Evening all, it's a pretty wet night here in the UK and with the children tucked up asleep in bed and the YL at work it seemed a pretty good idea to get some shack time in!

I’ve put together some pictures of the Perseus, QS1R and the Perseus running using the HOKA SDR interface. I have tired to keep them pretty similar on settings so you can get a look at the lay of the land as it were when it comes to the current crop of SDRs. I will say this and that is the QS1Rs SDRMAXII interface although not as polished as the Perseus GUI does has the advantage(?) of the waterfall and FFT spectrum at the same time; again the HOKA SDR also shows the two together.

It is a shame that as yet Nico has not decided to offer this feature – I am sure it is on someone’s Christmas list! As far as performance goes the HOKA SDR is in very early beta and as such does not benefit from some of the changes Nico has made to the firmware loads for the Perseus. I am sure this small issue will be corrected in a later version along with some more control over the GUI and spectrum monitoring bandwidths etc now as the native Perseus GUI has 2MHz on tap.

For all the screenshots have a look in the gallery.

Best 73 & good sDrX!

Being new to the TADX scene I notice that a lot of the US shows are either the same content (similar to the likes of the GOLD network in the UK) or carry each others programs for sports etc. This can make a positive ID a challenge - top of the hour helps if they break for news but then again the indents’ can be "Talk Radio Sport AM" or similar. Not very helpful!

I've read about and used myself online radio players for checking DX in the past and have found that the CBS radio player at http://www.cbsradio.com/streaming/index.html a fantastic resource.

There are many AM and FM stations listed by US county and it makes comparing content a pretty simple task of matching the frequency you're on with the ones listed. It is not 100% as some will be using affiliate audio - but it helps with narrowing down just who "Talk Radio Sport AM" really is.

The various streams seem pretty reliable as well as fast and a few checks this evening on some of the early TADX stations to appear here shows that 660 KHz is the same as the WFAM web stream. :-) The pop up player even allows you to add stations to your own presets list; making it quicker to jump between them whilst checking those Perseus files!

73

QRM, a nasty three letter word to anyone with a radio.

Ever since I moved to somewhere a little quieter (read not a suburban housing estate) I noticed that even with the loop between 250 KHz and around 600 KHz there was always this mush, no matter what I did or how I worked the antenna feeds or what options I choose as for feed line this mush was omnipresent. At times it would be evident higher up in frequency at other times nothing about 2 MHz at all. So having a little of the TADX bug inside me I decided it was time to swat this pesky noise once and for all! Armed with my Perseus (which is great for spotting noise) and a UPS I went for the big switch!

A recording of the the noise 390Khz_QRN.mp3 (469.39 kb)

Killing my own mains power removed the noise completely, A Ha! It was my QTH that housed the problem, in some ways great in others not so great! If it was somewhere else I could call on OFCOM and its team of QRM investigators to find it and cure it! However being my noise it was my problem, darn! So back to the QRM DFing, now I knew it was me I could turn on the houses’ electrical outlets one by one and see when it appeared, sure enough I discovered that once the lower floors “mains” was restored the noise returned.

I was glad it was not the central heating or anything like that! This now left me with basically the downstairs and the items plugged in or hard wired – not much really to “check”. Grabbing my trusty Yupiteru and tuning to where the noise was strongest 390 KHz I began to wonder around the house (-pretty glad my YL was not about as she always looks upon this hobby with some suspicion!) each time I got anywhere near anything electrical the noise would peak, so if I moved near a light switch, wall outlet or where the wiring runs in the walls the noise would appear. Which at least shows it was the house wiring that was radiating!

This meant it was findable … moving from item to item the kitchen appliances seemed to radiate the most – well! Now I was getting somewhere. The three items that had displays were the fridge, cooker and microwave; in turn I switched them off – voila! Switch the microwave off and the noise is gone! Switch it back on and a swish and the noise returns. Hmmm now this is not some relic from the 80’s this is a state of the art combo microwave from Panasonic, nothing cheap about it, metal cabinet, screwed together and with a bloody decent screen on the back of the unit, but even with all this as noisy as a junk yard dog on a good day!

Even moving the unit to other mains outlets did nothing, boy did this throw some junk up the house wiring. There is no local radiation as running it from a UPS there is only noise (the same noise) within a few inches of the mains lead and the back area where the PSU is located, so it is not the “item” that radiates but it is throwing QRM up the mains lead into the house wiring.

Anyway I have fired off an email to Panasonic detailing what I have found and I am awaiting a reply. Hopefully something will come of this, in the mean time I just leave it switched off until I need it.

Probably a good thing as I have read some reviews on web sites and someone noted that on standby they consume 75 watts! What the hell for, the front display? If it needed 75 watts to display the clock I would be able to see if from another town it would be that bright! Below are some screenshots of the noise so you get the idea of what it looked like on the Perseus spectrum and waterfall displays.

Narrowed in on the center where it was strongest.

A view of the lower part of the spectrum with the peak.

Zoomed in to see the noise in all its glory.

A waterfall view of the same spectrum

The audio component of the QRM from the microwave.

73

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