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WA3VJB
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« Reply #25 on: April 11, 2007, 09:59:38 PM » |
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A bit more of W9AD, with less QSB phase distortion as I received Dave.
He had the synch detector on my signal, something worth the price of admission to that little SDR receiver I have heard a little about.
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Ian VK3KRI
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« Reply #26 on: April 12, 2007, 07:33:46 AM » |
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The way things are going now, today's SDR looks like it may eventually evolve into nothing more than a plug and play card to go inside your computer. Finally taking ham radio to it's last technical step; a computer application with no real hardware needed beyond an antenna and a mouse.
The real breakthrough will be the Antenna done in software.... |
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WA1GFZ
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« Reply #27 on: April 12, 2007, 08:27:49 AM » |
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I use I2PHD software on my SDR it has a nice sync detector.
It also doesn't need 60 meg of gatesware to run.
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Tom WA3KLR
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« Reply #28 on: April 12, 2007, 09:59:17 AM » |
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My Drake R-7 and my HQ-120X don't use any bytes.
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73 de Tom WA3KLR AMI # 77 Amplitude Modulation - a force Now and for the Future!
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WA1GFZ
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« Reply #29 on: April 12, 2007, 11:42:51 AM » |
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Tom,
But you don't have a FFT spectrum monitor or sync detector.
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WA3VJB
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« Reply #30 on: April 15, 2007, 10:33:16 AM » |
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More Flex action Saturday on 40m, including a possible newcomer to AM, Greg, WB9DNZ in central Indiana.
It's hard to argue with the kind of transmitted audio quality possible out of the SDR-1000.
Certainly, I can take Frank's analysis at face value regarding the receiver, but I wonder how many people with more average expectations would notice the comparsion he makes, and shortcomings he finds. Recordings from the SDR's receive section that come back of my station and others sound very clean to me.
Greg's station:
These recordings of the transmit section of the Flex from W8BAC and WB9DNZ are off the diode of the R390A Saturday Apr. 14, 7288Kc. No EQ, AGC is on slow.
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WA1GFZ
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« Reply #31 on: April 15, 2007, 02:32:30 PM » |
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Paul,
They do sound very good but the DDS source with BB spurs down only 70or 80 dB is very poor in my view. They plan the same thing for the 5000 which puts in in computer toy status in my view. You would think they come up with something cleaner for the big price. Even a DDS running at a 1 GHz clock has the same spur problem. I was building synthesizers cleaner than that back in the '70s knowing they were crappy. The cleanest synthesizer I have seen is the harris 590 slightly better by a couple dB close in than the RA6830.
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Steve - WB3HUZ
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« Reply #32 on: April 15, 2007, 04:35:16 PM » |
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And a Maserati will go much faster and corner better than a Toyota Camry. But for the schmo driving to and from work on crowded highways with a maximum speed limit of 55 MPH, the Camry is plenty good enough.
Ham equipment usually doesn't compare favorably to mil-spec gear. How could it? The mil spec stuff is 10-50X the price, maybe more when you throw in all the NRE paid by the government.
Each ham must decide what is good enough versus the cost when they buy, build or otherwise acquire equipment. Some decide by not even thinking about the issue (I got the 756Pro cuz all my buds have one). Others go towards one end of the continuum (entry level, low cost and such) while others go for the other end (mil-spec, custom made, homebrew, hot-rodded and the like). The majority fall in between these two. And that's who Flex is going after. Could or should their synth be better? Probably. But for the vast majority of the uses and users of these radios, it just doesn't make any difference. And that's why they are selling.
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WA1GFZ
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« Reply #33 on: April 15, 2007, 10:53:10 PM » |
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True Steve, but you can't P&M about BPL if you are generating spurs all ofer the band only down -70 dBC.
me, I still think the biggest bang for the buck is mil gear built after middle 80s. Easy to work on. no real weird parts. and real specs.
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Steve - WB3HUZ
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« Reply #34 on: April 16, 2007, 09:35:33 AM » |
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True. Although I don't recall Flex Radio P&Ming about BPL. And creating spurs within a receiver is far different than transmitting spurs that affect many receivers. Apples and oranges.
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WA1GFZ
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« Reply #35 on: April 16, 2007, 10:38:54 AM » |
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The receiver will respond on spur frequencies and that same crappy lO is mixed with the modulation so it is also making crud.
The dynamic range is degraded on a spur frequency. You can't claim 100 dB of dynamic range when your LO is that dirty unless you sell used cars for a living.
The R390A is still a great RX because it has one of the cleanest LOs on the planet.
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Steve - WB3HUZ
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« Reply #36 on: April 16, 2007, 04:53:16 PM » |
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Not sure what this has to do with BPL complaints.  |
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WA1GFZ
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« Reply #37 on: April 17, 2007, 10:37:06 AM » |
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Steve, I was just making a point. If your rig is a crap generator then you can't complain about other crap generators.
The WJ 8718 synthesizer noise falls below -100 dBC between 2 and 3 KHz off center. By the time you are out 100 KHz it is -144 dBC by my numbers. So -70 or -80 dB spurs and less then impressive performance compared to a 30 year old RX.
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Steve - WB3HUZ
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« Reply #38 on: April 17, 2007, 07:21:02 PM » |
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I think if BPL was -70 dBc, not many hams would be complaining.
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W1ATR
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« Reply #39 on: April 17, 2007, 07:46:07 PM » |
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My dogs bigger than your dog.
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Steve - WB3HUZ
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« Reply #40 on: April 17, 2007, 08:38:45 PM » |
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WOOF! |
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W1ATR
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« Reply #41 on: April 17, 2007, 10:43:49 PM » |
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poochie
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WA1GFZ
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« Reply #42 on: April 18, 2007, 09:05:03 PM » |
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But I have to say their software is very cool!
I just got the latest version working and will try it on my SDR set up.
I want to see how well the software noise blankers work.
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