I've had a hankering to build something lately and happened across a relatively new offering from the 4 States QRP Group: the Hilltopper Tallboy, a monoband QRP CW transceiver kit.
Available for 15 to 40 meters (and maybe 60m soon), I ordered a 20m version. It arrived 5 or 6 days later and I started building it right away.
The Build
The kit's contents were well organized as were the accompanying instruction.
Parts are sorted into one of 10 bags and the assembly follows the bag's numerical sequence. There are exceptions to this as parts are sometimes required from the ESD bag or the bag containing the matched crystals.
The largest bag - and the one responsible for my initial impression of "Man, that's a substantial kit!" - is the one containing the mechanical components: knobs, jacks, hardware, etc.
A printed inventory of parts accompanies the kit. The assembly manual is online and is updated as need be. I did find a couple of typos that had me scratching my head for a minute common sense kicked in belatedly and I was able to see what was intended. That typo is being corrected as we speak.
And finally, the case itself which is made of circuit board material, precisely cut in order to result in an interlocked series of 6 panels, all soldered together at strategic points, making a solid and very rigid housing.
There are two SMD components, both of which are pre-installed. There are only three toroids to wind.
Total time to stuff the board was about 5 hours over three evenings. A lot of the very tiny caps, whose values would be hard to read, had their values annotated in large print by some kind soul at 4SQRP. Very helpful - thank you!
For the very tiny print on caps so not annotated, I simply used my smartphone's camera to zoom in. Good lighting is a must, both for that process and for the build itself.
There is ample room on the circuit board; the parts aren't crowded together. I think a first-time kit-builder could assemble a Tallboy as long as they had some prior solder practice and could pay attention to printed instructions.
Calibration & On The Air
The 2-step cal procedure is simple and no test equipment is needed other than your Big Rig. If you have one, a tinySA can be used in 'signal generator' mode. I did it both ways, just to verify results.
Also useful for the alignment would be one of the many audio spectrum analyzer apps for smartphones. I recommend Spectroid for Android users.
With the dummy load on the output of my WM-2 wattmeter I read about 8 watts out, however my DC input voltage to the rig was 14.2V - a bit over the 12-13.8 called for in the manual. So let's consider it a full QRP gallon at specified voltage.
The rig first comes up in Iambic-A keying mode if using paddles. This caused a few mis-keys on my part until I realized I was not in the more common Iambic-B. Once I switched to B, all was good. QSK is great - no thumping at all. And once the rig is changed to Iambic-B, it stays that way - no need to do it every time you power up the rig.
The rig is easy to tune around by tapping the tuning know (which is also a button) to change the digit that is tuned when turning the knob. Tapping the 'Function' button causes the radio to annunciate the frequency of the 10kHz, 1kHz and 100Hz digits in Morse Code.
In other words, for a frequency of 14050.20 displayed, the Morse for 05R2 would be sent.
Time to get on the air.
I tuned around and heard a fair number of stations on 20m CW, mostly POTA activators. I called the strongest one and was answered immediately. Thanks to Jeff KE8NJW for being First Contact with the new Tallboy. Second was Alan W2AEW, also activating a park.
I like having a front-panel speed control for the built-in keyer. Turning it all the way CCW put the rig in straight key mode, useful for making power out measurements or adjusting an ATU.
What I Don't Like
The manual for the Tallboy states that its bandwidth is 400Hz at the -3dB points. This is probably true, but it doesn't mean that the BW is 400Hz as we are used to perceiving that value. Usually, bandwidth measurements are taken at -6 and -60 dB points. This defines the bandwidth and shape of the skirt.
400Hz at -6dB and -60dB is going to sound very different (with much better selectivity) than 400 Hz at -3dB. I don't know what the actual BW of the Tallboy is but it is much wider than "400Hz" would lead one to believe.
It is also asymmetrical. Tuning up from a station gives the impression of a good, tight filter. But tuning down is where the broadbandedness manifests itself.
As a practical example, a station that was S7 on my main rig could be heard on the Tallboy over a 1600Hz range of the VFO when tuning down from the station; 300Hz when tuning upward. This is not a 400Hz bandwidth!
Summary
The radio was fun and easy to build, thanks to the level of detail that went into its packaging and documentation. The way the case goes together must have taken several iterations to "get it right" but they got it right and it is a thing to behold.
I think the Tallboy would make a great group or club project. Builders - even new ones - would end up with a good transceiver for park activations or casual operation on the band of their choice. Unlike some kits out there, the construction of this radio is not at all intimidating.
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