jb12

[1skywalker]

Was digging through the radio closet and found a jb 12 "didn't remember i had one". Well it works fine for about 20 minutes then it will not un-key. I have to switch it to standby to get it un-keyed. Its the older two tube type, one for keying and one for output. Is this a sign of a weak keying tube or maby a relay problem? The swr's are fine

[rev ike]

it sounds like a tuning issue you may need the black cat input tuning instructions to make the circuits work well .... i dont know how familiar you are with running this / its a modulator
key low /swing high