Impendance transformer

Genuine Red Pitaya 14:1 Impedance Transformer
Optimized for connecting HF antennas to the STEMlab 125 series

Steps up 50 ohm antennas and pre-amps to the high impedance inputs
Improves sensitivity and performance

Less than 1 dB insertion loss from 2-50 MHz

How to use

  • Place a jumper across pins 2 and 5 of each input to bypass the internal attenuators, then connect the transformer:


  • Gold-plated male and female SMA connectors
  • Shrink-wrap insulation
  • Small and compact, room for one on each of the two antenna inputs
  • Low insertion loss using a MiniCircuits® T14-1 wideband step-up RF transformer

What's Inside?

One example of Improved Performance

  • Using a passive antenna (VE3DO loop) with a Clifton Labs Z10042 11 dB Norton amplifier connected directly to Red Pitaya at N6TV, strong intermodulation from two nearby FM broadcast stations on 92.3 and 106.5 MHz was clearly visible (106.5 - 92.3 = 14.2 MHz):

Inserting the 14:1 transformer between the pre-amp and the Red Pitaya reduced the intermod significantly, and atmospheric band noise (wideband sensitivity) improved by about 4 dB: