Perseus22: Increase your hard drive budget

The IQ files from the Perseus22 are proprietary, with the extension p22. So you can't read its properties like you can with a wav file. Since I thought the megabytes added up rather fast, I decided to find out exactly how much.

If you record one channel only, the IQ file will increase with roughly 15 MB per second.  If however  you record two channels (HF1 & 2, or VHF1 & 2), it will double. Which is quite natural. So, we're talking around 30 MB per second, or 108 GB per hour.

Compared to the original Perseus, which also records IQ files off a 2 MSPS range, it only uses around 7.5 MB per second. More exact: 61,000 bps. Now, Perseus recordings are 16-bit, so I'm quite confident that the Perseus22 is using 32-bit recordings.

Now, isn't a 32-bit recording better than a 16-bit? In theory, yes. In real life, no. Several years ago I spent quite a few hours comparing 32-bit recordings from the Winradio G33DDC with Perseus recordings. It was impossible to tell the difference.

It would be nice if Microtelecom/Elad made 16-bit recordings optional in a software update.

Perseus22 - Evaluation

So, after having tested the Perseus22 to the best of my abilities, I did a 10-page evaluation based on its current software version 1.1. Although it must be regarded as a rather unfinished product, at least with regards to parts of the software, it shines in other areas, like nulling and enhancing signals, not only in live mode but from IQ recordings as well. I spent a few hours testing it out, and it didn't disappoint! Report is here.

Enjoy!

Perseus22 - Skins

Which program was the first to use "skins"? Winamp? People have different preferences with regards to how they want their software to display on the monitor. Perseus22 offers three variations; User, Army and Hewlett. In addition, the "User" skin is configurable beyond belief - so instead of "skins" maybe Perseus22 should have offered a suite of "Styles". The current default skin looks good, but suffers from small fonts and unsatisfactory contrast. Especially as age has taken its toll on vision. And admit it: Which 20-year old will buy a Perseus22?

Anyway, below are the three skins currently (July 2024) available in Perseus22:

Default "User"

"Army"

"Hewlett"

If of interest, the three images were made when I had two antennas connected to the HF ports, one (left) sampling the 19-metre band and the other sampling the 31-metre band.

 

Perseus22 - DAB

 Back at the KONG HQ after a couple of weekends spent running! First, Midnight Sun Marathon in Tromsø on June 22 doing a half-marathon that exceeded my expectations. A week later I attempted a Backyard Ultra in Kirkenes, near the Russian border, where I bailed out after six rounds and 40 km. Thighs still aching.

 Now: Vacation! So, I thought I'd connect my FM antenna, pointing perpendicular to the DAB transmitter in Kongsfjord, to the Perseus22. No problem. The DAB transmitter is only 4 km away and 100 watts.The only available MUX here is the NRK MUX, comprising 18 channels including my favourite NRK P13. The screen dump below shows how DAB+ is received. Indeed, I have my doubts if legacy DAB is decodeable, as the manual specifically mentions DAB+ and not DAB. As far as I know, legacy DAB is only available in the United Kingdom now. Maybe someone in the UK could confirm.

With the "Snap DAB Freq" option selected, one can move from MUX to MUX by scrolling the mouse up or down. No keyboard up/down entries available in version 1.1.

No program info (show, artist, title, image/logo) is available in this version, unless I have overlooked something. Channel selection is excellent, instant decode.

Perseus22 - Some Observations

 It's far too early to pass any judgement on the Perseus22 on my side. For instance I have had no opportunity to evaluate one of its core features: Correlation/decorrelation. Still, here's what I've learned from a few hours of use.

The SDR itself is stunning. And heavy! 1723 grams on my digital kitchen weight!! The manual says 1680 g. Whose weight is wrong? Almost as heavy as the Elad FDM-S3. But then, who would have considered a 2 kg communications receiver heavy 20 years ago.

A few observations:

Sensitivity is slightly better than the original Perseus, 2-3 dB better on MW, equalling -106 to -107 dBm (AM, 6 kHz bw, 30 % modulation of a 400 Hz signal for 10 dB S+N/N).

Four DDC sampling rates: 0.25, 0.5, 1, 2 MHz. Alias-free bandwidth appears to be 0.2, 0.4, 0.8 and 1.6 MHz as with the original Perseus. The 2 MHz bandwidth also applies for FM. The bandwidth should allow reception of one DAB MUX (1536 kHz).

The hardware has an on-off button. Why on earth etc. A PC restart did not require a physical "on", but moving the hardware from one PC to another did. And alas... so does a real power outage. This might seriously limit remote control - on the other hand I had the same problem initially with the FDM-S3 so maybe it resolves.

Direct frequency entry is a lot easier than with the original Perseus. Just tap the numbers in the active window and press Enter.

You can have several "radio windows" open, probably one for every antenna. A clever twist is that only the window in focus submits audio - the others are automatically muted. No need to turn off and on audio.

HF2 (9525 kHz) is muted, while HF1 (1557 kHz) submits audio

IQ recording: The resulting IQ file is proprietary with the extension "p22". I tried to change the extension to "wav" and open the file in HDSDR and SDR Console, but no cigar. So, what you record with the Perseus22, you need to play back with the Perseus22. You're not required to have the receiver physically connected to the PC though. It loops playback automatically - which is good because at this stage there are no other commands available to the playback mode except "Open File".

When running in 2 MHz mode, my power supply says current is around 1A. A 9VDC power supply is required. Unfortunately the submitted Mean Well switching PSU is not quiet, at least not on the MF and LF range. And why 9 VDC? The FDM-S3 can take anything from 8 to 15 VDC. The manual warns strongly against using anything else than the power supply provided with the receiver (section 4), and doing so actually voids the warranty (section 1.1). There is no indication in the manual that the SDR is protected from higher voltage input. An omission that fried many legacy Perseus SDRs.

Correlation/decorrelation: I haven't tested properly yet, I need to put up a couple of decent antennas. And currently the MW band is dead as a dodo here. Other users report good results nulling local noise and groundwave stations. To do this, you obviously need two antennas, where one should serve as a "noise" antenna. It would be wonderful to have decorrelation of skywave signals, but I don't expect to see that.

So far, tuning is available only with mouse control - apart from the excellent direct frequency option. Up/down/left/right arrow keys do not work..

Tuning options (frequency step, snapping) brings you all over the place. It snaps ok, but not at the assigned frequencies. 

I understand there is no API or SDK available. Will there be?

It's pricey.

I am sure (or at least I hope) that the software will improve over time. However, there are some GUI design and cost issues that do not quite appeal to my usage. Thank dog for the legacy Perseus.

Perseus 22 !! First Looks

 So! It's here! Not mine though, OJ Sagdahl ordered it and handed it over to me while we were at Smøla HQ last weekend. Now it's at the KONG HQ, ready to be tested. 

(Edit:) Apparently drawing around 1000 mA at 2 MHz sampling, the DC in is 9 V.

The station is TWR Eswatini, closing down at 16:20Z. Captured on the 250-metre coax feedline from the 80-degrees beverage antenna (disconnected).

Next on the list: Sensitivity! More as it happens.

SDRPlay RSPdx-R2 SDR Released

SDRPlay yesterday announced an improved version of the RSPdx, the RSPdx-R2, with further design improvements for use below 2 MHz.

I measured sensitivity levels (as I usually do), and I can confirm that sensitivity is improved quite a bit especially in the LF ranges. On 1000 kHz the difference is only a dB vs. the RSPdx, but when I measured on 500 kHz the difference was a full 6 dB, measuring -104 dBm (10 dB S/N for a 400 Hz signal modulated 30 % at 6 kHz bandwidth). HDR mode was used during measurements.

On 1000 and 1500 kHz, sensitivity levels were -102 and -101 dBm respectively. On 200 kHz I measured -101 dBm which is a lot better than for instance the RSP1A.

My sensitivity measurements document has been updated and listed under "Some DX-related Stuff...." on the right-hand column, and downloadable here.

Physically, the RSPdx-R2 doesn't differ from the original RSPdx. It's listed at USD 235, less than 10 % over the RSPdx price.

SDRconnect Preview Look - The Server

As I mentioned in my first post about the SDRconnect Preview, I hadn't looked much at SDRconnect's server function. Today I have. Now, SDRplay are very good at making tutorial videos. How to set your RSP up as a server is described in detail here so I'll focus mainly on what I regard as strengths and weaknesses from a user's point of view. A few key points are worth mentioning.

• The server can be configured for use in your internal LAN, or across the Internet (WAN). Say you have multiple PCs connected to a LAN in your radio room, then any PC can connect to the server as long as SDRconnect is installed. 
• A LAN or WAN server will be set up either in IQ mode (corresponding to the IQ bandwidth of the RSP) or in Audio mode. IQ mode is obviously more useful in a LAN than in a WAN environment as it would require an extremely fast internet connection to sample say 10 MHz over the WAN.
• Up to 8 simultaneous users are allowed, so you may ask: Can't I replace my KiwiSDR with this one? Take care though, because only the first connected user has full control of the RSP. Users 2-8 can tune around within user one's selected bandwidth, change modes, bandwidth etc but are at the mercy of user no. 1 not changing the frequency band.
• Beware the dreaded CGNAT! No, I hadn't heard about it before either. Carrier-Grade NAT is a workaround for ISPs since the pool of IPv4 addresses is exhausted. When you set up your server, you have to look for the necessary public IP address. If you see something like the port numbers in section 2 in the image below, you are in trouble.

        There are workarounds, but they may be expensive. I won't delve more into this now, but the                   Internet  is at your disposal should you want to learn more.

• After setting up the server and testing if connectivity is ok, it's time to get running. It is well described in the video I linked to above. My personal opinion is that it is unnecessarily tedious to start the server. Maybe it's a compromise because SDRconnect is multi-OS, I don't know. Anyway, after keying ".\sdrconnect --server", this window shows up on the PC hosting the server: 

• There are loads of parameters one can use to set up the server, but you need to use the Terminal window for all this. It could be that you only need to set up this only once, in which case it may not be too much of a hassle. The last frequency range is remembered upon restarting the server, so you don't have to start on 100 MHz every time.

My own setup (which is temporary) is from a relatively cheap and modest speed fibre connection via a TP-Link router. The public IP address from my ISP is dynamic and will change over time, so I chose to use a dynamic dns provider. Everything on my setup is cabled.

Is the server stable? I haven't tested it long enough to tell. What I do know, is that if the router reboots, the server will disconnect. I have set the TP-Link to reboot every night, because I'm 170 km away from it, and consumer-grade routers are not 100 % fail-safe. It tends to "freeze" once every several weeks. A nightly reboot has proven to be a very good solution for 24/7 operation. It would indeed be nice if there was a workaround to provide server to restart and restore connectivity.

I have also had one instance of the terminal window not responding, resulting in a loss of connection and having to restart the terminal window. At this instance, both the local and remote PCs reported OK on the connectivity test, but returned an error message when actually trying to connect.

To end this post, here is a "panorama" of two displays showing two types of configurations at two different locations at the same time. To the left is the LAN (local, although it is labelled "remote") IQ client at the KONG HQ; to the right the WAN (labelled "internet") client at home, also running IQ mode.

SDRconnect Preview Software - A Primary Look

SDRPlay's current proprietory software for their SDRs is SDRUno - a program consisting of many more or less independent windows that can be moved around, and possibly tied together - in any case it always looks like a mess on my PC desktop and the lettering is hopelessly small for a modern PC monitor, hence I never use it for my RSPdx. Nice then, to have HDSDR and SDR Console to do the job. Others may feel differently about this - I'm not the judge.

The past few months though, another software has begun to emerge from SDRPlay: SDRconnect is their multi-platform (Windows, Mac, Linux) 64-bit software with built-in server capacity. So, while at the KONG HQ this early March weekend, I took some time to play with it.

First off, the full display (click on image for a larger version)

The layout consists of three sections: Primary SP, Aux SP and Recording, in addition to a Control panel that can be toggled on and off. The sections can be resized relative to each other. SDRUno users will recognize the "Bands" control which has been supplemented with a keypad. An IQ or audio recorder is now easily available to the lower right - at the moment the functions are very rudimentary but at least it's there and not hidden in "Scheduler". And as you can see, it works.

By the way, at the time of testing the software I was on 6185 kHz for a reason: Young Finnish radio enthusiast Joakim Wickström was granted permission to set up a temporary SW station from Raasepori on Finland's southwest coast, 1230 km away from me. His 15-watt transmitter was heard with a weak, but stable signal and was also heard in Austria. RealMix Radio is the ID to look out for.

A brief test on the MW band was next:

There is a "Toggle Assymetric Filter" function  (top red circle) which allows full flexibility on both sides of the bandwidth settings, in both AM, SAM, USB and LSB mode (those I tested). With it enabled, I was able to keep a wide bandwidth for a readable signal from CJWI Montréal 1410 while keeping the stronger signal on 1413 out. I was actually quite pleased with the result. You can't move the passband itself (yet?) though, like you can with the Perseus software. There is also a Notch Filter function which I haven't tested.

Another MW view here, WWKB Buffalo NY 1520 with signals on 1510 and 1530 as well, this time with "Toggle Preview Filter" on (red "circle") and Control Panel toggled off. At this time of the morning, almost all European stations are gone.

Both visually and operationally SDRconnect is a huge improvement over SDRUno. What potential users should note is that only 64-bit systems are supported, and Windows users should note that there is no support for pre-Windows 10 systems. Hence, I suppose that SDRConnect is an alternative to and not a replacement for SDRUno. At least for now.

Server functionality has not been tested yet.

But remember: It's a preview for dog's sake! Now is the time for SDRPlay users to report inconsistencies and omissions.

More info from the manufacturer here.

Radio, Radio!

Not much to report from a storm-ridden area. Storm-ridden in two meanings - solar storms and wind storms! Since earth weather doesn't encourage any outdoor activities like jogging, I decided to sit down with my Spotify and see if I could set up a playlist with radio related music.

There was a lot to choose from! I compiled 50 tracks spanning different genres as far apart as Donna Summer and Frank Zappa, including two versions of Bob Seger's "Rosalie", celebrating CKLW broadcast legend Rosalie Trombley. Here is Radio Radio! if you're a Spotify user. Enjoy three and a half hours of (mostly!) great music!