Category Archives: QRP Radios

Dennis reminds us how much times have changed for portable ops

Many thanks to Dennis (WQ7O) who shares the following article:


POTA – Getting There

by Dennis (WQ7O)

POTA activity seems to be popular and growing. I have been a ham since the 60s and I am excited by how fun POTA hunting and activating this “new” radio sport can be. I have heard it called “Field Day” every day.

Drawing on decades of hamming experience, I contemplated how we got here. I remember my first field day and the effort required. Basically, equipment meant to be used in an indoor and fixed environment was adapted for portable use. Let’s take a look at what that might mean.

Power supplies that operated on DC were available but expensive. Looking at say, a Drake

TR-4, a popular transceiver at the time, the rig cost $700 in 1968 dollars. The power supply and speaker ran another $200 or so. You’ll need a mic and key, which were not included. Few tuners were available. You could go for a Johnson Matchbox. Drake made the MN-4 and

MN-2000 to match your TR-4. Count on another $200 or so. If you are a CW op and you want a keyer, the Hallicrafters TO keyer and a Vibroplex paddle were another $200. The gear described here would just fit on an office sized desk and don’t ask about the weight.

Now just gather that up and take it to the park, right? Well for starters the DC supply was for mobile use not portable use. You won’t operate for long off a battery with the amperage needed to warm all those tubes. So, bring along a generator and that’s what we did. BTW, we used a truck to transport it all because we needed it. Backpacks weren’t useful.

Antennas were all for fixed use as well. We brought a tri-band yagi and lashed it on a mast to the truck. We ran some wire antennas and we were on the air. Antenna analyzers simply did not exist, we tuned around and graphed it by hand.

Image Source: RigReference.com

This may sound much like a modern field day but hardly the “light and fast” deployment of a SOTA/POTA activation. Also, take it from me, running tube gear in the field is tough. I had a Gonset Communicator (2 meters) issued to me by our ARES group. It was about 100 times the displacement of your trusty handheld and many times the weight.

So since the 60s, the microprocessor, large scale integration and SDR technology have reduced the size and power requirements for all the gear we use. Today a radio that fits in a pocket can include a rechargeable power source, an antenna tuner and run from 160 meters through UHF offering all modes.

From lead acid, NiCads, NiMH, Lithium Ion and now LiPO batteries, the availability of reliable and portable power sources to power rigs and accessories is a fairly recent development. The increased efficiency coupled with decreased power demand have set us free. How many of us have quick deployment solar panels to keep those batteries topped off during extended operation? It beats the noise, smell and mess of gas cans and a generator. Also, you do not want to backpack a lead acid battery for a SOTA activation. Too much weight and not enough power.

Then there is the internet. If you do POTA like I do POTA, you go to the web page and look for spots. How many would you find without the spots and the RBN? When an activation is deployed one of the first actions is to spot it on the POTA app. Thus, as with other digital modes, the internet becomes an integral part. We could do POTA without the internet, but it would be a whole lot harder. And our taken for granted cell phone brings the internet right to the picnic table.

Image Source: Universal Radio

What about the gear? What should we use and how available is it? Early rigs for portable and QRP use were not plentiful or feature rich. The styling of the popular Penntek TR-45 is reminiscent of the Heathkit “Benton Harbor Lunchbox.” At the risk of understatement, the features do not compare.

The manufacturers responded. We weren’t all going to home brew our QRP rigs. So came the Yaesu FT-817. In 2001, Yaesu introduced the 817 which did all modes, 160 through UHF, ran on batteries, fit in your backpack and was affordably priced. Suddenly, portable operation was possible, versatile, affordable, reliable, practical and fun. We were freed from attics, basements and garages and embraced nature.

I recently built a QRPLabs QCX mini. This tiny rig has more features than we ever knew we needed when we were operating that Drake TR-4. If you want more bands the LNR Mountain Toppers are wildly popular. Other manufacturers, large and small, increased the offerings with different form factors and features.

This included antennas. An early entry was the Buddipole. Many cottage industry entrepreneurs followed and today the selection of quick and easy deployment antennas is broad and deep. From a whip antenna to attach to the rig itself to wire antennas for 160, there are a lot from which to choose. Don’t forget that 3D printing also accounts for a lot of our accessories like keys, cages, stands and winders.

Want to add a tuner to your station? The Elecraft T1, I built mine as a kit, is a superb, self contained tuner and offers broad, automatic matching running on a 9 volt battery. Since the T-1, LDG, MAT MFJ, Icom and others have offered great tuner choices that travel easily as part of your kit.

Anyone who owns a Baofeng knows that the Chinese have entered the ham radio market. While the quality and availability of these rigs can be an issue, they are quite affordable. This brings in new users who learn the hobby and progress to greater things. I have heard hams criticize the quality of MFJ products. MFJ makes the accessories the major manufacturers don’t and at popular prices. When there are more licensed operators, the manufacturers can offer more products at better prices as markets expand. Xiegu HF radios have powered many activations with its built-in battery, tuner and microphone. If POTA and QRP were not driving activity would Icom have brought out the IC-705? The Elecraft KX-2 and 3, the Lab 599 TX-500 and these types of boutique radios answer market demands.

The “Prepper” movement evolved from natural disaster “EmComm” and operating “off the grid” has increased the demand and thus the supply of gear. Building a portable kit has gotten easier and more affordable with a broad selection of choices and options. More is better.

Lots of other simple things have come together to bring us to the “10 minute setup” of the QRP SOTA/POTA activation of today. A whole room full of heavy, power hungry gear has been reduced to a device that literally fits in a pocket. Add a wire and you are on the air. My ham career began as a boy with a tube driven Heathkit transmitter with crystal control fixed frequency in the attic of our family home. I don’t think anybody appreciates more than me opening a backpack and in a few minutes setting up a modern station, wherever I am. QSOs around the country and around the world roll in with a few watts and a wire.

CQ POTA…73 de WQ7O

From idea to kit: Adam introduces the Arduino Digital Modes HF QRP Transceiver (ADX-S) kit

Many thanks to Adam (BD6CR) who shares the following guest post about his latest project:


From Open Source Project ADX to Kit ADX-S

by Adam (BD6CR)

BD6CR @ CRKits.COM

Original Design: WB2CBA

Modification and Kitting: BD6CR

I knew Barb, WB2CBA from his uSDX design a few years ago and I introduced both DL2MAN and his designs in my blog. So, when I came across the ADX – Arduino Digital Xcvr a few months ago, I immediately ordered both the ADX (through hole) and the ADX UNO (surface mount) PCB samples.

I started building the ADX UNO and put it in a dental floss case and made a few contacts on park bench. However, the soldering is too much for my eyesight. So, I turned back to the ADX because I don’t need to solder any SMD parts, since both the M328P and SI5351 are module based. I could build the project in 3 hours and it worked the first time.

However, I felt unsatisfied with the strong BCI since the CD2003 radio receiver chip was connected as a direct conversion receiver. JE1RAV mentioned in his QP-7C modification project that he tried JA9TTT’s idea to build a superhet SSB receiver with the TA2003 or CD2003, so I tried and it worked very well. I have decided to name the new circuit as ADX-S, where S stands for Superhet.

I shared the great news with Barb and he encouraged me to carry the flag to make it a kit, since my design D4D was his first digital radio and he loved it.

You can refer to Barb’s page on ADX here.

My hardware modification can be outlined in this schematic. I have added an FL1, PFB455JR ceramic filter by Murata and a C25 coupling capacitor from CLK2 of SI5351 module. The RX audio comes from pin 11 instead of pin 4.

I modified it by cutting two traces on the ADX PCB and it looked ugly, so I redrew the PCB. Continue reading From idea to kit: Adam introduces the Arduino Digital Modes HF QRP Transceiver (ADX-S) kit

Field Report: More Xiegu G106 POTA time and I rope in Brooks to log!

On Friday, February 10, 2023, I had a hankering to fit in a POTA activation that morning. South Mountains State Park was an easy detour on my drive back to the QTH, so I scheduled an activation.

I’d also been meaning to meet up with Brooks (KO4QCC). Brooks started his POTA journey not even one year ago–here’s a field report from his first SSB POTA activation.

Brooks has been steadily working on his CW skills and is dangerously close to doing his first CW activation. We’ve managed to set up one late evening casual CW rag chew and I think his CW chops are very good.  We plan to do more evening rag chews when our schedules align. He’s made amazing progress.

I contacted Brooks that Friday morning and he was game to meet up and do some POTA. He wasn’t quite ready to do a CW activation, so I suggested he log for me using the HAMRS app on my iPhone. I find that logging for CW ops during past Field Days really helped build my own confidence before I started using CW daily.

Brooks was 100% game to log for me.

And let me just say what a luxury it is to have someone log to HAMRS for me on my iPhone! It frees up my brain to simply log on paper (which I always do) and enjoy working stations without the extra busy work! Hat tip to good ole’ Brooks.

South Mountains State Park (K-2753)

I arrived at South Mountains State Park (the Clear Creek Access), put on my hiking boots, then Brooks pulled into the parking lot only a few minutes later.

We agreed in advance to fit in a quick hike up the Clear Creek Trail prior to the activation. I, for one, really needed to stretch my legs!

After the hike, I grabbed some gear from the car and we set up at the one picnic table at the Clear Creek Access.

Brooks and I both had commitments that day so could only play radio for 45-60 minutes max including set-up and take-down.

I deployed the same antenna I’d used the previous day: MW0SAW’s homebrew EFHW on a SOTAbeams winder.

Deployment didn’t take long–since the 40M EFHW is resonant on both 20 and 40 meters, there was no need for an external ATU. I powered the G106 with a 3Ah LiFePo4 battery via my Ham Radio Workbench DC Distribution Panel. Continue reading Field Report: More Xiegu G106 POTA time and I rope in Brooks to log!

Jens shares current, voltage, and power comparisons between the IC-705 and FT-818

Many thanks to Jens (DJ2GMS) who recently reached out to share results from some very simple tests he performed on the Icom IC-705 and Yaesu FT-818. Jens writes: 

A comparison of the Yaesu FT-818 and the Icom IC-705 (no comments, just facts):

On ext. 10,1V the FT-818 only needs 32 mA more than the IC-705

IC-705 (342 mA):

FT-818 (374 mA):

Min ext. voltage for TX of the IC-705 is 10,1V (appr. 1,8 Watts)

With 10,1V the FT-818 delivers 5 Watts

Minimum ext. voltage for TX of the FT-818 is 8V (appr. 3,5 Watts)

Thanks for sharing this, Jens!

LnR Precision taking orders for the next batch of MTR-4Bs

Many thanks to Jim (N9EET) who notes that LnR Precision is now taking orders for the next batch of the Mountain Topper MTR-4B V2.3.

LnR notes the following on the MTR-4B order page:

Update: 2/24/22: MTR4 V2.3 online ordering is now active! We are releasing 100 units and they will be available as first come, first served. We have a handful of units built now but are expected to quickly have a 3-4 week lead-time before they ship. This could be LONGER and we can’t guarantee shipment in that timeframe but will do our best. We have enough parts in hand for 250 units so there will be another release of this model once we have shipped the first 100.

Also, the MTR4b pricing was increased slightly (up $20) to cover part cost increases. The overall costs were much higher but we know how bad overall inflation has been so we want to be as reasonable as humanly possible. Thanks so much for your continued patience and we know you will enjoy this radio!

This is great news for those of you who have been wanting to reserve an MTR-4B.

If you’re on the fence about ordering one, consider checking out my full review here.

Click here to check out details on the  MTR-4B order page.

Thanks for the tip, Jim!

Pairing the Elecraft K2 with the AX1 at Tuttle for some QRP P2P DX!

If you recall from my last field report, I’ve been pairing the Elecraft AX1 antenna with a number of radios. For me, it’s been a fun exercise because I always enjoy seeing what sort of results the AX1 might produce. So far, it has never disappointed.

On Thursday, February 2, 2023, I packed two radios in my car with the idea of fitting in two consecutive park activations.

At my first activation of the day–Lake James State Park–I paired the AX1 with my Mission RGO One transceiver. The activation was a blast! Not only did I stay busy working stations, but I also managed a little QRP DX thanks to a hunter from Italy.

K2 and AX1 Under Shelter

Little Guatemala Café

After grabbing a curried chicken salad wrap at Food Matters and a coffee at Little Guatemala roasters in Morganton, I hit my second and final park of the day: Tuttle Educational State Forest (K-4861). It was rainy, so the park was empty which allowed me to take over the very large picnic shelter at Tuttle.

Even though this particular shelter is in a bit of a dip in the land and has a large metal roof, I’ve had successful activations there in the past employing the AX1 antenna.

My hope was that history would repeat itself!

Setting Up

Attaching the AX1 antenna to the back of the Elecraft K2 was not complicated because the K2 has a BNC connector with nothing protruding to get in the way of the Bipod. Continue reading Pairing the Elecraft K2 with the AX1 at Tuttle for some QRP P2P DX!

Taking the Xiegu G106 on its maiden POTA activation!

Last year (May, 2022), Xiegu announced a new compact field radio that would be added to their line of transceivers: the Xiegu G106.

As I was capping off my summer in Canada (August, 2022), Radioddity started shipping the G106. Radioddity had me on their list of folks to send a loaner G106 to, but I didn’t have time to even look at the radio I was so busy upon my return, so didn’t immediately request it.

I did watch, however, K8MRD’s initial review and updated review of the G106. It was less than stellar [understatement alert!] but more than relevant to me because Mike shipped his second unit to me on behalf of Radioddity.

I connected that G106 to a dummy load, checked the transmitted signal, and it simply didn’t look very clean. It looked worse than it did when Mike checked it only a couple weeks prior.

I shared my results with Radioddity, told them I didn’t feel comfortable putting it on the air for testing in the field, and they asked to have that unit returned and checked out.

Updated G106

Fast-forward to January 2023 when I was once again contacted by Radioddity to see if I would like to field test an updated G106. I was happy to do so, in fact, because I was curious if the whole G106 experience had improved.

In the spirit of full disclosure: keep in mind that Radioddity is a Xiegu retailer/distributor–they are not the manufacturer nor are they owned by Xiegu. They are a sponsor of QRPer.com, but have no say in what I post nor any sort of editorial input. Indeed, this is always a condition of sponsorship from day one.

To Radioddity’s credit, some of my most critical reviews have been of products they’ve sent me on loan (especially the GSOC).  They take criticism on the chin and keep on moving forward. This is why they are still a sponsor and I like working with them. They understand that I call it like it is and stand by what I publish.

This G106 has been sent to me on loan for a few weeks to review. I plan to take this unit on a number of activations and pair it with a variety of antennas and accessories.

Very early impressions

I will eventually publish a full review of the G106 (likely in The Spectrum Monitor magazine first) once I’ve put in a lot more field and shack hours with the G106. In the activation video, below, I do make a lot of comments about the radio–thinking out-loud–so if you’re considering purchasing the G106, you might at least listen to a few of my initial impressions.

I will say this: for a modern SDR-based transceiver, it’s pretty bare-bones. It lacks a number of features I assumed it might have despite the incredibly affordable $320 US price point:

  • No SWR meter
  • No Power meter
  • No CW or Voice message memories
  • No RF gain control
  • No AGC control
  • No dedicated headphone audio output

But, again, it has more features than many of the bare-bones CW-only QRP transceivers out there, so for the price perhaps expectations should simply be in check–?

Zebulon B. Vance Birthplace (K-6856)

On Tuesday, January 31, 2023, I took the G106 on its maiden POTA activation to K-6856.

The G106 doesn’t have a built-in ATU (which I would never expect at this price point) so I decided to pair it with a resonant antenna. Since it was a very rainy day and the area/ground where I tend to deploy my wire antennas at Vance was squishy and soft, I opted to deploy my Chelegance MC-750 next to the picnic shelter. Continue reading Taking the Xiegu G106 on its maiden POTA activation!

Last batch of new Yaesu FT-818NDs: List of retailers and pricing

Many thanks to a number of readers who’ve pointed out that some of their favorite ham radio retailers have now received their final batch of Yaesu FT-818NDs.

I’ll post a list of retailers below (in alphabetical order) who are showing stock at time of posting (Feb 16, 2023):

Should you bite the bullet?

If you’ve been considering a new-in-box, fully warranted FT-818ND, it might be worth purchasing one of these units.

As I mentioned in previous posts, I would certainly not panic-buy an FT-818ND because there are so many tens of thousands of these in the wild I think there are deals to be found on the used market. I do suspect there may be a temporary increase in prices on the used market, but in a few months they’ll go back down.

Other retailers with inventory?

Am I missing a retailer in the list above? Please comment with a link and I’ll add them.

Penntek TR-45L: Adjusting the sidetone level

Many thanks to David (KQ4CW) who writes:

I received my Penntek TR-45L on Friday.

Just for your info: if anyone wishes to adjust the sidetone level there is a way to do that:

TR-45L Internal Sidetone Adjustment

The sidetone level adjustment can be accessed by removing the front panel assembly from the rear case.

First, remove the six screws that secure the panel to the rear case half. Separate the panel assembly and lay it face down on the table. Be careful with the interconnecting cables.

While operating the unit, adjust the sidetone level pot (circled in red) for the level of your liking. Reassemble the panel to the case rear. You may need to squeeze hard on the corners to make the panel fit. Be careful with the dress of the internal cables.

Thank you so much for sharing this, David. This is a very simple procedure and shows, also, how WA3RNC designed the boards so that the pot is accessible without having to pull apart the two main boards!

Replacement battery for the Xiegu X5105?


Many thanks to Chuck (K8HU) who writes:

Hi Thomas,

The battery in my Xeigu 5105 seems to have bit the dust and have been looking for a replacement part.

Any sourcing suggestions?

Best

Chuck Rippel, K8HU

Chuck had checked with the dealer, but their only suggestion was a battery (model BP-X5105) at Sinotel in the UK. Here’s the battery image from their catalog:

Unfortunately, they will not ship batteries internationally.

I did a little research of my own and the only other company I could find with a replacement X5105 pack is Limmared Radio & Data in Sweeden. The image above is the battery they have listed in their catalog.

Readers: if you’ve replaced your Xiegu X5105 battery pack, can you comment on this post with a link to the source?  Many thanks in advance!