HFU HF Underground
Technical Topics => SDR - Software Defined Radio => Topic started by: S. McArdle on January 30, 2014, 1612 UTC
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I've been thinking of purchasing one of these. I understand it will allow u to record 192 khz of band spectrum to hard drive for later searching/replaying. Are there any other, cheaper alternatives out there that will allow one to record this amount or more, of band spectrum to hard drive? How about recording 2 separate bands at once to hard drive? Thanks in advance. Regards, Scott.
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There's also the AFEDRI.
The netSDR, while certainly not cheaper, does have the capability to produce I/Q streams for two separate bands. I am not aware of any software taking advantage of this yet, however. I keep prodding the SdrDx author, but no luck yet. Maybe if some other netSDR owners mention it to him... :-)
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thanks chris. a cursory check seems to show that the afedri can record way much more band spectrum, at about half the price. i'll keep checking them out.
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I'm happy with the Afedri, you can see some samples of it on my youtube channel under "desmoface."
Steve
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I bought an afedri back before christmas and im really happy with it.I havnt had any problems so far seems to work great.
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Has anyone used the Cross Country Wireless SDR-4+? I think it also looks interesting:
http://www.crosscountrywireless.net/sdr-4.htm
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Has anyone used the Cross Country Wireless SDR-4+? I think it also looks interesting:
http://www.crosscountrywireless.net/sdr-4.htm
It looks like a Soft Rock variant?
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Has anyone used the Cross Country Wireless SDR-4+? I think it also looks interesting:
http://www.crosscountrywireless.net/sdr-4.htm
Note, it appears to only cover a portion of the BC band if that matters? Starting at 850 kHz.
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Thanks for the responses. BDM: I did notice that its range ends at 850. That's probably OK for me--at least pirates are currently on 1710 and not 530 kHz. CS: Is that a good or bad thing if it's a Soft Rock variant? I've been trying to evaluate what I'd need/best use. I had originally thought that I should pay more for a really good SDR--something that I could regularly record the European band range with and maybe be equivalent to an NRD-535, but lately I've been thinking maybe I should just go more into the Afredi/RF Space range and use it to supplement my analog receivers. As you can see, I'm not exactly an impulse buyer...
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. As you can see, I'm not exactly an impulse buyer...
No, you mean a smart buyer ;) Better safe than sorry with a product you dislike and wasted money 8)
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Thanks for the responses. BDM: I did notice that its range ends at 850. That's probably OK for me--at least pirates are currently on 1710 and not 530 kHz. CS: Is that a good or bad thing if it's a Soft Rock variant? I've been trying to evaluate what I'd need/best use. I had originally thought that I should pay more for a really good SDR--something that I could regularly record the European band range with and maybe be equivalent to an NRD-535, but lately I've been thinking maybe I should just go more into the Afredi/RF Space range and use it to supplement my analog receivers. As you can see, I'm not exactly an impulse buyer...
If you want to record a band, then this type of an SDR isn't going to work for you, the bandwidth isn't enough. You need something like an AFEDRI or an SDR-IQ / netSDR.
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I'm glad Afedri owners here seem happy with theirs but I did read some other stories about bad overload issues. It probably depends on your environment. I'm a NetSDR guy myself but that's 3x the cost of an SDR-IQ.
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I use an SDR-IQ, and plan to pick up an Afedri in a bit. I am really not that concerned about overloading issues for the simple reason that I prefer to use highly resonant loops when possible. This form of antenna represents a tunable bandpass filter ahead of the receiver, which goes a long way to protecting a receiver from the nasties.
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Got my Afedri running last Friday. I found that if I had the RF gain cranked up I'd get lots of images from local AM broadcast stations. Leaving RF gain at around +10 with the FE gain at 2.00 seems to fix all the problems and still have plenty of sensitivity.
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I have been playing with an RTL2832 USB stick SDR. These things are cheap and plentiful on eBay now. They do not use a soundcard for I/Q processing and will cover up to a 3 MHz bandwidth. The frequency range is given as 26 to 1700+ MHz. They do work great at 26 MHz but performance drops off fast below that frequency. I've been using mine with HDSDR and SDR# software.
I haven't tried this yet, but an upconverter may be a way to record a couple MHz worth of shortwave spectrum. Maybe convert shortwave up to to 40 to 50 MHz or even higher.
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being able to record at least 3 mhz of bandwidth would be nice. i suspect it's only a matter of time before we see a usb stick with lots of bandwidth with coverage from 0-30 mhz.
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The RTL SDRs are even more susceptible to imaging and overload than the AFEDRI. Note that this is not a slam on either product, but the fact remains that there ain’t no such thing as a free lunch. Lower cost always cost you something.
The RTL SDRs bring a tremendous value to the table, they are dirt cheap and when combined with an upconverter, such as the Ham-it-Up, they provide HF to near microwave tuning range for under $100. The cost is that they are not very stable in frequency and they have poor dynamic range and image rejection. They also are not really very sensitive. But hey, it is under $100 and you are not going to get that capability in anything else until you spend many times that cost.
The AFEDRI is fairly sensitive and is good on HF, but at the cost of dynamic range, image issues, and potential overloading. But again, for $250 you will not find anything else that can compete with it. And it really is not bad, just not very good when compared to higher cost options…not really a fair comparison anyway.
The SDR-IQ has fair sensitivity, decent image rejection (compared to the 2 above), and is not overly prone to overload. It has more dynamic range than the other 2 I have listed. But it also has only 190 kHz of recorded and displayed bandwidth, and is about $500. A few years ago it was the no kidding best entry SDR you could get, today the question is much harder to answer.
And then once you are at this price point, for only a little more you can start to talking about SDR with really excellent performance and capabilities. Between $500 and $1000 things get really very good, by almost any measure.
T!
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thanks a lot for that info, token...very helpful.
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Take a look at the ELAD FDM-S2. Great SDR!