Monday, July 22, 2024

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.

Monday, July 15, 2024

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!

Monday, July 08, 2024

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.







 

Monday, July 01, 2024

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.