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USB-DVB-T-DAB-FM-RTL-SDR-Realtek-RTL2832U-R820T-Tuner-Receiver-PAL-IEC-Inp

Started by DavePEI, August 18, 2015, 02:41:58 PM

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twocvbloke

Got a reply from the seller, their offer was to send another (which will probably vanish too), or refund, so, I'm taking the refund option, I can source one of these devices somewhere else...

19and41

Use the filter on the left to limit the search to your own nation then you can see items from those who have already imported them.
"Any sufficiently advanced technology is indistinguishable from magic."
— Arthur C. Clarke

twocvbloke

Tried that, but most of them have the tiny antenna connector rather than the standard belling type...

19and41

"Any sufficiently advanced technology is indistinguishable from magic."
— Arthur C. Clarke

twocvbloke

Not really likely, plus being in the EU bumps up the price...

I've ordered stuff from china before, it usually takes two to three weeks to get here, some more, some less, but usually it gets here regardless, just depends on the seller and how they write out the address I suppose...

DavePEI

After running into problems with SDR# V. 1361 setting the offset so it will display  the correct frequency for Ham It Up, I have switched to HDSDR V, 2.70. SDR# would crash every time I tried to set the offset at -125,000,000 as it needs to show the correct frequency.

HDSDR also has a number of enhancements which aid HF reception, and does an excellent job of monitoring all modes.

It also has an excellent frequency manager and S-Meter

http://www.hdsdr.de/

HDSDR is relatively easy to set up - you do need to download in addition to the program, the appropriate ExtIO for your dongle at:

http://www.hdsdr.de/hardware.html

And place it in the same directory as you have HDSDR set up in.

The following photo shows HDSDR receiving the Canadian Time signal, CHU on 3330 hhz.

I still intend to keep SDR# for VHF and UHF reception, as it will eliminate my having to change parameters when I receive without Ham it Up!, but for HF, HDSDR will be my go-to program.
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

DavePEI

One thing I am finding interesting with the SDR are the waterfall displays of the spectrum. As a Ham who was active before such displays were available, at first they looked like interesting graphic images, and they appeared relatively meaningless.

However, as I get more and more used to them, I am discovering how much information they contain. Now after acclimatizing myself to them for a week or two, I can determine the nature of most signals they show without even tuning to them. I can tell is a signal is just a carrier if it is CW, if it is SSB, or AM. I can see signals that are fax or facsimile, and  it is amazing how many types of digital signals I an see. I am still learning to identify other signals, just by viewing their traces on the waterfall.

What is also interesting is the number of sweeping signals are on the bands now, some sweeping up and down the band for a few hundred kilohertz, and some sweeping from the lowest parts of the spectrum to the upper parts, than beginning back at the lower end. So far, I don't know what these are, but no doubt I will learn.

I truly wonder what the "Russian Woodpecker" signals of the 80s would have looked like on a waterfall display. It would have been interesting.

Below is a typical spectrum display for the frequency range of 9 to 9.76 mhz with a number of digital signals, and a couple of AM SW broadcast stations. The AM stations may be identified immediately - they are the white blotchy traces on the screen. SSB (although there are none showing in this range right now), appear the scalloped edges only on one side of the carrier showing the modulation. Pulse type signals such as CW show as dotted lines going up the screen. I have no doubt if one became really proficient reading the waterfall displays that on strong CW signals, one could actually visually read what they were sending as they sent the message. Frequency shift signals such as RTTY show similar to CW, but with the lines separated into two tone ranges, the mark and space frequencies.

So, while I have been a Ham since the early 80s, and listening to shortwave all of my life, I am still learning, thanks to the SDR. Every day, I come cross something new!

Some might feel, "How awkward, not having a tuning knob", as I did at first, but the spectrum waterfall display makes a knob unnecessary. You can skip over blank areas of the spectrum, and directly go to the next station, and most often know exactly what type of signal it is. Technology is changing, and even this old mind is learning!
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

twocvbloke

I've yet to buy another USB doohickey, night be out of the game before I even got in it the way the chinese postal system is at the moment... :-\

TelePlay

Quote from: DavePEI on October 18, 2015, 05:51:47 AM
. . . as I get more and more used to them, I am discovering how much information they contain. Now after acclimatizing myself to them for a week or two, I can determine the nature of most signals they show without even tuning to them. I can tell is a signal is just a carrier if it is CW, if it is SSB, or AM.

Dave, you are right and the FM waterfall from a local station distant from other frequencies easily shows the modulated signal when one person is speaking. Music is much more complex in the waterfall but both are similar to the sound waves I've used for years in Audacity, just vertical instead of horizontal and not as clean.

DavePEI

I just wanted to show you another Waterfall chart - this one showing an SSB station broadcasting USB on 14.188 mhz. Note that unlike an AM signal, the fuzzy (or information) side is only on the right - on LSB, the fuzzy portion is only on the left. On AM, it extends to both sides.

What is interesting in this capture, is I caught one of the sweeping signals that starts at the lower end of the band, and sweeps up to the top. In is the diagonal line which shows in the waterfall. If you watch the lower screen as it happens, you can see it sweeping across the band, bottom to top. I don't know what this is yet, but I am intrigued by it.

Unlike the Russian Woodpecker of the 1980s, it doesn't interfere much with what you are listening to - it only causes a momentary little blip over the signal when it crosses that frequency. It is some form of spread-spectrum broadcast.

Dave
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

DavePEI

I received another SDR today, a NooElec NESDR Mini 2+ 0.5PPM TCXO USB RTL-SDR Receiver (RTL2832 + R820T2) w/ Antenna and Remote Control $34.95   

Sort of the Cadillac of SDR's with a far more stable oscillator than in the normal Chinese SDRs. Their description:

QuoteThis custom NooElec SDR is a modified DVB-T USB dongle tuned for SDR usage, including a high-accuracy, Japanese fabricated, GPS-rated 0.5PPM TCXO crystal, and improved capacitors and inductors compared to generic devices. Full compatibility with a large array of software packages, such as HDSDR, SDR Touch, SDR#, Planeplotter--too many to list.

The perfect device for learning software defined radio, on the cheap. Amateur radio, ADS-B, police & fire scanning, trunking, satellite images--you name it, this little guy can probably do it. Outperforms many devices 10x its cost!

These units are based on the R820 (R820T2) tuner IC made by Rafael Micro. This provides substantial performance improvements over R820T in both lab and real-life usage scenarios.  They have a frequency capability of approximately 25MHz-1750MHz, though this can vary somewhat from unit to unit. There is also an RTL2832 (RTL2832U) IC on board of course, which acts as the de-modulator and USB interface.


The first thing I noticed about it is its heavier construction. It is enclosed in a much stronger, and some what larger case. It runs cooler than the Generic SDR. It is more stable in the USB port, and the cable connection seems more secure than that on my generic dongle.

The biggest difference I have noticed so far is it is far more stable than the generic one. You set it on a frequency, and it stays on precisely that frequency. Whether is is more sensitive than the Generic one will take time to determine. It is at least as sensitive.

Temperature-wise, yes, it gets warm after a long period of operation, normal for SDRs, but it appears to reach a certain temperature, then stabilizes and doesn't seem to get any warmer.

Switching between the cheap SDR and this one requires no configuration changes.
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

TelePlay

I've seen this or these signals several times now, actually, every time I get up to 186 mHz.

Just discovered what this is. It's the hard disk on my lap top when my lap top is sitting on my lap. If I lift it up, they are greatly decreased. If the HD is inactive, they disappear. We've all heard the cautions of devices interfering with others and this must be one of those related to use of a computer.

TelePlay

Since my last post, I've purchased a NooElec SDR dongle and it works well. As Dave said, a better device.

Built a "broomstick" antenna Friday night (100' of 16 gauge stranded copper wire wound tightly around a 6' section of 1" PVC pipe. Put a 10" aluminum pie plate on the top end. Attached a short section of RG-59 to the other end, center lead going to the antenna and coax shield connect to copper rod ground. Works better than I expected sitting in front of an upstairs window.

20 meters has some sort of contact sweepstakes going on so a lot of activity. Conclusion, the NooElec SDR dongle and Ham-It-Up work very well and the broomstick is acceptable as a permanent indoor antenna.

Here's the current activity on 20 meters.

DavePEI

HDSDR today on 20 Mtrs (14 mhz band). Sweepstakes is keeping the band pretty busy! This is all in USB, the standard for 20 mtrs.
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

twocvbloke

Well, I finally got one of the USB sticks at long last... ;D