Category Archives: Antennas

MW Loop antenna sale at Anon-Co

Many thanks to SWLing Post contributor, Ron, who writes:

Anna at anon-co has both the AN-100 and AN-200 for $12.99 plus
$9 shipping by First Class Airmail.

This $21.99 total delivered is less than *anyone* else:

https://www.anon-co.com/category/radio-reception-antenna

Thank you for the tip, Ron.  I’ve had the AN-200 for years–it’s a brilliant loop for portable medium wave DXing!

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Guest Post: Summer Daytime DXing 2019

Many thanks to SWLing Post contributor, TomL, who shares the following guest post:


Summer Daytime DXing 2019

by TomL

I took note of the mediocre band conditions this summer amongst amateur radio operators as they were making off the cuff comments about still being in a solar minimum.  Some had gone out and bought upgraded transmitters to solve the problem (MOAR WATTS!). And more power thrown at a weak ionosphere does seem to help get a signal farther.  I had not been out since the spring and decided to find out for myself. But instead of more watts, I wanted more height.

Greene Valley Scenic Overlook is open to the public from May through October on weekends only (and only from 11am-6pm).  It was the largest land fill (aka, garbage dump) in Illinois, now covered over and producing captured methane gas. On August 3 & 4, I ventured over there to see if its 190 feet above the surroundings might help my radio reception.

After trying my luck with a 12 foot vertical antenna on a tripod (and numerous children running around it chasing butterflies or looking at the view of Chicago), I went out the next day and parked away from anyone and put up my 19 foot vertical on the roof of the car.  This setup is still amazing to me and works much better than the tripod mounted antenna, probably because it has a proper ground plane as well as being 7 foot taller.

So, yes, the conditions were so-so, not too bad and not too good.  Lots of weak signals and some empty frequencies that I had expected to hear some South American stations around the 5 – 10 kw range.  Weak stations from Asia were more scratchy sounding than usual even with the extra 190 feet of height. Here are 5 broadcast recordings as a sample (times in UTC):

9920 kHz at 21.14 – Radio Thailand in Thai, just catching the end of the broadcast:

9685 kHz at 21.20 – Radio Free Asia in Chinese from Kuwait:

9650 kHz at 21.23 – Radio Guinea in French:

9445 kHz at 21.30 – All India Radio in English (fighting off computer generated noise on my SDR and cheap Dell laptop) and just getting a station identification:

11780 kHz at 21.44 – Radio Nacional de Amazonia booming in with the usual annoying host yelling enthusiastically over every tune he played:

Running out of things to listen to, I wandered over to the 20 meter amateur radio band and found a different situation.  Propagation was decent between the Western hemisphere and Europe. Lots of “pile ups” going on with people trying to make contact with their trans-Atlantic counterparts.  Some said they were running 500 watts or more, so more power does seem to help! Here are 5 recordings to show how active it was:

14171 kHz at 21.55 – Inaki (F5RAG) from southwestern France conversing with Carlos (YV3CRT) in Venezuela (surprised anyone is left in Venezuela with operating radio equipment and not sold off for food with the ongoing difficulties there).  Then Inaki makes contact with Alejandro (CE2ATS) from Chile with a good signal. All in Spanish:

14199.38 kHz at 22.04 – Ervin (VE3GAL) tries his QRP portable setup from Ontario to contact Ron (F4VSM) in Southwestern France who has a 500 watt setup and large Yagi antenna. Sometimes things do not go so well but that is the challenge of using low power, maybe around 10 watts (meaning that just because you can hear them, you cannot always transmit to them with the same effectiveness and vice-versa, for various reasons):

14228 kHz at 22.12 – “BAN” (IZ1PNT) from Italy makes contact with Norman (N3PVQ) in FL after asking everyone to be quiet. Good control over the frequency:

14238 kHz at 22.17 – Slavko (S57DX) booming in, making a contact (Rob, KK4HEQ) in Florida:

14245 kHz at 22.24 – Gabrielle from the Czech Republic, participating at a Youth event using station OL88YL contacting Ira (VP2EIH) in the British Virgin Islands and then another dude from Florida, Roy (AD4AN).  She handled it very well:

This outing was quite educational and I find it curious that people running 1000 watts or less are able to be heard well between continents but the large broadcasters were difficult to hear.  Antennas pointed in the right direction, at the right time of day and frequency, can certainly do amazing things, plucking those weak signals out of the air so easily. And I do think the extra height had something to do with hearing this magic, too!

Happy Listening,

TomL

NOTES:

  1. An easy way to lookup amateur radio operator “call signs” is to go to web site QRZCQ.com which does not need a login.  Some records may be out of date, but most of it is accurate.
  2. Setup used was a cheap Dell laptop, Windows 10, SDR Console 3.03,  connected to the AirSpy HF+, a Palstar amplified preselector, and an old Kiwa BCB filter, then going up to the car roof magnetic balun (a Palomar MLB2) which is then connected to the 4 magnet base and the MFJ 19 foot stainless steel antenna.  You can read about it here:

https://swling.com/blog/2018/07/guest-post-backpack-shack-3-0-part-3/


Brilliant report, Tom! It’s true: the bands are fickle, but like you I always find interesting things to hear on HF. I think your setup using your vehicle as the ground plane for the antenna is a fantastic idea. Plus, set up is easy, self-supporting, and you’ll never have to worry about a park ranger, for example, complaining because you have a wire suspended from a tree. And when there are no trees? You’re still golden. 

Thanks for sharing your experience and DX! Amazing that even with mediocre conditions, you still snagged some distant signals.


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QRPGuys Active Antenna Splitter Kit

Many thanks to SWLing Post contributor, Eric McFadden (WD8RIF), who shares the following announcement from Ken (WA4MNT) via the QRP-L forum:

QRPGuys is open for orders after this year’s Summer shutdown. We have  added a product that may be of special interest to SWL listeners and some hams. It is an active antenna splitter that will enable connection to three receivers from a single antenna.

Product Deescription:

The KN8TND Active RX Antenna Splitter will allow you to use one antenna with mulitple HF receivers simultaneously. Many hams and SWLers like to monitor several bands and/or frequencies, i.e. 14.300, international nautical emergency freq, 14.100, world HF beacons, etc, etc. Having two or three HF receiving antennas is a luxury some Hams and SWLers can’t afford. With the active receiver antenna splitter you can use one antenna and three receivers at the same time. Keep abreast of what’s going on on the bands, put some of those dust collecting receivers back in action. On a difficulty scale of 1 to 5, this kit is a 2. Build time is about 2 hours, depending on your experience, with the normal kit tools. Bear in mind, this is for receiving only. For HF transceivers you would need a T/R switch to your tuned transmitting antenna.

Come by and see it at:
https://qrpguys.com/k8tnd-active-antenna-splitter

QRPGuys makes amazing QRP kits. Immediately after receiving Eric’s email, I purchased the active antenna splitter kit. Total cost with shipping was $25 US. A true bargain! Although I already have an ELAD Active antenna splitter, this one would be nice to take to the field as it’s much smaller and lighter weight.

Click here to check out the new Active Antenna Splitter at QRPGuys.

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Radio World: History of Directional AM Broadcast Antennas

Many thanks to SWLing Post contributor, Marty, who shares the following article by John Schneider in Radio World:

In the early years of AM radio broadcasting, all stations utilized non-directional antennas. Most all of these were wire antennas suspended between towers or buildings. Interference, especially at night, was severe. An interfering signal of 5% or less in signal strength was enough to disrupt reception of the desired station, and if the frequencies of the two stations were slightly separated, there would be a heterodyne beat note. As a result, only a few widely-spaced stations could operate on each of the AM broadcast channels in the entire country at night. This limited the number of stations that could coexist to about 500 nationwide, with many of them sharing time on a single frequency.

As antenna technologies were developed and improved in the early 1930s, a few progressive stations began experimenting with multi-element directional arrays. This approach offered two attractive benefits: 1) It could reduce radiation towards other stations on the same or adjacent frequencies, permitting more stations to share a frequency; and 2) a broadcaster could direct more signal towards the desired coverage area, and away from wasted areas such as open water in the case of coastal stations.

WFLA-WSUN

The first known use of a directional antenna was by a pair of stations in Tampa/St. Petersburg, Fla. In 1927, the Clearwater Chamber of Commerce acquired station WGHB and changed the call sign to WFLA. A companion station, WSUN, was operated by the St. Petersburg Chamber of Commerce. The two stations shared the frequency of 900 kHz, broadcasting on alternate evenings to promote tourism and business opportunities in their respective communities. In reality, they operated with two station licenses, but there was only one transmitter and one antenna.[…]

Click here to to continue reading the full article in Radio World.

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August 2019 Rockwork DXpedition

Many thanks to SWLing Post contributor, Gary DeBock, who shares the following guest post and update from the August 2019 Rockwork DXpedition:


Gary DeBock DXing with Craig Barnes at the Rockwork 4 ocean cliff near Manzanita, Oregon, USA

Once again the largest FSL antenna collection on the planet made its way across the Columbia River bridge during an overnight trip to NW Oregon, finally being deployed at the original Highway 101 plunging cliff turnoff– Rockwork 4. There has been a drastic decrease in the squatter population, so that Craig Barnes and I were able to easily set up all four PVC bases for all-out DU-DXing at the dream site this morning (see photo). Unfortunately Chris Black came down with a health issue at the last minute, and needed to cancel out.

Craig and I had some excellent signals from the regulars (including 531-More FM, 558-Fiji and 1017-Tonga), although it wasn’t quite a stellar morning for rare DX. We were kind of spoiled last year with 1017-Tonga staying a S9 practically throughout the session, but this morning it was “only” at S9 for a few minutes at a time. This meant that as soon as I notified Craig of 1017’s potent status, the signal tended to nosedive. Maybe the cumulative effects of humidity and salt water exposure are beginning to take their toll on the Tongan big gun? 558-Fiji showed up with decent signals for a couple minutes at a time, which meant that Craig got the short end of the stick after I notified him of the potent signal. 531-More FM hit an awesome S9 peak around 1312 (including the usual split-second female ID), making it once again seem totally bizarre that no trace of the 2 kW modern rock station has ever been received at Grayland for the duration. The Rockwork Cliff is typically focused in like a laser on New Zealand, and this was a typical morning!

531 More FM Alexandra, NZ 2 kW Potent S9 modern rock signal from this Rockwork regular, with female “More FM” ID at 19 seconds:

Click here to download.

558 Radio Fiji One Suva, Fiji 10 kW Island music at temporary potent level at 1257; typically hit the skids after reaching this level:

Click here to download.

1017 A3Z Nuku’alofa, Tonga 20 kW Female Tongan speech at S9+ level at 1317:

Click here to download.

1017 Newstalk ZB Christchurch, NZ 10 kW Presumed the one under A3Z’s meltdown-level signal:

Click here to download.

73 and Good DX,
Gary DeBock (DXing with Craig Barnes at the Rockwork 4 ocean cliff near Manzanita, Oregon, USA)

DXpedition equipment:

7.5″ loopstick CC Skywave SSB and XHDATA D-808 Portables
15″, 15″ and 17″ Airport Unfriendly FSL antennas (see photos above)


Again, thank you so much for sharing your DX, Gary! I’m so amazed by the signals you snag each year with your homebrew loopstick antennas!

To read more of our posts by Gary DeBock, click here.

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