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Title: Rectifier plate caps?? Post by: AG5UM on January 26, 2020, 01:52:45 PM I have a Hallicrafters S-40B reciever I rebuilt a couple of years ago, no problems-works great.
Question.... the chassis looked original-wax caps etc...However it had two Mallory (.004 mfd.), 1600 volt, paper wax capacitors, one from each plate directly to ground,on the 5Y3 rectifier tube. This is not on the original Hallicrafters schematic. they looked "original", was this a 1950's modification?? I suppose it was done for noise suppression, keep RF out of the supply,etc.??? I replaced them with new 1600 volt orange drops, just to see, they've been in there a couple of years now. Also... I fully tested the old mallory wax caps for Insulation resistance/leakage, capacitance etc.. and to my surprise.. they test perfect, still good! Is this a common modification? could it have been original? what was it for? AG5UM Title: Re: Rectifier plate caps?? Post by: AG5UM on January 27, 2020, 07:51:12 PM Anyone seen this done before? Is this a common mod ? or should I remove them? AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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