On the far right are the input connectors, followed by the front-end switches. These switches allow the input to be bypassed to either the main output or an auxiliary output, and allows the main output to be connected to an auxiliary input.
The switches on both the left and right of the filters (in the centre), switch the signal to one of the twelve filters. All of the filters are from K&L Microwave, with the designator “X” in the part number indicating that they are a special model, most likely made for HP. Interestingly, all of the filters have the serial number of “2”, indicating that this was most likely a very early build.
The two largest filters, numbers #11 and #12, are low-pass filters of the 6LL10 model line, and the remainder of the filters are tubular low-pass filters of the 10L250 model line.
At a future point, we’ll hook this unit up to the VNA and sweep each of the filter paths to characterize the transmission and reflection characteristics.
Module Resources
No manuals for this unit could be located.
