IC-7410 tests – 03 – Noise Figure

An article in a series documenting measurements on an IC-7410.

This focuses on receiver Noise Figure.

Noise Figure is simply the ratio of So/No to Si/Ni usually expressed in dB. It has the advantage of being independent of receiver bandwidth (Duffy 2013).

The Noise Figure was calculated from measurements using a RFD-2305 calibrated noise source using the Y Factor method. NFM software (Duffy 2007) was used to perform high resolution measurements of noise with the source OFF and ON.

IC-7410-NFM

The calculated Noise Figure is 5.9dB.

The Effective Noise Bandwidth of the nominal 2400Hz soft filter was measured to be 2040Hz (Duffy 2009). The IC-7410 specifications state a sensitivity of 0.16µV for 10dB S/N with that filter, from which an expected Noise Figure can be calculated (Duffy 2006) to be 8.0dB. The receiver exceeds specification by just over 2dB.

 References

  • Duffy, O. 2004. Noise Figure Y factor method calculator. VK1OD.net (offline).
  • ———. 2006. Receiver sensitivity metric converter. VK1OD.net (offline).
  • ———. 2007. Noise Figure Meter. http://owenduffy.net/software/nfm/index.htm.
  • ———. 2009. Measuring receiver bandwidth. VK1OD.net (offline).
  • ———. 2013. Noise and Receivers. VK1OD.net (offline).