RSP2 Upgraders - What Do You Find Better than RSP1?

[NoelC]

I have only had my RSP1 for a short time, and frankly I don't find too many faults with it - I'm enjoying it immensely.

But now that I am getting to know it, I'm starting to understand the limitations that led to the design of the RSP2. Whenever the IF Gain needs to be turned down I think to myself, "maybe this is one of those times than an RSP2 (possibly Pro) might be better to have".

Or maybe not. I just don't know.

On the one hand, my RSP1 often works well right up to max IF Gain, and sometimes even with the LNA on (e.g., for VHF). My clock doesn't seem to drift much - usually SAM mode shows single digit Hz values for WWV, for example. Who doesn't want for a bit more SNR and sensitivity, but it's hard to complain.

For those of you who have upgraded from RSP1 to RSP2, are you seeing practical benefits of being able to switch in AM and FM filters, of the differently tuned front end filters, of the ability to tune below 100 kHz.?

What do you actually find to be better, in day to day use of the box?

Oh, and - assuming one already has a good antenna delivering 50 ohm coax to the RSP1/2 - does the 50 ohm port still work okay for HF signals or does one HAVE to switch to the High impedance connector to get the best from HF stations?

I mean, if the RSP2 is a "must have", I can imagine gifting the RSP1 to a needy friend...

-Noel "A happy user who's not unwilling to be even happier"

[13dka]

I wrote up my first impressions here and made a few comparisons that may or may not answer some of your questions:

viewtopic.php?f=5&t=1509

Short summary: The RSP2 seems a bit more susceptible to overloading while it is capable of presenting signals with a slightly higher SNR than the RSP1 (on the hi-Z input) on HF. Other than that, the filter regime did not change on HF (still minor improvements re images can be seen). The bandstop filters are not of particular use for me, partly because they're not available on the hi-Z input, and the redesigned input filters already clean up the VHF/UHF ranges that were infested with images from the FMBC band.

BTW, your RSP1 can go below 100kHz too (e.g. with SDR Console) but it may not receive anything real below 20kHz. The RSP2 can (f.e. when using a VLF loop) present a relatively clean spectrum down to DC and I already heard my first tweeks and plenty of sferics down there, so "natural radio" reception can now be added to the feature list.

What do you actually find to be better, in day to day use of the box?

Of course I find all of the added features much better than the lack thereof, in particular because I seem to have lost a bag of antenna seeds in the backyard and now they keep growing there like weeds. I plan on making some experiments with LNA4ALL and I'm not fond of using the bias-T box that came with my active antenna, so the internal bias-T is quite helpful and removes the need for an extra cable and power supply. If that's all not very compelling for you, you could at least postpone the decision for a while. But besides the added features, the small and big improvements in image reception outweigh (for me that is) the little new quirks it comes with and I'm still happy I bought it.

[NoelC]

Thanks for the insight, 13dka.

I wonder how many quirks might be due to the newness of the RSP2 design, and how many are just going to stay there.

From what I can see the RSP1 is not without a few quirks itself. On the other hand I have no idea how many they may have fixed since the first box rolled off the line. It actually works surprisingly well. And of course the software is being improved all the time. I do hope it doesn't stop receiving updates for the RSP1.

It sounds like the Hi-Z input is not necessary, but possibly an advantage to use. Since I listen to HF and have set up what seems so far like a great long wire antenna outside complete with matching transformer and low loss coax, mostly I am most concerned that it would have to be at least as good as the RSP1 on the 50 ohm connector. I don't see running new antenna wire in my near future.

-Noel

[g1hbe]

I agree with everything I3DKA has said. The three selectable antenna inputs are very useful as it saves mucking about with external switches or diplexers.

The Hi-z input produces a lower noise floor than the two SMA inputs on LF/MF/HF and as it rolls off above 30 MHz the annoying FM sproggies are gone.

The bias-T is very useful. I occasionally take a look around L-band using a homebrew active yagi antenna and it is made much more convenient with the built in bias-T rather than using an external one flopping about with supply leads etc.

I do quite a lot of LF listening. As the RSP's are not filtered below 12 MHz, there is a certain amount of imaging in the LF area from MW and SW stations. It's not bad by any means and the images can be moved by retuning, but I've kept my home-made filter bank that I built for the RSP-1 and it is now stuck in front of the Hi-z input on my RSP2. It allows me to apply a LPF (rolloff at 100KHz), another LPF (rolloff at 500KHz), a BPF for the 160m amateur band (1.8 to 2.0 MHz) and finally a 2MHz HPF for HF. Belt & braces, that's me.

VLF (say below 50 KHz) reception is clean, free of the clutter that I've seen on other budget SDR's. I listened to the Christmas Eve transmission from Grimeton on 17.2 KHz, even though my Wellbrook loop is probably well below par at this low frequency.

All in all I'm very happy with the 2.

[NoelC]

How, physically, do you bring antenna wiring to the Hi Z input? Just curious.

It's fairly urban here and there are FM stations, several close by, completely filling the band - yet I'm not seeing a whole lot of what I would call FM "sproggies" or interference I don't think. Mostly what I see in the wrong places sometimes is an AM station at 980 kHz that comes in at nearly S +60. I'm concerned about the comment that the RSP2 overloads a little more easily than the RSP1 for that.

The other kind of interference I see most often is from computer-controlled motors - e.g., in our clothes washer and dishwasher, and from an old plasma TV monitor. For these the Wideband Noise Blanking filter often works surprisingly well.

-Noel

[g1hbe]

Hi Noel, you might like to take a look at this. Although there is a mis-match between a 50 ohm antenna system and the 1k Hi-z input, it works just fine and gives better results than the SMA inputs.

http://www.sdrplay.com/guide-to-using-t ... -the-rsp2/

[NoelC]

Thanks.

I read that article... Maybe what I don't know won't hurt me, since I don't really want to manage another separate antenna.

The EF-SWL antenna I've set up is doing a great job, frankly, across the entirety of the RSP1's range. I'm quite often able to run the SDRuno IF Gain reduction all the way to minimum for HF stations, I'm getting good FM performance, I'm hearing airliners and airport towers, and I have discovered about 50 first responder channels up around 850 MHz coming in clearly from many neighboring towns.

It's hard to want much more. I admit that I don't hear much below 540 kHz, but I'm not sure there's that much to listen to in VLF in the US.

Thanks for the insights, guys. At this point I believe I'll hang onto the RSP1 for a while.

-Noel