MSI-sdr sdr key not working?

[Brookline]

Hello, i m new with sdr and using since two weeks the sdr key MSI-sdr panadapter, see picture herewith. Is there somebody else than me, on Earth, using this device? The problem is i can hear only very strong radios, there is a very high noise with this key: 9+10 without antenna. Impossible to find on the web who has built this key!
i use this key with HDSDR 2 76 and the set up for hdsdr is not easy... To adjust something, for me it is as to find a needle in a hay stack! There are many hdsdr pages on the web, so you can search a long time, but without finding a reply to your problem...
So if somebody has the msi-sdr key i will be pleased to know how it works.
herewith is also a picture of the hdsdr panel , WITHOUT antenna connected to the msi key so you will see the noise level... thank you for your attention.

 

[spongella]

Your frequency indicates that you are in the 6 MHz area. SDR dongles (or as you say "Key" ) do not cover that portion of the band and generally receive from about 25 MHz and upwards. Somehow your HDSDR settings are off.

I suggest that you try SDR# before trying HDSDR or other programs. In my many years of experience it's the best software for beginners.

You can find this information on www.rtl-sdr.com Search the articles on how to use SDR#.

 

[hamradionl]

@Brookline
Gain set to high?
MSI-sdr is the same unit as SDRplay-1 (RSP1) Look/read there.
Not/No the same RSP1A

 

[slicerwizard]

Your frequency indicates that you are in the 6 MHz area. SDR dongles (or as you say "Key" ) do not cover that portion of the band and generally receive from about 25 MHz and upwards. Somehow your HDSDR settings are off.

I suggest that you try SDR# before trying HDSDR or other programs. In my many years of experience it's the best software for beginners.

You can find this information on www.rtl-sdr.com Search the articles on how to use SDR#.

I think that all of that was poor advice. An RSP1 clone should RX that low and last I heard, SDR# doesn't support SDRPlay devices or their clones.

Hopefully, the OP just has the gain through the roof.

 

[Brookline]

Your frequency indicates that you are in the 6 MHz area. SDR dongles (or as you say "Key" ) do not cover that portion of the band and generally receive from about 25 MHz and upwards. Somehow your HDSDR settings are off.

I suggest that you try SDR# before trying HDSDR or other programs. In my many years of experience it's the best software for beginners.

You can find this information on www.rtl-sdr.com Search the articles on how to use SDR#.

hello spongella, thank you for the reply. i have seen sdr dongles work usually above 25 mhz. The dongle picture in my first post is not very good so i send a new one and on it you will see the range indicated is 10 KHZ to 2 ghz! However i will have a look to SDR#...

 

[Ubbe]

I have the same msi.sdr device and it performes better than than the rtl-sdr in VHF/UHF with better sensitivity and less internal spurioses.
I have a level of -95dBm in the 6MHz range without antenna and I use SDRUno. What levels are shown in the windows can be calibrated so I don't know what the actual lowest receivable signal are at 6Mhz. -95dBm equals 4uV. I can dust off my signalgenerator and check what the actual sensitivity are at different frequency bands.

The major difference to other dongles are that it can sample a 10Mhz wide area and are worth the extra money just for that feature. The whole VHF air band can be searched between 1 and 2 seconds depending of active interfering signals in the band.

/Ubbe

 

[Brookline]

thanks to everybody for your help.
speciel post for Ubbe because you have the same device.
it seems your msi dongle is working normally? so i have questions:
1- i have a red light on my dongle near the antenna plug. on your device is this light always ON and red?
2 -i made test with sdruno , sensitivity seems to be always low in 6 mhz band. But the s meter seems to be more normal, maybe too low ( it shows s6 but i am sure the station is normally at s9 minimum). I hear only 2 or 3 broadcast stations, late in the evening when propagation is good.
I add to this post a picture with sdruno. Maybe you could have a look to see if someting is wrong?
thank you.

 

[Brookline]

thanks to everybody for your help.
special post for Ubbe because you have the same device.
it seems your msi dongle is working normally? so i have questions:
1- i have a red light on my dongle near the antenna plug. on your device is this light always ON and red?
2 -i made test with sdruno , sensitivity seems to be always low in 6 mhz band. But the s meter seems to be more normal, maybe too low ( it shows s6 but i am sure the station is normally at s9 minimum). I hear only 2 or 3 broadcast stations, late in the evening when propagation is good.
I add to this post a picture with sdruno. Maybe you could have a look to see if someting is wrong?
thank you.

hello everybody, here some news after i made some tests.
i compared the sdr signal with the signal of my trafic radio receiver.
iI have put the sdr antenna ( wip antenna about about 1 m long delivered with the sdr dongle) on my trafic receiver in the 6 mhz band: the signal was about same level as sdr on pc, with sdruno : about s 6 (exactly on the same radio station). when i used the normal antenna of the trafic receiver, the signal was s9+ 20! I have to say this antenna is a 30 m long wire in my garden... so may be my msisdr is probably normal and for short waves i should try tu put a correct antenna...
however it seems there are problems with HDSDR,because the s meter is absolutely not correct and impossible to calibrate with the options functions.
one question for you Ubbe if you read this: : what about the light on the msi sdr?
thanks for all.

 

[Ubbe]

I don't know what the red light indicates, it's always on, so probably that it has power from USB.

I measured the MSI and the RTL-SDR and the RTL looks like expected but my MSI is really strange in its sensitivity.
I calibrated the MSI in External Front End Gain to +8 and the values in SDRUno then match exactly with my signal generator.
First row are MHz and second are MSI in uV and third row RTL-SDR. I tried directsampling with RTL-SDR in SDR#
but it's dead below 25MHz.

I used SDRUno for MSI and setting the IF to ZIF gave worse sensitivity and terrible audio quality, it has to be in LIF mode.
The gain has to be at max, or one step above lowest as the lowest and third dosn't give enough gain, that are shown
above the gain adjustment. The gain should be around 60-70dB. The MSI has less internal noise and interference
and seem to handle strong signals better than RTL-SDR with less IM but I measured only the test bench sensitivity.


1010 2,5 1
810 0,5 0,25
751 0,5 0,25
450 0,3 0,3
421 0,25 0,2
381 3 0,2
331 1,7 0,2
311 1,5 0,15
281 1,2 0,3
251 3 0,25
221 1 0,5
211 1 0,2
171 1,3 0,3
161 1,3 0,25
151 1,5 0,5
141 1,7 0,2
131 2,5 0,3
121 2,5 0,4
120 2,5 0,4
119 0,3 0,25
118 0,3 0,25
85 0,3 0,25
75 0,4 0,35
65 0,4 0,5
55 1 0,35
45 1 0,5
35 0,8 0,6
25 0,8 0,7
17 1
14 1,2
11 1,2
9 1,7
7 1,7
5 1,2
4 1,2
3 1,5
2 1,7
1 1
0,5 1

/Ubbe

 

[Brookline]

hello Ubbe, thanks for these informations.
I find this red light on the msi a few strange because red is usually used when someting is wrong or if there is some trouble...
if you have the same that means it is normal with msi!
as i said above the level signal on sdruno is the same as on my trafic receiver with the small whip antenna. so i will try to connect the 30m long wire antenna to the msi. As a long wire is high impedance and the msi input impedance is 50 ohms, i believe , i will make an impedance adapter with a transistor in emitter output. the problem is i do not have at this time the plug to connect to the msi!
one problem for me is sdruno does not record the audio (HDSDR is ok for that but his smeter does not work with my msi)... it seems sdruno is only recording all the spectrum... But i used audacity and it works well, in AM as in FM...
today i tried also SDRdharp but no result, it does not see the msi, even if using zadig...
I am asking if some noise could not come from the usb supply? i will try to make a circuit to connect the msi usb powser supply lines to batteries
thank you again.

 

[Ubbe]

At least with my different computers the USB are a major source of interference and needs to be reduced with ferite cores on the cables.

I believe the sdrplay receiver have bandpass filters and that the clone msi also have it, but isn't used properly from sdruno. It has good sensitivity up to 119Mhz but at 120MHz something happens and it gets a lot worse. The same thing seems to happen at 380Mhz, some kind of filter action that are not working as its supposed to do. Mil air UHF are not impressing at all.

The original sdrplay seems to have filters that are 30-60Mhz and the msi looses half its sensitivity in that range but gets better above 60Mhz. Next filter are 60-120MHz and the msi gets a dramatic change at 120Mhz. Then comes the 250-420Mhz filter where the msi are really terrible until it hits 421Mhz where it regains full sensitivity. Maybe it's the msi hardware that's not a real clone or the software in it doesn't function as it should.
Maybe there will be a MarkII of msi-sdr or the firmware can be upgraded to correct any potential bugs. As it stands now and run from sdruno it seems to have some major issues.

/Ubbe

 

[vhfpower]

I'm curious what kind of antenna you're using? I've several of these running SdrUno on dipole/OCF/sloper without sensitivity issues. I did read the thread but am unclear what you're connecting your receiver to. I'm all 50 ohm, borrowing rx/tx antennas from the hf rigs.

 

[Ubbe]

I'm connecting my receiver to a professional RF communication analyzer to check the RF sensitivity. It is the actual sensitivity figures at 12dB sinad for my msi.sdr and it shows that some of the pre-filters have problems at the band edges and in some bands the whole range are compromised.

/Ubbe

 

[Brookline]

I'm connecting my receiver to a professional RF communication analyzer to check the RF sensitivity. It is the actual sensitivity figures at 12dB sinad for my msi.sdr and it shows that some of the pre-filters have problems at the band edges and in some bands the whole range are compromised.

/Ubbe

I'm connecting my receiver to a professional RF communication analyzer to check the RF sensitivity. It is the actual sensitivity figures at 12dB sinad for my msi.sdr and it shows that some of the pre-filters have problems at the band edges and in some bands the whole range are compromised.

/Ubbe

Hello Ubbe, thank you and sorry to be a few late... I am not surprised msi sdr has some sensitivity problems... it is a low cost device, 50$ at amazonn so i cant hope high performances... now i use it mainly with sdruno... But i plan to buy an other sdr dongle, msi is only a test... I plan to buy ''ham_it_up_plus'' from nooelec... Maybe you know something about it?

 

[Brookline]

I'm curious what kind of antenna you're using? I've several of these running SdrUno on dipole/OCF/sloper without sensitivity issues. I did read the thread but am unclear what you're connecting your receiver to. I'm all 50 ohm, borrowing rx/tx antennas from the hf rigs.

hello vhfpower,
sorry to be a few late... you question about antenna is interesting me very much because for me antenna is a major device when you try to listen weak signals. The antenna i have now is a simple 30 m(100 ft?) long wire in my garden. I listen mainly short w and would like also to hear long distance on medium w. I remember some years ago i heard usa stations on my trafic receiver, early in the morning... I am located near Paris, France...
With the msisdr i got a telescopic antenna in the package and it seem to work in vhf but absolutely not in shortwaves... So what i did was to connect the long wire to the telescopic rod with a clamp ! Signal is much better, of course, and i can hear amateurs radio in the 80 m band.... I think the msisdr input impedance is 50 ohms. So what i plan to do is to make an impedance adapter for the long wire. I will use a tansistor, antenna on gate or base and output on source or emitter... But the msisdr and computer are not in same room than the antenna plug so i will have tu use about 10meters coax cable... i m curious to see the result.... I will be pleased to have your opinion.
One question: what is the sdr dongle you are using?

 

[jcat1948]

Hello All!

First, thank you for your efforts. I have had a MSI,SDR for two months and have been struggling with the same uneven sensitivity you have reported. However, there are a number of reports from people using the MSI.SDR reporting wonderful results.
Are they not discerning or not experienced?
Another possibility is that the problems are common to one supplier.
I purchased mine on ebay from 2012moon816 .
Where did you people purchase yours?
Thanks again for restoring SOME of my sanity.

 

[Brookline]

Hello All!

First, thank you for your efforts. I have had a MSI,SDR for two months and have been struggling with the same uneven sensitivity you have reported. However, there are a number of reports from people using the MSI.SDR reporting wonderful results.
Are they not discerning or not experienced?
Another possibility is that the problems are common to one supplier.
I purchased mine on ebay from 2012moon816 .
Where did you people purchase yours?
Thanks again for restoring SOME of my sanity.

hello jcat1948, sorry to be so late but i have seen your question only to day, dont know why.... The sensitivity seems to vary with the frequency you are listening. That depends also, of course , of the antenna... however for 50$ we can t hope more i think. Probably you have seen my post any days later ''msi sdr noise ratio'' with more details . i bought my device 2 month before at amazon france... and may be it is also a kind of
lottery... some devices are better than others and may be also not working at all... Very curious: i searched a long time on the web to find the msi-sdr maker and did not find anything! That could explain many things....

 

[jcat1948]

Hi Brookline, Thanks for your reply and your work. As you said the sensitivity is all over the map! I use the NOAA weather stations (162 Mhz) as a gauge of VHF sensitivity. Compared to my RTL-SDR V3 the MSI's sensitivity is way down.
The easiest (and cheapest) solution I have found is using an inline low noise amp SPF5189 Z. These are available on eBay with various specifications. I use a 50-4000MHz, NF = 0.6dB which has a typical gain of 11dB. The price is around $5-$7. It requires 5 volts DC at less than 100 ma. This can be obtained by soldering two wires to it from a salvaged USB cable. This is then connected to the USB port of a computer or a 5 volt phone power supply.
With the amplifier in place the MSI.SDR VHF/UHF sensitivity is equal of better than my RTL-SDR V3. Not sure what happens below 50Mhz. It "seems" to work on HF below it's quoted frequency limit. Hopefully we will hear from more MSI owners and find a pattern of problems.

 

[Brookline]

hello jcat1948, thank you for the informations... it seems with the preamplifier the sensitivity is better... however the SPF5189 Z is for 50-4000MHz an i am more interested in 200Khz 30 mhz range. But i looked on amazon and there is a lot of amplifiers for this range also... may be i will test this. The problem will be the choice and we probably will not find on the web some users comments for such specific products. But considering the price, that will not ruin me. Other problems : these devices are low cost, usualy made in china so no information from the maker... and if the present virus problem continues, it will be hard to find some chinese products even at amazon... but i am not so much in a hurry....
I was also looking at the ham it plus from nooelec. for low frequencies there is a converter... I asked some questions to nooelec via the contact and they replied allways very kindly and quickly...
maybe you have seen the thread i opened on this forum a few days later about ''sdr and noise ratio''? There are some msi informations also...