[Johnson] Thunderbolt problem

[John Lyles]

A friend just got a Thunderbolt and was testing it, and hearing HV breakdowns. Unfortunately, he ignored them until the big one got him. It appears that the multimeter got changed, in that the meter movement is no longer a mA but needs like 10 mA to get full scale. So the calibration is off by a large amount. He said that the sparks would occur only when he switched on the HV power. This sounded like a slight overshoot on the HV, and a marginal component or insulation somewhere. Anyway, after finding the breakdown, he will need a new meter or a repair of his. I suspected that the high peak current (of the 8 uF charged capacitor) was dumping through the plate current meter (which is a high current movement) as well as the HV meter/grid meter to get to ground in the HV position. Any advice here? Anyone got a parts unit that they'd be willing to sell the meter out of? 

73
John 
K5PRO