sunwave wrote: Thu Nov 02, 2023 9:38 pm
The real issue is evaded horribly. Close the thread moderators.
I suggest you read this:
https://www.sdrplay.com/wp-content/uplo ... SDRuno.pdf
For software other than SDR-Uno, all the developer (Simon in this case) can only implement the API as provided by SDR Play. One has to assume that the API controls the hardware in exactly the same way as for SDR-Uno. It may, it may not. As SDR-Uno is proprietary software we can't know this.
It does look like as far as the gain and AGC controls are concerned they mirror those offered in SDR-Uno, so no reason to assume they act any differently. Where there may be differences is in the way the software handles the IQ data thrown at it. Here I guess it's possible there could be some processing differences that change the apparent behaviour. Only the programmer will know this. But as far as the hardware is concerned, what you are seeing is how the HARDWARE of the radio is acting under the influence of a signal that's outside the focussed/tuned area. A perfect receiver won't do this. Very few of us can afford a "perfect" SDR, though any come much closer than the RSP radios, but at a much higher price. Nobody is criticising, just observing from long experience.
Nobody is evading your issue horribly. Just explaining the likely cause. Yes, RSP1A is a step up from RTL-SDR V3 for sure, and maybe from RTL-SDR blog V4 (although the latter is impressive for tiny cost) but if you are a serious HF listener then you need to read the advice being given here. At the prices we are talking, all radios have their own individual issues. If your main interest is HF listening then many on here will tell you from broad experience that the RSP1A is far from the top of the tree. Next step up for HF is most definitely the Airspy HF+. As Kriss says, it's usually offered at a big discount once a year on or near to Black Friday.
I suggest you go on the SDRC server and try out Kriss's excellent selection of SDRs and there you can readily compare the use and operation of Airspy HF+ versus SDR Play and decide for yourself. Having done that you might consider (if you like what you find) purchasing an Airspy HF+ Discovery in the Black Friday sale. It's usually a massive bargain. If you decide we are wrong you would be able to sell it again and not lose a cent of your cost. They are very sought after in the used market. My guess is you would never want to sell it once you've tried it.
HF+ has been optimised for HF work and does not cover upper VHF or UHF bands. Also the maximum bandwidth is less at 768kHz. However, wider bandwidth on the RSP is largely pointless on HF as it reveals some more serious misdemeanours. The RSP1a and other variants are more of an "all rounder". Excellent for a general tool. Not so great for specialist LF/MF/HF listeners. But does many frequencies the HF+ does not offer. Ideally you would keep both.
If you want to go the next step up consider a "direct sampling" SDR like Elad Duo etc.
Anyway, yours to take or leave as you wish. Just be aware that people on here take the time out to answer questions when they could be doing other stuff. There's no agenda. We just give advice to the best of our ability based on our own experiences and with no other agenda.
Max
