Abstract : During the past year, we have made progress on frequency shifting by means of plasmas. Theoretically we have demonstrated that a rising plasma density tends to slow down and trap microwaves passing through the plasma-filled region. This increases the interaction time, so that a very rapid rise in plasma density is not required to produce very high frequency shifts. A preliminary version has been submitted to the Transactions of Plasma Science, and more updated version is in progress. An attempt to provide frequency upshifts by use of multiple transverse arcs was attempted without the use of equalizing resistors. The plasma discharge was observed, and the frequency upshift was seen, as was expected but it was not as extensive as in previous systems. A more balance system is being developed.