Tag Archives: FSL Antenna

Guest Post: Pavel’s Homebrew “Monster” Drain Pipe FSL Antenna


Many thanks to SWLing Post contributor, Pavel Kraus, for the following guest post:


Building a Drain Pipe FSL Antenna

by Pavel Kraus

Hi, I greet all DX fans and the entire SWLing Post community! I enjoy reading reading this blog and the diversity of contributions from our authors and contributors; many thanks from me for so much useful information.

The following are the construction notes of my FSL antenna, which I designed thanks to the suggestions of GaryDeBock, and other FSL designers.

The antenna is a classic design featuring 60 ferrite rods 200x 10 mm, which are placed on a plastic sewage pipe.

Pict 3: Pipe with ferrite rods and windings

Pict 4: Pipe with ferrite rods and windings

In addition, sewer pipe sections are used for the entire antenna cover. I assume that this material can be obtained in other countries as well. Continue reading

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Paul’s thoughts about Mediumwave DXing in Alaska

Many thanks to SWLing Post contributor, Paul Walker, who has kindly allowed me to published some notes he recently shared among MW DXers about DXing in McGrath, Alaska, USA:
During a Zoom hang out with a bunch of Pacific NW DXers, one of the things that come up was why my DXing in Alaska is beyond amazing, and we’ve come to a few conclusions.

The extended darkness. Sunrise in the middle of winter here is 3+ hours later than the west coast, so once their Skywave burns off, I’m left with darkness over the pole and to my west.

There’re no operating AM stations within just under 200 miles from me which is a big help. I have heard distant signals on the same channel as “semi locals” such as 780 and 1080.
And I’m pretty sure there’s something to the fact I’m close to the North Pole. Still far, but closer than most.

Interesting to note though: pre sunset DX isn’t a thing there. What I’ve unscientifically discovered is it seems to be that the entire Pacific has to be dark for DX  to be worthwhile for me in the evening … despite my evening DX being Canada and the lower 48 US States.
What most everyone else hears at night, such as the transpacific signals from Japan, China, Australia etc…, I hear in the morning. Hearing anything from Asia or the Pacific at night is EXTREMELY rare.

[Since I’m DXing outdoors in extremely cold conditions] I’m getting extra batteries, extra audio cables (to go between the recorder and the radio), another radio, and another recorder. Oh and some hot hands hand warmers. Also have some extra gloves and hats ordered too.. getting prepped for winter DXing well ahead of time!

The hand warmers are as much for my gloves as they are for my digital recorder… AA batteries don’t last long during continuous use in extreme cold.

i also have a portable battery and extra cable so I can use it for my phone. Those lithium ion batteries hate cold even more than aa alkaline batteries–they will shut off in the cold. In fact, you have to not only warm it up but charge it. The cold causes it to think tis dead…. and even warming it up won’t work.

Here’s a video link to my FSL antenna designed and built by Gary DeBock:

DXIng is one of the reasons I moved back up here to Alaska and it’s entirely fascinating. I learn something new every “DX season”.

Lower 48 theory and ideas just don’t hold a bunch of weight up here … I’ve had ideas and suggestions from some really smart people that just didn’t work out.

Until you’ve DXed in Alaska, it’s hard to explain and understand.

Thank you for sharing your notes, Paul! Having never done DX in those latitudes, I can only imagine how different conditions might be–especially in those long, dark winters!

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Gary DeBock experiments with FSL antenna nulling to eliminate a “pest” station

Many thanks to SWLing Post contributor and Ultralight DX enthusiast, Gary DeBock, for sharing the following guest post:

Nulling a local pest with dual FSL Loops

by Gary DeBock

After many dual FSL antenna experiments I’ve finally determined how to effectively cancel out QRM from a local pest that is off to the side (ideally 90 degrees different, but practical from 50 degrees to 90 degrees different) from a weak DX station, although I’m not quite sure of the theory behind this discovery.

This experiment was an attempt to cancel out QRM from a local pest, 950-KJR in Seattle, WA (35 miles/ 56 km to the north) and chase 950-KKSE in Parker, CO (1005 miles/ 1617 km to the southeast) during the early morning hours. The receiver was a basic (non-SSB) C.Crane Skywave, and two identical 5 inch ferrite rod FSL antennas were used. Please refer to the photo (above) to follow this description.

Step 1) Null out the pest station with the portable radio’s loopstick (away from the FSL antennas). Set the radio down in this nulled position, so that the pest station is as weak as possible, while ensuring that there is space to set up the FSL antennas to the back and side (see photo).

Step 2) Take the “Reception FSL” and use it to peak the pest station’s frequency, setting it up parallel to the portable radio as shown, at the position providing the maximum inductive coupling gain. This will temporarily boost up the pest station, which previously was nulled.

Step 3) Take the “Nulling FSL” and pretune the frequency to that of the pest station. You can do this either by adjusting the variable cap plates to match those of the “Reception FSL,” or by temporarily peaking the pest station’s signal in a position in front of the portable radio. After setting this frequency, set the “Nulling FSL” off to the side of the portable radio as shown, with the spacing identical to the spacing between the radio and the “Reception FSL.”

Step 4) Slowly and carefully tune the “Nulling FSL” until you hear the pest station’s signal take a sharp drop. This setting will be very sharp, but once you find this position you will have nulled out the pest very effectively, and if another station is on the frequency, it may suddenly become dominant, even if it is far away (like 950-KKSE in Denver).

Some MP3’s from this morning’s experiments:

950-KJR in nulled position with the portable only

950-KKSE generally dominant over the local pest KJR when the “Nulling FSL” is peaked


Fascinating, Gary! I don’t understand the dynamics of why this works, but it’s amazing that it does so effectively. I can think of two MW frequencies in particular where I could put a system like this to the test. 

Thank you for sharing!

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Gary Debock’s report from the 2020 Rockwork Ocean Cliff Ultralight DXpedition

Many thanks to SWLing Post contributor, Gary Debock, who shares a short report he originally posted on Facebook from the Rockwork 2020 Ultralight DXpedition:


Rockwork 2020 started off with a monster session, with S9 signals from the likes of 320-AI (Aitutaki, Cook Islands), 352-RG (Rarotonga, Cook Islands), 558-Radio Fiji One, 603-Radio Waatea, 1017-Tonga, 1107-Magic Talk and the new 1503-Gold.

The session was kind of wild, with three different sets of visitors asking about my gear setup at Rockwork 4 (typically during critical moments of live DXing, of course :-). Despite this both Longwave and Medium Wave featured great propagation to New Zealand, with the long range beacon 238-KT (Kaitaia) opening up the fun around 1225. Switching back and forth between Longwave and MW in a live DXing format wasn’t exactly ideal, and no doubt my long time DXpedition partner Tom R. could have really cleaned up on the South Pacific beacons this morning with his SDR and broadband loop setup. As it was I came away with 238-KT, 320-AI (a monster signal), 352-RG and 366-PNI from across the equator, with 558-Radio Fiji One probably having its best session ever at the awesome ocean side cliff (extended S9+ periods between 1300-1330).

I promised long term “Cliffhanger DX” partner Craig Barnes that I would go all-out to receive some exotic DX in his honor, and the Cliff more than cooperated.

The Longwave and Medium Wave DX this morning [Auguest 5, 2020] was phenomenal, and there are still two more days before Tom gets here. Hopefully these conditions will stick around!

Audio samples

320 AI Aitutaki, Cook Islands Great signal but shaky sounding CW tone at 1239– best signal ever at the Cliff:

352 RG Rarotonga, Cook Islands In an S9 snarl with 353-LLD (Hawaiian mega-beacon) at 1256:

558 Radio Fiji One Suva, Fiji Overwhelming S9 signal and ID’s both before and after an island music song at 1312:

1017 A3Z Nuku’alofa, Tonga Female Tongan in an S9 snarl with DU sports co-channel (2KY?) at 1253:

More New Zealand monster signals from yesterday morning, courtesy of the “Kiwi Cliff.” This place’s preference for New Zealand signals is wacky to the extreme!

603 Radio Waatea Auckland, NZ 5 kW S9 Maori island music // 765 followed by a female Maori chant at 1309:

1107 Magic Talk Tauranga, NZ 10 kW Meltdown level Kiwi conversation between host and lady caller at 1255:

1503 Gold Wellington/ Christchurch, NZ 5/ 2.5 kW The old Radio Sports’ Yankee-accented English (from Fox Sports Network) has now been replaced by rocking oldies, such as Phil Collins with powerful strength at 1307:

73 and Good DX,

Gary DeBock (DXing at the Rockwork Ocean Cliff near Manzanita, OR, USA)
7.5″ loopstick CC Skywaves, PL-380 & XHDATA D-808
12″ Longwave FSL + three new 8″ Medium Wave FSL’s


Thank you so much, Gary, for allowing me to share your reports on the SWLing Post. Many of us would love to experience mediumwave DXing from your Rockwood perch, but we’ll have to live it vicariously through your excellent reports! We wish you excellent DX!

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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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August 2018 Rockwork DXpedition: Top ten recorded signals

Many thanks to SWLing Post contributor, Gary DeBock, who shares the following notes and recordings from the latest Rockwork DXpedition.


Top Ten DU signals from the August 2018 Rockwork DXpedition

– Gary DeBock

Life is good– breathtaking ocean scenery, an innovative compact antenna, thunderous DU signals and even a partner (Craig Barnes) to share in the bounty. Who could ask for more?

Listed below are the Top Ten DU signals recorded during the recent Rockwork ocean cliff trip (near Manzanita, Oregon) from August 1-9, including several low-powered Kiwi stations which acted like “big guns” pretty much throughout the DXpedition. All of these were recorded with 7.5″ loopstick portables (CC Skywave SSB and XHDATA D-808) and “Airport Unfriendly” 15″ and 17″ FSL antennas (guaranteed to send TSA agents into a security alert).

531 More FM Alexandra, New Zealand, 2 kW The obscure modern rock station usually managed at least one S9 peak each morning, and was fully competitive with Kiwi co-channel PI for the first time. This TOH recording at 1300 on 8-8 demonstrates its potent capability at the cliff

Click here to download.

531 PI Auckland, New Zealand, 5 kW Pacific island music at a huge level at 1248 on 8-7 was typical from this low band powerhouse, which was frequently in an all-Kiwi snarl with its overachieving co-channel More FM

Click here to download.

558 Radio Fiji One Suva, Fiji, 10 kW The donated Japanese transmitter still puts out awesome signals for this native-language powerhouse, including this island music with a Song Medley ID (“Radio Fiji One, na domoiviti”) at 1:38 into this recording at 1252 on 8-1

Click here to download.

567 RNZ National Wellington, New Zealand, 50 kW After demolition of its old tower the RNZ big gun has sometimes sounded anemic on the west coast, but certainly not at 1320 on 8-3 with Indian-accented English

Click here to download.

585 7RN Hobart, Tasmania, Australia 10 kW The RN network Tasmanian must have somehow hacked into the Kiwi propagation pipeline at 1306 on 8-6; at the time it was much stronger than its 576 parallel

Click here to download.

594 Star Timaru/ Wanganui, New Zealand 5 kW/ 2 kW Another Kiwi overachiever, this low powered network was socking it to the Oz big gun 3WV all week, including with this powerful Christian music // 657 at 1326 on 8-3

Click here to download.

657 Star Wellington, Tauranga, New Zealand 50 kW/ 10 kW The flagship Star station sure was playing the part with Christian music at an overwhelming level at 1238 on 8-6, including an ID at the end of the recording

Click here to download.

765 Radio Kahungunu Napier-Hastings, New Zealand 2.5 kW The overachieving Maori station was its usual potent self with island music and Maori chants at 1218 on 8-1; it was usually slightly stronger than its 603 parallel (Waatea)

Click here to download.

936 Chinese Voice Auckland, New Zealand 1 kW One of the most incredible signals of the entire DXpedition– the 1 kW ethnic station pounds into the cliff at an S9 level at 1309 on 8-2– ocean cliff propagation at its finest!

Click here to download.

1017 A3Z Nuku’alofa, Tonga 10 kW Yikes! The rejuvenated Pacific island big gun thunders into the cliff with the strongest signal I’ve ever heard recorded in North America, featuring island music at 1314 on 8-1… almost loud enough to wake up the sleeping squatters

Click here to download.

73 and Good DX,

Gary DeBock (DXing at the Rockwork ocean cliff near Manzanita, Oregon, USA with Craig Barnes from August 1-9)


Thank you for sharing those catches, Gary!  It’s amazing what DX you can snag with an ultralight radio and a homebrew FSL loop antenna. Someday, I hope to join you guys on the cliff!

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Gary shares some catches from the first day of the Rockwork 5 DXpedition

FSL Antennas poised to grab DX! (Photo: Gary DeBock)

Many thanks to SWLing Post contributor, Gary DeBock, who shares an update from the latest Rockwork (Utralight) DXpedition. Gary notes (in bold):

First day FSL antenna setup at the Rockwork 5 ocean cliff near Manzanita, Oregon (Craig Barnes in the photo)– outstanding conditions for 558-Fiji and 1017-Tonga!

558 Radio Fiji One Suva, Fiji Awesome signal with island music and medley song ID on the half hour at 1230 (including “Radio Fiji One, Na Domoiviti” at 1:36) :

Click here to download audio.

765 Radio Kahungunu Napier-Hastings, NZ The usual S9 signal from this 2.5 kW overachiever with distinctive Maori music at 1218:

Click here to download audio.

1017 A3Z Nuku’alofa, Tonga Monster signal with island music at the start of the session at 1221:

Click here to download audio.

Monster signal with island music near the close of the session at 1314 (in other words, all session long):

Click here to download audio.

Wow! Impressive catches, Gary! Someday I would love to join your team as you snag signals from the edge of the Rockwork cliff.

Thanks for sharing, Gary and good DX!

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