Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 89 bypass capacitor voltage
#1

I'm working on a Philco 89 (code 123) and I'm ready to replace the 5 bypass capacitors in the metal can under the chassis (part no. 4). They are .05,.05,.09,.09 and .25 uF.

I have some capacitors of those approx values rated at 200V. Can I get away with that voltage? or do I need to get capacitors with a higher voltage?
Thanks,
Mark Icon_problem
#2

Yes and no Icon_smile For #4 and #39 200v would suffice but for the other three you really should use 400v or higher.
#3

Thanks for the help.
One more question, if I may, at the risk of showing my electronic ignorance....
There is a bakelite cap block no. 17 which has two 0.09 caps in it. One is labeled 17 on the circuit diagram while the other is labeled 29. It is unclear to me if I can use my 0.1uF, 200V capacitors to rebuild that block??
Thanks,
Mark
#4

Yes, on both caps. There's minimal voltage on both of those. Without doing math its probably about 20 volts or so. And 0.1 is fine to replace 0.09. Philco did some funny things like noting "99k" resistors instead of 100k because of poor factory lighting. I suspect that their choice of "0.09" was intended to mitigate reading errors between 0.1 and 0.01
#5

Thank you exray. I can continue with my rebuilding now.
Mark
#6

Hi again, Mark.

Next time buy all 630v caps and this will never again be a question! A few cents more but at the price for shipping when you only need onesie-twosies you'll be better off in the long run.
#7

exray Wrote:Hi again, Mark.

Next time buy all 630v caps and this will never again be a question! A few cents more but at the price for shipping when you only need onesie-twosies you'll be better off in the long run.

That's good advice and what I usually do. I happened to run out of my 630V caps and was scrounging through my supplies when I found a bunch of 200V and 250V caps.
That's what prompted the questions along with my limited knowledge of electronics.




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Philco Model 80 Transformer resistance
The DC resistance of the primary is 8 to 9 Ohm.morzh — 07:54 PM
Philco Model 80 Transformer resistance
I have a feeling the primary winding on the power transformer is bad. My resistance reading on the primary side is 9 ohm...Mike L — 07:48 PM
Rusty Tuning Condenser
I would try Naval Jelly and use a soaked pipe cleaner to get it where it needs to go.RossH — 06:56 PM
38-10T chassis Restoration begins
Hello Dconant , they sold mica to use as a insulator between transistors and their heatsinks too. Rob I will remove th...radiorich — 02:52 PM
38-10T chassis Restoration begins
Thanks for the info guys. I always wondered why the use of mica. Now I know.dconant — 01:52 PM
38-10T chassis Restoration begins
Most common plastics have a dielectric constant in the 3-4 range whereas mica is around 6. This means that even if you w...Steve D — 01:46 PM
38-10T chassis Restoration begins
It is acceptable but not desirable. Plastic is not an approved cap dielectric, and even though a reasonably thick piece...morzh — 11:52 AM
38-10T chassis Restoration begins
I have a question about the mica sheets. I thought I saw somewhere on the Phorum where someone used thin plastic report ...dconant — 10:44 AM
38-10T chassis Restoration begins
Yes, you should carefully remove the mica sheets from the trimmers otherwise you risk trapping foreign material in the t...RodB — 10:34 AM
American Bosch Model 802 auto radio
Hi Joe, Thank you again. The American Bosch Model 634A has the same tube lineup as my Model 802 and the parts layout dia...Antipodal — 03:09 AM

[-]
Who's Online
There are currently no members online.

>