Took the chance to recal. the unit using better precision gear than specified in the manual.
Improved the 6Mhz reference accuracy to -0.06dBm vs -0.12dBm with the R270 & R280 amplitude adjustments. Given the several connections from the new SMA leveling heads (adapters & 10dB attenuator to an N type power head). I'd guess the 0.06dBm loss is to be expected at 6Mhz.
All reference power levels are about spot on from 1Vpp thru 5Vpp now with the 6Mhz freq. Sometimes a little glitch helps u improve your instrument!
At the frequencies 245Mhz to 700Mhz I am seeing at most a 0.15dBm loss at 4Vpp thru those connectors, sometimes a bit less (freq dependent). The new Leveling head stub tuning offsets/negates the connector loss (by compensating upward) at the hi end of the range (1Ghz). So from about 700 Khz to 1Ghz the connector losses steadily diminish to nil.
8D
Ancel