My FT-891 has been retired from POTA service … why?

Following high level, wide-ranging, bilateral talks with senior management (XYL) a far-reaching, binding agreement was today handed down to me. The focus of the agreement is contained in the executive summary which reads: “ya got enough radios already”.

And it’s true

I own more radios than I really use. Nearly all of my radios are of the vintage variety. The sole exception is my QRP Labs QMX. The QMX is unique in that it is an SDR radio so it can be updated as needed. One day, perhaps, even the hardware will become obsolete although it is more likely to succumb to the fragility of its low-cost construction – or the indelicate treatment to which it is subjected in the rigorous outdoor environment where I like to operate.

Radios become obsolete quite quickly as technologies evolve. Many modern rigs incorporate what I like to call a “fish finder” – a waterfall display enabling an operator to “catch” another station with a simple tap on a touchscreen. Fantastic yes, but is it just “nice to have” or an essential convenience for modern operating?

Most of my own outdoor operations are related to POTA. Once out in the Big Blue Sky Shack, preferably far from the madding crowd, in a location accessible only via Shanks’ Pony (an old Scottish expression – “shanks” are legs), I set up my station, find an open frequency, call CQ and work the hunters until they quit coming. What level of technological sophistication does that require? Even a very basic, unsophisticated, boat anchor rig can accomplish that. Does it really require a “fish finder”? Well, a fish finder would be nice, but spinning the dial and listening up for active stations worked for many years. Wanna go high tech? Check the clusters on a mobile phone.

Technological advances can even be detrimental. Remember old tube rigs? They were robust (until the tubes needed replacing). Tube rig operators never had to obsess about SWR. High SWR in a modern radio can result in voltage peaks that can send delicate FET PA transistors to the semiconductor cemetery. Sure tubes (or “thermionic valves” as they are known in the Land of Hope and Glory) can be big and fragile. I remember, when I was a kid exploring the thrill of electromagnetrickery, I owned a receiver with tiny, wire-ended tubes. But this isn’t a post about boat anchor technology – no matter how our romanticized recollections of youth bring out fond memories of days gone by.

Back to the future

I bought my Yaesu FT-891 a few short years ago based on recommendations I read online. I wanted a radio that would pack a punch and make getting QSOs from a campsite almost a sure thing. I remember self-spotting on the POTA website with the comment “100 watts!”. I wanted to attract hunters who wouldn’t have to struggle to hear me. A hundred watts for a CW signal is equivalent to AM broadcast signal strength compared to SSB. Alright, I exaggerate, but it quickly occurred to me that a QRP CW signal into an efficient antenna would get the job done equally well. Since that time I have rarely strayed from QRP – or sometimes QROp (20 watts for a 1 S-unit signal boost) when conditions are bad.

The Yaesu FT-891 is an interesting radio. It’s compact format makes it easy to carry into the field, but also has a downside. Small radios bury most of their impressive set of features in layers of menus. And the FT-891 has an impressive set of features. Audio bandwidth can be set as wide as the mighty Mississippi or as tight as Scrooge’s purse strings. Zero beating the other station’s frequency can be accomplished in a single button press if the “ZIN” function is programmed to one of the A, B, C buttons on the front panel. Then pressing the <F> key repeatedly brings up another four layers of menus. These menus allow the operator to select and adjust other levels of IF filtering like “APF – Audio Peak Filter”, “CNT – Contour”, “SFT – IF shift”, “IPO – Intercept Point Optimization” and “NCH – Notch”.

Filters can get you into trouble

During one POTA activation I recall hearing a hunter respond to me, but his signal sounded like a series of atmospheric clicks. “What the heck is that?” I remember thinking. “Is he testing whether I can copy railroad code?” (I can’t). I set my RIT (Receiver Incremental Tuning) a little off frequency and suddenly his signal was perfectly clear. The problem was my filter was set too narrow. Responding to an activator a little away from zero beat is a technique often used to stand out in a pile-up; it works in SSB too. Since my filter was too narrow the hunter’s signal was just outside my passband. Some CW operators are able to use the filter between their ears to separate a signal in a busy band. It takes some concentration – more than I have.

Tis a gift to be simple

All those menus are such fun to play with while working a pile-up out in the back country with mosquitoes, deer flies and other winged pestilences trying to have lunch on the back of your neck. As you swing an arm wildly to crush the airborne assault your CW key crashes to the forest floor and the contacts fill with wet sand and soil turning dits and dahs into incomprehensible gibberish. The hunters have fled and you are back to sending CQ trying to entice them to return. Wouldn’t it be nice to have a simple radio instead?

It get’s worse

It’s fine and dandy reducing a QRO rig’s power to peanut level. On the FT-891 it’s a simple matter of holding the <F> key down for 2 seconds, rotating the Multifunction knob to select section 16 of the Mariana Trench level menus, then choosing which of the six HF power sub-menus to adjust. Then click the Multifunction knob again, rotate it to the desired power output, from 5 watts to 100 watts; click the <F> key again and in no time at all you’re all set.

But there’s still a problem. The FT-891, like many other QRO radios adjusted for low power, still sucks power out of your battery like a camel filling its hump before a trek across the desert. The FT-891 draws over 5 amps even when the output power is wound down to 5 watts. By contrast, the QMX and other QRP radios can run when powered by a tiny 9 volt alkaline battery.

Big eyes, small wallet

Twenty years ago I worked for a few months in a Toronto establishment known to local hams as “the candy store”. Every day I had every one of the big Japanese manufacturers radios to play with. The staff were encouraged to become familiar with all the radios on display so that we could offer expert advice to customers. My big wide eyes fell on one particular radio from Yaesu; it was the FT-897 – a radio that I began to covet but couldn’t afford to buy at that time. I left that employment to start my own business and after a while I had the funds to buy that rig.

The Yaesu FT-897 is a big and chunky, yet rugged looking QRO radio that was intended for use in the field. I used it as a base station radio instead and it served that purpose until quite recently. It is old-tech now but maybe that’s a bit of an advantage. You see, it is relatively simple compared to the later FT-891. The FT-897 was introduced before IF filtering was widely available to the low budget ham market. Instead it has audio frequency filtering – accessible from the front panel – that works remarkably well. I can narrow the CW receive bandwidth down to 60Hz (danger of missing calls), 120Hz or 240Hz very easily without diving deep into a menu system.

The FT-897 does not integrate very well with common programs like FLrig and FLdigi. Too few functions can be controlled with CAT commands – unlike the newer FT-891. So the momentous decision was made to switch the two radios. Who cares if it takes a lot of clicks, twiddles and turns to select a desired feature on the FT-891 if the clicks, twiddles and turns are replaced with on-screen slider controls? The FT-891 is now my shack radio and I am very happy with it in this role. My XYL is equally happy that we don’t have to have another full and frank discussion about my urge to deplete our retirement savings to buy yet another whizz-bang box of tricks that will only keep me happy until the next whizz-bang box appears.

And the old FT-897? Is that going to be my regular portable rig now? Sorry old fella, you’re still a little hungry on battery amps. Maybe field day, perhaps.

Help support HamRadioOutsidetheBox

No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please follow/subscribe using the link at the bottom of my home page, or like, comment (links at the bottom of each post), repost or share links to my posts on social media. If you would like to email me directly you will find my email address on my QRZ.com page. Thank you!

The following copyright notice applies to all content on this blog.

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

#amateurRadio #CW #FT891 #FT897 #OutdoorOps #POTA #QMX

KD5ZZU’s very elegant build of “Old Barebones” – a Z-match tuner

Back in October 2024 I wrote a post with the title “Old Barebones” – A QRP Z-match Builder Project. The project’s purpose was to construct a simplified version of the Norcal Z-match tuner (which I also owned) to use with my QRP Labs QMX transceiver. The Norcal tuner included some features that I simply did not need – such as balanced transmission line terminals, a simple LED SWR indicator and three switches (Balanced line/BNC, Tune/Operate, High/Low impedance). The schematic was copied from the Norcal tuner – a superb design that I didn’t think I could improve. The end result was a very simple device with three BNC connectors, a toroidal inductor and two polyvaricons, all packaged in a small Amazonian plastic enclosure. Alright, it is an ugly device mainly due to the inelegant knobs I chose to use. But it works very well indeed and has become my main QRP portable antenna matching unit. Heck, it cost me a big fat nothing to build thanks to my extensive junque box stocked from years spent hoarding miscellaneous bits and pieces. When I have finished twiddling the knobs I can always put my hat over it to hide its lack of elegance.

Then, out of the blue, I received an email from Mallory KD5ZZU who expressed an interest in building her own version of “Old Barebones”. Mallory queried whether the design would work on the high bands. I had only tested mine on 20m, 30m and 40m, so I hooked it up to my home 80m EFHW and my portable 13ft tripod vertical antennas to test whether a low SWR could be achieved with Old Barebones on 17m, 15m 12m and 10m. Fortunately Old Barebones did a splendid job on both antennas so Mallory took the plunge and built her own version.

Note: My 80m EFHW (End-Fed Half Wave) is used primarily on 80m but is also useful on 40m and 20m. Using a tuner to obtain a low SWR on the higher bands protects the radio from high SWR but does not imply that the antenna is useful on those bands.

Mallory experienced a hitch in the construction though. Her first build did not function as expected and she asked for ideas on what to look for to resolve the problem. It turned out to be the connections to the polyvaricons that were the problem. Polyvaricons often have several sets of vanes and multiple connection points. I had used a capacitance meter to identify the correct connections in my original build. Realizing this may be the problem, Mallory quickly identified the correct connections and got her tuner working. She wrote that she was able to achieve a nice low SWR on all bands from 20m to 10m with her 71ft EFRW and 9:1 unun. A great result.

But Mallory doesn’t need to cover her version of Old Barebones with a hat to disguise its appearance. It is a beautiful design built into a custom 3D printed case with 3D printed knobs and looks terrific.

If anyone else is interested in building this simple construction project Mallory has kindly provided links to an online source for the parts and the 3D print files:

• Polyvaricons: https://a.co/d/hOYgP2f
• Toroids: https://a.co/d/7mItRXw
• Magnet wire: https://a.co/d/ffqdHo9
• BNC posts: https://a.co/d/5mwLEVI

Here is a link to the 3D print design of the knobs:  https://www.thingiverse.com/thing:3035549/files

Here is a link to the file to 3D print; it’s a print profile (modification) from the original designer of a customizable enclosure box: https://makerworld.com/en/models/2002942-custom-enclosure-box#profileId-2400746

A note on the use of Old Barebones

I designed Old Barebones for use with my QRP Labs QMX transceiver which has a convenient “Tune SWR” feature that reduces the output power to 25% to reduce the stress of high SWR on its delicate finals during the tuning process. I have also used Old Barebones with my Yaesu FT-817 but I manually reduce the power to 1 watt or less during tuning. If using Old Barebones with any radio that does not have an SWR indicator I recommend incorporating an SWR indicator in the tuner circuit similar to the original Norcal BLT design.

Polyvaricons?

The word “polyvaricon” is presumably a contraction of “Polymer Variable Condenser” meaning a plastic enclosed variable capacitor using a plastic dielectric. It is believed to be the trademark of a Japanese company that manufactures these devices. But shouldn’t it be called a “polyvaricap”. I remember back in the dawn of my existence that capacitors were called “condensors” but that term disappeared a long time ago. Strange old world.

What is a Z-match?

“Antenna tuners” are often named after their topology. For example, an L-match comprises a series inductor or capacitor and a complementary parallel capacitor or inductor. The combination of inductor and capacitor forms an “L” shape. However, there is no immediately apparent “Z” shape to the components in a Z-match, so I presume the “Z” refers to impedance. Let me know in the comments if I am wrong.

Pros and Cons of the Z-match

From the GQRP organization in the UK:

Advantages of the Z-Match

• Matches balanced loads without the use of lossy baluns.
• Being a parallel resonant circuit, the Z-match can provide some band-pass filtering for your receiver and harmonic attenuation for your transmitter.
• A well-designed Z-match tuner has a high Q and is more efficient (less lossy) than other types of tuners.
• The fixed inductor simplifies construction (no switches or rollers needed).

Disadvantages of the Z-Match

• Tuning is usually very narrow and can be a bit touchy sometimes to tune up

Thanks again to Mallory KD5ZZU for sharing her build with Ham Radio Outside the Box and congratulations Mallory for turning my original inelegant build into something with class!

Help support HamRadioOutsidetheBox

No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please follow/subscribe using the link at the bottom of my home page, or like, comment (links at the bottom of each post), repost or share links to my posts on social media. If you would like to email me directly you will find my email address on my QRZ.com page. Thank you!

The following copyright notice applies to all content on this blog.

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

#AmateurRadio #OldBarebonesZMatch #QMX

The ultimate rebuild of an ancient Yaesu FT-817.

I think it was a couple of years ago now I ordered a QRP Labs QMX transceiver. It quickly, but temporarily, became my favorite radio for portable field operations. I have written before about why I believe the QMX is a mighty fine piece of miniaturized technology but is less suitable for the rigors of being operated in the kind of field operating environment to which I expose my radios. My QMX is the low-band version and I also miss the opportunity to explore the higher bands when propagation conditions permit.

What’s a poor Ham to do?

I could buy another QMX, but order the high band version this time. It would be a very modest investment, but would still require ruggedizing. Another downside is the long, long wait time betwixt ordering and receiving the tiny parcel from Turkey. I could also order a QMX+ which is a fine all HF band radio, but then what to do with the QMX low band? There is another solution.

The Paranoid Android

I recall a quote from the book “The Hitchhikers Guide to the Galaxy” by Douglas Adams in which the perenially depressed robot “Marvin the Paranoid Android” moans: “The first ten million years were the worst.” When I look at the front panel of my ancient Yaesu FT-817 non-ND version it kinda has a Marvin look about it. It has spent almost a quarter of a century waiting patiently in a drawer for the day when it might be called into action again. Many radios have come and gone during that time but – even though I had planned to sell it on many occasions – I still own it and it’s day to see the sunshine again has finally come.

Where are the features?

The non-ND version of the FT-817 is a barebones rig. I needed a CW memory keyer – it doesn’t have one. Activating a POTA park sometimes requires great patience and many, many CQs. My QMX at least has that covered. I also needed an audio filter. It used to be possible to buy a Collins mechanical filter but they are no longer made. My QMX also has that feature covered, but the FT-817 requires an external audio filter.

Failure is not an option

The FT-817 does have a higher level of ruggedness than the QMX. With a few extra precautionary measures it can be protected from the ingress of sand particles during a beach activation, or unexpected spray from waves on the shores of the Great Lakes. The QMX will not tolerate wide variations in DC supply voltage; the FT-817 has that covered. The QMX uses inexpensive but fragile PA transistors (mine have not succumbed to failure – yet). Well, the FT-817 also had fragile PA transistors in its early days and mine did indeed fail during a field deployment. The FT-817’s PA board is a small module that is easily replaced with the new upgraded module – as was mine.

I get by with a little help from my friends

The feature shortcomings of the FT-817 have been overcome with two “helper modules” assembled inside aluminum Hammond project enclosures. The front enclosure contains a K3NG Arduino nano based CW keyer and a very simple no-thrills set of 3D printed paddles. Well who really needs to spend $300 on a fancy set of paddles for a brief POTA exchange? These paddles get the job done FB. The same cannot be said about the fist that operates them!

The front panel controls are very simple. The paddles protrude through a cutout in the Hammond enclosure.

Beside the paddles is a knob. This knob is used to operate a rotary encoder inside. Clicking the knob operates the switch built into the rotary encoder and triggers the sending of a “CQ CQ POTA de VA3KOT VA3KOT k” stored message in the Arduino keyer.

Rotating the knob adjusts the speed of the CW over a wide range. I have found this to be a very useful feature. I usually send at 20wpm and receive responses that are slower and faster than my sending speed. With this prominent control front-and-center I can quickly adjust my sending speed to suit.

I built the K4ICY audio frequency filter module around a quad op-amp DIL chip. This is a very simple circuit that provides 2 or 4 stages of filtering to narrow the bandwidth of a received signal. Each stage contains identical components whose values are selected according the operator’s desired sidetone frequency. The whole module can be bypassed if required allowing an audio bandwidth wide enough to pass a crosstown bus sideways.

Both modules are rigidly secured to each other using two aluminum rails made from scrap material. I hoard scraps of metal, plastic and other materials – you just never know when you’re gonna need ’em.

The dimensions of the two modules provide an ample flat surface on which to mount the ancient, but revered, transceiver. I purchased some “peel & stick” Gorilla brand “Slipstick” gripper pads and applied four of them to the base of the FT-817. This is a genuinely useful product I recommend to any hambrewer. The radio has been secured to the top of the helper modules with two woodland zip ties made from thin cordage. These simple cord fasteners work just as well as plastic zip ties and can be easily undone for servicing the modules.

I purchased a box load of these Hammond enclosures at an auction many years ago. They have proved very useful. In another build, using the same enclosures configured in an identical manner, I was able to construct two battery modules each containing four 18650 Lithium Ion batteries in 4S1P configuration for powering another one of my ancient QRP transceivers.

This is not the first time I have revived my FT-817, but previous rebuilds were clumsy. It is one thing to put together multiple modules on the shack bench. Clumsy, cluttered, loose modules might work in a picnic-tables-on-the-air type activation. But would it work in a situation where there are no convenient surfaces to mount the equipment; where – at any moment – we might be politely asked to vacate the area by a hungry bear looking for a space to eat his lunch? This new build is a grab-and-go package that works in small, tight spaces – even on top of a rock in the backcountry – and that’s the kind of environment where I like to operate.

Help support HamRadioOutsidetheBox

No “tip-jar”, “buy me a coffee”, Patreon, or Amazon links here. I enjoy my hobby and I enjoy writing about it. If you would like to support this blog please follow/subscribe using the link at the bottom of my home page, or like, comment (links at the bottom of each post), repost or share links to my posts on social media. If you would like to email me directly you will find my email address on my QRZ.com page. Thank you!

The following copyright notice applies to all content on this blog.

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

#AmateurRadio #FT817 #OutdoorOps #POTA #QMX

Post 004: Finding My Frequency
Every ham remembers their first official contact. For me, it was the man who “pestered” me into the hobby: my husband. Being able to log him as my first-ever contact was a moment of immense pride. I got into this to share a hobby with him, and suddenly, we were finally on the air together.

With that first log entry, the floodgates opened.....

https://substack.com/@k1kig

#HamRadio #POTA #CW #QRP #QRPLabs #QMX #ArkansasHams #ParksOnTheAir