Sunday, June 27, 2021

Two Great Little Power Banks

 I keep telling myself that I have enough power banks, but then I buy another. Except when I buy TWO.

I saw a couple of lovely little 10Ah power banks, and the specs intrigued me. One claimed to support BOTH QC 3.0 and PD 3.0. The other claimed to support both as well, but I couldn't get PD to work on it. Maybe I did it wrong. I'll try again.

The Ainope power brick is the one that supported both right out of the box. It's a VERY small power bank, smaller and lighter than my other 10Ah units, with a shell that looks to at least resemble carbon fiber, but probably isn't. It has a very bright LED 3-digit display, to show the percentage of available power. I connected each of the QC USB-A sockets to my IQ32 using a QC "magic cable" I bought pre-made on Amazon. Both powered the radio just fine. I connected my PD Magic Cable Mark II to the USB-C connector, and it also powered up the radio without issues. I haven't done any stress testing yet, but plan to soon.

The other, by Silicon Power, is definitely supports Quick-Charge on the two USB-A sockets. The
documentation is a little vague on the USB-C connector. I saw conflicting information, at one point saying it only accepted input on the USB-C connector, but at other points claimed it was also PD output. I tried to use it with the IQ32 on the USB-C connector, and it did not power up. I strongly suspect it only partially supports PD output, at only 5V and 9V, but not 12V. I will double-check this later. But as with the Ainope power bank, it worked perfectly with a 12V Magic Cable designed for QC, and powered the IQ32 perfectly. It's not as small or light as the Ainope, but it has a different benefit: It is currently on sale for $24.99 with a $10 off coupon -- so it essentially costs only $15 for a 10Ah power supply.

I will be testing these banks to see what their lifespan is, and I'll test the Silicon Power PD socket with my QCX, which will work on 9V. It doesn't really matter to me if it works on PD or not, as I only purchased these two power banks to use with QC. Both can, at a minimum, be charged using a PD charger. 

Ainope 10Ah QC/PD Power Bank: $26.99 w/$2 off coupon.

Silicon Power QC Power Bank: $24.99 w/$10 off coupon

Coupons are only currently available for these items. If you read this some time after I published it, you may miss the coupons.

Thursday, June 24, 2021

More Research on USB Power Bank Use With QRP Transceivers: Qualcomm Quick-Charge

Good news, everybody!

No, this isn't Futurama, but sometimes I think it should be. There are wonderful things happening in the tech world in recent years, wonderful things that stagger the mind.

Even the small stuff is really, really cool!

In my presentation, I mentioned that the PD trigger boards I use for my "magic cables" can't help with non-PD power banks that have "QC", or Qualcomm Quick-Charge protocol instead. I proposed that it be the topic of yet another article, and that someone else interested in it might want to write it. Well, I take that back.

Because this is my article for just that!

I happened to check to see if QC could even be used for this, and found already-extant boards for Quick-Charge that pretty much do the same thing as the PD trigger boards. Moreover, there are pre-made cables in a variety of voltages! QC doesn't provide the high power that PD does, but the top voltage it provides is 12 volts, at 1.5 amps! This is perfectly adequate for all of my 5w QRP radios!

There's only one very small snag...if you even see it that way. The pre-made cables I've found have 5.5x2.5mm barrel connectors on them. Most QRP radios are sold with 5.5x2.1mm sockets, including the Elecraft KX3 and my HobbyPCB IQ32. So I looked for -- and found -- 2.5mm pin to 2.1mm pin adapters. I bought a couple of cables and a couple of adapters. The last piece arrived an hour ago. I plugged a cable into an adapter, plugged that into my IQ32, and checked my power banks for the QC legend on one of the USB-A sockets. Finding one, I plugged it in and flipped the switch on the radio.

It started right up. Turning on the external speaker, the 80m CW segment blasting from it. It works quite nicely! I haven't done any stress testing or timed operations, but it appears to work just fine. There are some very new versions of QC that will provide up to 22V if the source will deliver it, but 12V is a common top voltage for such applications. Some will go from 3v to 22V in .2v increments. I'm concentrating on the ability to supply 12V for the majority of QRP CW transceivers. I haven't seen a battery bank that supplies more than 12V under QC, because most QC power banks use USB-A sockets, and those are not rated for higher voltages.

The cables I bought were by JacobsParts, the same company I got my tiny Power Delivery trigger boards from only a couple of weeks ago. They also had a separate board, to which you can attach your own wire to connect it to your radio. It has a USB-A plug on the end of the board, and, like on the PD board, solder terminals for your wire. These options remove the need for a jumper cable between the power bank and the magic cable; you can connect it directly to the power bank and the other end to the radio. With the separate board, the board would plug into the power bank, and the wire would then run to the radio.

There are a LOT of power banks out there that don't support Power Delivery, but DO support Quick-Charge. These cables and boards will support QC 2.0 through QC 4.0, being forward compatible. As with PD, the power bank has to support the voltage you want, and some do not have 12 volts available, so you won't be able to use that power bank with these cables on 12v radios. If the top voltage it provides is 9v, you CAN get a 9v cable or board, and use it with a radio that will run off 9v, such as my QCX. 

So if you don't want to buy new PD power banks to take advantage of this option, check the ones you have to see if they have Qualcomm Quick-Charge at 12v. You may find that the old 10Ah power bank you bought for your phone supports QC, since it is an older protocol, and you'll be able to use it on your radios with this cable or the separate board and your own wire.

JacobsParts USB-A QC - 12v/1.5A 5.5x2.5mm coaxial plug:

UxCell 5.5x2.5mm female to 5.5x2.1mm male adapter:

JacobsParts USB-A QC - 12v/1.5A fixed voltage trigger board: (other voltages available)

Friday, June 18, 2021

USB-C PD "Magic Cable" version II

Jim Fisher AJ3DI from the Phil-Mont Mobile Radio Club asked me back in May if I'd do a presentation on my USB-C Power Delivery system for QRP radios, since my original article (posted here and published in QRP-ARCI's QRP Quarterly, July, 2020) was published in a recent issue of The Blurb, the PMRC monthly newsletter. How could I say no to the Jedi Master? The presentation went extremely well a week ago on June 9th. 

You can see the slide deck I used here:

And you can watch the Zoom/2m Repeater meeting, complete with the presentation, at:

While preparing for the presentation, found out that the original PD Buddy Sink board by Clara Hobbs I bought from was no longer available, so I did some shopping on Amazon to find some replacements. I'd used some other PD sink boards, that I detailed in another article on this blog about the subject, but didn't really find anything I liked well enough to make a cable using one. 

What I mostly found earlier this year were sink boards that would cycle through a series of configuration settings when you pressed a small tactile button on the PC board, a method I did NOT particularly like. It was far too easy to wind up sending too much power to the radio, since there was no actual feedback to tell you what setting the board was on. You'd have to test it with a DVM every time, which is very impractical. I have a tiny PokitMeter brand micro-DVM/single-channel oscilloscope the size of a keychain fob, that works in tandem with an app on my phone that I could use to easily test the voltage selected, but it really wasn't what I wanted to do. So I waited. My patience would be rewarded.

It was, and a little more so! I found that the PD sink (or trigger) boards had gone through a major evolution during that time, resulting in two major shifts in the boards now available: They're now extremely tiny, and they no longer rely on a button-press or serial terminal programming to select the output. Under most circumstances, you'll want a static voltage/amperage setting, and in my circumstance, that's precisely true. I want to set my sink boards to 12 volts at the maximum current available. So I was very pleased when I discovered that there were now PD sink boards barely larger than the USB-C jack it bore! 

There are two main varieties: 

A) Boards that can be solidly set for a particular voltage by jumpering PCB pads with a solder blob, and... (

B) Boards pre-set for a specific voltage at the factory and sold as an option at purchase. Such as 12 volts... (

I bought some of each type. Some of the jumper-controlled boards provided the whole gamut of supported PD voltages. I got some of the universal boards that can be jumpered for 5,9,12,15, and 20 volts (the red ones, above), a couple that provided 9v and 12v, and I got a 5-pack of the blue board above, that could be ordered for any single voltage desired. I chose 12v, obviously. ALL of the above boards will provide up to 5A of current, even though the maximum current for Power Delivery is 3A. That's fine with me!

I made a "proof of concept" cable using a  5.5 x 2.4 mm coaxial plug with screw terminals, attaching the contacts to a wire pigtail that I soldered to one of the 12v/5A sink boards. It worked, but the quick-connect coaxial plug I used had too large a central pin size, so it would drop out when nudged. 

This was unacceptable, so I attached the pigtail to a longer piece of the same thin zip cord with a proper 5.5 x 2.1mm right-angle DC coaxial plug. I was still experimenting, so I just used solder-seal butt splices to replace the mismatched plug with the screw terminals. It looked awful, with electrical tape still insulating the board and covering the solder seal splice job. But this one worked reliably and solidly, not losing contact if jostled. 

Now it was time to make the actual Magic Cable II. I removed the electrical tape from the sink board, desoldered the wires I'd attached, and cleaned the pads with solder wick. Some isopropyl alcohol made short work of any remaining flux. Then I shortened the wires coming from the good plug to about 10" long, stripped and tinned the ends, and soldered them to the pads on the PD sink board. I gave it a single wrap with electrical tape as a precaution, then I slipped on a piece of marine-grade, glue-lined heat shrink tubing and used my hot air rework pencil to shrink it and seal it around the board and the wire. I tested the result, and it works perfectly.

I also found a short but very heavy-duty USB-C/USB-C jumper cable. This cable is stubby, only about 6" long, but is flat with thick conductors under a reinforced "FlexCore" outer cover. It'll take maximum PD power and data, rated for 100W (20V @ 5A) and 10 GBPS of data transfer. I only intend it for power, so I chose a cable that'll take the 12V for a QRP radio without any question.

The radio I used for the test is my HobbyPCB IQ32, an all-band, all-mode 5W SDR transceiver. I have a small steel plate on the lower left corner of the faceplate, where my tiny Supmotor paddles reside. The base of these paddles is a very strong neodymium magnet. It's the smallest set of paddles I own, the body being only an inch on a side, and the fingerpieces sticking out another inch. The only paddle I have that rivals it would be my NOARC "Te-Ne-Ke" (Teeny Key), that's about the size of a pack of gum. This paddle comes in a little steel can, embedded in foam, including the paddle (with magnet base), a stick-on steel plate, a hex wrench to adjust the tension, and a 3.5mm jumper wire. It's a very comfortable paddle to use, despite the size, and it is easy to adjust for as light or as heavy a touch as you want.

I tested the setup with 3 different PD USB-C power banks: A 10Ah Monoprice "Obsidian" PD power bank and two 20 Ah RavPower "Pioneer" PD power banks, one an older model with a digital readout showing power level, and a newer model with fewer ports that uses LEDs to indicate remaining power. I will be testing with other radios and some other PD power banks later. I've also ordered more of the 12V sink boards and some 5.5 x 2.1mm DC coaxial power pigtails, since I'm lazy and don't like soldering small connectors. This will let me make a few spare Magic Cable II's in case I ruin or lose one, and leave me some sink boards to install in radios I'll build in the future. I'm looking forward to being able to just plug a USB-C cable directly into a QRP rig!

A note on the availability of the power banks I typically use: This month, all of the RavPower power banks are unavailable from Amazon, as Amazon has stopped carrying several brands, of which RavPower is one. Others they stopped carrying were Aukey, TaoTronics, Vava, and Mpow, all subsidiaries of Chinese company Guangdong SACA Precision Manufacturing. The reason cited was that these brands have been allegedly engaging in a practice of giving gifts in exchange for good reviews, which is against Amazon's sellers' agreement. The Monoprice Obsidian bank I used is no longer available, but it was discontinued. (Monoprice is owned by Amazon, in case you didn't know that.) You may still be able to buy the RavPower devices from other sources, including the RavPower website -- though some of them were simply linked to Amazon pages for sale. I expect RavPower, and the other sites removed, will be changing their ordering so they no longer point to Amazon.

For more information on the delisted brands, visit:

Sunday, March 21, 2021

Continued 2021 Field Preparation

In my previous post, I mention the radios and supporting gear I'm setting up to take into the field this summer. I was intending to take my DSW-20, but decided I'd rather go with another radio with wider capabilities. I didn't mention it in the previous post because I hadn't decided if I was going to use it or not.

I'm speaking of my HobbyPCB IQ32 5w SDR. It supports CW and Phone on 80-10m, with a lovely color touch screen interface, and built-in PSK31 support with a PS/2 keyboard. The firmware can be easily upgraded through a USB port using a thumb drive (must be under 4gb storage, though). 

Here are the specs, shamelessly borrowed from the website:


  • Frequency Range: 3-30MHz (performance guaranteed on 80/60/40/30/20/17/15/12/10M ham bands)
  • Sensitivity: MDS < -128 dBm on 80M dropping to < -135 on 10M
  • Noise Figure: < 8 dB
  • TX Power: 5W typical, 4W minimum
  • LO Feed-thru: < -50 dBc @ 5W output
  • Spurious and Harmonics: < -50 dBc typical
  • DC Power: 13.8VDC, 2 amp max
  • Size: 172mm x 105mm X 75mm
  • Weight: < 700 grams
  • Display: 3.2" Color LCD Touchscreen
  • Modes: USB, LSB, CW, PSK 31
  • DSP Processor: STM-32, 32 Bit

I was looking at the QRPVer Minion SDR as a potential field radio, given its coverage and its small size, but it has serious issues in CW mode, which plagues a lot of small phone/CW radios -- it isn't full break-in, and the transmit tail is long and terribly formed. This can cause you to miss part of a transmission because your radio hasn't fully switched back into RX mode after sending CW. It also doesn't appear to have been updated since 2019, or at least its website hasn't changed. I've tried sending requests for info to QRPVer, but I have found reviews that say the radio's creator is basically a one-man shop and he doesn't keep up with his emails. Given that he requires 40 days to build and ship a radio, the lack of communication pretty much makes it a non-starter for me. I want to ask a few questions before I order one, and if the creator can't be bothered to answer them, I'm not going to buy a radio from him. So I decided that I was going to revisit the IQ32.

I hadn't used it much because it, too, suffered from difficulties with the CW mode TX/RX switching. But unlike the Minion SDR, the IQ32 is still being updated. The firmware had at least 3 significant revision levels since I'd last updated my radio's code, and the changes made were significant. I think the CW is a lot better than it was, and it seems to recover from the transmit mode far more gracefully than before. It certainly doesn't have that telltale THUMP sound that all too many SDR devices have when switching mode. Semi-break-in is okay, so long as the envelope of the transmission is clean, and doesn't cause you to lose characters from a reply.

The radio has some significant history for me. I first backed the radio's core components on Kickstarter, when it was just the HobbyPCB RS-HFIQ 5w SDR project. I used it for quite a while when it was released, as an adjunct to my computer/ham radio "shack stack" next to my powered recliner, where I spend most of my time. It was a good radio then, using the typical USB/sound card interface, along with HDSDR and Omni-Rig software. But when they announced an upgrade kit to the RS-HFIQ to turn it into a self-contained SDR rig, I jumped at it. I think I have upgrade kit #0002. My order for it was in less than four hours after it was announced available.

Now that the firmware is fairly mature, the radio is a very viable candidate for a field rig. I had hoped to use a uBitX for this, but my uBitX was an early evolution, and I fried some circuitry when I accidentally tried to tune on 160m, a band it'll let you access, but really isn't designed for...and the antenna was my half-size W3EDP end-fed, which definitely was NOT designed to support that band (though the full-sized model I have up as my main wire is). So, until I can find and bodge-wire the PA 12V+ rail, and possibly replace the IRF510 finals, the uBitX is down for the count.

But the IQ32 will do just fine. Technically, I don't really need to take the QCX along if I use the IQ32, but a) I don't believe in having just one radio, and b) the QCX has built-in CW decoding, so I can double-check my copying of incoming code.

I've checked my wire antenna bag, and the ones I like best are in good shape. That'll be a QRPGuys 40/30/20 end-fed with built-in tuner, my Slinktenna, and my homebrewed 40/30/20 link dipole. I still have to check over the Wolf River Coils "TIA" antenna kit I have in the back of my van, and put the short telescoping whip I bought into the kit, to join the standard-length telescoping whip, and the extra-long 209" telescoping whip I already have.

I keep an MFJ-223 1-60 MHz Color Graphic VNA Analyzer in that field kit, mostly for tuning up the Wolf River Coils antenna, but I also have a NanoVNA that I haven't had a lot of experience using as yet. Most of my antennas are pre-tuned or have built-in tuning, but I have an Emtech Z-2 Z-match and an Elecraft T1 tuner. I just have to FIND the's buried someplace in my gear around my chair and isn't immediately visible. That's a task for the beginning of this week. My goal for this week is to get my field gear down to the crash case, the antenna bag, and the long repurposed fishing rod case for the vertical -- a load that I can reasonably carry without using a wheeled hand cart. The cart does make it easier, though, and will likely still do it that way, I just want to be ABLE to carry the requisite gear by hand if I must.

I still plan to make a smaller, field-expedient radio bag, holding only a 40m QCX-mini and a VN-2002 20m Japanese rig, made by Haru JL1VNQ. Those two radios together bulk and weigh less than an original QCX, but each has full 5w CW capability. Those, along with a new Magic Cable, a PD power bank, paddles, headphones, and a purpose-built lightweight 40/20 link dipole, will go in their own bag, something small that can be grabbed and carried easily. It'll probably be the "hoist the feedpoint into a tree" type inverted-V antenna, because that gives the best coverage for the lowest weight and bulk.

Now, I just need to make sure I have the sundry other items that make field operating fun as well as possible. Clipboard, log, phone, maybe my old Chromebook, set up with ham radio apps under GalliumOS Linux. I need to check the ancillary gear I always keep in the van, such as small gas stove, fuel canisters, mug, 3-in-1 coffee packets, utensils, and even some freeze-dried food. I usually don't use them, but they're nice to have in case things are going well and I don't want to have to tear things down in order to get hot coffee or food from the Wawa convenience store a mile up the road. If I can get away with boiling some water to make instant coffee, that's a better solution.

An eventual project will be a field station specifically for digital mode operation. It'll consist of the aforementioned Chromebook, with external USB sound card dongle, cables, and my Midnight Design Solutions "Phaser" 40m 5w dedicated digimode transceiver, magic cable, power banks, and antenna. I can make a pre-tuned dipole for that, given that the frequencies are fairly fixed. I won't bring a tuner or analyzer for that setup.

The weather is beginning to cooperate, with sunny days around 60F starting to happen, so I hope to soon start going to the parks in my area to play some radio!








Saturday, March 13, 2021

Power Delivery and QRP, Revisited

 Power Delivery and QRP, Revisited

Well, Spring is getting awfully close to springing once more. The Vernal Equinox, aka the First Day of Spring, is on March 20th, Daylight Savings Time jumps forward tonight (March 13), and the weather has been a lot warmer lately. It's beginning to look a lot like operating weather at the parks once more.

This means, it's time for me to get my field kit reassembled for the summer. I've got several radios to build, so if I get bored I can start putting some together. Cycle 25 is starting to ratchet upward notch by notch, and the propagation is starting to be worth something again! As per my usual key-shyness issues, I haven't done a lot of CW operating over the winter, but I have practiced a bit and done a lot of listening. Time to finally beat that key shyness and start using the skills I so laboriously built!

I have chosen two radios for the time being, my 40m QCX and my venerable 20m DSW-20. The latter especially will force me to deeply ingrain the Morse numerals in my head, since it has no display of any sort and will announce the frequency the radio is set to with Morse Code. All of the prompts on the radio are in Morse, including the ones to set Speed, Reversing the paddles, and Tune mode. I need to track down my Elecraft T1 tuner, which is around here...somewhere...but for now, I have an antenna analyzer for my vertical, and a pre-tuned link dipole that'll handle both radios perfectly. That reminds me...I need to take the short telescoping whip for the Wolf River Coils Silver Bullet to the van and put it in the antenna bag with the standard whip and the big whip.

I have two portable speakers to use with my radios, since neither one has a built-in speaker. I also have headphones, the kind where each speaker clips over the earlobe. I prefer those, as actual earbuds hurt like hell for me, no matter how I fiddle with them, and regular over-the-ear "cans" get way too hot when operating outdoors and you can't hear anything outside them. With the clip-on headphones, I can even take one side off, so that ear is unobstructed. I can hear if someone tries to talk to me, such as a curious passer-by, or a park ranger wondering what the heck I'm up to (it has happened before).

But the main thing I got squared away, to go with the headline of this post, is what I call my "Magic Power Cable" -- my Power Delivery sink and the PD USB-C power banks that go with it. I'd had some difficulty getting radios to work properly with it last year, so I decided to go through everything and find out why. Well, I did, and boy is my face red!

Turns out that one of the big power banks I was carrying doesn't have a 12v output mode. It has 9v and 15v, but no 12v for some reason. The cable was set up to support a range of voltage, from 9v to 15v, but I don't really want to put 15v through any radio intended for a nominal 12v. I also had the current set way too high, at 2.5A. None of my PD banks actually support 2.5A at 12v. I found this out by reading the tiny, hard-to-make-out writing on each power bank, instead of the advertising copy on the page where I bought them. Let this be a lesson: Do not take the sales page's word for it! Look at the legend on the device itself!

This made me look at the mode settings I had in the PD Buddy Sink in my Magic Cable. I had it set for, as I said before, a voltage range of 9-15v, and a current of 2.5A. I changed this to a strict 12v, but instead of setting current, I set output power to 18W...which determines the current to be 1.5A. All of my PD power banks support this setting. I double-checked with several radios, and it works reliably on each one. The only radio that requires more than 1.5A at 12v would be my KX3, which needs more as it is not a 5W radio. It will do 10W without the amplifier, which requires more current at full power...but 18W out should handle the KX3. The specs call for 1-2A at 12v, and 1.5A is what I have available at 18W out from the power bank. So the new settings will work fine. Sort of moot, given that I really dislike risking the KX3 in the field, but it's nice to know I can use it in the field if I want to on the power banks I have in the case. I also have a 12Ah 12v LiFePO4 battery that I can use for the KX3 if needs be, and the Talentcell 12v power banks that are NOT USB, much less PD, at 12v. I can revert to those if I need to, and I have my larger one in the field crash-case already just in case.

For keys, I have two I've set up for the field. I can set up the NOARC Te-Ne-Ke if I want, and I still might, given that I can mount it on my clipboard with a small nut and bolt to make it very convenient. But this summer, I'm going to try using an inexpensive Supmotor paddle I got on eBay, a cubical thing about an inch on a side with a strong magnetic base and 3d printed fingerpieces and top cover. It's downright tiny, and is very comfortable to use. I'll probably stick a steel plate it came with on the aforementioned clipboard to keep it firmly in place, since both radios have aluminum cases. I may get some additional stick-on steel plates, so I can put one on each radio, but I haven't done that yet.

This summer promises to be a very good operating period. The solar activity level should be very conducive to good DX, and even good local contacts. When it starts looking like 17m is going to pick up, I have a Kits & Parts 5w 17m rig waiting to be built. I also have a QCX-Mini for 40m, and a Japanese VN-2002 5w 20m kit on the bench. If nothing else, I also have another older QCX kit for 30m I haven't built yet, and a 10W 40m SSB rig from CWKits to put together.

I haven't even started to think about digital modes in the field yet. I have my 40m Phaser and its accompanying Chromebook (re-flashed with GalliumOS Linux) for FT8 and JS8 that I can take to the field with no difficulty.

Heck, I even ordered a new package of nanofilter face masks, in case I need them. I usually have a cloth mask in my back pocket just in case, and a member of the Rooster Club sent me a lovely cloth mask with roosters on it I can use. But these are supposedly excellent at filtering out all sorts of stuff and not interfere with breathing, and are touted as very comfortable. We'll see. Nobody should be able to yell at me to get back in my house THIS summer! Seriously, my neighborhood was downright mean about it.

Well, see you on the air! 


Thursday, May 21, 2020

A Different Power Source for Field Ham Radio Operating

Smart Cable connected to PD supply and QCX transceiver

We're coming up on a confluence of two things: Nice weather, and relaxing of the Covid-19 lockdowns in much of the United States. This means more hams leaving their home shacks and taking their operating to the field. For some, this means climbing mountains and doing SOTA activations. For others, this means hiking on trails, and doing POTA activations. For yet others, this means gearing up for Field Day, or doing HF Pack operating, with a manpack station on their back. But no matter what they actually choose to do in the field and why, all of them have a similar need.

They need to power their gear.

This can be a really complex issue. It has a lot of factors, like what radio the person plans to use, what its power requirements are, how many watts do they want to transmit with, how much does the radio draw during receive, will they have access to mains current at any point, if not, will they have gear to recharge their power source, will they be on foot, are they operating from a vehicle...the list goes on and on. But again, there's a need that intersects all of these issues.

They need the power source to be as flexible as possible, and to provide the maximum in available power for as long as possible, but as small and lightweight as practical.

When you're getting to your operating position by backpacking, every ounce and every cubic inch counts. So you want your power source to be small and light, yet you need it to provide enough power to fulfill your goal.

The default position seems to be: figure out how much juice you'll need for the duty cycle you expect, the power consumption your equipment will require, how much weight you can carry for the requisite distance, and what you can do to replenish that power in the field if you have to. It pretty much falls to: carry a lead-acid gel-cell, or a lithium-ion source with similar storage capability. If possible, carry some means of charging it, which usually means "solar panel".

A lead-acid gel-cell with 5-10 amp-hours (Ah) of available juice is fairly inexpensive, between $2.00-$3.50 per Ah (Amazon prices) depending on brand and what the seller says it's for. Some use cases have higher price points, because it's a more or less "elite" use case. You can get a lead-acid 12V 9Ah gel-cell for around $25. But lead-acid batteries are heavy and bulky. If you plan to charge one in the field, it requires a special charger, or your charging device needs to have an output suitable for charging lead-acid batteries. They have a limited lifespan, and can be damaged or destroyed by drawing their voltage down too far before recharging, requiring replacement. Then you have a hazardous material to clean up, as your typical trash service won't take them. They're cheap, but can be a hassle. If you're willing to accept the hassle, though, you can get them very inexpensively.

Some radios, such as the Elecraft KX3, can be upgraded with an internal battery tray. The recommended battery for it is a set of Nickel-Metal Hydride AA cells. The rig will charge them, but ONLY NiMH batteries, the charging process is slow, and if you draw the batteries down too far, may damage the batteries so they no longer take a charge. They're lighter than lead-acid, but provide less power, and have special charging needs.

Lithium-Ion batteries tend to be lightweight, have a fairly high efficiency, and while more expensive, have a longer lifespan, requiring replacement less often. But they require a special charger, can take a long time to charge, and are considered to be a very hazardous material. Lithium-ion batteries have been known to explode or catch fire while charging, while in use, or following some kind of damage from incidental accidents, such as dropping. There are heavy restrictions on shipping them, and over a certain size cannot be taken on an airplane in carry-on baggage. The best chemistry for lithium batteries are the relatively recent Lithium Iron Phosphate (LiFePO4) variety. They're lighter, have an even longer useful lifespan, can be drawn down further without damage, and the chemistry isn't as explosive or prone to fire as other lithium-based cells. But they're expensive, running $8-12 per amp-hour.

The least expensive brand I know of are Talentcell brand. They even have small battery packs, at minimum 12v at around 3A, but some models having 9v and even 5v USB outputs. The 12v and 9v are coaxial jacks, and the units have power switches, power level indicators, and can be charged while in operation. My only complaint about these devices is that they're single-taskers -- they are designed for a limited set of tasks, such as running LED lighting, or IP cameras.

What I had in mind was something of a multi-tasker. Something you could use for powering ham radios, or perhaps other gear as well. I've been looking at the little USB power banks for years, wishing there was a way to operate ham radios from them, but the power and voltage available on them was too low. But now...there's USB-C, and a new protocol for output power on USB-C, the Power Delivery standard.

PD is a handshaking protocol, whereby a device will communicate with a power delivery device and tell it how much power it needs to operate. PD can provide a whole host of values, from 5v at 50mA, to 20v at 5A, with reasonable steps between. It can specify a range of acceptable values, in case the supply device doesn't support the precise value required, but DOES provide something close. The key to the whole thing is a small circuit called a "sink". There are a number of them becoming popular online.

The "PD Buddy Sink" by Clara Hobbs is the first I encountered, on the maker site Tindie. It's a board a little smaller than an inch on a side, with a USB-C socket on one side, and either bare solder pads or screw terminals on the other. To specify the power setting, you connect to the board via a terminal program such as PuTTY over the USB-C connection, and issue the appropriate commands. Then you can write the result to the internal memory of the board and reboot it. The board will retain the setting until you change it. Another board, the ZY12PDN "Type-C USB-C PD2.0 3.0 to DC USB decoy fast charge trigger Poll detector 100W MA", as named on Amazon, is very similar, but instead will cycle between available values when a button is pressed. It's a slightly smaller and less expensive board than the PD Buddy Sink. The Buddy Sink costs $30 on Tindie, while the ZY12PDN costs between $13-18 on Amazon, depending on configuration.

PD Buddy Sink by Clara Hobbs
ZY12PDN Board - Amazon
There is a Thingiverse project for a 3d printed case for the PD Buddy Sink in two configurations, one to accomodate a simple wire going to the output pads, and another where a pair of Anderson Power Pole connectors are incorporated into the case, allowing it to be connected to any device that supports Power Poles. But the first one I built, I used a small project box, and ran a two-conductor wire into the end opposite the USB-C connector. I thinned the lid directly over the LED power light, so I could see when the board is on and responding. Eventually, I'll put a small hole over the board's reset button, so I can put it in programming mode.

But why go with a cable? Why not put the Buddy Sink board inside the radio itself, with a slot for the USB-C plug? Because a Buddy Sink board is $30, that's why! With a smart Power Delivery cable, I can support a whole collection of 12v QRP radios with the same board setting (12v, 2.5A). With a Y-adapter, I can even supply power to both my KX3 and PX3, though I really wish it had more current. To use a sink in each radio would be a very expensive solution, though it would of course work. It also wouldn't be necessary to leave a way to reprogram the board, since it would only need to supply one range of values, the one necessary to power that radio, and no other. But this is a far more flexible solution, and a far cheaper one!

Now that the smart cable is out of the way, what about the OTHER end?

There are a number of Power Delivery options for power banks and chargers. I bought a 45W GaN (Gallium Nitride) PD wall charger as a backup for my USB-C Chromebook, but found that it also charged PD power banks quite adequately and quickly. Since it is a PD device, it can also provide mains power to the PD smart cable, and is smaller than a deck of cards. The battery banks I purchased are a 10000mAH model and a 26,800mAH model, both by RAVPower. Both will supply around 30W of power, and will power any of my QRP radios at full output, including the KX3 at 10W.

They may not be able to supply as much juice at 12v/2.5A as a dedicated 12v battery, but they also don't weigh nearly as much or take up nearly as much space as a 12v battery. I have a Talentcell 12Ah LiFePO4 battery that weighs about 2 1/2 pounds. The RAVPower 10000mAh PD bank weighs about 6 ounces. The 26,800mAh PD bank weighs about 15 ounces. They also cost much less. The 10Ah model cost about $20, the 26.8Ah, about $50. The 12Ah battery cost around $100, and appears to be no longer available from Talentcell. By my calculations, the 26,800mAh bank should provide around 8,250mAh at 12v, and the 10,000mAh bank, around 3,000mAh.

RAVPower PD 26,800mAh Power Bank, Buddy Sink Cable,
and QRP-Labs QCX 40m Xcvr - 7 hour test
To give a real-world test to this technology, I charged the 26.8Ah RAVPower pack completely, then connected it via the PD smart cable to my 40m QCX transceiver. I was able to run it, with intermittent transmitting, for 7 hours before I personally got too tired to continue the test. The power bank had only reduced its available power by a single indicator light, roughly 25% of its total. Now, it's certain that if I'd spent that time ragchewing, it would have consumed much more power, as 5w out takes a lot more juice, but I'm not a ragchewer on CW as yet. For casual use, this seems like an adequate power supply for the size and weight. For a device that only provides 8.25Ah at 12v, it seems quite efficient, powering a 5w transceiver for 7 hours with only a 1/4 reduction in capacity. With greater transmission time, this would certainly be a greater draw on the power bank, but even if it were 1/2 or 3/4 discharged, that's an 8-hour day's worth of continuous operating in a battery bank 1/4 the size of the 12Ah Talentcell I have.

It's also a multi-tasker. It can charge my phone via the USB-A port while operating the QCX. It can charge my USB-C Chromebook. It can charge other USB devices, such as my watch, or the flashlight I wear on a chain around my neck. It can charge my Baofeng BF-T1 Mini 70cm handy-talkie. It can charge my electrolytic water purifier, which equates to 150 liters of purified water. It can run a USB LED lamp, or my TS100 soldering iron. Except for the soldering iron, I'd need an adapter to use the 12v battery on any of those other devices.

I also have more options to charge it back up. I have a solar panel set, also by RAVPower, which can charge either of the PD power banks. I also have two different thermoelectric generators, that provide USB level power from a strong heat source. I can make hot water for drinks or freeze-dried food while charging the power banks. If my car is available, I can recharge the banks from my lighter socket, a source that isn't clean or stable enough to power the radios directly. I can use the GaN charger to recharge the banks, or I can run the radios from that charger with the smart cable while I have access to mains power. It's all very compact and lightweight, making it easier to transport into the field, such as when hiking on a trail or climbing a mountain. (I'm disabled, so my hiking and climbing days are over, but I still go to parks to operate, on picnic tables convenient to nearby parking!)  Talentcell put a battery management board inside the case for the large battery, so it can be charged from a charger for a lead-acid battery, but that would still require AC mains power to use!

Power Delivery is still a very new power bank technology, but it appears to be getting more popular. I think it'll be easier in the long run to use such multi-tasking power bank options to run portable ham radio gear than to lug about heavier and less convenient power sources as the technology improves over time. I have a new PD power bank on order, also by RAVPower, a 20,000mAh model with a digital power meter, so I can better gauge how much of the power bank's capacity is being consumed during use.

From some questions I've received since posting this, I have a couple of points to add.

  • If your power bank has a low-drain timeout feature (it shuts off if the device you connect doesn't draw enough current), it will NOT turn off if your radio doesn't draw a lot in receive mode. The power bank is not seeing the RADIO'S consumption level, it's seeing the handshake from the sink board, which does not automatically turn off if the draw is "too low".
  • There is no oscillator noise from the sink board because it is not boosting 5v from the power bank to 12v. The board is requesting 12v from the power bank, and the power bank is supplying it under the USB-C PD standard. So there's no oscillator boosting the voltage, hence, no noise from the sink board.
  • You need to use a USB-C Power Delivery power bank for this. Qualcomm fast-charge is a different standard, and will not work. There will be a "PD" logo on the power bank if it is supported, and should say it is Power Delivery in the documentation. Here is a document explaining the PD standard:

Gwen Patton, NG3P

Links to items:

PD Buddy Sink:
ZY12PDN Sink:
RAVPower 10Ah:
RAVPower 20Ah:
RAVPower 26.8Ah:
Inateck 45W GaN Charger:
3d Printed PD Buddy Sink Case:

This article Copyright © 2020, by Gwendolyn S. Patton. This article may be reprinted in Amateur Radio publications without prior permission, so long as it is reproduced in its entirety, with author credit preserved, and a link back to this page. Derivative works and edited versions require express written permission from Gwendolyn S. Patton. Send inquiries to

Saturday, March 28, 2020

Welcome to my new Ham Radio Blog!

It's been a while since I put together a new blog. I forgot completely that I even HAD a Blogger account, and had to tell it to use the "new" Blogger. Then I decided to bite the bullet and buy a new domain, and let Google handle it. That way it doesn't impact my heavy-lifting domains on my private hosting. Besides, in this day of hackers and spammers and such, diversification of site hosting may be a good idea. If I don't like it, I'll move it later.

So what's this blog going to be for? Well, I've been posting most of my ham radio chatter in one of two places: On my MeWe profile, and on my biography page. It's practically impossible to easily link someone to a MeWe post, and the QRZ page is all or nothing. So I need a blog for my radio stuff, and I wanted it reasonably easy to find. Hence, a Blogger blog and a custom domain with my callsign.

Of course, I couldn't just use ng3p.blogspot, etc. Someone else had that domain. So I had to go with gwen-ng3p, etc. But that's starting to get too busy. So I let Google sell me Works for me.

I'll copy over some of my posts from MeWe, along with the pictures I took for it, and will start posting dedicated blog posts here when I work on various projects. When I make Youtube videos, I'll link them here, but don't hold your breath for them, my house is a mess and I don't like to show it off. Besides, I'm not the most photogenic person in the world, and don't like to fuss about it. But pictures of projects, radios, field ops, sure. I'll have lots of those.

So, welcome to my little slice of the Interwebz, and my "virtual ham shack".

Just a quick note about my actual non-virtual shack.  It's currently a 7' tall "bread rack" -- a set of wire shelves -- next to my powered recliner. My PC is at the bottom, then a shelf with my power supply, a USB hub, and the things I need to reach most, then a shelf with my old Icom IC-746 Pro (currently being used primarily for 2m repeater use), then two shelves of various books, keyboards, mice, and other gear, and atop the whole mess, 3 large, flat "Really Useful Boxes" with the bulk of my slide rule collection in them. My main radio is currently my Elecraft KX3/PX3, on a RAM mount swung out a bit from the wire rack, with the KXPA100 amp on a separate shelf near the window. I have an extendible boom for my main PC microphone, a Zoom H4n stereo mike with USB interface. That connects through my PC, which runs VB-Audio's Voicemeeter virtual mixer, then to a Starlink USB sound dongle that connects to the KX3. Another cable connects the I/Q output from the PX3 to a spare mike input, so I can run the waterfall from WinK3Suite on my PC.

The powered recliner is where I do just about everything, from writing this blog to operating phone and CW. The chair sits atop an "Armchair Mount" with a swing arm for my monitor, so it's over my knees at a convenient height. The keyboard is wireless and on my lap. The mouse is a Logitech trackball. The chair I bought has a small table built into the right arm, that can fold away when not in use. It bears my trackball and my W1SFR "Torsion Bar Cootie Paddle" key. Even though the KX3 is mounted so I can get to it on a RAM mount, it's canted too far to the right so I have to crane my neck to operate. So I have everything running through WinK3Suite right on my screen to avoid neck strain.

I've got two main antennas currently. The main wire is a full-size W3EDP end-fed wire, run off a 4:1 balun. It works excellently on all bands except 160, where it runs so-so, tuning through the KXPA100's internal tuner. The second antenna is a Comet CHA-250b vertical up about 30 feet behind the house, attached to a GAP tilt-over mount with a Channel Master telescoping mast, which is secured to the wall of the mudroom with a wall mount, just to give it a little extra support. If I shove the antenna up higher, I have guy lines already set to be attached to screw-down anchors, but it hasn't needed it yet. I have one guy rope attached to the west side of the mast and tied to a convenient post, in case of a strong gust out of the west. It is resonant on all bands and doesn't really require tuning. The vertical has a beefy transformer on it already tuned so the antenna doesn't need external tuning.

I have that antenna on a 3-way switch, so I can feed it from my KX3/KXPA100, my ZachTek 6-band WSPR beacon, or from my Midnight Design Solutions "Phaser" FT8/JS8 dedicated transceiver. The Phaser is connected to an Acer 11" Chromebook, flashed over to GalliumOS Linux. It works VERY nicely, and was a fun build project! I'll post my MeWe article about it on this blog soon.

This whole arrangement makes me feel like a roach inside a stereo sometimes, but it's actually quite convenient and comfortable to run. I'll go into more detail on each section over time.

Stay tuned, and I hope you enjoy my blatherings!