getting a cheap aliepress radio to work.

[p.larner]

i have a cheap ali sdr radio,says :RSP1 10KHz-1GHz Portable SDR Receiver Msi2500 Msi001 Simplified SDR Reciver Amateur Radio,it works ok with windows,but i cant get it to work with my tab,the seller says it also works with android but i cant get it to work with my samsung galaxy phone or tab,any ideas?,its like this one: https://www.aliexpress.com/item/1005006697235070.html?spm=a2g0o.productlist.main.37.78704db4rIA6AY&algo_pvid=2ffacf95-467b-48a9-9b15-e5c6cef091ea&algo_exp_id=2ffacf95-467b-48a9-9b15-e5c6cef091ea-18&pdp_npi=4%40dis%21GBP%2134.18%2115.72%21%21%2142.28%2119.45%21%40211b600217105763782103044ea50b%2112000038035510912%21sea%21UK%212308464272%21&curPageLogUid=WkgOecQovNIM&utparam-url=scene%3Asearch%7Cquery_from%3A

[radiolistener]

I suggest you to buy RTLSDRv4 it has better signal quality, less CPU power requirement and better software support for different platforms, include linux and android.

RSP receivers are based on MSi chipset which had proprietary drivers with different non fixable issues and didn't supported well on different platforms.

[p.larner]

thanks for the reply,are you saying its not possible to use it on an android device then?.

[A.Z.]

oh, it will work on Linux (and probably Android too); just a matter of reading the infos on the SDRPlay site regarding the setup on those systems

[shabaz]

Hi,
By coincidence, I tried that device (or a very similar one; the photo of the insides is below) a couple of months ago, too. By 'works OK on Windows', do you mean you successfully demodulated a transmission, or that you got a noisy spectrum view? I got the latter and ended up wondering if the software had detected that it was not a genuine RSP-1 device and silently was not configuring it appropriately. I didn't test for long and uninstalled.

I eventually got it to work with Windows and an open-source driver (long process) and successfully tuned it to an FM station, but the reception was extremely poor (I didn't try other bands). I played with the software and even took a VNA to the input and confirmed when it was selecting the input (the impedance changes). I even tried replacing the entire input filter/matching on the input. The current assumption (no full conclusion as of yet) was that something in the design was not right, it could even be noise from the connected PC not being adequately suppressed in the design, but I don't know what for sure, and there's only finite time available for troubleshooting (it would have been cheaper to buy a RSP-1 device than the time spent; but I'm not too keen having realized that MSI chipset inside it wasn't intended for anything much other than what a cheap RTL-SDR was intended for.
I've reverted back to using a RTL-SDR device whenever there's a need to quickly look at parts of the spectrum. The RTL-SDR plays nice with Windows and Android software.

[A.Z.]

on windows the main issue is... windows itself

If you connect the SDR without first installing the driver, windows will "detect" it and install a generic driver which will cause all sorts of problems (including not working at all btw)

The solution is to disconnect the SDR and uninstall SDRuno, then download this tool

https://www.nirsoft.net/utils/usb_devices_view.html

run it "as admin" and use it to uninstall whatever leftover driver, done that, reboot and install SDRuno, reboot again and ONLY THEN connect the SDR which will then be correctly recognized and will work

By the way, you'll also need to connect a decent antenna otherwise you won't receive much

[shabaz]

It could well be the case I didn't have the correct driver.

At the time, I unsoldered the input filter, and noticed the input impedance into the chip wasn't anywhere near 100 ohm (which is what the datasheet states), it was closer to 200 ohm. I reworked the input, got it close to 50 ohms, and then tried the usual two lengths of 75cm, which work great for any other SDR (e.g., LimeSDR [which I don't like using for other reasons]). Granted there's a mismatch there between antenna and device, but no more than for any other SDR.

The result was still so bad, which led me to think it could either be the (a) software, or (b) hardware design issue, e.g. supply noise. For (b) I quickly tried adding some ferrites to the USB cable and tried a couple of different USB ports, switched to battery on laptop, etc, no detailed investigation. I might even have had a faulty device from AliExpress, no idea.

Regarding (a), the chipset is actually pretty simple, very few registers. I peeked at the source code (since I had given up with the ready-made software although that could have been a driver issue as you say) and to me the register settings in the code looked reasonable. I didn't delve into it a ton though.

[A.Z.]

check this

https://github.com/EndlessEden/msiSDR/tree/RSP1-S

[shabaz]

That's a good link, I did check that out, but there's no guarantee that's what the AliExpress board is using. There are no values on any of the filter components since they are small SMDs. The circuit is broadly similar since it's the same chipset. In any case, I had a good match once I modified the input, for at least the lower part of broadcast VHF (and that's what the chip is designed for; broadcast bands), which was the region I was interested in. Unfortunately I didn't write notes at the time, but I believe the 85m-when-powered.png file is with the filter removed, looking into the front-end chip (but not 100% sure since I didn't keep notes).
Plus, it's a lot of effort to measure and modify a single input, let alone all six. So if the other inputs are just as bad, it would be a nightmare to fix the entire SDR.
So, I'm fairly convinced something's not right with the hardware (bad design, and/or fault), but you can imagine just to get that far, took a fair amount of effort. I'm not sure it's worth putting more effort into it, so I gave up. But one day if I'm feeling adventurous, I'm going to isolate the input to the second chip (requires cutting traces), and use it as just an IF processor (i.e. feed my own I/Q signals into it). More fun doing that I think, than try to repair all six inputs (and even then, not being sure if there is another issue causing the deafness, e.g. poor supply rails).

[A.Z.]

I've one of those, but the "full" version (as they call it), that is the one with a single SMA connector, works pretty well, better than the RTL units, at least, and then there are full schematics around, I just can't find the link right now

[shabaz]

If/when you get time, a photo of the internals would be appreciated, just to visually compare if (say) your version has an LNA for instance, or if there's any power supply filtering or difference in LDO used, etc.

I guess your version may have an RF switch at the yellow highlighted area, but perhaps additional circuitry there.

Also, does your version work with Android? Mine doesn't. I see "No compatible devices found" when using SDR Touch. Whereas, that app detects RTL-SDR just fine.

Do you have a web link to the specific device you purchased?

In any case, the particular unit I have doesn't seem fit for use, for all the above reasons. I've reverted back to RTL-SDR, and (when needed) Lime SDR, until I find something better and affordable.

[A.Z.]

the one I bought is like this one

https://www.amazon.it/Doumneou-Ricevitore-Amatoriale-Software-Defined-Aviazione/dp/B0CTM6GB1B

as for the images, at the moment I'm not home, will shoot some pics as soon as possible

as for Linux, here are some pointers and infos

https://revspace.nl/Msi2500SDR

[p.larner]

did i not say it works ok with sdruno on windows,its getting it to talk to my phone or tab where the problem lies,that was the point of my post windows is fine android not,did i not make that clear enough?.

[radiolistener]

it has proprietary close source drivers and software, so the only guys who can help is sdrplay. But since you bought not genuine device it is not supported officially and there is no guys who can help with it.

[A.Z.]

https://www.sdrplay.com/legacy-software/

notice that some Android devices won't offer power at the USB port, so one will need to use a powered USB HUB

[shabaz]

I see a link to a driver on that site, but that's for the official SDRplay RSP-1 product. The AliExpress products can (or should) only be used with open-source drivers as far as I'm aware (there's a license term that the SDRplay site has, which caused me to delete it and stick with the open-source drivers, which certainly do work (but in my case, with poor RF performance, which could be the particular model I have).

[A.Z.]

Here's a first pic, hadn't time to open the unit yet, the lighter is there to give an idea of the size, the SMA connector to the left has a SMA-BNC adapter plugged; regarding the Linux drivers, those are "legacy" that is, contributed by 3rd parties so there's no usage limitation, some of those even have their source code available on github, also, if my memory is serving me correctly, the latest version of "libmirisdr" supports those units w/o problems

[edit]

also see https://github.com/SDRplay/ExtIO_SDRplay

[p.larner]

all that link does is display a spinning white square on a blue background??.

[xrunner]

all that link does is display a spinning white square on a blue background??.

This link? It works fine for me.

also see https://github.com/SDRplay/ExtIO_SDRplay

[radiolistener]

also see https://github.com/SDRplay/ExtIO_SDRplay

it calls to sdrplay driver, but it seems that there is still no open source code for it.

[mike449]

also see https://github.com/SDRplay/ExtIO_SDRplay

it calls to sdrplay driver, but it seems that there is still no open source code for it.

Search for libmirisdr. I have it working fine on Linux.

[p.larner]

As i already said it works on pc,i dont care for linux mike,its android i have issues with,the seller states its android ready but try as i may i cant get it to work with a tab or phone,hence the reason i made this post.

[tanveerriaz]

i have RSP1 (china clone) work with SDR Touch. (with SDRply driver)

[shabaz]

Unfortunately I think that combination may not work on recent Android versions.
I tried that using the SDRplay driver on the Play Store, and there's a note that it is last updated in 2019. When run, it prints a warning that it is not supported (screenshot below).
If I continue to try to use it regardless, then SDR Touch doesn't like it, and it suggests rooting the phone (not a viable option).
I looked at the SDRplay website downloads (https://www.sdrplay.com/downloads/) in case there's a more recently built SDRplay driver there, but there doesn't seem to be one there, unless I've missed it.

[p.larner]

both my tab and phone are rooted phone is on androd 6.0.1