Post by oldgeezer on Aug 3, 2019 10:06:16 GMT -5
If you own this CB, it is a great radio. The Cobra Cam 88 is very sensitive with regard to the 1st RF 6EA8 tube. The tube is not next to the crystals that make up the 23 channel synthesizer. It is on the same left side in the middle of the chassis across from the 12BA6 on the far left. GE or Sylvania 6EA8s are a disaster. They provide very low S units readings on the meter and just do not hear well. The best tube I tried is a 1950s Tung Sol with 1/2 a grey area on tube glass. It may have been made in the early 1960s too. That is one side has the grey glass coating about 3/8" high. Another more common tube that may perform well is a Mullard. I did not try it, but likely a winner. Never use a 6GH8 replacement as at times listed as 6EA8/6GH8 on the box. 6GH8 will not even work.
The Tung Sol 6EA8 took a zero S meter reading NOS Sylvania 6EA8 from a zero reading on the S meter up to 4 S units on the meter with no CBers transmitting and on channel 6 with a band opening had many signals at 10 to 20 over S9.