WinRadio - Any Experiences - and some questions.

[steve_qix]

Hi!

Bill KC2IFR made a recording of me using his WinRadio, and emailed me the audio file - and I was VERY impressed with the low distortion and the quality, of what I heard so....

...I've been looking at the WinRadio product (the 313 series - external).  This is a new product for them, however it appears to be very similar to their previous version (303 series), but has some upgrades and slightly better performance in the dynamic range area.

WinRadio doesn't seem to have any specs about the skirt selectivity.  I would *assume* (bad word), that with DSP, they COULD achieve a near-perfect IF slope (straight lines).  However, they don't say anything at all about this.  Also, I would think one could achieve any slope - but no specs or info about the IF other than the bandwidth.

The receiver has a synchronous detector as one of the demodulators.  Boy, would THAT be great!

I have considered getting this product,  building a standard receiver control panel (with physical knobs, buttons, etc for common functions) to control the receiver (I can write the software for this) and using a rack-mounted flat panel display.  In this way, the receiver will "feel" (physically) like a standard receiver, but of course all of the really advanced functions will be available through the computer keyboard and mouse, if needed.

I don't know if they have a trial period or not - need to check this out!

Any experiences, good or bad?  Comments?

Thanks and Regards,

Steve

[Mike/W8BAC]

That's an interesting concept Steve. I have no first hand knowledge of the WinRadio receiver but I will say it might be worth a look deeper into the software defined receivers before you take that step.

The RFSpace SDR-14 has some fantastic specs. Check out QST December 05 issue page 63. Team that up with Moetronix SpectraView software and you not only have a great receiver but a spectrum analyzer that works from 0.025 to 260 MHz all (analog) mode. The other SDR receivers worth mentioning have been discussed here recently. Keep a look out. Flex Radio made a small USB plug in receiver some time back. I understand it runs on the same Power SDR software used today. It's small and works well from what I'm told. Sorry no model number.

Your idea of mounting it in a rack with knobs and a display sounds neat. It is the second time in 10 days I have run across an idea like this. The January 06 issue of QST is the annual vintage issue. On page 92 the author talks about his childhood dream of owning a National SW-54 and his later life realization the rig was not as hot as he thought. Further the author shows an SW-54 converted to play back internet content. They put a mini computer on the chassis and replaced the slide rule dial with a digital display.

Good luck. Let us know how it turns out. 73

Mike

[WA1GFZ]

Steve,
I have been playing with SDR software all week. Check out sdradio.org. new version .99. I've been playing with it all day. The Racal has a base band output of 6.4 KHz. that goes into the sound card. Down load it and check it out as it is free.
 I just bought a TCI8174 that does 3 conversions down to 5 kHz. The dsp samples it at 20 KHz. then does internal I/Q sync detect with image reject. It sounds real good.
No lock up time like a PLL sync detector it is right there almost no delay.
Some software packages have as much as a 3 word delay.
BTW Mark is working on a pic processor with display to control his 8174.

Flex used a DDS lo that has spurs at -75 dBC I think it needs to be a lot cleaner. They do not publish enough specs for me but it is a cool project. Bob ZM  bought a flex and Mike ZE is supposed to do some serious testing we are waiting for results.
Flex is the most popular. The software guys working on the project are very sharp.
Youngblood did a 3 part article in QEX a couple years ago down load it at flex radio and read it about 100 times.

I still feel there needs to be one stage of conversion before base band to eliminate all the crud or there needs to be a serious preselector.
You can't claim 100 dB of dynamic range if you have LO spurs at -75 dBc. The 6830 phase noise falls below 100 db at around 8 kHz dBC. My latest project I looking at almost 100 dB at 5 KHz spacing and 113 db at 20 KHz. Still working on it

I have 4 different SDR software packages I'm playing with. So far I find the SDR hanging off the racal has a slight advantage of pulling signals out of the noise.
I think the real hot set up is SDR hanging off an analog hot rod.

I just put a 1 gHz machine in the shack but still using the stock sound card.

Check out flex radio. Win radio was big bucks if I remember and early dsp.

Alberto I2PHD .99 performance closest to the TCI8174 performance.
I have not fed it an I/Q signal yet though just single ended. .99 has 2 am modes
regular AM and a phase lock mode both work well.

I have a cool LTI eval module that takes the 40.455 first IF of the Racal and converts it to base band. I think this will be a cool way to go but have not had a chance to check it yet. This would give me  1 stage of conversion with dual crystal filters of 20 or 8 KHz bandwidth depending on which chassis I interface to.

Then there is another group of very sharp guys I lurk. They want to shove everything in a FPGA and just read an A/D and drive a D/A

All you need to get started is a I/Q converter off your receiver but single ended will work is you can down convert your IF to 5 to 10 KHz.

I just noticed my novice crystal 3725 divided by 8 is around 465 kHz. flip flops make getting a 90 degree phase shift easy a splitter and 2 mixers and you are there.

Your software skills would really get some use with this stuff.
It is kicking ass and taking names performance.  Steve!