[ckc]

my radio is missing is missing bakelite capacitor no. 81 any help to rebuild what it was and wire it properly would be appreciated if anyone has a picture of a original or restored chaissis of this model code 125 version it would be appreciated. i think whoever previosly owned this tried to update this the capacitors left this spot and perhaps other things altered .

[Chuck Schwark]

CKC,

In Serv. Bull. 205, Part No. 81 in the Model 16, Code 125 parts listing, chassis layout diagram and the schematic is a 1.0 Meg resistor, not a capacitor.

Do you perhaps mean Part No. 82, a .25mF wax/paper capacitor? If so, use a 630 volt replacement part.

[ckc]

sorry i checked the schematic i work outside in our garage by time i walked in i made a mistake giving the wrong number, the part that is missing is part no. 97 a philco bakelite block capacitor

[Chuck Schwark]

Thae bakelite block cap is 0.3 mF. It was used to "tune" the filter choke (96) at 120 Hz. - the AC ripple freq., due to the less efficient filter caps of that day.

It's not really needed and if it's not the exact value, it wouldn't be effective, since the inductance value of the choke has drifted with time anyway.

The fact that the two main filter caps, parts 98 and 91, being replaced will more than make up for any effectiveness of that 0.3 mF. cap may have added.

Those 8 mF. filters should be 10 mF. with today's modern cap values and this will counteract any need for that "choke tune" cap.

Chuck

[ckc]

when i got the radio a capacitor was bridged across the choke , there was one other i think mistake a capacitor .o5 was bridged from end of resistor 92 140 ohm end to speaker plug terminal that connects to resistor 90 7,750 ohm . when this radio was first turned on like this it didn't work and looked odd tube 80 glowed purple no other tubes lit i turned it off in 20 seconds. i later disconnected this ( the capacitor .o5 bridged in this spot ) and tried it again borrowing the part 97 from another model than it lit one tube ( on this second try i had variac so it was only powered to 90 v. one tube no. 78 rf lit but no others the purple tube problem was gone. i'll have too return this part to the other radio i hope though if i try it again i can get more filaments lit i wondered if people had changed any wiring around the 73 capacitors

[ckc]

the part i borrowed for the block was part no. 99 6287 du from my working radio philco code 121 116 b , i'll soon return it back , there is different end letters on it but it seemed the sme part so i tried it . i have a variac and a light bulb type circuit tester ( home made )

[Sean]

If you are having problems getting some of the tube filaments to light, you should pull the rectifier tube and power the set up and start checking for filament voltage at the un-lit tubes.

I have a 16X code 125 on the bench now that I have almost finished recapping. I can shoot some photos of the chassis for you if that will help.

[Sean]

Here are a couple of photos of my chassis so far. They are pretty good size so they may take a little while to load. All of the bakelite block caps have been rebuilt but I have not finished the electrolytic cans yet.

Chassis Underside

Chassis Topside

[ckc]

thanks for the really great pictures , there quite clear mine still has so many of the big older parts it looks quite different . I 'll be looking at them a lot; other family members use this computer so I might not be able to write back quickly; there might be more questions; this is a nice radio your work looks excellent i've only worked on Philco 70 a relative gave me and philco 20 much simpler, this has so many parts (when i got it 6 tubes missing ) i was looking at the three resistors in series near part 97 and wondering which part they replaced i assume the large resistor under them is part 95 ( 13,000 ) ohm; again thanks for the pictures, I don't know anyone in this area of NY with this radio or similar.

[Sean]

Those 3 resistors are actually replacing the 13K resistor (three 4.3K in series). The other end goes to the can cap with 1uF and 2uF caps inside that I haven't rebuilt yet. I figured there is no sense in soldering that lead to the cap can if I'm just going to have to unsolder it when I rebuild the can.

[ckc]

so than 95 ( i assume when you first found it ( i see it on edge ) went from middle terminal of cap 97 ( bakelite BLock to 1.0 micro farod to left side of filter choke 96 a wire somewhere in here ( the middle terminal goes off to speaker terminal ( the first one if you go right in your picture near chaissis )

[Sean]

Yep. Cap 97 actually contained 2 caps. I wasn't able to find info on this exact cap as to what the values of the caps were. The total is 0.3uF so I put a 0.1uF and a 0.2uF caps in it. IIRC, they are both tied to the terminal closest to the mounting screw and a jumper that is barely visible in my photo connects the other two terminals together to parallel them. The terminal sticking off the end of 97 has a wire going to one terminal of choke 96.

[ckc]

then the wire at this junction goes off to the speaker plug ( going right ) toward floor of chaissis , it would also connect to resister 81 ( the silver one toward bottom pf your photo , then the other side goes to cap 73 on mine a mallory replacement 10 microfarad i think ( they grounded this replacment part to around bakelite cap 71 at it's screw ) then the other side goes across to 37 on my top of radio the shadow tower was broke of we reattached it , two wires have nothing i think shadow tuner lamp no bulb or scket, two other loose wires must be power for the lamp and shadow area. your wires look all new , our wires could be better around top of if cans

[Sean]

That 10uF Mallory replacement should be 1uF. The resistor 37 should connect between pin 2 of the 76 oscillator tube and the junction of the 10K and 12K resistors 94 and 95 that connect to another 1uF section of capacitor 73 (where my 3 series resistors would end up connecting).

The Shadow Meter has 4 wires going to it. The black and white wires go to the meter coil, then a pink-ish looking wire (probably originally red) and brown wire go to the filament to power the lamp.

[ckc]

the wire from the terminal at cap block 97 ( last sentence in the may 3, 3:10 pm post you wrote is going to the right side (as viewed in picture ) side of choke ?