Antenna Tuner Model 291


The Ten-Tec Model 291 is a "T" network tuner rated for 200 watts. Two series capacitors and a shunt inductor are used to transform the complex impedance at the feedline of the antenna to 50 ohms for the transmitter. No SWR or power metering is provided.

The two capacitors used in the 291 are 1000 volt 50-250 pF variables connected in series with a 47 tap rotary inductor (0.5-24 uh) shunted to ground. This tuner can be used with a single 50 ohm coax input and output, or has a wing-nut lug for use with end-fed longwire antennas. Extra capacitance can be added externally to the back panel for increasing the matching range if desired.

Earlier Version


  • RF POWER: 200 watts
  • INPUT IMPEDANCE: 50 to 75 ohms
  • OUTPUT IMPEDANCE: 10 to 350 ohms
  • REAR PANEL CONNECTIONS: Input, SO-239 Output, SO-239 and long wire terminal grounding bolt
  • INDUCTOR: 47 tap, 18 gauge silver plated wire on 2" diameter powdered iron toroid
  • FREQUENCY RANGE: 1.8 to 30 MHz
  • SIZE: HWD (in inches) 3 x 7 x 5.5 (7.6x17.8x13.8 cm)
  • WEIGHT: 3.5 lbs (1.6 kg)

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