Many thanks to Sam (WN5C) for sharing the following guest post:
A Compact CW Filter and Speaker Build for the TR-35
by Sam Duwe, WN5C
I recently built a Penntek TR-35 and, like seemingly everyone, I love it.
Once the rig passed the smoke test I was having too much fun and wasn’t quite ready to put away the soldering station. I had two non-essential wants for this project: a narrower CW filter for listening comfort, and an external speaker. Here’s a quick description of how I crammed both of those into an Altoids tin. Nothing is new or groundbreaking here, but it has been a fun and useful project for me and hopefully will give some inspiration for others.
The heart of the project is a Hi-Per-Mite 200 Hz CW filter, designed by David Cripe NM0S, and sold as a nice kit for $28 by Four State QRP Group. Hans Summers G0UPL uses the circuit in the QCX so many will be familiar with the filter’s sound. It’s nice and narrow with no ringing, and makes using my base station (a Kenwood TS-520 with the 500 Hz crystal filter) a joy.
To be clear, the existing narrow filter in the TR-35 is great, but I like the option of going narrow(er). It’s a Pixie-level build difficulty so it should come together in an easy couple of hours. I originally built mine in an Altoids tin using inspiration from Phillip Cala-Lazar K9PL’s review and it worked very well. It sips current and is powered by a 9-volt battery. With a DPDT throw switch connected to both the audio path and the power you can easily switch the filter on and off.
A neat aspect of the TR-35 is that there is a lot of audio gain so you can drive a non-amplified speaker. I have a little Bluetooth speaker that does this trick when I want to use CW to annoy people, but I figured if I’m already hauling an Altoids tin to the field maybe I could get it to talk, too. I looked around my junk box and found a broken Baofeng speaker mic and salvaged the speaker. It works really well: a robust but comfortable volume.
I’m sure any little speaker would do the trick… nothing fancy here, it gets hot glued it to the lid of a mint tin after all.
After I built the Hi-Per-Mite here’s what I did: first I ate a tin of Altoids and felt a little sick. Then I drilled some holes. The one on the left is for the audio input, the one on the bottom for the headphones (both of these are 1/8” stereo jacks), and two on the right for two mini DPDT switches. I also drilled holes in the lid for the speaker sound to come through. I gave the tin a good sanding and tried to remove sharp edges, and then sprayed the lot with black primer and spray paint.
Many thanks to Jonathan (KN6LFB) who shares the following guest review:
A review of the EGV+ QRP Transceiver Kit
by Jonathan (KN6LFB)
The EGV+ is a QRP CW-only transceiver that covers the 40-, 30-, and 20-meter HAM bands. Designed by Javier Solans, EA3GCY, it is sold in kit form from his website, qrphamradiokits.com.
Javier designed the EGV+ in honor of his friend and co-founder of the EA-QRP Club, Miguel Montilla, EA3EGV. The first page of the instruction manual dedicates the radio to Miguel with this tribute:
This EGV+ transceiver is probably the kit that I have produced with more care and illusion in my life. It is a great honor to name this kit “EGV”, the callsign suffix of the late Miguel Montilla, EA3EGV (SK). With no doubt, this is the kind of kit he liked most. It was my privilege to establish and share with him the first years of the EA-QRP Club. He has always been a referent in my life; when I remember those wonderful years his humbleness, work capacity and generosity are the virtues which shine his image.
How lucky I was to be able to share the path with you, Miguel. Thanks!
Javier Solans, ea3gcy
Frequency Coverage: 40m, 30m, 20m
Power Requirements: 12–14VDC, 1–2A transmit, 0.14–0.25A receive.
RF Output: 5W @ 13.8V
Harmonics Output: -45dBc or better below fundamental
AGC: acts on the receive path according to the received audio.
Audio Output: 250mW, 4-8 ohms.
I purchased my EGV+ kit with the optional enclosure from qrphamradiokits.com. Javier requests that US customers email him using the contact form on his website for the current pricing in USD prior to ordering. At the time of my order (February 2022), the cost with the optional enclosure was $203.37.
The EGV+ is a single large (180x140mm) PCB, with separate modules for the OLED display, processor, and Si-5351 frequency generator. All components are through-hole and placed on the top of the PCB. The kit arrived well packaged and well organized. There were no missing or mislabeled parts in my kit, which is impressive considering the high number of components. There are 53 100nF capacitors alone!
The manual contains detailed lists of the components by value/quantity and individually. One of my favorite features of the manual, and something I wish was more common, is a grid-based layout map of the entire PCB [see above], with the grid position called out in the list of individual components. This greatly speeds assembly and diagnosis as you can find component positions more easily.
Since my early days in the world of radio, there have been radios I found very intriguing, but have never owned. I’m sure I’m not alone in this regard.
These radios have enticed me, but not enough to pull the trigger…you know…to actually buy one.
Not yet, at least.
Here’s a small sampling of radios I currently window shop:
The Elecraft K3/K3s
There’s a reason this particular radio series has been on so many DXpeditions: it packs a lot of performance and is efficient for its size.
I’ve owned all of Elecraft’s QRP radios and I love them. I know I’d like the K3 or K3s as well.
There are a couple reasons why I haven’t purchased a K3 or K3s. First of all, I already own a KX3 with a CW roofing filter and a KXPA100 amplifier. In a sense, I feel like this is a rough equivalent of the K3. The KX3 doesn’t have all of the features or options of the K3 series, but it has everything I need as a primarily portable op. Secondly, the price of the K3 or K3s–depending on the installed options–range anywhere from $1,100 – 2,900 used. The lower priced ones tend to be QRP and lack some of the performance options.
That said, if I ever landed a super deal on a K3, there’s a decent likelihood I’d buy it.
The Yaesu FT-897D
I know what it is about the FT-897: it looks like it means business. I’ve always found the rugged design of the ‘897 appealing even though a friend jokes that it’s the ugliest radio Yaesu’s ever made. Of course, folks who buy an 897 aren’t looking at the form, they’re going for the function.
Many thanks to Brian (K3ES) who shares the following field report:
Field Report: Reflections on a Kilo at Cook Forest State Park
by Brian (K3ES)
Cook Forest State Park in northwest Pennsylvania has always been a special place for me. It abounds in trees (including some of the last virgin timber around), wildlife (deer, turkeys, song birds, squirrels, and the occasional bear), and also includes the scenic Clarion River. When I found out about Parks on the Air (POTA) after getting licensed in 2020, I knew that I had to put POTA entity K-1345 on the air.
Our family cabin; which has been central to all of the phases of my life – including milestones, joys, sorrows, and unadulterated wonder – is located on a plot of land bordered on two sides by the park. It just seemed natural and right for me to do my first-ever POTA activation under an ancient hemlock tree just a few steps over the line from the back corner of our property. That mostly-SSB activation happened in May 2021 with my TX-500 pushing 10 watts into a homebrew dipole suspended from a dead branch up 30 ft in the hemlock.
Last weekend, I reached a meaningful personal goal by completing my 1000th activator contact from K-1345. After the first activation I never again operated mostly-SSB, and I never increased radiated power. Nearly all of my contacts since have used CW, and many were completed at 5 watts. The added challenge of QRP CW undoubtedly made the Kilo more difficult, but it was also much more fulfilling. It has taken me 28 successful activations, a lot of work to improve my CW skills, and a lot of patient support from the hunters who have shared this journey with me.
My activations at K-1345 tell the story of my journey as a CW operator. I took my first steps on that journey in late 2020, months before I had a portable radio or a plan for my first activation. I started with an Android app, V-Band, and listening to CW exchanges on webSDR. Eventually that progressed to CW Academy basic, intermediate, and advanced classes. The classes really upped my CW game, but what helped even more was using CW on the air. I finally got my HF station on the air in March 2021 and started hunting parks, SSB at first, then increasingly CW. During my first mostly-SSB activation I did manage to hunt down three park-to-park contacts using CW. I started my second activation by calling CQ using CW, and I have not looked back. Wow, those hunters were patient during that first first CW activation! My skills have improved greatly since then, but I’m still not where I want to be. The next goal for me is to gain confidence and proficiency in less-structured QSOs.
I want to thank Thomas – K4SWL, whose real time, real life activation videos challenged, motivated, and inspired me to learn and use CW. I greatly appreciate the work of the CW Academy advisors who guided me through some of the hard work needed for improvement. I also need to thank the hundreds of hunters who have patiently endured my developing CW skill set. Finally, my hat is off for the dedicated POTA volunteers, who continue to improve and expand this amazing activity to the benefit of radio amateurs around the world.
Completing the Kilo activation would have taken me longer if it were not for the tremendous encouragement provided by my gracious, intelligent, and beautiful XYL. As I was contemplating indoor chores on a Friday morning, she pointed out the opportunity to go out and activate during the best weather of the weekend, and save the chores for a rainy day. Who am I to argue with such impeccable logic? Off to the woods we went!!!
I made a point of using the TX-500 with the homebrew dipole suspended in that ancient hemlock tree to complete the Kilo activation, going back toward the starting point, as it were. Of course I did finish with CW mode and 5 watts to commemorate my personal growth during the journey, too. I was set up to go by mid-afternoon. Needing 57 contacts to complete the Kilo, I decided to get some contacts on 20m, then move to 40m a bit later.
After calling CQ for almost half an hour to get two contacts, I decided to move to 40m a bit sooner than planned…
40m was hot! I completed the eight additional contacts needed for a successful activation in less than 15 minutes. By the 2 hour mark, I had racked up a total of 69 contacts and finished the Kilo.
As a final note, I picked up 55 more contacts on Saturday, bringing my total CW mode contacts over 1000. The rain started early Sunday morning, and I got my indoor chores finished after all.
This spring, as we planned our two months of travel in Québec, Canada, I jotted down one location in particular that I wanted to visit: Baie-Comeau.
Baie-Comeau is located about 420 km (260 miles) northeast of Québec City on the north shore of the mighty St-Lawerence river. It’s a small city with a population of around 21,000 and is pretty darn isolated. For many travelers, Baie-Comeau is the last major stop before a long, lonely road journey north to Labrador City or further northeast along the St-Lawrence.
I’ve always wanted to visit Baie-Comeau and my wife and daughters were game to make a proper trip out of it!
While in Québec, we plotted the details of our trip to coincide with a good weather opening.
We packed our gear, left the home base near St-Anne-de-Beaupré on July 13, 2022, and drove up the St-Lawrence, crossing the Saguenay River by ferry, and on up to Baie-Comeau with a few stops along the way.
It’s a beautiful drive.
We reserved lodging at the Hôtel Le Manoir Baie-Comeau (an excellent hotel, if you ever find yourself overnight in Baie-Comeau). We’re frugal travelers, so this was a bit of a splurge, but the stay coincided with our 20th wedding anniversary, so why not?
I was very happy to see that the Manicouagan Uapishka Biosphere Reserve was on a hill only a short drive from the hotel. It was approaching dinner hour, so I didn’t want to fit in a late afternoon activation with the family; we had other plans that evening. My wife suggested instead that we check out the park and walk the trails before dinner which would allow me a bit of time to scope out an activation site.
Manicouagan Uapishka Biosphere Reserve (VE-0054)
We discovered that Google Maps doesn’t have the trailhead marked very well. It led us to a neighborhood street a short walk from the park. I remembered reading a note from a local (online) mentioning there was ample parking at “the church” so we drove to a beautiful church nearby and immediately spotted the trailhead. If you ever find yourself in Baie-Comeau, here are the coordinates for the trailhead.
Turns out, the church is no longer a church, but has has been converted into the headquarters for the park which is a part of the Jardins des glaciers.
There are some brilliant views of the St-Lawrence from the parking lot.
We quite easily found the trailhead of the sentier which led into the biosphere reserve. I used my GPS to confirm when we were well within the boundaries.
We enjoyed a scenic hike that evening.
As I mention in my activation video, this is one of the amazing things about doing POTA during travels: you discover so many incredible parks that would have otherwise gone unnoticed. My family truly appreciates this particular aspect of POTA. It opens the opportunity to find spots only locals might otherwise know about.
After our hike that evening, I had a pretty good idea where I could set up in the morning. We made our way back to the hotel and enjoyed dinner and a movie.
So that my activation time wouldn’t interfere with family plans that day, I scheduled an early morning activation for July 14.
QRPer.com readers know that I’m a big fan of the venerable Yaesu FT-817 and FT-818 series transceiver. So much so, I own two FT-817NDs–I purchased a second unit last year primarily for full duplex satellite work.
As I mentioned in a previous post, the one gotcha with the FT-817 and FT-818 is narrow CW filter availability. The YF-122C 500 Hz and YF-122CF 300 Hz Collins filter boards are no longer produced. Neither are the Inrad equivalents.
With the renaissance of CW we’re experiencing along with the growth of POTA, WWFF and SOTA, narrow CW filters for the FT-817/818 are very difficult to find and come at a premium when you do find them. I saw one sell recently for $250 US–over double what I paid two years ago.
In addition, this same filter not only fits the FT-817/818, but I believe it also fits the popular FT-857 and FT-897 series transceivers (please correct me if I’m wrong about this).
The Problem: I wanted another narrow CW filter
One of my FT-817NDs is loaded with a Collins 500 Hz mechanical filter that I purchased from my buddy Steve (WG0AT) nearly two years ago.
The second FT-817ND had a narrow Inrad 2 kHz SSB filter that came with the radio when I purchased it used (see image above). Initially, I had no intention of buying yet another narrow CW filter because I’d only planned to use the second unit for FM and SSB satellite work.
Then, during field day this year, I decided it might be fun to build a quick-to-deploy portable HF station with something like an Armoloq TPA-817 pack frame. That thought experiment made me realize that I should simply bite the bullet and get a narrow CW filter for the second FT-817ND.
I started searching in late June and was simply not willing to pay the price for the very few filters that have shown up on the the used market.
The Solution? Assemble one!
I owe QRPer reader, Petr (OK1RP), for this tip. Thank you, Petr!
The process of assembling your own narrow filter is actually quite simple and affordable. If you have even the most basic soldering skills, you’ll be able to manage this easy project. If interested, keep reading and I’ll show you how you can assemble your own…
We hams have a tendency to unbox our new radios, toss the manual to the side, and get on the air. We sort out radio functions by playing with the radio and using it.
By “we” I’m certainly including myself…
Typically, there’s no harm in doing this. Experienced ham radio operators know how to hook up their radios, and know what common functions and features they must identify. In fact, when I review a radio, I rarely read the manual for this very reason: I’m curious how intuitive the controls are.
With that said, I’ve had no less than three emails from readers this past week asking questions about their radios–questions that all could have easily be answered by even skimming over the manual.
Sure, I’ve had this happen to me before. Subscribers to my YouTube channel have watched my activation videos and pointed out shortcuts and features I hadn’t yet used on a radio. Many times, I was aware of the function/feature, but while on the air couldn’t remember how to engage it. (This is where a printed cheat sheet come in handy!)
Truth is, modern rigs are simply chock-full of features. Many of these features are incredibly useful, but not obvious on the front panel.
Case in point: MTR-3B Direct Frequency Entry
In the past, you may have heard me mention that that the MTR-3B “isn’t a good transceiver for hunting stations” because it has no rotary encoder to quickly move from frequency to frequency. There’s no number pad for direct frequency entry either.
Instead, the user has up and down arrow buttons that you push and hold until eventually you reach the desired frequency. If the frequency is 50 kHz away? Yeah, you’re going to be holding that button down for a while (there is a fast tune option, but it’s still slower than an encoder).
Early this year, I pulled out the MTR-3B manual to give it another thorough read-through–from cover to cover. It’s not a large manual. My goal was to refresh my memory about recording and playing back CW message memories. In the process, I also discovered that the MTR-3B has a clever (and quite unconventional) direct frequency entry method.
Via the DFE function, you simply enter four digits of the desired frequency, 0 to 9 via Morse Code, starting with the 100 kHz digit. It’s a little quirky, but it works quite well!
This doesn’t make band-scanning any easier, but it does help me while hunting since I can directly enter the frequency I find on the POTA or SOTA spots page.
This one function made my MTR-3B that much more usable. Somehow, I missed this part of the manual when I first purchased the MTR-3B–I’m so happy I took a deep dive later.
Getting to know you…
Advice from Julie Andrews:
If it’s a rainy day, or you’re simply trying to stay awake during a mandatory remote meeting for work, or like today there’s a radio blackout, use that time to get to know your radio by taking a deep dive in its manual.
Read it from cover to cover: I guarantee you”ll learn something new about an old friend.
Many thanks to Steve (KM4FLF/VA3FLF) for sharing the following guest post:
A Great Homebrew Vertical Antenna
by Steve (KM4FLF/VA3FLF)
Last spring, I was going through my many boxes of ham “stuff” looking for items to sell at our club tail gate sale. I came across a couple of Hustler SM Series Resonators (20 /40 Meters) that I had acquired. I am not sure where I obtained them, but I decided they were keepers. That decision turned out to be the first step in a year long process that has given me an awesome homebrew vertical antenna.
After doing a little research I found the resonators and accessories at most of the online ham dealers. They are used primarily as mobile and marine antennas. I had seen where a ham had used these on a ground stake as a portable antenna as well. I ordered a Hustler MO1 mast which is 54 inches tall and thought I would attempt to make a portable POTA antenna.
I had a couple of small aluminum plates that I drilled out a few holes. I cut out a notch to put a SO-239 Stud Mount on the plate as my antenna base. I now had a ground plate, connector, and antenna with resonator. By putting a stake in the bottom of the plate, I was able to get the antenna to stand up. The Hustler resonators have a hex screw for tuning that can be loosened. The antenna can be adjusted for resonance by lengthening or shortening the radiator length. After adjusting the radiator my SWR was still horrible on the two bands.
I had some 14-gauge wire laying around and attached it to the plate using carriage bolts and nuts for my ground radials. I didn’t think about the length of the wires at this point but went with three or four lines around 20 to 30 ft. I was able to use my vertical a few times with moderate success. My SWR on 20 and 40 Meters was around 2:0 to 1 at best. It was bulky and very delicate. Sometimes screwing in or unscrewing the MO1 the SO239 would slide off the edge of the aluminum plate. I put away my contraption for the winter and decided to move on to something else.
A simple “side-by-side’ method can be deployed with the use of a Calibrated NanoVNA to read back “S21 Gain” which is, in this case, signal loss from the output of S11 back into S21 through the identical windings. The gain (loss) reading in negative dB gives us the total signal loss through the windings. We can then divide by 2 to get the loss through one winding and then convert with a bit of math to an efficiency number.
p = 10^(x/10) * 100 where p = percentage 0-100% and x = loss in dB
Example: -2dB reading on “S21 Gain” on the NanoVNA divide by 2 for a loss of -1dB on each winding would be 10^(-1/10) * 100 = 79.4%
We have a 50 ohm signal coming out on S11 of the NanoVNA through the first winding to some unknown exact impedance but that is then converted back through the second unun into the S21 port where the signal is measured. It is therefore necessary to use identical windings for each test to ideally match the impedance change.
I like to run the signal test with the top and bottom of each band, take the average of the two, and then convert to efficiency, 100% being perfect. I record these values to then chart each band’s efficiency for the winding pairs. The goal here is to compare the different windings. For example, with a 9:1 used for a long/random wire, compare toroid sizes, number of toroids and in some cases the number of windings. One nice advantage to a 9:1 Trifilar winding is that you can increase or decrease the winding count in multiples of 3 while maintaining a 3:1 winding ratio. Take the square of the windings ratio (3) to find the impedance ratio of 9:1.
Here is one example of two different windings compared. Both are Trifilar but one with a single T80-2 toroid and 9 sets of turns and the second with a Double T80-2 and 12 sets of turns. 100% would be zero signal loss through the windings, 0% would be full signal loss. -3dB (loss) per winding would equate to a 50% efficiency in either single winding.
The difference between these two windings across the Amature Bands was quite surprising to me. I assume typical, often used windings will be decent across the bands. Here we saw a large improvement in access to the bands by adding several extra turns.
When each component of the station induces loss to the radiated signal, or the ability to receive, you have to improve each area for the best transmit and receive capability. This test is not foolproof, it is not the most accurate way to measure efficiency and maybe not the easiest but it gives me a comparative analysis of various windings with the tools available to me. If I can increase the performance of my windings, I can increase the performance of my station. Time to wind some more transformers!
To date, I believe I’ve activated 11 parks (1 in Ontario, 10 in Québec) during our extended family vacation. Instead of hitting the same parks over and over, I’m trying to activate new parks during each outing because it’s giving us an opportunity to explore some really amazing spots that we might not otherwise discover.
Before we leave La Belle Province, I’ve at least two SOTA summits in mind and 3-4 more parks, family time permitting. Indeed, as I mention below, I hope to activate another park sometime today.
Ham Radio Workbench Podcast
Once again the fine crew of the Ham Radio Workbench Podcast made the mistake of inviting me on another episode of the podcast.
In truth, it’s a proper honor to join them each time (don’t let them know I said that!). Seriously, they’re an amazing group of friends.
This episode was dedicated to our Field Day activities. For many of us, it was an unconventional Field Day and perhaps that’s what made the event so much fun.
John (W7DBO) was invited back to the show and it was great hearing how he integrated his whole family in his Field Day activities.
George had to operate from home, I operated from our condo/chalet here in Québec, and Vince from his very unique club setup in Alberta. Rob had a project that took priority on Field Day, and it’s worth listening to the podcast just to hear Smitty’s tale of life as a Field Day RVer (hint: not for the faint of heart).
I did finally choose that one extra radio: the Discovery TX-500.
I chose the TX-500 because 1.) it would be a great “bad weather” radio, 2.) it could operate from my KX2 battery packs, 3.) it’s multimode and also covers 6 meters, and 4.) it has such a slim profile. I could easily the TX-500 in my Tom Bihn Synapse 25 backpack with the Elecraft KX2 and it didn’t make the pack feel any bulkier.
I came very close to choosing the IC-705, but it was just a bit too bulky for the way I had my pack configured.
Back to the hypocrite part…
The day before leaving North Carolina, I removed everything from our Subaru and gave it a deep cleaning.
When I pulled up the floor panel in the trunk/boot area to check the first aid kit, spare tire, and emergency gear I discovered that there was a fairly large unused area under there–a spot where I might be able to sneak a few extra radio supplies.
After a little finagling, I discovered that I could fit spare batteries, two folding PowerFilm panels, the Buddipole PowerMini 2, and two more radios: the MTR-3B field kit, and my Elecraft KX1.
This essentially amounted to contraband since I tend to be the guy who enforces “one bag per person” policy during our family travels.
I got some serious eye rolls from the family when they discovered the hidden radios after we reached our destination. I might not ever live this down.
If I had even a shred of dignity upon our arrival here in Canada, I can confirm it’s gone now.
Elecraft KX2 getting heavy use
Other than Field Day where I primarily used the TX-500, the Elecraft KX2 has been getting a heavy workout on this trip.
The reason why is because I’ve been activating a number of urban parks where an all-in one radio paired with a random wire or the AX1 vertical has been very useful.
Conditions have been very rough during some of these activations as well, so it’s nice to have both CW and SSB modes available and a full 5 watts (the KX1 and MTR-3B are CW-only hover around 3 watts). I’ve snagged some excellent QRP DX at times, but everything has been so unstable.
I didn’t bring the KX2 hand mic on this trip, so all of my SSB contacts have utilized the KX2’s built-in mic. It’s actually worked brilliantly!
I’ve recorded a number of activations here in Canada and will likely post a couple of these out of chronological order while I’m still on this side of the border.
Uploading from our chalet hasn’t been possible–the upload speeds are about as dismal as they are at my QTH. Download isn’t too bad, though.
While at the hotel in Baie-Comeau a few days ago, I uploaded at least four videos with their high-speed internet, so I’ll soon post a couple of them.
In short: the activations here have been amazingly fun. Some of the sites have been truly spectacular in terms of scenery and others are in urban settings taking me well outside my comfort zone.
In short: I’ve loved every minute of it!
We have had an amazing time here in Québec as always.
Our flavor of travel is the opposite of many: we tend to rent a home or apartment for a few weeks or couple of months and use it as a base for exploring the region. We do this as opposed to traveling long distances and only spending relatively short periods of time at multiple stops.
I plan to activate a park while in Québec City today. I’ve no clue which one it’ll be yet, but I’ll announce it on the POTA site once I’ve got a plan together. If you have the time, look for me on the POTA spots page (as VY2SW) or via the RBN! I’d love to put you in the logs.
Here’s wishing all of you a week full of radio and fun!