In my quest to recap this unit, I have discovered the following and don't have a clue: 1. the schematic shows 33 caps, I count only 22 with 1 multisection tubular. 2. How do I determine the values of the multisection? It is connected between 25Z6GT, BK42B, & 25L6. 3. on the shcematic some caps values are given some are not. Is mfd assumed? i.e. C24-.005 = .005mfd? 4. Do I need to figure the max working voltage for each cap, or can I just use say 400 volt to be safe?
Thanks again!

Hi Rod

If a cap value is given on a schematic and is less than 1 mfd, it will be considered in mfd. If 1 or larger and not marked, the value is in mmf (pf).

It is very important to change capacitors, C6 (30mfd), C7 (30mfd), C16 (50mfd) and C28 (10mfd). These are electrolytic filter caps and will dry out causing hum and they could damage other components in the radio. Be very careful to watch polarity of the filter caps. On your schematic, the short line indicates + .

Don't worry about the exact capacitor count. Some are within the IF Transformer cans, others may not look like caps. Where are the caps on the schematic that are missing values?

Use 400 or 600 volt units for all caps except eletrolytic filters. Electrolytics must be equal to or higher voltage rated than the originals. Since your radio uses a voltage doubler circuit, I would use filter caps rated at 300 volts or more.

You mentioned the lamp burns out. Check the resistance of both sections of the ballast tube, BK42B.

Norm

: In my quest to recap this unit, I have discovered the following and don't have a clue: 1. the schematic shows 33 caps, I count only 22 with 1 multisection tubular. 2. How do I determine the values of the multisection? It is connected between 25Z6GT, BK42B, & 25L6. 3. on the shcematic some caps values are given some are not. Is mfd assumed? i.e. C24-.005 = .005mfd? 4. Do I need to figure the max working voltage for each cap, or can I just use say 400 volt to be safe?
: Thanks again!

Thanks for the help Norm! What about the Multi-section tubular? I don't know it's internal values/polarities. It is connected between 25Z6GT, BK42B, and 25L6.

Thanks!

It's not marked as multi-section tubular on the schematic however the electrolytics leads are coded with colors. They are often in one unit. Look
closely, if you have the Rider schematic, you will see grn, red, blk and blue. These identify lead colors.

Norm
: Thanks for the help Norm! What about the Multi-section tubular? I don't know it's internal values/polarities. It is connected between 25Z6GT, BK42B, and 25L6.

: Thanks!

Yellow, green and Black are the colors...I still don't see this unit on the schematic, it isn't leaking, but could be dryed out? Thanks!

Hello, after cutting free the multi-section I see the common and 2 other values for replacement purposes, Thanks!

: Yellow, green and Black are the colors...I still don't see this unit on the schematic, it isn't leaking, but could be dryed out? Thanks!

Rod

Electrolytics don't always short out. Sometimes they just dry, losing capacity and allowing hum.

I'll email you a copy of the schematic that I am looking at.. It may be slightly different? Colors are shown but may be hard to read. Maybe the part was changed before and there is differences in colors of the wires?

Norm

: Hello, after cutting free the multi-section I see the common and 2 other values for replacement purposes, Thanks!

: : Yellow, green and Black are the colors...I still don't see this unit on the schematic, it isn't leaking, but could be dryed out? Thanks!