[Radio Wrangler]

The base of the teledyne relay is a ferrous disc with holes for the wires, so it looks like a multi-hole magnetic bead. it introduces series inductance and also series loss.

A colleague, Ian Matthews devised a compensation scheme to use them to 200MHz and above. One trip through the relay looks like 1.4 Ohms resistive plus I've forgotten how many nanohenries. He added shunt resistance and capacitance at each contact connection so the loss resistance became the series part of a low attenuation Pi attenuator section while the L term and the two shunt Cs added created a lowpass section. This improved flatness and return loss at the price of base attenuation and the rate of the eventual roll-off.

I later did an attenuator with Takemasawa or Midtex DIL relays where milled screening around each relay created distributed shunt-C to make the loops up to the contacts and back into 50 Ohm transmission lines.

At one time Teledyne's West coast facility burned down and its East coast facility got flattened by a hurricane. The US government responded by sequestering all stocks for their military whizz-bangs and oooh-narsties. Customers like HP were left to find alternatives as best they could.

David