[R-390] 5814A/ 6C4 tube placement

[Ed Zeranski]

Subject: [R-390] 5814A/ 6C4 tube placement


I have read that 6C4's can be very micro-phonic

Not sure how it relates to R390s but I had several brand new (NIB) 6C4s used
in osc ckts that had cathode/fil leakage causing noise under strong sig
conditions in Hammarlund communications receivers. Not mixer but osc
circuits in my HQ-170AVHF and the 6C4s were from new sticks of tubes.