Re: SR2000 and P2000 restoration continues
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AFAIK, withstanding voltage has little to no affect on capacitance.? Capacitance is plate area vs dielectric thickness.? I have seen capacitors test within their capacitance tolerance but fail for withstanding voltage way below the rated value. If the dielectric reforms to a lower withstanding voltage, would not the dielectric be thinner?? A thinner dielectric would indicate a higher capacitance, would it not? Regards, Jim Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Saturday, May 4, 2024 at 12:47:32 PM CDT, W7WRX <clark@...> wrote:
Good point
This particular Dual section FT Germany cap is rated at 450 working voltage for 34,000 hours.? It states your allowed 500 volts 5 x a minute.? I think that is the standard greater than 315 volt x 1.1 spec for surge. I think I will install it
on a terminal strip. The can cap is dated 1967.??
These are floating voltages.? When keyed these of course all drop down.? I wouldn't let the rig sit on high for long periods of time anyways.? I run it on low 99 percent of the time.
C
C
On May 4, 2024 10:22 AM, "waltcates via groups.io" <cateswa@...> wrote:
One thing to remember about electrolytic capacitors; A capacitor rated at Xuf at Yvolts means that at at Yvolts it will react as a X value capacitor. The max voltage on the capacitor is another spec.
A capacitor that is run at less than its specified voltage will reform at the lower voltage and yield less capacitance.
Walt Cates, WD0GOF
?
A majority of acceptance is not proof of correctness.
From: [email protected] <[email protected]> on behalf of W7WRX <clark@...>
Sent: Saturday, May 4, 2024 12:01 PM To: [email protected] <[email protected]> Subject: [HallicraftersRadios] SR2000 and P2000 restoration continues ?
The SR2000 is working great now with thr offset fox in place.? ?Today was time to go through the P2000
The high voltage meter was reading way low.? I took the supply apart. Cleaned it, removed the meter bezel and adjusted the needles to zero. They where both below the lines Next I found the smaller of the two 2 Meg meter resistors was reading 7.5meg!? ?I replaced it and now the meter reads correctly. I used my fluke HV probe to find 2050 volts low and 2950 volts high.? I also found screen at 320 low and 426 high.? My line voltage is 126 today. The PS had been recapped but the can cap and the screen cap where factory.? I replaced the screen with a new 20mfd 500 volt sprauge.? I don't have the can cap.? I do have a 30/30 at 450 volt FT cap.? It's very high quality.? I have reservations about running 426 volts on a 450 cap though.? Maybe I get look at the data sheet.? Otherwise I will have to order 500volt caps. |
Jim Whartenby