Bruce compares two homebrew NCPL antennas to the Airspy Youloop

The Airspy Youloop

Many thanks to SWLing Post contributor, Bruce (VE3EAR), who writes:

I decided that more testing of the Noise-Cancelling Passive Loop (YouLoop) antenna was needed, but I wanted to start with a clean page.

I built two identical loops using some 3/8 inch heliax scraps I had on hand. Both are one metre in diameter and employ the same feed arrangement, with a balun wound on a half inch square binocular core of type 75 mix. There are four turns on the antenna side and eight on the feed line side, of #24 gauge plastic insulated wire. The feed line shield connects to the antenna shields. The only difference between the two antennas is at the top of the loop, opposite to the feed point. One has a simple one inch gap in the shield, with the centre conductor passing across the gap, while the second one uses the crossover connection of the YouLoop design.

I’ve been running some A-B comparison listening sessions, both mid-day and in the evenings after local sunset. The testing is done outside, with the antennas hanging on a low limb of a maple tree in front of the house. The feed line is about twenty feet of coax which connects to my Realistic DX-440 receiver on the front porch. Testing is done listening to the AM broadcast band and the 160, 80, and 40 metre ham bands, with the loop aligned both E-W and N-S and about one loop diameter off the ground.

Both loops work well, but I do have to give the nod to the YouLoop (by Airspy), which produces a stronger signal of two S-units higher than the conventional loop. It also has deeper and sharper nulls, which can sometimes produce total nulling of the station!

73, Bruce, VE3EAR

Thank you so much, Bruce, for sharing your findings with us! I, too, have found that the Youloop generally outperforms my homebrew NCPL antenna. I believe one of the reasons for this as Youssef at Airspy once told me is because the Youloop has a lower loss transformer than anything that can be wound by humans (0.28 dB)–this improves gain.

Click here to read our review of the Youloop and click here for step-by-step instructions on building your own Noise-Cancelling Passive Loop antenna.

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Any advice on compact Lipo batteries, in-ear earphones with volume control, and portable amplified speakers?

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The MTR-3B 3 band transceiver is about the size of a pack of playing cards.

SWLing Post readers: I originally published the following post on QRPer.com. I thought I might share it here on the SWLing Post as well since we’ve so many readers who regularly use compact battery packs, earphones, and portable speakers. I’m looking for some advice as I build a super-compact SOTA/POTA field kit around the Mountain Topper MTR-3B. If interested in helping me sort this out, read on:

I received my Mountain Topper MTR-3B last week, and I’ve already taken it on a POTA activation.

Last weekend, I decided to break it in on a POTA “two-fer” site: Hampton Creek Cove State Natural Area (K-6246) and The Overmountain Victory Trail (K-4577) in Tennessee. Hampton Creek Cove was actually an ATNO (all time new one) so it was a trial by fire!

In short, the MTR-3B was marvelous. I’m so impressed.

As I mentioned in a previous post, I’m building a full SOTA/POTA activation kit for the MTR-3B. I already have a kit built around my KX2 and I don’t want to “borrow” any items from it (so I’m not surprised later in the field when an item is missing).

The TalentCell Rechargeable 12V 3000mAh Lithium Ion Battery Pack is the little black box.

For this activation, I powered the MTR-3B with this inexpensive 12V battery pack a friend recommended on Amazon.com (affiliate link). The battery pack is almost identical in size to the MTR-3B and works perfectly. The battery, charger and cable all set me back a whopping $25.

I also used my Whiterook paddle (which needs new paddle arms at this point) but that will soon be replaced with a set of N0SA portable paddles I recently ordered.

Since the MTR-3B has no volume control, I used a pair of 20 year old Sennheiser earphones I bought when I lived in Munich. These have been in a drawer for ages because I now prefer using in-ear earphones with silicon earpieces for better comfort and sound isolation. But the Sennheisers have one thing none of my other earphones sport: in-line volume control.

While the earphones worked well for this activation, I’d still prefer a set of in-ear earphones with in-line volume control. Any suggestions from MTR-3B owners? Also, I’d like a compact amplified speaker with volume control to carry as an option when needed. If you can recommend one, please comment!

I’m writing an article for The Spectrum Monitor magazine about portable power later this year. I noticed that a number of MTR-3B owners swear by 11V rechargeable Lipo cells that are used in the RC and drone markets. Many have a similar compact form-factor as the common 9V battery. I understand, however, some of these cells need special chargers and equipment to balance them.

I would appreciate any and all information about these batteries.

In the meantime, Rich (N8TGQ), recently shared a pic of his Mountain Topper portable pack. Check it out:

I think it’s brilliant how he’s mounted everything on a compact plastic cutting board inside the case. Rich says that what he loves about this set-up is that everything is there, ready to go–simply plug in the antenna!

Please comment or contact me if you have any suggestions as I build out a compact MTR-3B kit!

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WBCQ purchases World Harvest Radio (WHRI)

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WBCQ’s Ampegon antenna at the Monticello transmitting site.

Many thanks to SWLing Post contributor, Benjamin, who shares the following news tip via Radio Insight:

Family Broadcasting Corporation is selling shortwave Christian “World Harvest Radio” WHRI Furman SC to Allan Weiner for $1.25 million. Weiner also owns shortwave Talk “The Planet” WBCQ Monticello ME as well as Talk/Rock 780 WXME/98.3 W252DW and Classic Country “Kixx 94.7” WBCQ-FM Monticello. The seller owns multiple Christian television stations as well as Christian AC “Pulse-FM” 103.1 WHME South Bend IN, 96.9 WHPZ Bremen IN, and 92.1 WHPD Dowagiac MI.

Click here to read this item at Radio Insight.

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Elecraft KX2 3D model tour with Wayne Burdick (N6KR)

Val’s Morse Code videos and practice sessions

Don recommends “Ham&HiFi” for late-model and vintage radio gear

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Many thanks to SWLing Post contributor, Don, who sent a message recently recommending Ham&HiFi as a source of late-model and vintage radio gear. Don writes:

They buy amateur radio, audio, vacuum tube collections from around the US.
They ship worldwide and have lots of inventory!

They are a good source for both vintage, newer equipment and accessories. They’re always looking for good quality items to buy.

Click here to check out Ham&HiFi’s website and click here to view their items on eBay.

Thank you, Don. I’m often asked where people can sell radio gear when they don’t want deal with it on eBay or at a hamfest directly. This could be a nice option!

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