Hello and thank anyone for responding to my issue. I have a Zenith a.m. model 6D015 that wont seem to respond so I purchased another one like it for 10.00 on a website that sells estate merchandise. Its the same chasis and wiring, but a newer model. Instead of a wooden case its plastic. The wiring is the why I'm here.
It looks like it was repaired during its original life and rewired to include a hycap with a 20uf capacitance and working DC voltage of 150 volts.
All resistors and caps were replaced with minor speaker repairs and heater wires replaced. Once I plugged it in to the dim bulb tester and waited two minutes Rush Limbaugh came in loud and clear. No adjustments to the IF cans were needed.
Given this success Id like to rewire the Zenith my wife found in her mothers basement some years back. The one that doesn't even hum regardless of a shotgun attempt to get it running.
The question is the hycap. It is a tubular axial lead paper covered monstrosity with thick wires connected by rivets. It is not on the schematic. Is it electrolytic? Is it full of PCB's? Can I use a non electrolytic polyester cap to replace it, or is their a special hy cap available?

I was going to include the steps needed to convert an AC/DC hot chassis to cold, but I used too much space as it is.

If the cap in question is really 20 uF, it most likely is electrolytic. A non-electrolytic cap of that value (and presumptive age) would be about as large as a one-pound box of butter.

Another clue is if the "hycap" (whatever that is) has polarity markings on both of its terminals. If it does, it almost certainly is electrolytic.

Oil-filled caps often used PCBs but use of these compounds was phased out by the late 1970s.

Try to determine where the "hycap" is attached on the schematic. That will help you figure out why it was added. My guess is that it was installed to replace a failed section of the electrolytic filter cap.

:If the cap in question is really 20 uF, it most likely is electrolytic. A non-electrolytic cap of that value (and presumptive age) would be about as large as a one-pound box of butter.
:
:Another clue is if the "hycap" (whatever that is) has polarity markings on both of its terminals. If it does, it almost certainly is electrolytic.
:
:Oil-filled caps often used PCBs but use of these compounds was phased out by the late 1970s.
:
:Try to determine where the "hycap" is attached on the schematic. That will help you figure out why it was added. My guess is that it was installed to replace a failed section of the electrolytic filter cap.
:
Thanks for the response. It is an oil based electrolytic that replaced a bad 20uf 150 volt electrolytic tied to the can. I should have seen it given the value and the tie in from the 20uf electrolytic can lug to pin 4 on the 35LG to pin 8 on 12SQ7. What fooled me was that the bad can capacitor lug was not removed. Why did this not effect the sound?

::If the cap in question is really 20 uF, it most likely is electrolytic. A non-electrolytic cap of that value (and presumptive age) would be about as large as a one-pound box of butter.
::
::Another clue is if the "hycap" (whatever that is) has polarity markings on both of its terminals. If it does, it almost certainly is electrolytic.
::
::Oil-filled caps often used PCBs but use of these compounds was phased out by the late 1970s.
::
::Try to determine where the "hycap" is attached on the schematic. That will help you figure out why it was added. My guess is that it was installed to replace a failed section of the electrolytic filter cap.
::
:Thanks for the response. It is an oil based electrolytic that replaced a bad 20uf 150 volt electrolytic tied to the can. I should have seen it given the value and the tie in from the 20uf electrolytic can lug to pin 4 on the 35LG to pin 8 on 12SQ7. What fooled me was that the bad can capacitor lug was not removed. Why did this not effect the sound?
:Also, their were not polarity markings. The word positive and negative are typed onto the capacitor. The mold was covering them up.

"Also, their were not polarity markings. The word positive and negative are typed onto the capacitor. The mold was covering them up."
:
:
I'd consider the words "positive" and "negative" also to be "polarity markings". Non-electrolytic axial-leaded caps either have no markings (text or symbols) at all, or are marked on one end to indicate the lead that connects to the outermost foil layer (which typically is connected to chassis ground to facilitate- at least notionally- achieve maximum electrostatic shielding.

:::If the cap in question is really 20 uF, it most likely is electrolytic. A non-electrolytic cap of that value (and presumptive age) would be about as large as a one-pound box of butter.
:::
:::Another clue is if the "hycap" (whatever that is) has polarity markings on both of its terminals. If it does, it almost certainly is electrolytic.
:::
:::Oil-filled caps often used PCBs but use of these compounds was phased out by the late 1970s.
:::
:::Try to determine where the "hycap" is attached on the schematic. That will help you figure out why it was added. My guess is that it was installed to replace a failed section of the electrolytic filter cap.
:::
::Thanks for the response. It is an oil based electrolytic that replaced a bad 20uf 150 volt electrolytic tied to the can. I should have seen it given the value and the tie in from the 20uf electrolytic can lug to pin 4 on the 35LG to pin 8 on 12SQ7. What fooled me was that the bad can capacitor lug was not removed. Why did this not effect the sound?
::Also, their were not polarity markings. The word positive and negative are typed onto the capacitor. The mold was covering them up.
:
:I meant to say the words positive and negative were covered in mold. What I thought was mold were actually PCB's. It made reading the label a little difficult. This cap was handled with tools, not fingers.

...What fooled me was that the bad can capacitor lug was not removed. Why did this not effect the sound?
:

Electrolytics have two normal-operation failure modes: (1) loss of capacity due to drying out of the wet electrolyte, or chemical decomp; or (2) shorting due to "punch through" from one plate to another. Failure mode #1 is more common than #2. Whoever repaired the set just soldered on a "helper" cap to the defunct original cap. This is bad repair practice because the original cap, being still wired into the circuit, could still eventually fail "shorted". It's fine to leave the old cap in place for cosmetic reasons, but its positive terminal(s) must be totally disconnected from the circuit.

:
:...What fooled me was that the bad can capacitor lug was not removed. Why did this not effect the sound?
::
:
:Electrolytics have two normal-operation failure modes: (1) loss of capacity due to drying out of the wet electrolyte, or chemical decomp; or (2) shorting due to "punch through" from one plate to another. Failure mode #1 is more common than #2. Whoever repaired the set just soldered on a "helper" cap to the defunct original cap. This is bad repair practice because the original cap, being still wired into the circuit, could still eventually fail "shorted". It's fine to leave the old cap in place for cosmetic reasons, but its positive terminal(s) must be totally disconnected from the circuit.
:
Thank you for the details. What complicates the issue is the oil cap tied directly from one tube to the next, compensating for the bad electrolytic. It was tied to a bad section of a multi-layered can capacitor. The down and dirty repair still allowed the radio to function to the point where the AC power lines on the plug up to the chassis were exposed to the point of being ridiculous. This radio was used and abused.

Is it possible to jumper all the electrolytic from instead of tying the grounds?