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Assembly & Ops Manual
     (June 13, 2023)

QHB Article

Rainbow Tuner for 2023 ...
is the popular N2CX-designed resistive-type SWR bridge that displays the relative SWR by illuminating combinations of colorful LEDs. It handles up to 5W RF power and includes a tunable parallel resonant circuit ("ATU") using a tapped inductor that readily tunes an end-fed half wave antenna to cover 7.0-10.16 MHz. When assembled, pc board mounts nicely in an Altoids mint tin, included in the kit!

... designed in 2007 by the great Joe Everhart, N2CX




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The Rainbow Tuner doesn’t really tune rainbows, but it does use a rainbow of sorts to show the SWR of the antenna system connected to it. The "Rainbow" embodies the Spartan design philosophy exemplified by the 40-9er, the Pixie, the Fireball 40, the MRX-40, and many other simple QRP radios that have been available over the years. It combines a very special antenna tuner with a simple-to-use and accurate SWR meter. Intended to fit in popular mint tins, it can be built for about $30. The heart of the Rainbow Tuner is a colorful, user-friendly SWR indicator that can be used by itself or in other homebrew projects.


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Fine Print
Prices, availability and product specifications are subject to change at any time.
Customers accept all responsibilities for following safe and approved assembly practices and product usage.
Orders are typically shipped within 1-2 weeks due to order preparation.
All orders are acknowledged by email, usually within 24 hours.  If acknowledgement is not received, please contact N2APB directly.

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