May 19, 2023 - LN vs LN+ Options

We will first identify that LN stands for “Low Noise,” i.e. further lowered phase noise parameters. The LN option achieves this by implementing a particular Model 100MHz oven controlled crystal oscillator (OCXO) onto the signal reference board. The LN+ option uses the same implementation, but with a different model OCXO with better long term precision specifications. This translates to higher precision over longer duration applications. The standard unit will see internal reference frequency degradation of up to 1000 ppb/year, while the LN and LN+ will see 30 and 20 ppb/year respectively. 

One will want to consider upgrading to the LN option when low phase noise and accurate signal is desired. Further consideration of the LN+ option is necessary for longer duration applications. BNC offers the LN and LN+ options in the Models 825, 855B, and 865B RF signal generators and in the Model 875 vector signal generator. 

What is the difference beween LN and LN+?

The key difference between the two is that LN+ has better long-term performance. Option LN adds a 100 MHz OCXO on the ref board, applying to all channels. LN+ adds a different Model 100 MHz OCXO with better long term stability. For short-term performance they are nearly identical, but for longer time applications the better Allan Variance of LN+ yields a more accurate result. One can incorporate either LN or LN+, the options are priced per unit and cannot be combined.