This Antenna Tuner was designed with the popular Jackson Bros. 5250-1-365 single gang 365 pF variable capacitor. Please make sure you can get one because one is no longer supplied with this kit. A possible source is www.midnightscience.com/catalog5.html#part2. Other capacitance values such as 410pF or 518pF or wiring two smaller gangs in parallel will make small changes to the calibration.
  Cambridge Kits
Antenna Tuner
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BOOST DX and reduce interference, IDEAL for HF150 etc or 10 W TX. 100kHz - 30 MHz in 6 overlapping ranges, BANDPASS design, not just usual highpass. DETECTOR output, connect voltmeter for free WAVEMETER, field strength meter etc. SO239 socket for receiver, single pole 3 mm for antenna and ground, 2.5 mm for detector. HIGH Q coils and air dielectric capacitor, 4 x 7 x 14 cm, 350 g.

"certainly improved reception ... signals easily peaked up", Practical Wireless.
"performance outstanding", PJO'N in New Zealand.
"efficient and effective for DX reception ... small size", PB in Notts.
"effective with a short antenna at low frequencies ... gives excellent results", Practical Wireless.

The kit includes all parts (except 365 pF variable capacitor, Jackson 5250-1-365 ), screws, wire etc, pre-wound coils, and the detailed assembly and operating instructions include a circuit diagram and description.