This auction is for one 2X multiplier board for the HP 5087A distribution amplifier. This board takes 5MHz as an input and outputs a 10MHz sine wave. The board is assembled as shown in the picture. This is similar to the HP 5087-60011 doubler board.

The multiplier board would normally reside in input slot B (picture shows it configured for slot A), getting it's input from the pre-amplifier output from slot A or directly from the BNC for slot B. It can also be configured to reside in input slot C and get it's input from the slot A or B output or directly from the slot C BNC input. There is no metal cover for this board, but it fits the original HP covers.

Solder bridge the A B C jumper pads as below :

The multiplier board has a comparator connected to the input that converts the 5MHz sine wave to a square wave for the multiplier IC. The multiplier output is buffered and fed to a four pole band pass filter followed by an output amplifier. The board output is 50 ohm transformer coupled but can drive a higher impedance load such as presented by the output amplifier boards. The output voltage is variable and is within the range provided by the original input amplifiers. The board is shipped with the output at 0dBm (630mV p-p into 50 ohms, 1.23V open circuit). If amplitude is increased too much, clipping will occur and higher levels of harmonics will be generated.

I also have a DIY divider (by 2,5, or 10) and a DIY output amplifier board that can support 10MHz, 5MHz, 1MHz and 500KHz by changing filter components. Both are currently available in other listings...