Important to know when calibrating a tuner using a frequency sweep

June 12, 2024

Tuner Calibration

Symptoms / Solutions:

When calibrating a tuner for many Fo frequencies, to save time the user can perform less calibrations and save time, by calibrating the tuner for a frequency sweep and splitting the calibration later.

When calibrating a TC (twin carriage) tuner, such as a CCMT-606-HR, there are some limitations on the tuner calibration frequency list if the user will be splitting the calibration later to use each frequency as a fundamental one (Fo).

The TC tuners have what we call a crossover frequency (Xfreq). We use two different internal mechanisms to cover the full frequency range.

The crossover frequency changes slightly per tuner, however the XFreq is on the front of the tuner at the base along with the limits. It is also in the tuner properties stored in FDCS. You need to calibrate the tuner such that the frequency list does not cross this division.

For example, if the XFreq is 1.8 GHZ, then you can create two frequency lists from

  • 0.6 GHz to 1.7999 GHz
  • 1.8 GHz to 6 GHz

The software does not prevent users from purposely crossing the Xfreq during the calibration as there are some situations where this makes sense: if the user will not be splitting the calibration, for example a frequency sweep of Fo, 2Fo and 3Fo (1GHz, 2GHz, 3GHz).


Keywords: Tuner calibration, splitting calibration, crossover frequency

Last date modified:  3-Nov-2017