On sunspots, amplifiers, and transceivers: An overview of the K-Line


Seeing the eclipse first-hand was amazing! I encourage everyone to get out there and see it in 2024 if you missed this one.

This adventure also reminded me of sunspots, or lack thereof. And where an amplifier can really make a difference. In this regard, our new KPA1500 would make a timely addition to anyone’s arsenal.

Of course the KPA1500 and KPA500/KAT500 will work with any transceiver. But I wanted to take a moment to explain why our other K-Line gear (K3S, K-Pod, P3, SP3) is still your best choice in complementing our amplifiers.


The K3S is truly an operator’s radio, in the classic sense. Virtually every control you depend on during focussed on-air use (DXing, contesting, etc.) is at hand in the form of a “hard” switch or knob, right where you need it. Some high-end radios depend on the use of a mouse and keyboard for basic control activation, or are almost entirely controlled by deep dives through a touch screen interface. These may not provide a satisfying ergonomic experience or adequate response time for the serious operator.

To mention some of the specifics, the K3S has dedicated 400-count optical encoders for both VFO A and B; a full set of message memory and user-programmable controls; and top-level (non-menu) controls for all common TX and RX settings as well as RIT/XIT/offset clear. There are also rear-panel jacks for headphones and mic, allowing you to keep the front panel area free of cables.

The K3S also has outstanding CW performance, unlike some radios that depend on networked interfaces or suffer from computational latency. Break-in is fast (up to 100 WPM in QRQ mode), transmitted keying bandwidth is the cleanest in the industry, and our sidetone uses ultra-smooth sigmoidal shaping (not a harsh square wave). It also has unbeatable receive dynamic range (20 dB better than the closest competitor on rejection of blocking signals). These attributes, along with outstanding diversity receive capability, make the K3S an obvious choice for who tackle the most difficult operating scenarios. Like, say, 160 meter CW contests.

Finally, the K3S’s full-stereo audio (AFX mode) can dramatically reduce operating fatigue. AFX creates a sense of space you just can’t get with a single audio channel.


You can extend the K3S's hard controls by one 400-count optical encoder and 16 switch functions by adding a K-Pod. The K-Pod allows you to create your own full set of new controls in the form of macros, allowing one-touch complex splits, etc. Many of our customers have created clever macros that they’ve shared on our forum. Those who do make frequent use of computer applications have told us that the K-Pod provides just the right level of instant manual controls to supplement their software use, minimizing effort during extended contesting.


Like the K3S, the P3 emphasizes hard controls to quickly assert settings you use frequently, such as specific scan widths, noise blanker or VFO B cursor on/off, pan/waterfall height selections, etc. There are 8 user-programmable functions you can adapt to suchrequirements. The P3’s display is also very fast, and very clean. We’ve heard comments from those using other high-end radios that their built-in displays often reflect evenly spaced spurs that result from inadequate shielding of DC-to-DC converters, etc. This can’t happen with the P3, which is separately shielded and is connected only to the analog IF of the radio.


Besides being a ruggedly built, aesthetic complement to the K-Line, the SP3 speaker has full-bodied sound and convenient source switching. You can use one SP3 with two radios, or use two SP3s with two radios when using stereo audio.

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If you have any questions about the new amplifier or any K-Line product, feel free to contact us.


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