I am recapping a Philco 38-690. The reciever is done and it playes well, but the power chassis is still original, so I started recapping it today.

I have all caps done except fot the electrolytics. I am out of 8 and 10 mf caps. Can I sub a 22mf everywhere it calls for an 8 or 10(as I have a lot of 22's)?

I have all the smaller value caps, so they are not a problem.

Thanks,
Steve

:I am recapping a Philco 38-690. The reciever is done and it playes well, but the power chassis is still original, so I started recapping it today.
:
:I have all caps done except fot the electrolytics. I am out of 8 and 10 mf caps. Can I sub a 22mf everywhere it calls for an 8 or 10(as I have a lot of 22's)?
:
:I have all the smaller value caps, so they are not a problem.
:
:Thanks,
:Steve
:
Steve,

I have looked at the schematic and cannot find the voltage values of the E caps, can you post the voltage values?

I would not use a 22 Mfd cap to replace a 8 or 10 Mfd. The solution may be simple when we know the voltage values as these caps can be wired in series to lower the capacitance value of the 22's to meet the value of the other caps.

Again, need to know the voltage values of the E's.

Best regards,
Mitch

::I am recapping a Philco 38-690. The reciever is done and it playes well, but the power chassis is still original, so I started recapping it today.
::
::I have all caps done except fot the electrolytics. I am out of 8 and 10 mf caps. Can I sub a 22mf everywhere it calls for an 8 or 10(as I have a lot of 22's)?
::
::I have all the smaller value caps, so they are not a problem.
::
::Thanks,
::Steve
::
:Steve,
:
:I have looked at the schematic and cannot find the voltage values of the E caps, can you post the voltage values?
:
:I would not use a 22 Mfd cap to replace a 8 or 10 Mfd. The solution may be simple when we know the voltage values as these caps can be wired in series to lower the capacitance value of the 22's to meet the value of the other caps.
:
:Again, need to know the voltage values of the E's.
:
:Best regards,
:Mitch
:
Steve,
Congratulations on having the 20 tube "Mo-daddy" of all Philco's ever made. Since this is the best radio Philco ever made, only about 3,000 manufactured, I personally would stick with the original values for proper restoration. The 690 uses 5X4G rectifiers which are rated the same as 5U4's. On a capacitor input filter system like the 690 the maximum the capacitance can be is 40 ufd without circuit modification. However, I would order the correct values and install no more than 10 ufd for the 8ufd and 16 ufd for the 12 ufd.
John

:Steve,
:Congratulations on having the 20 tube "Mo-daddy" of all Philco's ever made. Since this is the best radio Philco ever made, only about 3,000 manufactured, I personally would stick with the original values for proper restoration. The 690 uses 5X4G rectifiers which are rated the same as 5U4's. On a capacitor input filter system like the 690 the maximum the capacitance can be is 40 ufd without circuit modification. However, I would order the correct values and install no more than 10 ufd for the 8ufd and 16 ufd for the 12 ufd.
:John
:

I've looked at 3 tube data charts and they indicate 4uf up to 10uf as the 1st cap after the rectifier in a "capacitor input filter" system
Going up to 40uf or better requires input resistance to change the plate impedance.

So it's safe not to exceed 4-10uf.
If all you have is 22uf caps rated @ 450vdc.. you can connect two 22uf caps in series (plus to minus to plus) which will give you a relatively-safe 12uf @ 900vdc

But I'd stick with less than 10 for the 1st cap and the 2nd cap can be anything larger like 22us or whatever.

:
::Steve,
::Congratulations on having the 20 tube "Mo-daddy" of all Philco's ever made. Since this is the best radio Philco ever made, only about 3,000 manufactured, I personally would stick with the original values for proper restoration. The 690 uses 5X4G rectifiers which are rated the same as 5U4's. On a capacitor input filter system like the 690 the maximum the capacitance can be is 40 ufd without circuit modification. However, I would order the correct values and install no more than 10 ufd for the 8ufd and 16 ufd for the 12 ufd.
::John
::
:
:I've looked at 3 tube data charts and they indicate 4uf up to 10uf as the 1st cap after the rectifier in a "capacitor input filter" system
:Going up to 40uf or better requires input resistance to change the plate impedance.
:
:So it's safe not to exceed 4-10uf.
:If all you have is 22uf caps rated @ 450vdc.. you can connect two 22uf caps in series (plus to minus to plus) which will give you a relatively-safe 12uf @ 900vdc
:
:But I'd stick with less than 10 for the 1st cap and the 2nd cap can be anything larger like 22us or whatever.
:
Thanks. I did find some 10mf caps so I used them in the input side and the remaining two I was missing I used after that stage. I'll reorder and replace them next week. For now it is playing great.