Category Archives: Accessories

A 3D-printed cover for the Mountain Topper MTR-3B QRP transceiver

Many thanks to SWLing Post contributor, Eric McFadden (WD8RIF), who asks:

Thomas, what’s the orange thing on the MTR-3B in the last photo in your post about the Red Oxx Booty Boss? [see photo above]

Glad you asked, Eric! It’s a 3D-printed protective cover.

My daughters have been asking for a 3D printer since they’ve used them at Maker Faires, the Pisgah Astronomical Research Institute, and most recently the Huntsville Hamfest. Both of my girls love designing and creating things, so this year we got them one for their birthday.

After loads of research, I purchased a Creality Ender 3 Pro 3D from Amazon.com (affiliate link) for about $240 US. My daughters were thrilled when they unwrapped the box on their birthday to find a 3D printer inside! We spent the following morning assembling it, calibrating the print bed, and printing a sample file.

Like most, our first prints were fun, simple things we found on Thingiverse.  The girls printed a Saturn V rocket, a cat, and an X-Wing fighter. Those prints gave us an opportunity to learn about slicing 3D files, building support structure, and proper bed calibration.

Covering the MTR-3B

When the printer arrived, I already had the Red Oxx Booty Boss on order and was assembling my field radio kit.

One concern I had about the MTR-3B (in any pack) was that the small band switches could catch on a zipper or pocket mesh and be damaged. I had read a few accounts of this happening to others.

The LnR Precision MTR-3B transceiver

I thought about keeping the MTR-3B in a thick poly bag, but I knew that wouldn’t offer a lot of protection for the switches. Out of curiosity, I searched Thingiverse hoping perhaps someone had designed a small case that could possibly house the MTR-3B.

To my surprise, I discovered an engineer actually designed a snap-on cover for the MTR series of radios. It was then a simple matter of downloading the file, slicing it, and setting it to print while I slept that night.

The next morning, I had a cover sitting on the printer bed.

I purchased a pack of multi-color PLA filament knowing it would give my girls an opportunity to play with color a bit. The printer was already loaded with bright orange filament which I thought would be brilliant for the MTR-3B.

Those of you familiar with 3D printing are probably aware that ABS would be a better, stronger material for the cover since the side clips are certainly the weak points of the structure. We haven’t ordered ABS filament yet, but I think the PLA will actually function well for a while–it’s sturdier than I anticipated. When we have ABS in the house, I’ll plan to re-print it.

I couldn’t be more pleased because the cover fits the MTR-3B like a glove and doesn’t add a lot of bulk to this pocket-size transceiver. It was also a great print for beginners.

And best of all, I know the front switches and buttons are well-protected in my field bag.

I’d like to thank Thingiverse designer CockpitBob for designing this little cover and sharing it!

We’re also super pleased with the Creality Ender 3 Pro 3D printer. Thanks to my friends who helped guide that purchase decision.

Care to share?

3D printers are incredibly useful tools for radio enthusiasts of all stripes. I’m still very new to this world, so I would love to hear about your 3D-printed radio projects. Besides this post, we’ve featured at least one in the past, but I’d love to share more.

Please comment or contact me if you’d like us to feature your 3D project!


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The $50 tinySA spectrum analyzer is here!

Many thanks to SWLing Post contributor, Paul Evans (W4/VP9KF), who writes:

At last, the tinySA is out and target is $50 (orders at R&L): https://www.tinysa.org/wiki/

tinySA Introduction Video

The following information regarding orders and availability was taken from the tinySA Wiki Page:


Buying the tinySA

There are currently (September 1st, 2020) no clone tinySA. All are genuine and manufactured by hugen.

Various persons bought some small amount of tinySA and are now selling them on various sites. The sellers listed below are official partners and are guaranteed to deliver good service in case of problems.

The tinySA is on pre-order at Alibaba.com
For other payment methods, such as Paypal, hit the “chat now” button and Maggie will help you.

At the right top of the browser window there should be “my messages” where you will have a better overview of your messages

The tinySA is on pre-order at AliExpress

The tinySA is on pre-order at R&L Electronics in the USA

Shipment is expected to restart end of August

An additional re-seller is expected to appear on eBay, Amazon and other platforms, these will also originate from hugen.

How to recognize a genuine tinySA.

  • Look for the tinySA logo. As this is part of our trademark, no others manufacturers may use this logo.
  • Look for the nice black gift box with the golden logo and the accessories as you can see on the First Use page

For more info about the tinySA check out the tinySA Wiki.

Thank you again, Paul, for sharing this tip! I love how the tinySA developers recognize it’s only a matter of time before clones appear on the market. Sadly, a true sign of the times…

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lab599 TX-500 Discovery accessories and connectors

Many thanks to SWLing Post contributor, Don, who notes that in anticipation of the TX-500 hitting the market, W2ENY has posted a number of accessory cables, spare connectors and even a military-style handset on his eBay store and website.

To be clear, via Ham Radio Outlet, the TX-500 ships with everything you need to get on the air via SSB or CW. Here’s the full accessory set that accompanies the TX-500:

Screen grab from HRO’s TX-500 product page.

If you wish to build your own cables, or you’d like additional break-out cable options, check out W2ENY’s selection.

A note about TX-500 connectors

I’ve received numerous inquiries from readers regarding the “non-standard” multi-pin connectors used on the TX-500 to maintain water resistance. Truth is, the TX-500 connectors are only non-standard in the amateur radio world–they are not proprietary as some have implied.

The TX-500 uses GX12 mm connectors that are widely used in aviation, commercial and military applications. They’re easy to find online, but the price per each with shipping is typically around $7.00-8.00 US.  You get a better deal if you buy in bulk, but often bulk packages of 5 or more are of the same pin count/configuration.

After browsing W2ENY’s site, I see he’s offering a full set of TX-500 connectors for $30 via eBay and his store.  Not a bad price although I wish he’d also offer a package with three in particular: the speaker/mic, CW, and power ports (perhaps if he reads this, he’ll consider!).

If I were to purchase the TX-500, I would grab an extra set of GX12mm connectors to build my own cables.

Any TX-500 questions?

While I’m at it, feel free to comment with any of your questions about the TX-500. I only have this rig in the shack and field for a few more days before I need to return it. I’ve started a frequently asked questions post about the TX-500 that I’ll publish this week.

And if you’re wondering, yes, I’m very tempted to add this rig to my own collection. More on that later–!


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Upgrade the encoder on your Xiegu G90 for about $8.00 US

Shortly after posting some of my initial impressions of the Xiegu G90, SWLing Post contributor, Guy Atkins, encouraged me to upgrade the stock G90 tuning knob/encoder with one that is highly recommended by the G90 community.

While I didn’t really have an issue with the stock plastic knob, I couldn’t resist a larger, slightly heavier aluminium encoder with a dimple.

The stock G90 encoder knob (before pic)

I’m so happy I splurged for this $8 upgrade. Not only is the encoder much easier to use now, but it also gives the G90 a proper face-lift:

The upgraded aluminium G90 encoder knob (after pic)

Thanks so much for the tip, Guy! I, too, highly recommend this affordable upgrade!

Get your upgraded encoder knob from:

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Rob reviews the AirSpy YouLoop antenna

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

Thank you for your informative blog. As a longtime SWLer I enjoy reading up on your posts.

A few months ago I was considering the purchase of a magnetic loop antenna. Based on your “YouLoop is a freaking brilliant passive loop antenna” article, and the fact that I live in a fairly noisy RF environment, I made the purchase.

Since doing so I’ve been having plenty of fun with the YouLoop hanging in my loft. I have it connected to an Airspy HF+ Discovery.

I’ve made a couple of videos which I popped up on YouTube which show the YouLoop in action.

The first video shows a mix of utility and broadcast reception on HF.

The most recent explores LF & VLF.

Perhaps these would be of interest to readers, like me, who had seen your initial reviews and had been considering purchasing.

Thank you for turning me onto this little antenna, and keep up the great work in your blog!

Kind regards,
Rob (Frugal Radio)

Excellent videos, Rob, thank you for sharing! The YouLoop is an incredibly effective antenna when combined with a receiver that has a high dynamic range.

Readers, if you’d like to check out more of Rob’s videos and and subscribe to his YouTube channel, click here!

If you’d like to purchase an AirSpy YouLoop for a whopping $35, click here to view a list of distributors.

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Gerry Thomas of Radio Plus is Silent Key

I’ve just learned via Paul (N0CTF) that Gerry Thomas of Radiosplus passed away on June 19, 2020. Many of you are likely familiar with Gerry’s excellent antennas and accessories, especially the Quantum Loop series and Q-Stick.

Gerry was always very kind to work with and obviously a very talented engineer.

He will certainly be missed.

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