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PERSEUS
SDR TIPS & TRICKS A site mainly dedicated to Mediumwave Dxing |
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In this page, I am going to include as many little titbits and tricks for keeping the Perseus running smoothly. Some of them are copied straight from my monthly logs and news pages, and others will be added if and when something new comes to light, or is remembered, or suggested and shared by others. NB: The tips below come from a couple of years experience with Perseus and a PC which is only just within spec, and really may be outwith the spec for 1600kHz recordings. Some tips are designed around reducing system resource drain. Many users will find some of these tips irrelevant if they run the latest dual or quad core chips. The tips also come from a couple of years dxing on MW only. I have had virtually no experience of using the Perseus on SW, where I tend to use other receivers for casual listening.
CONTENTS: 20. NEW QUICK START GUIDE FOR WINDOWS 7 (MAY 2010) 19. PERSEUS SOFTWARE CORRUPTION AGAIN, SEE 15 18: PERSEUS DRIVERS 17: SHARING PERSUES FILES ON LINE - MONKEY'S AUDIO 15. SEEMINGLY SPURIOUS SIGNALS APPEARING ON STRANGE FREQUENCIES 14. RECORDED FILES AND FILE NAMES 11. SWITCH OFF ALL UNNECESSARY SOFTWARE WHICH IS RUNNING AT WINDOWS START UP: 10. CREATE A TIME LAPSE PERSEUS SCREEN CAPTURE: 09. SAVE A PERSEUS SCREEN CAPTURE: 08. REDUCE CPU USAGE DURING PLAYBACK: 07. AUTOHOTKEYS RECORDING TIMES: 06. WHEN THE PERSEUS SOFTWARE WILL NOT TUNE DOWNWARDS DURING LIVE DXING: 05. WHEN PERSEUS SOFTWARE STUTTERS AND STUTTERS ON 2000KHZ SAMPLING: 04. MOVING A WINDOW ON A DUAL MONITOR GRAPHICS CARD, BACK TO THE MAIN SCREEN: 03. PERSEUS OVERLOADING WITH AN EXTERNAL PREAMP: 02. WHAT SIZE OF RECORDED FILES DOES PERSEUS CREATE? 01. PERSEUS USER SETTINGS (FROM MY SEPT 2009 PAGE):
19. PERSEUS SOFTWARE CORRUPTION AGAIN, SEE 15: As stated before, (eg in 15. or 05. and 06.) the software can sometimes become corrupt to a fashion. As also stated before, this is absolutely not a problem, but simply a curiosity. The corruption is always easily cured by clicking from 2000kHz sample rate, to any of the other sample rates, and back again. This clears many similar types of problems. It may possibly be that this happens when other applications are being run on the PC at the same time. I don't know. I seem to remember the centre button also cured this one time. But I had a weird one in late November 2009. I had been recording a top of the hour, and just switched off. I restarted perseus maybe, or maybe it was still running. I tuned around 1575 and noticed a loud beacon I had not heard before. It struck me as odd, and decided it probably was the occasional corruption that happens. So I tried recording. And amazingly, the record button never cleared anything, and I managed to get a recording of the complete MW band for a few mins, with beacons from LW at the hf end of MW, mixing around the normal stations, There were also a few big signals where they shouldnt be around 1720. This was easy to fix once I stopped recording. A simple click on the lower values of sampling, and back again to 2000, and the ghost images were completely gone. I was rather surprised that I managed a recording. An interesting one.
The drivers of Perseus are available on the Microtelecom web site at the following address. http://microtelecom.it/private/PerseusDrivers.zip They are not generally advertised as available, although in the Yahoo group they are made public.
17. SHARING PERSEUS FILES ON LINE - MONKEYS AUDIO COMPRESSION: There are a few sites on the web where big Perseus files can be downloaded. Guy Atkin's site has a great collection. There should be no reason to have to endure really long downloads of big Perseus files, when a simple clutter free, cost free, and very small piece of software called "Monkey's Audio" can compress and decompress the large Perseus .wav file into a file less than half, sometimes much more, of it's original size. I don't have to tell you about the broadband speeds in country areas do I?? Not everyone has the very fast speeds of the cities. Into the bargain, the initial upload will in most cases be slower. Broadband companies deliberately limit upload speeds to around 30k/s at the time of writing. I did read some negative reaction on line for using this method, although I could see no reason for this unexpected response. The unzipped file is identical to the original file, so where's the problem, if it saves many hours of download time? The software is simple, small, free of clutter and spyware, and free from silly resource grabbing start up stuff. Do you think I would use it if it was any other way. It is also free. I wrote the following in May 2009.
MONKEY'S AUDIO COMPRESSION: I
have been trying out Monkey's Audio on Perseus files. Thanks to a detailed
pdf file by Elio Corbolante on the Perseus group. Monkey's audio reduced the file size to took it down to 109 meg using "Extra High" compression. "Insane" takes it down further to 97meg!! Bjarne's
929 meg file was reduced to 226 meg!!!! Dare I use the phrase amazing
again?? I may be easily impressed, but such a compression ratio is surely
a great benefit to wideband file sharing. Check
it out at <www.monkeysaudio.com>
16. PERSEUS WITH RPA-1 PREAMP: I have tried different combinations of my main beverage antenna with the RPA1 preamp. I have found that even in the European evening when the Euros are exceptionally strong, I have somewhat better results with the preamp in line as follows. Amp on, Perseus 10dB att on. This gives just a little boost to signals, especially on X Band (1600 -1700) which can be a little noisy in the early evening. If I do not use the Perseus ATT, there is a bit of noise from overloading. I also have to include a balun at the shack, even though there is a balun at the feed point of the antenna. This reduces noise and seems to somehow produce a better match. Don't ask me for the scientific reasons. I just know it works. It has the edge over perseus with no preamp, and 10db off. In the mornings, I have best results with the preamp on. On the winter's mornings when doing the tests, the amp is best on. There is no need for the 10dB Perseus att, as the strong Euros have diminished in strength. My locals don't seem to give me too much trouble. OK, this set up will be unique to my antenna maybe, and be of limited use to other dxers, but I feel the experiences should be reported, incase other dxers can make some sort of use of the text The antenna starts at the shack, with a 200m length of coax cable before the aerial begins. The beverage is a 500m cable, up on approx 7 foot sticks, through dense woodlands. None of which is ideal, but a better option than a lot of folks in the city, and much higher signal levels are achieved than with an EWE type antenna. On the down side, there is no brick wall stopping the strong Euros giving grief, especially 675 these days. (I am sure Arrow Classic Rock never had that signal!!)
15. STRANGE SEEMINGLY SPURIOUS SIGNALS APPEARING WHERE THEY SHOULDN'T: I have seen some odd signals appearing off channel, in places one would not normally expect to find any signals. Eg 10/11/09 I had something on 929, off channel, alongside the station on 927. Both were loud, clear, and not like overloading. I switched off the preamp I was using, but the stations were both still there. I tried the attenuator on the Perseus, but the unknown signals were still there. Solution: Like 5 and 6 below, flick from full 2000kHz bandwidth to any of the other sampling rate, and back to 2000kHz. Unknown image gone. Once I clicked the "centre" button and it disappeared too. Therefore just a little corruption on the software, nothing to worry about. This has happened a few times, oh, maybe three or four times during use, and is not regarded as a problem.
I have read questions about the file names created by Perseus. They can sometimes be a little confusing. If you were to write a long winded file name with underscores etc, chances are the file would not record with that name, but of a much shorted version of it. Eg xxxx_xxxxxx_xxxxxx would probably be cut off at the first underscore and become xxxx_001. Sometimes a file has been known to be created outside the folder of choice, if the folder has been renamed with underscores. The original file name is lost, and the file name taken from the folder name instead. I was advised not to use underscores in any folder or file names, or at least during recording. I keep my file names to simply the hour, eg 0900, or 0300. If the software requires a new file for say a 10m recording, the file names become 0300_001.wav etc. Files are kept within a folder, which is dated. NB: After recording, the files can be renamed to anything, and they will playback just fine. The initial recording is the only time there is some kind of a bug in the file name structure.
For MW dxing, what is the best mode to use? AM? SAM? USB or LSB. To be truthful, the SAM button is little different from the normal AM. Maybe on a busy channel, it will have a marginally better sound, but I wouldn't like to be put to the test. But USB and LSB both bring out the audio on weaker signals. But which one?? Traditionally, dxers have used the sideband farthest away from the usually stronger Euro, eg on 710, LSB would be used. But the obvious is not always the best option. I am finding it is best to try both. Some stations seem much more intelligable on one or the other. Some, such as 1630 La Grande can be completely one sided!! IE SSB + carrier. Others I have no explanation for. 790 produced a station in RI, identifiable not in LSB, away from strong Irish signals, but in USB, using a wide notch, and wide bandwidth!! In October and November 2009, 1590 was clear from the German jamming transmitter for a time. The stations heard during this period of grace, were all best on USB.
Many DXers probably fine tune Windows in the fashion I am about to describe, many may not, and run the default settings from day 1. To make Windows XP more responsive and less greedy on system resources, there are a handful of windows adjustments that can make a difference.
TO SPEED UP MACHINE RESPONSE: Right click "My Computer" and click "Properties" (Not a shortcut to my computer) Click "Advanced" Click "Settings" in the "Performance" section Leave only "Use common tasks in folders" ticked This will make the PC look like Windows 2000 / M.E. again, but it does become more responsive. So unless you like the big baby style colouring of XP, there is nothing to lose.
TO SPEED UP FOLDER ACCESS etc: On hard drive properties (My Computer, right click for example c:/ and click properties) Untick "allow indexing service to index this disk for fast file searching" Apply and if any errors show, click ignore. This will stop indexing running in the background
ALSO APPLY THE FOLLOWING: In "My Computer" - "Tools" - "Folder options" - "View" untick "show pop up description for folder and desktop items"
11. SWITCH OFF ALL UNNECESSARY SOFTWARE WHICH IS RUNNING AT WINDOWS START UP: The Perseus software will run a lot smoother is the system is running smoothly. On of the first things I do if repairing anyone's PC is to switch off all the ridiculous crap that comes on at start up along with modern software. This includes all the silly yahoo and google rubbish that some free software tries to install. It also includes the unbelievable amount of unwanted rubbish that some folks throw in along with their thirty quid printer drivers. It can be difficult to find a driver only install these days with a modern printer. Here are just some common applications I see running at system start up. All of these can be switched off easily to ease system resources. Microsoft Office, Adobe applications inc Acrotobat, Photoshop etc, HP/ Epson/ Brother/ Canon etc freebie printer software that is bundled with printers, Nero, Macromedia, Quick Time, and just about every other modern piece of software you can think of. Mobile phone software also comes into this category. MSN is one of the worst offenders if I am given a PC for repair that youngsters use. All their associated mess that takes I don't know how long to fire up at boot up is such an annoyance, and one which I would have to find ways around if it were my own machine. For some unknown and ridiculous reason, modern applications all seem to be written to run at system start up, and stay running. They also always want to log on to their home web sites to look for upgrades!! The more icons you have active on the system tray to the left of the clock, the slower the PC will become. It is for this reason that I have a dedicated web PC with nothing on it bar the bare essentials for the web. My main PC is never, and will never be connected to the outside world. To switch off applications at start up, use the old tried and tested MSCONFIG command. 1. On the start menu, locate RUN 2. Type MSCONFIG in the RUN box. 3. Click STARTUP. In the example below, it is 2nd from the right. 4. Untick most of the items, leaving anything that looks to be relating to Anti Virus, if you are on line with that PC. Untick especially software applications start up stuff.
10. CREATE A TIME LAPSE PERSEUS SCREEN CAPTURE: To create a screen shot of the carriers on one frequency like the ones I have on this site in my screen shot pages, try the following:
1. Set the Perseus to the frequency desired on AM 2. Set bandwidth to narrowest, 0.8kHz 3. Click the Zoom button 4. Click the SPAN setting (Below freq) to read 0.049/ 0.06 5. Run away and do something else for about 45 minutes. This is a slow proccess!!!!
Click here to see some of my examples
9. SAVE A PERSEUS SCREEN CAPTURE: Many dxers may be unaware of the simple old windows way to create a jpg of a screen capture of the current open window. This has been available for many years now with Windows, maybe even since WIN 95, or before??
1. Hold "ALT" and press "Print Scrn" ("ALT" - Left of spacebar on standard keyboards, "Print Scrn" - Right of F12 on standard keyboards). This produces a screen shot and stores the jpg in the clipboard. 2. Open any paint shop application, and press paste. (Eg Paint Shop Pro, Photoshop, Windows Paint, or any cluttered rubbish that comes free with camera or printer drivers). 3. Then you can simply go to "file" "save as". There are countless other screen grab applications available, but this simple little one has been built into windows since the years dot. NB: Holding the Print Scrn button itself on a dual monitor system gives a wide image the size of the complete desktop. The Alt/ Print Scrn command produces only the window which is at the front, eg if Perseus is on top, the shot will be only of the Perseus
8. REDUCE CPU USAGE DURING PLAYBACK: We all like to see the carriers on screen in waterfall mode. But if anyone is using a PC that is only just within the spec required to run Perseus flat out, you may have noticed the struggle to switch from AM to USB, to LSB and back to AM during playback of a 2000kHz file. Mathias and his Autohotkeys timer was quick to notice that if the zoom feature was activated on the waterfall during record, and the bandwidth set to minimum, the CPU load was drastically reduced. This has been used successfully here since Autohotkeys was introduced to Perseus users. There is not a lot of difference between the waterfall mode and the Spect mode in the narrow bandwidth setting. But when recording, if the dxer wishes to listen live at the same time, the bandwidth will obviously have to be increased to allow signals to be heard. But the CPU usage will increase, and if like my own PC, the system sometimes starts struggling, I have an answer. 1. Use AM for a start. Do not switch to USB or LSB while the software is making the recording. This can result in stuttering, or even a hang up. 2. Switch to Spect mode, not waterfall. Use the zoom and "freeze" the dancing wave by activating the "AVG Main" button, below the "USB" button. Move the lever to flat out, if you are distracted by the exceptional movement on screen using this function. The load on the CPU is much reduced at this bandwidth in Spect mode, than on the waterfall mode. See the images below. This extra spare CPU power is just enough to allow switching from USB to LSB to AM without the long pause or even complete hang up. It is a pity the main screen can not be disabled altogether during recording, when not in use.
7. AUTOHOTKEYS RECORDING TIMES: One tip which catches me out time and time again, is the setting of a record time, which ends up bang on the top of the hour. This is such a pest, as the Perseus navigation does not allow (so far at the time of writing) to go back 5s or so. Therefore to go back to listen 5 seconds back, one has to browse for the previous file, and find the frequency again, and find the place on the file, just before the change. It has been hoped for about a year now, (written Nov 09) that this navigation problem in the playback function, will be addressed. After all, for MW dxers, the selling point of the receiver is the unique ability to be able to record the whole MW band. So to overcome the changeover at the top of the hour, simply set the record time so that there is at least a minute either side of the top of the hour. (The time when most stations will identify themselves). Eg a 5m recording should be set to come on say at xx56, not xx55!!
6. WHEN THE PERSEUS SOFTWARE WILL NOT TUNE DOWNWARDS DURING LIVE DXING: Sometimes I have had the Perseus receiver mysteriously stop mid way on the MW band, when tuning downwards, using version 2.1f at 2000kHz sampling rate. It stopped just before I wrote this at 780kHz, and wouldn't move any farther down. It will tune upwards in freq, but NOT down below 780, as in the example. I don't recall if it happens to stop at random frequencies, or only 780. I neither recall whether this happened with any other versions. There is a simple solution. Switch from 2000kHz sampling rate, to 1000, or in fact any of the other sampling rates, and then back again to 2000. Cured!!
5. WHEN PERSEUS SOFTWARE STUTTERS AND STUTTERS ON 2000KHZ SAMPLING: Sometimes if I have been using a lot of other software applications, I have a bit of trouble running the Perseus software. Sometimes as above, switching from 2000kHz sampling rate, to 1000, or in fact any of the other sampling rates, and then back again to 2000 will help, or even cure the problem. NB: Bear in mind that I am using a 2.8g single core Athlon, 1g Ram. The spec for the Perseus at 2000kHz sampling rate, is at least a dual core proccessor. I am only just managing to run the Perseus at full bandwidth with my PC.
4. MOVING A WINDOW ON A DUAL MONITOR GRAPHICS CARD, BACK TO THE MAIN SCREEN: Someone on the Perseus group some time ago was using a PC with one monitor at a seminar, when he lost the Perseus screen, as it was automatically opening up on his screen two, which wasn't plugged in. There is a simple answer to save looking through all the settings, especially if you are unsure where to look. The fix is this: 1. Open the Perseus Software (This works for any window that is open on screen two, even a windows explorer window) 2. Right click the missing window on the taslbar at the bottom of the screen. 3. Click on MOVE 4. Without touching a mouse button, press one of the four arrow keys on the keyboard (Any one works) 5. Still do not touch the mouse buttons, and drag the mouse to the left (or right as the case may be) and the hidden screen will appear.
I use this tip all the time, as I use a dual screen system, but screen two can cause some rf interference, so it gets switched off while dxing!!!
3. PERSEUS OVERLOADING WITH AN EXTERNAL PREAMP: I noticed a bit of overloading one day with the Perseus, when I was messing around with a pre-amp. That wasn't there before, but I happened to notice that the three functions that don't seem to do anything were switched on. The preamp is one of them, and for the first time, I noticed this built in preamp was best switched off, and the problem immediately vanished.
2. WHAT SIZE OF RECORDED FILES DOES PERSEUS CREATE? The Perseus SDR creates large files when recording wideband. What size are the files? At 2000/ 1600kHz a 1m file is 468,749k At 2000/ 1600kHz a 4m file is 1.875g (Ideal for putting 2 short files on a standard DVD) At 2000/ 1600kHz a 5m file is 2.343g At 2000/ 1600kHz a max 8m file is 3.750g (Nearly the size of a standard dvd) Therefore around 28 gig per hour, and 224 gig per 8 hour recording, say from 0000-0800.
1. PERSEUS USER SETTINGS (FROM MY SEPT 2009 PAGE): I was reading the Perseus Yahoo group yesterday when I saw some questions asked about the user settings on the Persus, and in particular the AM high pass filter. It seems not all users are aware of the difference this makes to the audio. This can be set to suit the speaker set up used and the listener's ear. A high setting of 500 gives extremely tinny, cheap nasty sounding audio. The setting of 100 is the default setting, and is OK, but try reducing the setting to 30, or 25, and see the results. AM sounding as AM should sound. It has a nice LF response, like the "Orban Optimod" sound. Try it. If you have the Perseus plugged into a decent set of hi fi speakers, it will sound awesome. If you use the tiny and tinny little speakers you get for a tenner with a PC, you may well set them on fire though ...lol... I personally use 15 inch woofers in the old band / disco speakers I have, so the lf response is nice!! Click the blue icon on the top left of the Perseus screen to open the dialogue box.
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