Hey, guys, I have managed to take a look at this old girl today. It is the first vibrator unit I have experienced. I recall Marcc giving a little advice on these a few days back about a 1KV cap. Is this cap usually in the vibrator or is it the one in the underside of the chassis. Comments welcome please.

The set seems to use a lot of 600V caps with a test voltage in the order of 2KVV. This looks like most of the c70's are these and inside the vibrator unit. It is shown as a separate item in AORSM's.

The outside foil caps will all have to go (paper), along with the electrolytics. Do check resistors as you go and watch the volts on the filaments.

The new NP caps will be 630VDC but I still tend to use "X" ; "X/Y" type line caps in the vibrator section. I do prefer axial caps but where they are on a socket, I sometimes use the red "Greencaps" & leave the leads longish for heat & you can often get them close to the chassis (wall), to reduce RF radiation effects.

I have never had a Mica cap of that style, in that set, fail.

There is an art to adjusting those air trimmers. They were supposed to be one of the most stable made.

Yes the Vibrator is seperate. Just seeing these caps with high test voltages started me thinking. I will do the vibrator up first as it looks in good shape but the wiring harness will be replaced.

One thing to watch with the vibrator units themselves. A lot had foam inside & out to dampen the noise. This was a Formaldehyde based foam and turns to dust. If it has done that inside the can then it invariably stops it from working and it has to be cleaned out.

Well guys this has all been successfully done. Out of the 5 valves would you believe that 3 were shot, one being the output valve and another being the oscillator. I have managed to be able to secure NOS spares of all of them so its not so bad.