Category Archives: Antennas

The CCrane Skywave SSB 2 and long wire antennas

By Jock Elliott, KB2GOM

Frequently when people write about attaching a long wire to a portable shortwave receiver, readers will comment that you need to worry about desensitizing or overloading the receiver or ever harming the front end of the receiver. Clearly that can be a concern.

But recently I noticed something on the CCrane website in the FAQ section that shows clearly that CCrane has thought about and dealt with this consideration:

Q: When using the 2-wire adapter and wire attached, why am I not noticing any improvement on shortwave?

A: To see any difference using the 2-wire adapter you will need to have a wire that is more than 30 feet long (we recommend 60-100’) with a good ground wire. Insulated wire will last longer and should be stranded so it is more flexible. If you do not have a good ground, you are actually inputting noise. If you look at the 2-wire adapter (included) you will see an antenna icon and a ground (G) marking. You need to connect them properly when using an external antenna. When a plug is inserted into the antenna jack of the radio the internal rod antenna is disconnected. (See page 30 of the Instruction manual.)

If you check out my review of the CCrane Skywave SSB 2 you will read that I heard a noticeable improvement when connecting the SSB 2 to a 45-foot end fed wire.

Note, though, that if you plan to attach a wire to the SSB 2’s whip antenna, use the 23-foot reel antenna that comes with the radio.

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Loop-On-Ground Antenna Part 3: Tom’s low-noise, low-profile, portable antenna evolves

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Loop on Ground Antenna Part 3

(using multiconductor wire)

by TomL

It dawned on me recently, perhaps due to sloppy thinking or unintended distractions, that I never wrote about my modified Loop on Ground (LoG) receive antenna that I use at parks and such. For over a year now, I have been using 3-conductor rotor wire bought cheap at the local hardware store and have wired the conductors in series. Grayhat (Andrew) was the inspiration when he decided to create a folded dipole along the side of his house.

The usual construction of a LoG antenna for shortwave is a single wire of about 60 feet in circumference in order to not go above one wavelength for 20 meter band usage. If you recall, going above one wavelength will start creating weird lobes in the reception pattern. See – Loop-On-Ground Antenna Part 2.

However, I did not like this 19 foot diameter wire on the ground in public parks just waiting to be tripped over. Like, the time when a horse got loose from its owners and almost tripped over my 60 foot wire. I don’t think I would have liked the resulting lawsuit!

So out of fearful necessity I took some leftover RCA 3-conductor rotor wire, about 29 feet of it, and wired a loop with the conductors in series. This gives about 81 feet of total conductive length. But since it is folded onto itself, there is an undetermined loss of resonant length. Callum (M0MCX) of DXCommander fame has experimented and found folded dipoles need three times more length in the folded section to reach resonance, so my loop is probably around 69 feet (electrically). See – Fold the end of a Dipole Back – What’s Happening?.

In the picture below, the black wire with Ring Terminal at the bottom goes all the way around to the other side, soldered to the green wire, which goes around and is soldered to the red wire, which goes around to the Ring Terminal at the top, plus tie-wraps to hold the wires together.

The next picture is how the Wellbrook Medium Aperture preamplifier is connected to the loop with BNC cable that goes to the 12V power injector. I have had this Wellbrook unit for maybe 6+years with no signs of problems. WARNING – do NOT use the Wellbrook preamplifier in the presence of high powered RF energy like your Amateur Radio antenna pumped with 1000 watts from a linear amplifier; the Wellbrook premap might just overload and get damaged! I did use this loop and preamplifier at last year’s 2022 ARRL Field Day and was able to get away with it because we were only using 100 watts per station. Listening to the 9pm 3916-net trivia group was fun but I still needed to keep it away from the transmitting antennas. Continue reading →

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Jack remembers the Eavesdropper Antenna

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Many thanks to SWLing Post contributor, Jack Dully, who shares a link to this Eavesdropper antenna on eBay and writes:

When I had my roof top antennas, with the original building owner, I put up the Eavesdropper. There were 2 versions: this one with the twin lead-in and the second with a coax lead-in connection. I had both. One strung E&W and the 2nd N&S with a MFJ ant. switch. Both were up for about 7 years with a Zap Trapper surge protector and good cold water ground. They were pretty rugged withstanding blizzards, hurricanes and summer thunderstorms.

Back then, a company called Antenna Supermarket sold them for about 45 bucks a piece. Both worked great for me and they were only about 45′ long center fed From Yonkers, N.Y. I could pull in Madrid and Australia and New Zealand very clearly on my Eton E-1 XM. So I thought some readers might be interested in buying an eavesdropper on eBay, it works well. Take care and enjoy !

Thank you for sharing that, Jack!

I remember seeing the Eavesdropper advertised back in the day. I still believe it must have one of the best antenna names ever! The product image brings back memories of browsing radio catalogs!

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Frans add a Decca manual antenna tuner to his urban listening post

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Many thanks to SWLing Post contributor, Frans Goddijn, who writes:

Hi Thomas:

I bought a vintage antenna tuner, one that does not need a power source, very basic just a box with some beautiful coils and nice big variable capacitors and it works for the big magnetic loop antenna here.

I have four GRAHN loop antennas which each have their box with dials to fine tune the signal but the big loop didn’t have that yet.

The tuner works well, filters out some noise but I must say the iCOM radio also managed to select good signal from the loop with its own tuner system and the DSP noise filter at the speaker end of the system further clears up the voice sounds.

Video:

Best regards,

Frans

The internals of manual antenna tuners are simply hypnotizing, aren’t they? You’ve a beautifully-built tuner there that is functional and will outlive us all!

Thank you for sharing!

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Saturday morning fun: “fat” MW DXing with the MFJ-1886

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By Jock Elliott, KB2GOM

It was a reader, Mario Filippi, who set me on this path. He posted a comment that said, in part: “An interesting place to DX would be the segment between 1500 – 1590 kc’s where there are a number of news stations, one being federal news on 1500.”

Huh, I thought, federal news? I wonder if I can hear that. So I hooked up the MFJ 1886 Receive Loop Antenna to my Grundig Satellit 800 receiver and tuned to 1500. With the 800’s whip antenna, I heard mostly static; switching to the 50-foot indoor room loop, pretty much the same; same thing with the 1886 with the amplifier turned off. But turn the 1886’s amplifier on, and it was like getting slammed against the wall by the schoolyard bully: LISTEN TO ME! A big, fat, S9 signal, sounding like WGY 810 just a few miles from me. Wow, I thought, this loop can really pull out a signal.

A little research revealed, as nearly as I can tell, that Federal News 1500 is in Washington, DC, over 300 miles from me. Over the next few days I would occasionally check on Federal News 1500 using the 1886 loop, and typically it was loud and clear here in Troy, NY.

Hidden behind a curtain, the 3-foot aluminum loop of the MFJ 1886 works well for MW DXing.

Early this morning, Jan. 28, 2023, a thought crept into my brain: how many big, fat, MW signals could I detect with the combo of the Satellite 800 and the MFJ 1886 loop antenna? (Bear in mind that my 1886 rests flat against a window and is NOT rotatable in its current configuration.) Here’s the log, with station IDs when I could get them.

Time Frequency Station

1100Z 1520 WWKB Buffalo

1102Z 1530 Milwaukee? Sports, Australian open

1106Z 1540 CHIN Toronto, old time radio programs

1112Z 1560 religious music

1115Z 1660 orchestral music, Strauss waltzes

1118Z 540 middle eastern music

1121Z 660 WFAN, NYC

1124Z 700 WLW, Cincinnati

1127Z 710 WOR, the Voice of New York

1129Z 730 French language, Canada mentioned

1132Z 750 WSB, Atlanta

1134Z 770 WABC, NYC

1135Z 790 ortho doctor show

1138Z 860 French language, Canada mentioned

1140Z 880 WCBS, NYC

1142Z 1010 WINS, NYC

1144Z 1020 Talk

1146Z 1030 WBZ, Boston

1148Z 1050 WEPN, ESPN radio, New York

1149Z 1060 KYW, Philadelphia, PA

1153Z 1090 WBAL, Baltimore

1154Z 1110 WBT Charlotte, NC

Bottom line: it was immense fun, tuning around for “fat” MW stations in the early AM. Periodically I checked the other antennas as I traversed the band, but universally the MFJ 1886 was better at pulling them in.

Fat station DX? You bet! Try it; you’ll like it!

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PDF: Analysis and Design of FSL Antennas

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Many thanks to SWLing Post contributor, Zoltan Azary, who has written an extensive theoretical analysis of ferrite sleeve loop antennas. This article has a very academic flavor and for those who are interested in antenna design, he welcomes your comments!

Click here to download the 14 page PDF, “Analysis and Design of FSL Antennas: Open Source Hardware Engineering” by Zoltan Azary.

Thank you for sharing this work with us, Zoltan!

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Born in the ER: Andrew’s portable SULA antenna

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Many thanks to SWLing Post contributor, Andrew (VK2ZRK), who writes:

Just thought I would share some pics of my SULA build which I constructed in the Emergency department’s antenna building section in between catastrophies here in Australia.

I built it out of 8mm fibreglass tube from a kite supply, 8mm kite nocks, 13mm equal cross irrigation fitting and lots of double wall glue lined heat shrink. The 8mm tube with a short bit of heat shrink is a slip fit into the id of the 13mm equal cross which I secured with more heat shrink.

I then cut the frame to length allowing for the length of the kite nocks. I secured the kite nocks with more heat shrink. I then soldered the resister to 2 lengths of Davis RF 12g antenna wire and fed this through the kite nocks terminating it at the nooelec balun on the opposite side to the resistor.

I think it worked out well. It is very light. I built it to use with my SDRPlay RSPdx.

Thank you to everyone involved in the design process and for providing it to the swling.com community.

Cheers
Andrew VK2ZRK

In all the years I’ve been hosting the SWLing Post, I can safely say that we’ve never featured an antenna constructed in an Emergency Department of a hospital. Thank you, Andrew!

The feedback from the SULA antenna build has been phenomenal. The three-part series detailing the SULA antenna from concept to build was the most popular of 2022 on the SWLing Post.

Thank you for sharing the photos of your antenna. What a professional job, Andrew!

Readers, if you’d like to learn more about the SULA antenna, check out this three-part series–a collaboration between the amazing Grayhat and 13dka.

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