03-01-2012, 07:02 PM
Hello,
After chewing on this for a while, I decided to search for the AR88D manual online. Lo and behold, I came across the schematics for the original AR88 plus its descendants. The original AR88 did not use the bleeder resistors. The descendants did use them. I will bet the field technicians complained until they were added to the later versions. The resistor's combined value was chosen to provide a fairly long RC time constant. This would gently discharge the three electrolytic filters (smoothers). If you replace them, keep their total ohmic value at approimately 1M Ohm.
Question: Why are there two 560K Ohm resistors in series rather than one 1.1M Ohm?
Answer #1: RCA had a ton of them in stock.
Answer #2: The brother-in-law effect. David Sarnoff's brother-in-law made 560K Ohm resistors.
AR88 Full Wave Rectifier Circuit w/o Bleeder
After chewing on this for a while, I decided to search for the AR88D manual online. Lo and behold, I came across the schematics for the original AR88 plus its descendants. The original AR88 did not use the bleeder resistors. The descendants did use them. I will bet the field technicians complained until they were added to the later versions. The resistor's combined value was chosen to provide a fairly long RC time constant. This would gently discharge the three electrolytic filters (smoothers). If you replace them, keep their total ohmic value at approimately 1M Ohm.
Question: Why are there two 560K Ohm resistors in series rather than one 1.1M Ohm?
Answer #1: RCA had a ton of them in stock.
Answer #2: The brother-in-law effect. David Sarnoff's brother-in-law made 560K Ohm resistors.
AR88 Full Wave Rectifier Circuit w/o Bleeder
