[Milsurplus] vibrator repair, my experience

[Boeing377]

Dave S asked about non destructive repair methods for vibrators. I have a minimally destructive method.

My Dad's 2-3 MHz AM radio on our commercial fishing boat used a Mallory Vibrapack to get 12 VDC converted into 250 VDC for receive operation. It used a big dynamotor for xmit B+. Occasionally the vibrator would fail. It was always stuck contacts, never a burned out coil. I'd cut the can open carefully unstick and dress the contacts with a super fine contact file and carbon tetrachloride (remember that stuff?) and some GC contact lubricant. I used aluminum tape to seal the circumferential cut and it didn't look too bad. I found through experience that leaving the tip of a Q Tip lightly soaked in diesel fuel inside the resealed can prolonged the service life. It sounds like a mini-bomb recipe but apparently wasn't a serious fire hazard either, the fumes never ignited. 

We also smeared dielectric silicone grease over every connector on the boat. Where others had tarnish and corrosion probs on connectors we had NONE. Used it on Cannon plugs, boards, you name it. Messy but very effective. We bought DOW brand silicone stopcock grease as it was a lot cheaper then the same stuff labeled for electronic use. 

73
Mark
AF6IM