PA for some external device (like an HPSDR), somehow inputting at IF?

 

Flex is actually a DC (direct conversion) receiver that outputs baseband i/q signals. It's no use to have it output IF just to use it with Mercury. There wouldn't be any appreciable difference in performance had you used Mercury or Janus (or even a sound card).

Yes, that's correct. Janus is basically a souped up sound card.

No idea, you'd have to ask Flex that.'

Why not join the HPSDR yahoo group, search around and ask some questions? You sound interested and you sound like you want to learn a thing or two.