8" Ferrite Sleeve Loop Antenna Demonstration
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- Опубликовано: 27 май 2012
- Inductive coupling demonstration of a new 8" diameter FSL antenna, showing front and side lobe signal boosts on a barefoot Tecsun PL-380 Ultralight radio. Includes relative reception comparison with a portable 4 foot sided PVC tuned air core loop on weak daytimer 1070-CFAX in Puyallup, WA, USA (by Gary DeBock)
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I built a mediumwave loop based on a design that I saw in Popular Communications about 25 years, consisting of a square wooden frame about 1 foot by 1 foot, with I think 20 turns of magnet wire, and it performed at least as well as that for a lot less money than whatever you spent on all those ferrite rods.
Gary, what I did once years ago (around 1995) was string out two longwires about 8 or 9 feet off the ground in opposite directions (draped over lower tree limbs and bushes) and connect them to a homemade coil of about 100 turns of 24 AWG magnet wire wrapped close wound on a PVC or paper towel tube. The longwires were about 250-300 ft long each. I went from getting only 3 AM stations during the day to around 50. From NW Louisiana I could easily hear Dallas, Houston, Oklahoma City and New Orleans at noon. The coil wasn`t tuned.
At the time I wasn`t focused on DXing as much as I was just trying to get more stations and news so I never attempted to log the most distant stations which I`m sure extended out to at least 400 miles during the day. The ones I mentioned sounded like locals. Oklahoma City was 315 miles from that location and New Orleans 270. I could hear a lot of weak stations too but mainly listened to those. Maybe there was a better way of doing this but I accidentally figured out on my own that this was possible after I noticed that a crystal set near a portable radio boosted the AM signal.
I would also connect an LED to the longwires when thunderstorms were 30-40 miles away and watch it flash. LOL! I would throw the ends outside during local storms though. I fell asleep one night with a longwire connected to one of my best radios (I was drunk actually) and woke up during a severe thunderstorm in a room filled with smoke. Poor radio! I guess I was lucky to survive it. It actually hadn`t rained at all in about 3 months when this happened. It was a big surprise.
I used to get some incredible shortwave DX using a Radio Shack DX 392 made by Sangean using the longwires mentioned above. I listened to search and rescue on SSB from Louisiana when planes crashed off the coasts of New York and California.
I fell in love with AM radio as a child in the 1970s when I used to sit in my mom`s car at night tuning in distant cities. It was lke magic to a country boy living in the sticks to hear the outside world. Then in 1992 I saw a cheap broken shortwave radio in a Dollar Store and offered them five bucks for it and repaired it. I still listen to AM and shortwave every night. I fell asleep earlier listening to a shortwave station and started having nightmares about being trapped in a bus with Brother Stair yelling at me. He`d came on after the show I was listening to went off. LOL! Scary!
@ethiggins, Thanks! This 8" FSL is a tuned passive design, without amplification. 62 Russian surplus 200mm x 10mm ferrite rods are arranged in an 8" diameter cyclinder (with inner core padding), then wrapped with 660/44 Litz wire and tuned with a 381 pf variable capacitor. I'll try to make a TP-DXing comparison video when conditions allow... 73, Gary
Excellent video and demonstration. Your reviews of ultralight radios on the web inspired me to get a Tecsun PL-380 myself. Together with my homebrew loop antenna, it performs amazingly well on MW and even brought me some Trans Atlantic catches this winter.
73, Matthias
This 8" Medium Wave FSL was the antenna used for the July 2012 Cape Perpetua (Oregon) ocean cliff DXpedition, receiving about 16 New Zealand and 15 Australian AM stations with the Tecsun PL-380 Ultralight radio.
Thanks Bill, The video was fun to make, and I'm glad that you liked it. Good luck in your own antenna tinkering! 73, Gary
I like ur methodology on these different antenna setups Gary.. nice video presentation.. keep up the good work.. thank you
Fred
Dubai UAE
Thanks Fred, your comment is greatly appreciated! Gary (N7EKX)
Hi Gary. Mike Riordan -NRC Salt Lake City. That is good you can get CFAX in the day on your antennas. They point northeast day and night. They interfere with KNX occasionally at night here in SLC,Utah.
@cobrachobbergirl, the Select-a-tenna and other small air core loops will provide minor gain boosts to the PL-380 and other portable radios, but nowhere near the gain boosts provided by this new-design 8" FSL antenna. Its gain has been tested against a full-sized 9' sided box loop, and has been found to be roughly equivalent in weak-signal reception performance. The Select-a-tenna is a much cheaper option for those without the need for such high gain, though.
Greetings from PA. I have been into SW portables since the mid-80`s. I now oscillate between my Kenwood TS140S HF rig and a beat-up Kaito KA1103. For the last year or so, I`ve gotten into evening pirate radio on weekends and AM DX in the early morning. I have used as antennas, long wires, aluminum gutters, wire dipole invert V`s, slim jim`s and stock whips. I am in the market for a more simple receiver. I have had lousy luck with obtaining Chinese radios that will last more than a few days without something breaking. The KA1103 is the best I have come up with. I enjoy your videos and am viewing some today. Good DX and thanks. KC3BXZ Joe 73
@ Senderjaeger, Thanks very much for your comment on the FSL video, and my ultralight radio reviews! I'm happy to read that you have received some TA stations on your PL-380 ultralight, using your homebrew loop antenna. Good luck in your TA-DXing, and antenna experimentation. Gary
very nice and clean work!
@ADCASZIZA, Thank you for your comment, my friend. Your 8" FSL antenna video is also very interesting! Good luck in DX... Gary
@Diacetylm0rpheen, Thanks for your comment, and I hope that you keep up your antenna experimentation. Most of the current FSL antenna designs were made by guys who tried something bizarre, and found out that it worked! (like me)
@Mark, Thanks for your call. I am N7EKX, but sorry that I'm not active on qrz. Most of my communication is on the "Ultralightdx" Yahoo group (for Ultralight radio enthusiasts), where you can find lots of information on this FSL, and many other antennas. We welcome you to join! 73-Gary
In 2003 I made a FS loop antenna by gluing pcs. of old 3/8th ferrite antenna pcs. in a circle but wound it directly on the ferrites and it didnt seem to good in my cheesy tests.I of course didnt do it because of the same reasons Mr. Maynard did ( i am not a deep thinker) I just did it because I thought more is better!! Wish their was a roundtable for us antenna buildrs, I have a couple really promising designs that I need help with. Regards
thank you so much respected sir.please explain what is RSSI and design details of pvc loop antenna regards from india-bangalore
Design photo of this new 8" Medium Wave FSL is posted at the link given in "Annotations" to the video
I made ferrite antenna from CRT TV yoke coil ferrite... and works good ( I it use for TRF receiver,s tunning circuit )
Sounds great, Ingus! Good luck in your DXing. 73, Gary
Select-a-tenna and the same ilk won't work on this unit? Its a much smaller loop air coil?
@bbvc2000, These 200mm x 10mm Russian surplus ferrite rods were all obtained on eBay from the seller "Alexer1." Another eBay seller marketing these 200mm x 10mm rods is "Sovtube." The current cost of these rods is around $4 apiece (including shipping), so this particular FSL design is not an economy model. I have another demonstration video posted of a 5" Medium Wave FSL that works very well and can be built for around $95-- including a link to the full construction article. 73-Gary
How does it work compared to an usual ferrite antenna with just one ferrite rod ?
Yes very interesting 👍🐻🤗
Gary, here in Phoenix I can't receive WWVB strong enough for my atomic clocks to work. Do you think a huge ferrite loop antenna like this will help?
steve c
Get a new atomic clock that demodulates the QAM that was added to WWVB. This makes the receiver ten times more sensitive.
Excellent demonstration Gary. Would love to see another video comparing TP reception when conditions permit. Is that FSL powered or unpowered? Tuned or broadband?
Where did you find Ferrite rods? I am having hard time finding it...
Hi Gary,
Did you design same kind of ferrite antenna for Longwave DX? I am looking for that design or suggestion on it. GoodDX.
Hi Jiang, Yes, I did design and build a Longwave version of this 8" FSL antenna. Except for the Litz wire type (660/44, instead of the 660/46 used in the MW version) and the number of coil turns (60, instead of 14), the Longwave version is identical to the MW version. The Longwave FSL tunes from 153-550 kHz, and was used to receive South Pacific NDB beacons like 238-KT, 260-NF and 270-FA on a PL-380 Ultralight radio on the coast of Oregon state. 73-Gary
Your coupling in nonsense! Why not impedance matching and a timple coax cable to the receiver ???
Gary I am using my kids acct i am kc9aix leave a message on qrz for me will ya
Mark