HFU HF Underground

Technical Topics => SDR - Software Defined Radio => Topic started by: syfr on July 01, 2020, 1403 UTC

Title: Chinesium "msi sdr" (Blue dolphin)
Post by: syfr on July 01, 2020, 1403 UTC
I got one of these to compare to the RSP1 they're supposedly similar to.  First thing I noticed is that something was rattling inside the blue anodized case.

I took it apart (4 small screws on each end) and the board slides out of its extruded aluminum case.

That's nifty BUT what it means is there's zero electrical  connection from the board to the case.

I soldered a small piece of solder wick to the ground plane, filed off the anodizing from the mating surfaces of the housing, pinched the solder wick between one end plate and the case and tightened everything down tight. Now there's a good ground connection between the board and the case.

As usual, the Chinese ALMOST get things right.... but....

 Now, to see how it works with openwebrx.
Title: Re: Chinesium "msi sdr" (Blue dolphin)
Post by: ChrisSmolinski on July 01, 2020, 1415 UTC
Pride Of China  :)

Let us know how (if?) it works!

What was the price? eBay or AliExpress?
Title: Re: Chinesium "msi sdr" (Blue dolphin)
Post by: syfr on July 01, 2020, 1803 UTC
Indeed.... pride of China. The other one I got doesn't rattle. The guy who's in charge of making sure they rattle must have missed that one.

So far, I'm pleased.  I'm running the new openwebrx and though I won't declare victory from images until I take a peek at the low end of 40M this evening.


is the link. I can never remember how to post images on this board.  If you zoom in there, you can see a fair amount of detail in the waterfall.

Anyway, it's pretty decent.  I'll wring it out some more this evening.  I can already tell it's much better than the RTL-SDR, and it should, as it's got 4 more sampling bits to work with than the cheap dongle. This one is a semi-cheap dongle ~$45 delivered from an EBAY reseller.  It's a few more bucks to get the throw-away pigtail and vertical antenna.

More later, but good stuff so far.  It "chooses to identify" as a RSP1 (or 2) as far as defining it in a configuration file.
Title: Re: Chinesium "msi sdr" (Blue dolphin)
Post by: ChrisSmolinski on July 01, 2020, 1818 UTC
Interesting, from this page it seems like not only is it a RSP1A clone but also using fake Mirics chips  :) https://www.rtl-sdr.com/photos-of-the-msi-sdr-dongle-a-new-sdrplay-rsp1-clone/comment-page-1/
Title: Re: Chinesium "msi sdr" (Blue dolphin)
Post by: syfr on July 02, 2020, 1401 UTC
Messed with this last night and this morning and I'm satisfied with the performance. It's a RSP1A in performance (I have one to compare against).  For $45 bucks it's a keeper. Listening to CW on 40M this morning. \\
Title: Re: Chinesium "msi sdr" (Blue dolphin)
Post by: syfr on December 09, 2020, 1347 UTC
Here's a followup.

These things are not as good as the real thing (which is not stellar to begin with) when running and they don't reliably continue running on my RP3's.   They frequently latch into LaLa land when one changes the profile from one band section to another and they consume more power than the original. The latter might be related to the latchup even though I'm using a 3A Chinese supply (I know...)

When they work, they're not bad for a semi "disposable" SDR. When I have time I'll mess with it again on a more robust linear supply.
Title: Re: Chinesium "msi sdr" (Blue dolphin)
Post by: Quinta on September 19, 2021, 1614 UTC
i have both clones, boss sdr and msi.sdr.
On hf i don't see difference between them. But i got msi.sdr with wrong rf switches installed on pcb, and he start working properly only after replacing them. On radioscanner.ru user msi.sdr make schematics of msi's filter block.
Both receivers catch harmonics from 6 mhz on 0-3 mhz band.
Title: Re: Chinesium "msi sdr" (Blue dolphin)
Post by: JustGreg on January 08, 2022, 2144 UTC
I have gotten one today.  The quick look after installing the drivers via doing SDRuno install is my does work.  It only draws about 120 mA compared to 330 mA of my RTL-SDR.  The laptop battery life should be better.  I have Mini Circurits ZSJM-2-1 splitter installed.  This allows me to compare the MSi.SDR against the Malachite DSP SDR receiver with out switching.

I normally use Console program for SDR devices.  After getting the correct driver installed, Console works normally.  A quick check of the various stations in my favorites shows for:

Medium Wave  this is a bit deaf for the local AM,

Short Wave (HF), it appears to be as good as the Malachite, but, tonight's listening session should give the final verdict,

VHF, MSi.SDR is definitely deaf compare to the Malachite for FM broadcast and NOAA stations.  MSi.SDR is OK for local stations.

For the price, one I got is worth it.  I do not have any rattles with this unit.  I guess the manufacture saw the post by Syfr and got after QC (his brother in law) to perform better.    If I find any other "Oh by the Way" items, then I will up date this post.

"Oh by the Way":
I found the intermodulation products mentioned by Quinta.  Found Brother Stair at 1901 KHz.   I found 1 MHz bandwidth to be a little better for less intermodulation products.  The Malachite has similar problem.

Listening to some VOLMET stations (generally weak for me) show the MSi.SDR to be about 6 to 10 dB less sensitive than the Malachite.  Both use the same chip as RF front end.

After 2 plus hours of operation, the case is still about room temperature.  The device is not warming up like other dongles that I have used.

The bottom line on this one, is good for shortwave broadcasts, but, not so good for chasing weak signals.  For its cost, it is Okay.