Having some late starts has its advantages when it comes to LF DXing. This morning I was not needed in the office until 9am which meant some time having a look around the MW band for some US and Canadian stations. Don’t get me wrong I am up with the birds so if there is DX about at 6am then I am there to catch it! The sprogs do not as yet understand what a laying means …

I normally like to check 1010 KHz and 1050 KHz as both are pretty strong to me on the loop, well I was rewarded well this morning, Perseus was showing very strong carriers on all the 10 KHz channels across the MW band.

CFRB and WWZN were like locals to me. Pretty amazing to think that the 1.1 meter ALA330S loop was working that well! It’s not designed for MW DXing as the gain falls off below 2 MHz but even so – the recordings I’ve made this morning show that even at 8.45am they were still very audible. Much more so that the inverted L that I have up which is swamped by locals the moment the sun rises all trace of TADX more or less vanishes, whereas the loop is still going strong. That is one area that the wideband antenna and the Perseus are made for each other – showing the 2 MHz of the LF end of the spectrum at one time in waterfall mode allows you to spot the TADX a mile off.

With this in mind and what it seems a new aspect to my Perseus listening I have decided that father Christmas is bringing me something better for TADX – the ALA100 – this large aperture loop looks ideal for my QTH and would allow some lower frequencies to be DX’ed a little better. The ALA330S is great for UTEs higher up and to some extent the LF bands and the inverted L works very well all over, but the reviews of the ALA100 make it very tempting. I know what I will be doing on the 25th December this year! With the turkey in the oven cooking away I will be running some more RG58/U down the bottom of the garden to my new toy.

The TADX mp3 recordings are below; they were made at 8.43am and 8.45am. Most remarkable from my modest setup considering it was pretty much daylight by then.

CFRB-WINS1010.mp3 (4.58 mb)

WWZN_AM.mp3 (942.49 kb)

73

Not being a huge TADXer I recently had the opportunity to have a few late nights (or is that early mornings) which gave me the time and the band conditions to try some TADX. Going back in time I used to spend many late nights armed with my Kenwood R2000 and shortwave magazine looking for these elusive TA stations which “popped” up for everybody all the time it seemed! From the logs I could see that WINS on 1010 kHz and CJYQ on 930 kHz should be simple catches with my “DX” setup! Back then I knew that you needed an outside aerial and an ATU … That was it! TADX only happened at night and that it needed to be the depth of winter before you would hear anything. Fast forward and with the improvement in receivers, aerials and knowledge the TADX season seems longer and a lot more can be heard – if you spend enough time in headphones replaying that toth identification over and over.

It’s pretty easy with the Internet to get an idea of how well flags, pennants and beverages work for TADX and I must admit I am in awe of some of the logs and recordings I hear from people in QRM/QRN quieter parts of the UK and EU. Ken and David (Ken a big Perseus lover) I salute your logs! A true inspiration; to anyone who wants to try out TADX. And that is me included!

So what have I done then? Armed with my trusty 1.1 meter Wellbrook loop and Perseus I hit the medium wave band in the early hours. A quick scan of the 10 kHz channels in waterfall mode allows you to see the TADX carrier’s in-between the UKs 9 kHz spaced stations. A wondrous sight as they are pretty much inaudible but very visible on the waterfall. A godsend; no doubt to serious TADXers.

I’ve uploaded a few stations which I know to true TADXers are regarded as “easys” but for my 1.1 meter loop I am pretty impressed!

My logs for the night include:

880   WCBS New York
920   CKNX Wingham
1010 WINS New York (very deep fades over the 1/2hr I was listening)
1010 CFRB Toronto
1030 WBZ Boston
1050 WEPN New York
1200 CFGO Ottowa
1320 CJMR Mississauga
1390 WEGP Talk Radio (could have been a local at one point)
1430 WENE Endicott
1430 CHKT Toronto
1470 WLAM Lewiston
1500 WFED Washington
1510 WWZN Boston
1520 WWKB Buffalo
1700 KVNS Brownsville

Have a listen to the mp3’s below and see what you think. Not bad for such a modest setup would you not agree?

1520kHz wwkb.mp3

1010kHz cfrb.mp3

1030kHz wbz.mp3

880kHz wcbs.mp3

1390kHz wegp.mp3

When looking at running a random wire of any length the question of if to use a balun or not always comes up. Since they appeared in the early 90’s people have raved that feeding a random wire with a balun and coax is much better than bringing the feed line into the house where the QRM is much higher. Remembering back in the 90’s when there was not that many noisy plasma TVs or switched mode laptop PSUs or even the dreaded PLT using a random wire and bringing it into the shack via the window frame never seemed an issue. Fast forward to 2009 and with all the noise generated in a modern shack means that a coax fed antenna does have many advantages.  I am not going to enter into the variable resistance of random wires across HF and is 4:1 better than 9:1 – there are many sites on Google that cover this subject with much greater flair in technical depth that I could ever hope to.

Going back 15 years I was at a rally where the RF systems HF balun was for sale – and after reading some “spin” about the product and then seeing that in the very noisy hall signals were in fact not so masked by noise as at other stands where the antennas were directly fed into the radio. This stand was using a balun and a direct feed side by side where you could switch between them. Most interesting to me at the time! I had my first HOKA Code30 and a PC and a very nice (at the time) 17” screen – all which generated a larger amount of QRM than I really wanted. Enter the RF systems balun. A quick £40.00 later and I was the owner of a very small round item that would cure my shack noise on HF, wonderful!

A quick change in antenna layout at the QTH meant now my 40meter wire was fed with the balun and at the time some pretty decent double screened RG58. Quick tests showed that it was better, and yes the noises that splattered about HF were in fact gone! Well worth that hard earned £40.00. And has ever since then worked very well from QTH to QTH my trusty balun has always fed the random wire into the shack. 

This brings about today’s thinking - is my RF systems balun the best there is? Are there better baluns? Could I change it and notice a difference? Well they are some very good questions I asked myself! And you too should be asking yourself! Could my balun be good but could it be better?

A Google for baluns and peoples comments led me to have a look at the Wellbrook UMB. Now these are just a little more money than the RF systems balun but and it is a big but. I am so impressed with my Wellbrook ALA330S that I was already convinced that if they can make a loop that good surely they could make a better balun?

A quick search on eBay and volia! I was the proud owner of a Wellbrook UMB. Comparing the two physically the RF systems balun has an SO239 one end and a twisty on pole/stud the other end for the antenna, the UMB has a BNC (ugggh) coax connector and two twisty pole/studs for earth and the antenna.

Swapping the first balun out for the other was easy, I already had an earth running up to the body of the SO239 on the RF systems balun which was unwound from the coax and then connected to one pole of the UMB and the antenna swapped over to the other connector. The coax was terminated with a PL259 and not wishing to unsolder this I used a SO239 to BNC adaptor – I know not ideal but it was a test ok!

Before the change over I took three screenshots from Perseus with a spread of signals around LF and MF which I always find are a good test. I’ve added the screenshots in order which are before and after. Have a look and see what you think. I’ll do some more tests later on with the HF bands when there are actually some signals to test against. QRM wise I am pretty lucky that a quick sweep of HF shows they are more or less identical in the reduction of the local noises I have here.

Medium wave 1.6Mhz spread RF systems balun. (fullsize in the gallery)

Medium wave 1.6Mhz spread Wellbrook balun. (fullsize in the gallery)

If you check the qallery you'll see the rest of the screenshots taken this morning.

73

Since the wider bandwidth recordings for Perseus have been available there have been users who have suffered the dreaded "Audio Stutter" during playback. This either sounds like the audio has stuck in a very quick loop or the audio pauses for awhile then resumes.

So; let's see how we can tackle this. First off we need to ensure that we are really looking for a problem. Check to see if you can record lower bandwidths without issues. Let's assume anything up to 800 KHz is fine. Yes/No if no then you're going to have to look at issues like is the PC up-to making recordings and playing them back - A 800Mhz PIII with an old IDE drive is probably never going to do the job you want it to! Perseus LIKES modern hardware, remember here the software eats CPU cycles and disk IO when playing back very large files, you'll need your PC in tip top shape to work well.

So a check list of the PC "newbie’s", Is your CPU single or dual core? Dual is better. Is the CPU speed above 1.6Ghz?. Does the PC have IDE or SATA drives? SATA are much better at reading large files, IDE is *ok* but really you need to ensure your recording to and reading from a SATA drive if you have one. Are you using a laptop? Remember a laptop from the "box" is designed to give the longest battery life not best performance.

You'll need to delve into the BIOS settings and make sure that any power saving options are "Off" or "Minimal" AND if there are options for the speed then set these to "Fast" or "Performance". Once you've got those pesky battery saving options off you'll want to tell Windows that you’re a power user and not worried about battery life!

OK. Lets start in Vista. Open power options by simply typing Power Options in the search bar from the start button. Or, go the long way and, click the Start button / Control Panel / Hardware & Sound / Power Options. Click the radio button next to "High Performance" then click "Change plan settings" then click "Change advanced power settings" to continue … Change "USB selective suspend settings" and "Turn off hard disk" to "Disable" and "Never". Once you have made these changes click "OK" to dismiss the dialog box and then close the power settings applet from the control panel.

For laptop and desktop PC users they are probably the most important things to change. You can always have a fiddle with other options if you want to - if you get into a mess you can always choose the "Restore plan default settings" and you'll be back where you started.

For Windows 7 users (I know RTM is not here yet but a-lot of people have RC1 or have access to the RTM from MSDN or TECHNET so you might be using it now as your main OS) the procedure is the same. For Windows XP users click Start, click Control Panel, click Performance and Maintenance, and then click Power Options. In the Power Options dialog box, you set options for a power scheme. Windows XP comes with several preconfigured profiles. From the drop down list choose "Home/Office Desk". That's the one that offers the least power saving and maximum performance, which is what we want for Perseus recording. Don't choose "Minimal Power Management" which is misleading as this leaves the chipset and CPU to decide for you what power scheme they want to use and it is not a minimal power profile!

There are many articles on the web about power management and Google is your friend for XP, Vista or Windows 7.

Right, we have the power management sorted, moving on lets see what else we can tinker with. Under Vista and Windows 7 there are some options to improve the hard drives performance, lets have a look at them.

1. Open the Control Panel.
2. Click on the Device Manager icon.
3. Click Continue button for UAC prompt.
4. Close the Control Panel.
5. Click on Disk drives to expand it.
6. Right click on your hard drive device listing and click Properties
7. Click on the Policies tab.
8. For a ATA (Parallel) or Serial ATA (SATA) Hard Drive -
    A) Check the Enable write caching on the disk box.
    B) Check the Enable Advanced performance box.
9. For an External Hard Drive -
    A) Dot Optimize for performance.
10. Click OK to apply. Windows will require a reboot for this to take effect.

Note there is an increased risk with these options that should your PC or laptop lose power then all the data in memory due to be written to the hard disk will be lost. For a laptop user this may not be an issue. As you have a battery to fallback on but a home PC should be on a UPS (even a small one) if you're going to set these options this way.

You've been warned!

There are however some external options that can be explored. If you want better performance for recording and playback one way is to get an external drive. This can be USB2 or eSATA* it does not really matter the choice is based on what your laptop has for external connections OR what PCI card your desktop PC can take. All modern machines should have a USB2 port - that's want you want to use - in fact if you're using a Perseus YOU must have a USB2 port for it to work properly.

If you're buying an external drive then try and get one that needs its own PSU. They are faster than ones powered off the USB bus. You'll find they are normally a faster drive than the bus powered ones and that they normally have larger caches (which are important) and you get the advantage they are not sucking valuable USB power from your laptop or desktop PCs internal USB hub!

As for choosing an external drive look for these three features. The drive rotation speed needs to be 7200rpm (and not the older slower 5400rpm) make sure you get a cache size that is at least 16mb and most importantly a USB2 interface not 1.1. If you're getting one that is externally powered you should shop about as several do come with linear power supplies and not a switched mode supply and this will help keep shack RFI down.

As for what to get, I'm not going to promote any particular drive or drive maker but the Seagate ST305004FDD2E1-RK works well ;-)

* If you have an eSata interface then the rules are pretty much the same as for USB2 drives. A quick Google shows the 1TB Freecom 29416 would be a very good choice as a starting model to shop about for and good to compare specifications with. IO performance for eSATA should be better than USB2 but this should not be a reason to boycott USB2 in favour of eSATA. eSATA does cost more and you have fewer options in the market place to choose from.

Hopefully we are on our way now to getting reliable playback and recording with your Perseus!

In part 2 I will go over running Perseus in "high" mode, changing some registry settings, checking on what else your PC is running in the background that you may not need and setting up a new login profile with minimal options enabled that will offer a small working memory footprint and run only the most essential Windows services and programs at start up. Stay tuned!

73

If you’re a European DXer and one who hunts around the MW band then I am sure you've come across the French station on 864Khz France Bleu - but you probably did not know they broadcast in AM stereo! Whilst doing some work on another area of the hobby I noticed that there are some European stations that transmit AM stereo on the MW band.

The Perseus SDR does not come with AM stereo (Don't confuse the AMS button on other radios to for AM stereo it is normally for AM sync and not AM stereo!) out of the box but there is some free software that will allow you to listen to AM stereo broadcasts - and it works very well. Pop over to http://www.dsp4swls.de/sodira/sodiraeng.html and download version 0.075 of SoDiRa. It is a simple zip file, just unpack to a folder you want to start the program from and that's it for installation.

To configure SoDiRa open the main program and click on 'config' in here choose your line in either VAC or Stereo Mixer (if you have it) the other options on that tab can be left alone. Then go to receiver and change the receiver type to 'common IQ' for use with the Perseus SDR. The other options can be left as they are. Using VAC as an audio interconnect works very well with the software but you can use the stereo mixer option in Windows but it is not optimum for decoding.

Once you have the program running and altered the configuration as above start the Perseus main program, change to DRM (or USER) mode and in SoDiRa you should see the spectrum appear. If so; then so far so good! In Europe tune to 864 kHz and you should be able to hear (or at least see) the French station. In the dropdown mode list in SoDiRa check you’ve got AM selected and click ‘dialog’ you’ll be greeted by a popup window with some options. Select ‘AM stereo’ and the ‘synched’ and ‘pilot stereo’ indicators if the signal is strong enough should light up. That’s it AM stereo from your Perseus.

In fact you can then play around with the bandwidth in Perseus and SoDiRa for the best quality sound. I found that 5 kHz in both Perseus and SoDiRa worked best with the small amount of splatter I was getting from 9 KHz down.

Currently there are three stations transmitting in Europe that are using Motorola's C-QUAM AM Stereo standard, they are:

0864 - AM STEREO - Paris, France (France Bleu)
1485 - AM STEREO - Rome, Italy (Broadcast Italia)
1584 - AM STEREO - Italy (Radio Studio X)
1593 - AM STEREO - Italy (MiniRadio) No longer on-air, thanks to Andrea for the heads up.

It may also be possible to hear these stations from Africa in Europe:

0540 - AM STEREO - Ga-Rankuwa, South Africa (Radio Bop MW 540 Stereo)
0576 - AM STEREO - Meyerton, South Africa (Radio Metro 576 Stereo)
0954 - AM STEREO - Sidvokodvo, Swaziland (Radio Swaziland 954 AM Stereo)
1098 - AM STEREO - Ga-Rankuwa, South Africa (Radio Bop)

The screenshots below should give you an idea of the setup.

Remember that you’ll need Virtual Audio Cable or equivalent for optimal reception.

Maybe this is a mode that Nico may consider adding to the Perseus software in the future. I am sure there are Americans who would love to hear some of the AM stations still using C-QUAM in stereo from their Perseus!

Using DRM mode and SoDiRa to decode AM stereo from France.

And now using the USER mode in Perseus and SoDiRa to decode AM stereo. You can listen to the audio from the above setup by downloading this short clip AMStereo.wma (250.41 kb)

Again using DRM mode and SoDiRa to decode AM stereo from Studio-X, Momigno in Italy. As a side note you can see the AM stereo ASMAX-1 transmitter for sale here on iOffer, they even advertise that it is in use by Studio-X!