New crop of cheap SDRs suitable for SWLing? (long, rambling) - Page 1
Forum section: electronics / rf-microwave

author: cdev
author_rank: Super Contributor
timestamp: January 23, 2022, 03:56:37 pm
content: Sorry if this runs on and is boring..Does anybody have any of these?https://www.ebay.com/itm/144265605979https://www.ebay.com/itm/384316354210https://www.ebay.com/itm/255106602228There are a bunch of fairly inexpensive one chip radios which are based on the seeming quite versatile SI4732, also a new SDR board based on the MSI chips.And several others, some of which claim to be transceivers.I am just wondering if anybody has bought any of these. I have been looking for a receiver I can use in bed for HF reception, either there or over the network with my laptop.(I dont really care if its there or in my living room computer desk area and accessed over the network)Although it would be great if any of these cheap radios could work like a decent HF SDR.The new MSI onehttps://www.ebay.com/itm/255106602228appears to be (yet another) version of an MSI-chip-using SDR that has the many inputs on the chip broken out individually instead of combined in the half assed way that the "MSI-SDR" did. The ad says nothing about software compatibility, though. It doesnt claim to be an SDRplay, thankfully. Although it likely does enumerate as one USB-wise, still.To fully use the Malachit SDR seems to require buying extra software. (what?)The newer, black MSI SDR seems likely to be like the blue dongle thats sold that identifies as an early SDRplay RSP 1but with the individual inputs made availableit might be able to avoid the bizarre problems of the blue dongle, which @radiolistener has enumerated.However, as far as I know little other software works even marginally with it (the blue dongle with the single input) without sdrplay's proprietary software which they only want people to use with their own hardware, which are (IMHO) too expensive for a mere receiver (at least in my budget constraints)There is also the "Malachit portable radio (it has a waterfall display and an LCD) which is pretty.. and reportedly also uses the MSI chipset.(over $100) The other MSI-chip using radios now have been available for some time and I am wondering how they work, what driver they are using (especially if the driver situation has improved!) If they have improved since my last exploration of the issue.I am interested in getting a cheap multibit SDR (more than 8 bits) that has the sensitivity of a better SDR (12 bits dynamic range is much better than 8 bits, signals way down in the noise can be copied) without the cost.I am in the proces of putting up a new long wire antenna and kind of want to set up a new inexpensive SDR receiving setup that is better thn my soft rock, but the soft rock is actually pretty good (much more sensitive than my RTLSDR either direct sampling or using an upconverter, sorry guys) Because it uses diferent software usually, its hard to make a direct comparison. I usually use Linrad with the softrock.If my installation of CubicSDR worked properly I would be able to use that with everything but right now my CubicSDR is broken on USB. Only LSB works. So that makes it fairly useless for all reception above 10 MHz.The thing I really want to receive better is SSB on VHF and UHF. Nothing that I have does a decent job with that. My RTLSDRS all have loads of birdies in that region.Maybe I can make a receive converter to convert 144 MHz to 10 meters or something. My Softrock is my receiver that is the best, birdie wise, By a long shot.Is there anymixerthat is fairly inexpensive and very flexible so I can makead-hoc receiversand similar as needed/desired? In a modular fashion?I keep wondering if I could make a balanced modulator to pair up with my softrock (Ensemble III) to make a QRP ham transceiver. Having a decent receiver I am more than half the way there.I have a freuqency counter (PIC based) that has internal options to use as a display with an external device, such counter might lend itself well to building an accurate transceiver. Maybe one based around a Raspberry Pi? There are some cheap ADCs for RPIs that support 12, 16 bits and more that would make a good SDR receiver ADC with my Soft Rock. (Its performance is dependent on the ADC (sound card) its used with, pretty much. My desktop has a semi decent Realtec sound card that has 102 db signal to noise, in theory. But the actual SN on the input isnt that good. There is noise that so far cant be eliminated. Maybe I could add more bypass in the power supply or somehow improve the quality of the sound input interface, in a sort of straightforward way. That sounds like a low hanging fruit that somebody with fairly basic electronics skills can attack with the gear that I have available. Alternatively, if there is a REALLY good sound card for a RPI, several of which I have already, that might be a better route that wont break the bank. I like RPIs and know them fairly well, also their size makes them less prone to creating RF interference that goes far enough away to find its way into the signal chain, (although they do create a noticeable amount of RFI it isnt as severe as my monitors RFI, which is probably fairly typical. One of my monitors started out with much worse but I put a bunch of energy into shielding it better and that appears to have been time well spent.

author: UR5FFR
author_rank: Contributor
timestamp: January 23, 2022, 05:18:28 pm
content: Hi,I have had the official SDRPlay RSP1A for a long time and recently bought a Chinese MSI clone for comparison (https://www.ebay.com/itm/255106602228). On aliexpress, you can buy it cheaper - about $ 19 with delivery. The clone has less gain setting options, but overall it works quite well. On the HF bands, you will need to use an additional amplifier and filters - you can use, for example, MMIC. Also, the clone does not have protective diodes at the input and you can easily damage the receiver. Both receivers work well with SDRUno and SDR++.

author: cdev
author_rank: Super Contributor
timestamp: January 25, 2022, 12:25:54 am
content: Is there any Linux based open program that supports it natively? IN other words, not SDRplay-specific?When you installed it did it require that the real SDRplay be present, ? I dont own an SDRplay, its just too expensive for me for what it is. I dont want to use their software, I want to use an open library. That I trust.