WB2CPN Sudden recall: The Air Associates VHF, (could have been for ARINC), was the BC-201 receiver and the BC-797 transmitter. Both used dry air pressurized simi-rigid coax. I saw them in many AF control towers 1946 and after. Used 829 or 832's in transmitter. Receiver had a real relay squelch. A BK-35 it was. 73 Clete Still looking for RC-81 info.