We have an F1130, sn 2652, and the case is not marked A or B. How can I tell which model it is?
What is the difference between the A and B models? Is an upgrade available?
F1130
Difference Between F1130, F1130A, and F1130B
F1130 was TEGAM's first 7mm / N connector "wideband" 100kHz to 18GHz thermistor mount. This was introduced before NIST alerted the community to the "RF Leakage" problem, and no F1130 was shipped new with common-mode filters. Some F1130 have been upgraded to contain filters, and these had a sticker applied at that time that states that the unit has been upgraded to F1130A.
F1130A is a F1130 that was built new with a common-mode filter on the DC bias lines to reduce the impact of RF leaking into the bridge balancer on the DC bias lines. Other than those made by upgrading F1130, all F1130A are so labelled on the front-panel overlay.
F1130B uses the same internals and filters as F1130A, however these are packaged in a housing that uses the same mounting hardware as the TEGAM 1830A Power Meter, to facilitate easy rack-mounting of the mount and meter together. F1130B is labelled as such on the front panel.
It sounds as if the OP has an original F1130, without the common-mode filter. This unit could be upgraded to an F1130A by installation of the filter.
For reasons to consider upgrading, please refer to, viewtopic.php?f=7&t=11
F1130A is a F1130 that was built new with a common-mode filter on the DC bias lines to reduce the impact of RF leaking into the bridge balancer on the DC bias lines. Other than those made by upgrading F1130, all F1130A are so labelled on the front-panel overlay.
F1130B uses the same internals and filters as F1130A, however these are packaged in a housing that uses the same mounting hardware as the TEGAM 1830A Power Meter, to facilitate easy rack-mounting of the mount and meter together. F1130B is labelled as such on the front panel.
It sounds as if the OP has an original F1130, without the common-mode filter. This unit could be upgraded to an F1130A by installation of the filter.
For reasons to consider upgrading, please refer to, viewtopic.php?f=7&t=11