Saturday, August 22, 2015

Keeping the noise down

I've been trying out a new version of the Wellbrook loop antenna this week - the latest low-noise design. 



I always use 10db of attenuation with the Kenwood R-5000 receiver here which moderates the signals a little as the meter is quite generous. This also reduces the noise reading, and with the new loop I am now often getting just an S1 of noise at the top of the MW band, which is perfect for pulling in pirate signals big and small. So, I might hear a station coming in at, say, S4. You might think this is not very strong, but it's three s points above the noise level, so better than receiving a signal at S9+10 when the noise level is S9. 

A crucial factor with reception reports often overlooked is the noise floor - it's a vital piece of information, and this new loop certainly helps a great deal on that count. Trying it out on 48 metres alongside an inverted v antenna for that band is pretty telling. Even without looking at s meters, you can hear the difference in noise level. And the meter backs that up with a difference of a couple of points between the two antennas.

You might not think cutting down the noise level a little bit is a big deal, but it is really noticeable and after just a few days of use I cannot imagine going back to early versions of this loop antenna, which although were very good, have been well and truly trumped with this version. I guess it's a bit like washing powders . . . the adverts on TV always say they're brilliant - until the next one comes out and you cannot imagine how you managed without the newest version.

Here's what I've heard from the Dutch pirates since I installed the Wellbrook ALA1530LN+. All times are UTC as usual, so two hours behind local Dutch time.

Friday, August 21, 2015
1655          1915         Relmus 45444-55555 music progamme
1637          1930         Edelkampioen 45444 qsoing
1623          1935         Vrolijke Mijnwerker 45444-55444 music progamme
1638          1936         Dikke Betta 35333 qsoing
1635          1958         Boomerang 54444 testing
1610          2001         Mi Amigo 34333 music programme
1640          2042         Schaduwjager 55544 asking for report
1640          2052         Noordzee 45444 report for Schaduwjager
1665          2155         Polkaman 35333-45344 music programme
1661          2156         Nachtzwerver 23322-35333 music programme
1647          2259         Monte Carlo 45444 report for Nachtzwerver
1627          2316         Jeneverstoker 23222-34333 qsoing
1618          2317         Pioneer 24322 testing with FM relay
1636          2329         Pandora 55444 music programme

Tuesday, August 18, 2015
1620          2125         Batavia 25222-35333 music programme 
1611          2135         Desperado 24222 music programme
1636          2255         Pandora 45444 music programme
1623          2308         Jeneverstoker 25222-35333 qsoing
1606          2336         Desperado 32422 testing

Observations

  • It was little autumn had come earlier during Friday evening with some great signals coming through. It was great to hear Relmus doing the business all night long on 1655, and a surprise to hear Edelkampioen qsoing - I think that's the first time I've heard him chatting to another station. His signal, without doubt, was the best I've ever heard. Having seen his antenna, transmitter and general set-up when I visited last month, reception this time was just like I thought must be possible. Have a listen to how he was coming through on this recording:




  • Boomerang is not a regular on MW. In fact, looking at my logs shows I've not heard him up there since December 2011. He was testing on Friday night and coming through really well - his audio was very smooth as well. Perhaps he'll come on and do some programmes some time?
  • 1606 kHz is not a frequency you often hear pirates using, but Desperado was trying it out on Tuesday night. He had been on 1611 earlier in the evening with a music programme, which was coming in quite well at times here even though the power at his side was only 60 watts. His antenna was peaked for 1606 though and, sure enough, he was marginally stronger when he switched down 5 kHz. Trouble is, there was much more interference on that channel from 1602. He plans to adjust the antenna so the optimum frequency is 1611. 

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