The PTR is compatible with the Bridge12 bread-board for quasi-optical instrumentation. The bread-board is based on a 2.5 in. by 2.5 in. grid. It is commonly referred to as a 1 1/2 - 3 - 1 1/2 optic. This means, make sure that there are 2 empty cube positions between two refocusing mirrors.


To install the PTR:

  1. Slide the dowel pin into the clearance hole of the bread board
  2. Orient the PTR
  3. Lock the PTR position by fastening the 1/2-40 socket head screw

Optimizing the Position

The PTR, as all Bridge12 QO elements only have one degree of freedom (rotation about the dowl pin) to optimize the insertion loss or overall transmission loss of a QO system. To minimize transmission losses:

  1. Loosen the 1/4-20 socket head screw. Do not remove the screw from the bread board
  2. Monitor the transmitted power
  3. Rotate the PTR while maximizing the transmitted power


QO systems can have many individual configurations. In some systems it is easier to monitor the transmitted power, in others it is more convenient to monitor the reflected power. If you are not sure how to optimize the transmission losses in your QO system please contact Bridge12 Technologies, Inc. at


Do not touch the free-standing wire grid of the PTR. The grid is located at the front of the PTR. The grid is extremely fragile and can be easily destroyed by sharp objects (e.g. screw drivers).


The PTR is fully compatible with the Bridge12 QO bread board design. Bridge12 offers adapter plates if you are using a different bread board design. Please contact us at for more information.

Last modified September 27, 2022: First version of PTR documentation (abe48b9)