All posts by Thomas Witherspoon

Homebrew, How To, News, Portable, QRP

Curt builds an Icom IC-705 control interface for his Elecraft T1 ATU

1 Comment

Many thanks to Curt (WU3U) who recently contacted me and mentioned he had built an IC-705 control interface for his Elecraft T1 ATU. This is a homebrew project based on others’ work and uses the FT-817 control port on the side of the T1 tuner.

I asked Curt if he could share a little more about his tuner to post here on QRPer:

Hi Thomas, I can’t take credit for the interface, as a guy in Japan designed it. When I built mine the entire instructions and notes for code for the PIC controller were in Japanese. I used Google translate to translate all of the information and I was able to successfully program the PIC chip and build the circuit. He has since released the details and code in English.

There are two designs: one with an on/off switch, and a newer version without an on/off switch that has auto power save. Both circuits are the same but the software for the PIC chip is different. If you build the one without the on/off switch there is a very specific sequence of connecting and disconnecting the device and it’s my opinion that the one with the on/off switch is the version that makes more sense to build. It shouldn’t matter which order you connect everything up and you simply throw the on/off switch to turn the device on and off.

Building the interface takes an understanding of a fairly simple electronic schematic and acquiring the parts. You also have to have a PIC programmer and the software to write his .hex file into the PIC controller chip.

The parts for the interface are all very common parts. The resistors are standard values. My build cost me about $30 in parts but I had to buy many of them in bulk from Amazon like the enclosures, switches and 3.5mm jacks and circuit boards to name a few. Individually the parts were $30 but my bulk order cost me much more. I also had to buy a PIC programmer for $25 and figure out what software I needed to download to program the PIC chip with the author’s code. It takes an experienced builder about two hours to build the device but it’s not out of the realm of a semi-novice as long as they can get the PIC chip programmed.

Here is the original code using the on/off switch. Everything is now in English:
https://amateur-radio.cocolog-nifty.com/blog/2020/11/post-1eb3cf.html

Here is his newer version with the same circuit design eliminating the on/off switch by using a different PIC program allowing the interface to have auto power shutdown (low power standby) but there is a specific order for connecting and disconnecting the interface. With this version there is still drain on the battery but the designer thinks that drain is less than the normal self discharge of the battery. I feel that any discharge combined with the self discharge of the battery will be more discharge than using the design with the on/off switch.
https://amateur-radio.cocolog-nifty.com/blog/2020/11/post-591d17.html

Video

I think this is a brilliant project and certainly one worth considering for those of us who already own an Elecraft T1 ATU and would like full control from the IC-705.

Thank you for sharing these details, Curt!

 

Hams, News, QRP Radios, SOTA

Steve’s new Icom IC-705 SOTA lap desk

1 Comment

I’ve been in touch with Steve (WG0AT) recently. He happened to be selling his FT-817 at the same time I was looking for a narrow CW filter.  The stars aligned and I now have a 500 Hz Collins CW filter in my FT-817ND.  Thanks, Steve!

Steve also took delivery of his Icom IC-705 recently so we’ve been trading notes about this fine rig. He and I both have a fear of the ‘705 falling off our laps when using it in the field for SOTA and POTA activations.

Steve, being the king of ham radio customization, started working on a portable desk. He shared iterations along the way and his final product seen in the photo above.

The desk is a brilliant design: it’s lightweight, sturdy, has holes for managing wires/cables, a strap to hold it your leg, and even a cup holder. The cup holder is a bit of genius because he likes a good cuppa tea in the field just like I like a good cuppa joe.

The IC-705 will be able to bolt directly to the lap desk so there’ll be no fear of it falling off a cliff in the field.

Of course, the desk will work with any field-portable radio. Steve shared a few more photos:

I’m going to attempt to build a similar desk for my IC-705. The great thing about it is it’ll easily fit in a backpack, too.

Thanks again for letting me share your photos, Steve! We look forward to seeing this desk in action at a summit near you!

Check out Steve’s excellent YouTube channel here.

News

Bioenno Thanksgiving Sale

2 Comments
I typically pair my IC-705 with a 4.5 aH Bioenno LiFEPo battery pack.

Just a heads up that Bioenno Power is having a 2020 Thanksgiving sale and offering a 10% discount with the coupon code “THANKS”.

I’m a huge fan of Bioenno’s batteries and just pulled the trigger on yet another LiFePo battery. This time, a compact 3 aH battery. This will be more than enough battery to play QRP for hours without recharging.

Side note: I’m also working on a project for my parents converting their living room lamp into a DC LED lamp with battery backup. Their power outages seem to be so frequent as of late, I know they’ll appreciate a lamp that will work regardless if the power grid is up or not. I’ve already purchased a 12V LED Edison-style bulb and now will pair it with a 4.5 aH Bioenno battery.

Click here to check out Bioenno’s website.

Antennas, CW, Field Reports, News, POTA, Videos

Impromptu POTA activation using the Elecraft AX1 Antenna

3 Comments

A few weeks ago, I posted a report about doing my first park activation with the Elecraft AX1 super compact antenna. If anything, I felt the activation almost went *too* well using such a small antenna. I didn’t want to give others the impression this is all the antenna you’ll ever need–it’s just a brilliant compact antenna designed for convenience and accessibility. It’s a fun field companion and can be used pretty much anywhere.

Yesterday morning, I had a number of errands to run on the south side of Asheville and had not planned to do a POTA activation. While I was waiting on a curbside delivery, however, I was admiring the nice weather and thinking that I might venture out later in the day to do a Parks On The Air (POTA) activation. Part of me knew, though, that if I returned home, I’d get involved with projects and never make it back out to the field.

I always carry a transceiver and antenna in my car, so I opened the trunk and found my Elecraft KX2 transceiver field kit which included the Elecraft AX1 antenna. Technically, that’s a whole station! Why not give it a go–? I’m always up for a challenge.

Since I would be passing by the Blue Ridge Parkway on the way home, I quickly scheduled an activation on the POTA website via my phone so that the spotting system would know to grab my information from the Reverse Beacon Network (RBN) when I started calling CQ.

Blue Ridge Parkway (K-3378)

I knew this might not be an “easy” activation: I would be using a super compact field antenna that’s quite a compromise in terms of performance, propagation wasn’t exactly stellar, and I was activating a popular (hence somewhat stagnant) park on a Monday morning. Not necessarily ideal ingredients for a successful activation.

I also discovered my phone tripod in the trunk of the car, so decided to make one of my real-time, real-life, no edit videos of the entire successful or failed activation. (Hint: It turned out to be a success.)

Gear:

If you’d like to accompany me on this park activation, check out my video on YouTube:

At the end of the day, the AX1 continues to impress me. It is a compromise? Yes. Does it perform as well as a resonant wire antenna? No. Can it activate a park as well as my other antennas? Yes.

AX1 QSO Map

Click to enlarge

No doubt, part of my success with the AX1 is because I’m primarily using CW instead of SSB to complete activations. I’ve made SSB contacts with the AX1, but I’ve never completed full park activations with it yet–in truth, though, I’ve never tried.

In fact, perhaps it’s just a lucky streak, but so far the AX1 has been as effective as many of my wire antennas in terms of simply completing valid park activations in less than an hour. My signal reports aren’t as strong as they would be with, say, my EFT-MTR resonant antenna or Emcomm III Portable random wire antenna, but it’s enough to get the job done.

If nothing else, I’ll admit that the AX1 reminds me of the magic of low-power radio each time I use it. When I log stations hundreds of miles away, with such a modest station, I feel like I’ve accomplished something.

In short? It’s fun to use.

Black Friday Sale

FYI: I just received Elecraft’s latest Black Friday 2020 ad and noticed that the AX1 antenna package (which doesn’t include the 40M extension) is on sale. Click here to check it out.

Antennas, News

QRPGuys Tri-Band Vertical Antenna

5 Comments

On a tip from my buddy Eric (WD8RIF), I ordered a QRPGuys Tri-Band Vertical Antenna kit last week.

Not only will this antenna pair beautifully with my MTR-3B, KX1, and FT-817ND but I had completely forgotten I ordered it.

When I pulled the QRPGuys package from my post box, it was as if a little Christmas had arrived. I mean, is there a better feeling than getting a new kit in the mail–? I don’t think so.

Time to heat up the soldering iron!

Field Reports, News, POTA

POTA Field Report: One antenna and two transceivers at South Mountains State Park (K-2753)

3 Comments

On Tuesday (Nov 17, 2020), I decided to activate South Mountains State Park (K-2753) for the Parks On The Air (POTA) program. As with my activation at Lake James the day before, it was impromptu. Basically, the weather was beautiful, so I couldn’t resist.

In fact, the weather was so nice, on my way to South Mountains I passed by Bakers Mountain County Park and hiked their full trail including the summit. While on that hike, I ran into Kenneth (W4KAC) who had just activated Bakers Mountain for Summits On The Air (SOTA). This was a bit of serendipity because I, too, plan to activate Baker’s Mountain for SOTA and Kenneth provided some great details for finding the summit (which is not actually on the park grounds).  It was great running into a fellow QRPer and talking shop, too!  I hope to meet Kenneth again in the field.

I arrived at South Mountains State Park mid-afternoon and set up near one of their large covered picnic shelters.

Although I’ve activated South Mountains State Game Land numerous times in the past, I’ve never activated the actual park. The last time I popped by the park, there was already another ham there in the middle of an activation, so I moved to the adjoining game land that day.

South Mountains State Park is a very popular park–indeed, it’s currently the second most activated park in North Carolina.  Although I didn’t realize it at the time because I had no internet access, there was actually another operator somewhere at the park on the air at the same time I was.

Gear:

On the Air

Once again, I set up the Chameleon CHA MPAS Lite vertical antenna for this quick activation.

Besides being such a quick and easy antenna to deploy, I love how stealthy it is, essentially disappearing against a background of trees.

As you might imagine, activating a park while someone else is also activating it is not ideal. At the time, I couldn’t figure out why contacts were coming in so slowly, but no doubt many hunters probably thought they’d already worked me because they worked the other activator.

In the end, though, my biggest problem at South Mountains was the fact my battery died in the Elecraft T1 ATU after finding a match on the 20 meter band. A 9 volt battery should last months in the T1, but the battery I put in it several weeks ago had already been used in another device for a few months. I had meant to replace it with a fresh cell. I actually packed a new 9V battery in my main radio pack, but I didn’t have it with me on this trip because both South Mountains and Lake James were unplanned activations.

I spent a good half an hour on the 20 and 30 meter bands where I had a decent match, but only logged three or four hunters. Conditions were not ideal on the higher bands.

I really needed to move down to the 40 meter band knowing it would be more productive, but I had no way to find a match for the IC-705. (Lesson learned: I’ll never again leave home without my Emtech ZM-2 as a backup!).

Fortunately, I remembered I had the Elecraft KX1 field kit. The KX1 now permanently lives in my car so I know I always have a complete radio kit for impromptu field activations.

The KX1 has a built in ATU, but it’s not as robust and versatile as the T1 or the internal ATUs in the KX2 or KX3.

I tried loading 40 meters and got a 2.5:1 match. I’m sure the KX1 would have plugged along, but I don’t like pushing much over 2:1 when I don’t have to.

After tinkering with the CHA MPAS Lite counterpoise for ten minutes, I finally found a length that, if half suspended, allowed the KX1’s internal tuner to achieve a 1.9:1 match. Good enough!

I started calling CQ on 40 meters and within a few minutes, I logged a total of 12 contacts.

The KX1 saved my bacon that Tuesday!

All in all, I really enjoyed the time at South Mountains State Park. It was beautiful weather and I had an idea spot to set up and operate. I’ll certainly come back here in the future.

I’ve also decided that I’m going to start packing a resonant antenna option in the car with my KX1 field kit. It’s only this year that I started using multi-band and random wire antennas that require an ATU; they are mighty convenient indeed, but it’s always nice to have a resonant option on hand as well.

Field Reports, POTA, QRP

POTA Field Report: Lake James State Park (K-2739) with the Icom IC-705 and CHA MPAS Lite

2 Comments

Monday (November 16, 2020), I made a detour to the Catawba River access of  Lake James State Park (K-2739) to try a late morning POTA activation.

I didn’t plot this activation in advance, so had to work with what I had in the trunk/boot of the car.

I did a quick inventory and found my Chameleon CHA MPAS Lite vertical antenna packed and ready to deploy. (I always have an antenna tucked away in the car because…well, because!)

In terms of radios, I had the Icom IC-705 and Elecraft T1 antenna tuner packed as well. Woo hoo! A perfect combo! Let’s go!

Gear:

It was blustery and cold Monday morning due to a front that moved through during the night, so it was no surprise that the picnic area was completely void of (sane) people.

I found a picnic table on the bank that was relatively sheltered from some of the stronger gusts moving across the river. It was still quite windy, though, so I propped the MPAS Lite field pack on the table to provide a bit of a wind break for my log book.

Setup was quick. I don’t think I needed more than 4-5 minutes to have the CHA MPAS Lite deployed. This is one of the advantages of field portable verticals. The disadvantage? Verticals aren’t the most effective antennas in this part of North Carolina where ground conductivity is so poor. Still…I knew I could at least grab my ten needed contacts to have a valid POTA activation.

On the air

I won’t lie: it was slow-going.

For one thing, it was 11:00 local on a Monday morning–not exactly a prime time for a park activation.

I first tried making some SSB contacts on 40 meters and spotted myself on the POTA network. I managed to log 5 hunters in 30 minutes. With patience and time, no doubt, I could log ten SSB contacts, but I didn’t have time to wait, so I moved over to CW.

Oddly, the higher HF bands were in better shape than 40 meters that morning. One of my first contacts was NL7V in Alaska on 20 meters. A most impressive contact with 10 watts into a vertical.

I was on the air a full hour and did manage to log a total of 10 contacts. I’m certain if I would have deployed a wire antenna I would have had even better luck. Indeed, had I thought about it in advance, I could have actually deployed the MPAS Lite as a random wire antenna. (Doh!) That’s one of the great things about this antenna system is that it can be configured so many different ways.  Next time…

Still…I thoroughly enjoyed my time at Lake James State Park. I’ll make this detour again in the near future.

The Icom IC-705 continues to prove its worth as a superb little POTA transceiver!

Antennas

RigExpert rebates through January 15, 2021

Leave a comment

Many thanks to Paul Evans (W4/VP9KF) who writes with the following tip:

The following instant rebates will be valid for purchases made between November 15, 2020, and January 15, 2021: (direct or dealers)

Model Instant Rebate
RE AA-230 ZOOM 25.00 USD
RE AA-600 25.00 USD
RE AA-1000 50.00 USD
RE AA-1400 60.00 USD

Got it sent to me by e-mail…

Thanks, Paul! A good time to buy if one’s been eyeing one of these RigExpert products.

Click here to check out RigExpert’s website.

CW, Kits, News, Portable, QRP

Assembling the MFJ-561K Miniature Travel Iambic Paddle Kit

3 Comments

MFJ Enterprises has an amazingly deep catalog of products. So deep, I often overlook items that could be quite useful in the field.

MFJ recently sent me one of their travel paddle kits to evaluate on QRPer.com–no doubt, they heard my plea for paddle recommendations some time ago.

Paddles are a funny thing: they’re basically a very simple switch, so not terribly difficult to homebrew. Yet sometimes we want to simply purchase pre-made paddles instead of building them.

I don’t personally want to invest crazy money in field paddles because there’s a reasonable chance they could get damaged in my pack or I could even leave them on the forest floor after a POTA/SOTA activation.

Plus, paddles aren’t the weak link in my CW game (ahem, yeah…you might have guessed it’s the operator–!).

The price of MFJ-561K paddles hits a sweet spot at  $25 US. I know of no other paddles made in the US that are cheaper (although I know I might stand corrected on this point).

For $25, you’re not getting Begali quality: you’re getting something that’s simple and gets the job done.

The MJF-561K is actually a simple kit that you assemble at home. It’s a novice build for sure, taking (generously) 20 minutes to assemble and requiring no kit building experience. You will need to use a soldering iron to attach the three conductor wire to your paddles–otherwise, it feels more like a mini Meccano or Erector set.

At one point early in the build, I did find myself looking for a detailed photo to determine how the shoulder washers were placed. I couldn’t find one, so I decided to take my own photos to help anyone else building these paddles in the future.

MJF-561K Assembly Photos

Click on the photos below to enlarge:

The shoulder washer fits in the hole on the inside of the paddle as you can see on the upper paddle lever. The larger washer goes on the outside of the paddle, insulating the solder lug and Kep nuts.

One bolt and Kep nut holds the back of the paddles to the base.

This image shows how the center contact is screwed in. Note that another solder lug is held in place under the paddles and is not in this photo, but shown in the photo below.
Once you’ve attached the bottom solder lug and Kep nut, position the center contact (on top) so that it floats between both paddle contacts before tightening down.
Next, you’ll need to strip the supplied three conductor cable, tin the ends, and solder them to the three solder lugs. Check your radio manual to determine which side of the paddle to solder the tip and ring wires based on which side of the paddles will send dits and dahs.

Hint: when attaching the cable tie/strain relief, position the cable tie locking point so that it faces up rather than down (to avoid that part of the cable tie interfering with rubber feet contact.
Next, attach the rubber feet to the base.
And, finally, attach the rubber pads to the paddles

On the air

The building process was super simple as you can see from the photos above. I didn’t test the paddles in advance to make sure the shoulder washers were insulating the contacts properly, nor did I test that my ring/tip placement was correct before soldering. I would suggest you do this!

Fortunately, I plugged it into the Yaesu FT-817ND and it worked perfectly!

The paddles are lightweight and the action reminds me very much of Whiterook Paddles.

Any criticisms? For the price, these are brilliant. With that said, I wish the three conductor wire was just a bit heavier gauge. The conductors are very thin and I do worry how well they’ll hold with heavy use. Of course, it’s an easy process to replace this cable with one of my own.  Also, like most lightweight backpack paddles, the thin metal sheet base needs to be held in place while operating.

I think I might attach the paddles directly to a clipboard. If I drill two holes in the paddle base, I could mount them with small bolts onto the clipboard and remove them when done. I’ll give this some thought.

For $25, the MJF-561K paddles are a no-brainer.  I see keeping a set of these for ultralight operating and perhaps even as a set of backup paddles. And, hey! They’re a great stocking stuffer idea. I would suggest MFJ consider making a single-lever version as well.

Click here to check out the MJF-561K paddles at MFJ.

CW, QRP

Yaesu FT-817ND: Mechanical CW filter suggestions?

7 Comments

I mentioned in a previous post that I recently purchased a Yaesu FT-817ND package from a friend. The Yaesu had a number of upgrades including an Inrad SSB filter. Thing is, I rarely need a filter when operating phone, but desperately need one for CW since the the default filter width is quite wide.

Although I plan to purchase a SOTAbeams Laserbeam-817, I’d still like a narrow mechanical filter for the one available filter spot on the FT-817ND.

It seems the YF-122CN (300 Hz Collins Mechanical Filter) is no longer manufactured. Used prices can be quite high.

I’m curious if anyone has suggestions for alternative narrow CW filters? Please comment if you have any advice!