Category Archives: Antennas

QRP POTA at Fort Dobbs: No antenna? No problem!

I’m a pretty organized field radio guy if I do say so myself.

In all of the hundreds of field activations I’ve attempted since the days of the National Parks On The Air (NPOTA) program, I’ve only arrived on site two or three times and discovered I was missing a key component of my field kit.  Out of those times, only once do I remember that the missing component prevented my activation (it was hard to power my radio without a battery and power cable). The other times, I was able to improvise.

As I mentioned in this two-parter series, I tend to build two different types of field kits:

  • one that’s fully self-contained (like the MTR-3B kit),
  • or one that’s modular, where component families (transceiver, antenna, power, etc) are in their own packs and can be moved from pack to pack.

I always prefer having dedicated field kits, but they’re pricey because they require a dedicated antenna, battery, radio, key/mic, earphones, pack, connectors, and sometimes even their own throw line.

I assemble modular kits around a particular radio and antenna system prior to leaving the QTH to go on an activation. I have a method for doing this which prevents me from leaving stuff behind.

Save this time…

On Thursday, April 7, 2022, before leaving the house for a quick overnight trip, I grabbed my SOTA pack and disconnected my Elecraft KX3 from the KXPA100 amp in the shack.

My pre-side rails KX3 in the shack.

My KX3 is used a lot in the shack–along with the Mission RGO One and Ten-Tec Argonaut V–it’s one of my staple rigs at the QTH. I didn’t think I would have time to complete an activation on this quick trip, but if I did, I wanted to use the KX3. I also grabbed one of my pouches that contained a 12V battery, distribution panel, and power cord.

Also inside the pack was my Elecraft KX2 kit. It was in there from a previous activation, so I just left it in the bag.

When a window of opportunity for a quick activation opened on Friday, April 8, 2022, I grabbed it. I didn’t have time to go far afield, so I chose to activate the closest park to where I was running errands that day.

Fort Dobbs State Historic Site (K-6839)

As I was driving to the site on I-40, it dawned on my that I might have forgotten to pack an antenna.

Not a good feeling, but I was only 10 minutes from the park, so there was no turning back.

You see, a couple days beforehand, I did a bit of an antenna inventory at the QTH–I took all of my antennas out of their packs, checked them over carefully for any damage or fault points and  made notes.

I normally keep a 20M EFHW antenna in my KX2 field kit, but I remembered that also I removed it during the inventory.

Once I arrived at Fort Dobbs, I opened my SOTA pack and confirmed that I had no antenna. Not a one.

I kept a clear head and realized that if I wanted to complete the activation, I needed to do one of two things:

  1. Search the car in case, somehow, I had a spare antenna floating around in there. Unlikely, but I’d feel like a fool if I aborted an activation with an antenna in the car.
  2. Go to a nearby hardware or dollar store and find some cheap wire.  The KX3 has a brilliant internal ATU to match pretty much any wire I connect to it.

So, I searched the car. Continue reading QRP POTA at Fort Dobbs: No antenna? No problem!

Bob’s new stainless key and stealthy speaker wire that snags serious QRP DX !

Many thanks to Bob (WD4EWZ) who writes:

Thomas,

Let there be no doubt that your speaker wire antenna is awesome! I have been licensed for 46 years but was inactive during much of that time. I finally pulled the trigger, largely on your reviews, on a new Icom IC-705, AH-705 and PowerWerx PS.

I live in a very HOA restricted area so antennas were my bane. I built your speaker wire antenna not expecting much, and for the first few days I got nada. The bands were terrible and the antenna was looped around my lanai.

On Friday I had an inspiration. I made a throw line, moved an unused bird feeder anchor post and got the antenna about 40 feet up into a tree. The wire is invisible from the street, and we have more latitude in the backyard. My wife likes it so much she wants me to just leave it there, and make another for POTA/SOTA.

Does it work? Oh my goodness… Last night I nailed 9K2BM in Kuwait on 20m SSB, and this morning the JAs were melting the face off my IC-705.

This antenna is a wonder. As is the 705, after a week of learning how to optimize the settings.

Joe, at HRO in Winter Springs warned me that the 705 had a learning curve, and I foolishly said ‘yeah, sure.’ I do this (computer science/IT/data science) for a living. Don’t worry about me.’ Wrong! A huge learning curve, but I’m getting there.

Also, my new paddles recently arrived. I love this little stainless paddle — the magnets are strong enough to hoist a car, and the price is amazing… $69 on Amazon [affiliate link]!

I am using a 4″ square steel forging plate I had from my days of making metal jewelry. (Too many hobbies). It works a treat.

Thanks so much for your writings and 73.

Bob (WD4EWZ)

Thank you for sharing this, Bob! Loads of readers have asked me about those stainless paddles, so it’s great to get a report on them. 

I also love how you’ve implemented the speaker wire antenna in such a stealthy way! And the DX you’ve snagged? Simply amazing.

Thanks again for sharing!

Norm recommends the MFJ-212 Matchmaker for effortless tuning

Many thanks to Norm (VE3WNS & M0CEL) who writes:

Hi Thomas,

[…]At my condo QTH in downtown Toronto I’ve been using a balcony tripod mounted MFJ 1886 along with my Icom 7300. I heard about the MFJ-212 Matchmaker and decided to try it out. It worked brilliantly. What it does is put out a signal in the form of hash and you can see the resonant point moving along the band scope on the radio as you tune the antenna. Once the hash is centered you are on frequency without ever transmitting.

I’m back at my QTH in Manchester where I have a pretty respectable station, you can see both on QRZ. Anyway, your videos are responsible in a large part for getting me interested in POTA so I’ve purchased an ICOM 705 and a Chameleon F Loop 3.0. I decided to purchase another MFJ 212 Matchmaker and again, it works brilliantly. No transmitting required as the antenna can be tuned visually on the 705 band scope. The 212 can be powered externally or, as in my case, I’m using the 9 volt battery option. I figure the battery will last for ages.

[…]I have to say the MFJ Matchmaker has made working with a hi Q loop a pleasure, especially one that tunes as smoothly and finely as the Chameleon F Loop.

73

Thank you for sharing this, Norm and for the kind comments! I had no idea such a product existed. I love the concept, though–this could be especially useful tuning antennas like loops with high Q and thus narrow bandwidth. 

Click here to check out the MFJ-212 Matchmaker at MFJ ($149).

Update: A number of you have pointed out that the MFJ-212 is a noise bridge! I think it’s so cool that, in a sense, this accessory is even more useful when paired with a transceiver with spectrum display. Thanks for the comments!

Antenna Challenge #2: K6ARK End-Fed Half-Wave paired with the Elecraft KX1

I mentioned in a previous post that my personal Activation Challenge for 2022 was “to build a new antenna each month and deploy it at least once that month during a field activation.”

In January, I built a doublet with a military fixture/winder.

For February, I decided to purchase and build a counterpoise-less end-fed half-wave kit from from Adam (K6ARK).  This kit is available on Amazon.com for a mere $19.95 (affiliate link).

The build itself is pretty straight-forward and not terribly complicated. With that said, you do need a fine soldering iron tip and a little dexterity to manipulate these super tiny components. Adam includes instructions for building an EFHW with a counterpoise, without a counterpoise, or a random wire antenna. The coil can be configured as a a 49:1 Unun, 9:1 Unun, or 1:1 Balun.

If you choose the EFHW route you will need to solder one surface-mount capacitor on the board. If you’ve never worked with surface mount components before, take your time and use a good magnifying glass.

Blue Ridge Parkway (K-3378 NC)

On Monday, February 21, 2022, on my way back from town, I hopped on the Blue Ridge Parkway and drove to one of my favorite roadside spots on a grassy hill surrounded by trees.

Since I configured the K6ARK kit as a counterpoise-less EFHW, I wasn’t entirely sure how stable the SWR would be in the field. For this reason, I was a wee bit nervous pairing it with my MTR-3B since that little radio lacks an SWR meter and really needs a good match.

I decided, instead, to pair the K6ARK antenna with my Elecraft KX1 which has a built-in ATU that can both monitor the SWR and find an impedance match if needed. Of course, I turned off the internal ATU for the activation, but if I needed it, I knew I could engage and use it. Continue reading Antenna Challenge #2: K6ARK End-Fed Half-Wave paired with the Elecraft KX1

QRPer Notes: Simon’s World Map Update, RG-316 Assemblies, My-Key-Mouse (USB), and Canary Islands VCAN

Because I receive so many tips from readers here on QRPer, I wanted way to share them in a concise newsletter format.  To that end, welcome to QRPer Notes, a collection of links to interesting stories and tips making waves in the world of radio!


Simon’s World Map

Many thanks to reader, Mike Bott, who notes that Simon’s World Map has been updated to V1.2.3.

Click here to download Simon’s World Map.


RG-316 BNC to BNC assemblies

Don (W7SSB) shares two announcements.

First, he notes that Chameleon Antenna is now selling RG-316 assemblies with in-line RF Choke options and BNC fittings . They have a number of lengths available:

https://chameleonantenna.com/shop-here/ols/products/cha-50-coax-with-integrated-rfi-choke-cha-50-cx-wth


My Key Mouse

Don also notes that CW Morse is now offering a USB-CW keyer/ device interface called the My Key Mouse. Check out the product description:

New for 2022! Morse Code Key to USB Adapter!

Did you know that there is an ever growing list of Software and Apps that allow you to practice and/or learn Morse Code using Computers, Laptops, Tablets, Android and other devices? Truly a great idea, but, if you’ve ever tried using a mouse to send Morse Code, I am sure you’ll agree that it is makeshift at best. But why?

Because It takes the right tools for the job!
To Send Morse Code it takes a Proper Built Key Or Paddle.

Now You can practice with a host of software and apps using your own device!

Click here to read more.


Many thanks to Jesus Alberto de Lorenzo who shares a link to a fascinating field activity based in the Canaries: VCAN — a Volcano program!

Click here for full details.

Thanks to everyone for the tips!

Brent’s updated review of the CQHam TB Box

Many thanks to Brent (VA3YG) who writes:

Hi Thomas, hope you’re well.

Just a short message to bring you up to date on the performance of the new equipment.

In a nutshell, it’s brought me back to my old faithful friend, the FT-817. I bought my FT-817 20 years ago and it’s served me flawlessly all these years. It’s not the best at everything but it’s a perfect QRP shack-in-the-box.

The TB Box makes the little Yaesu a pleasure to use. The tuner tunes my 43’ vertical and K6ARK end fed random wire from 80-10 for the vertical and 40-10 for the ef random wire.

The battery tray slips out to reveal 6 Panasonic 18650 cells. The battery life is exceptional even with the 817 set on 5 watts. I’m just now in the process of topping the batteries up.

Attached are a couple pics of my operating situation today….it was such a nice day out on the driveway. I have a telescopic pole attached to the RV and strung the 41’ of wire up. Also, a closeup of the battery tray and one of the cells.

I can whole heartedly recommend this piece of gear to supplement an FT-817/FT-817ND/FT-818ND.

Loving it!

72/73,
Brent VA3YG

Very cool! Thank you for sharing the update, Brent! I’ll admit that I like the “old school” simplicity of this power and trans match system.

Click here to check out the CQHam TB Box on eBay. (partner link)

Brent’s initial impressions of the CQHAM TB-BOX

Many thanks to Brent (VA3YG) who writes:

Hello Thomas,

The Fedex courier just left my driveway. I ordered the CQHam TB box on Feb 29 and paid the $39 US for Expedited International shipping vs the Free Speedpack shipping from Hong Kong that promised it by June 1.  I really don’t like waiting for a parcel to arrive! Lol

I know there was some interest on your site about this product, so I thought I would write and give you some brief, first impressions.  Sadly,  I don’t have any more time to play with it until next week as I’m about to leave now to visit friends.

It arrived in 10 calendar days, well packed and everything inside survived the Fedex journey from Hong Kong to Southampton ON via Anchorage AK and Memphis TN.

No one would ever mistaken this equipment for gear made by Elecraft or Icom but it appears to work just fine. The variable capacitors are not smooth and the fit and finish is okay at best but I think, if you’re careful with it, and do your adjusting carefully, it should last you some time.

The “faux” leather case is actually quite nice and reminds me of the Yaesu FT-817 case.  As a bonus, a telescopic whip was included.

The batteries came charged and the rig showed 11.3vdc. I didn’t remove the battery tray as it didn’t want to slide out willingly and I didn’t want to force it. I’ll try that later when I have more time….

I connected my 43’ ZeroFive vertical with 30 radials to it and was able to tune from 80m right up to 10 meters with no problem.

I made a nice contact (my first phone contact in about 8 yrs) on 17 meters with a station in Biloxi.

It should be fun and it’ll give me an excuse to work the 817 again.

73 fer nw,
de Brent VA3YG

Thank you for sharing your initial impressions and the inside shots of the matching unit, Brent. We look forward to any updates you might provide as you spend more time with this field kit!

Any experience using the FT-818/817 CQHAM TB-BOX?

Many thanks to Motters (M7TRS) who writes:

For some strange reason I stumbled across something on eBay for the FT-817/818 as I am still looking for my first HF setup.

Anyway, it’s a tuner and battery pack for a 817/818 and when I saw it I wondered if you knew about it.

https://ebay.us/vSiNwc (partner link)

YouTube video demonstration:

[Update] And this video:

Thanks for the tip, Motters. I was not at all familiar with this pack. I do like the simplicity of the setup. 

The price is certainly right at $179 US.

There are so many FT-817/818 owners out there, I’m very curious if anyone has any experience with this particular pack and if you can report on the overall quality. Please comment!

Pairing the Xiegu X6100 with the Elecraft AX1 antenna…will it work?

If you’ve been reading QRPer for long, you’ll note that I’ve become quite a fan of the uber-compact Elecraft AX1 antenna.

Not only has the AX1 never let me down, but it can even outperform my other antennas in terms of snagging contacts during an activation. Yes, it can even work some DX as well.

Normally, I pair the AX1 antenna with my Elecraft KX2 (above) or KX3 (below).

I’ve even paired the AX1 directly to my Icom IC-705 using a homebrew simple capacity hat (thanks again for that idea LY2H!)

The AX1 needs a little help from an antenna tuner (ATU) to get a match across the 40, 20, and 17 meter bands. Of course, I could always mount the AX1 on a tripod and attach an in-line ATU, but I love the simplicity and speed of setup when paired directly to a transceiver that sports an internal ATU.  To be clear, the Icom IC-705 has no internal ATU, but I was able to get away with using a capacity hat to match impedance on 20 meters.

The new Xiegu X6100 (above) has an internal ATU–a good one at that! As soon as I took delivery of this loaner unit from Radioddity, I plotted hooking it up to my AX1 to see how it might shake out in the field!

The X6100 lacks only one thing that the KX2, KX3, and IC-705 have: a good, accessible grounding point on the chassis.  The AX1 needs a counterpoise to operate efficiently. Continue reading Pairing the Xiegu X6100 with the Elecraft AX1 antenna…will it work?

“What battery, antenna, and ATU should I pair with the Discovery TX-500?”

Many thanks to Vitor Morais who asked the following question in the comments section of my YouTube video:

Hi,

Greetings from UK.
I recently learned that POTA [is now in the] UK so I am really looking forward to it.

I also recently put an order for [the Discovery TX-500] so I am really excited as well.

I would like to create a very compact setup pouch for field use to pair with this radio; one that I could take to summits or parks and also travel abroad.

What battery and antenna would recommend?

Would you recommend an ATU?

Or would you compromise to fewer bands or pack a secondary antenna?

I love to know your opinion.
Thanks

Great questions, Vitor! In truth, these sorts of questions are easy to ask but quite complicated to answer due of the insane number of options and possibilities available. It’s impossible to cover them all so I’ll try to give you some suggestions based on what I tend to use in the field. Continue reading “What battery, antenna, and ATU should I pair with the Discovery TX-500?”