Posts: 130
Threads: 25
Joined: Apr 2016
City: Buffalo NY
(06-13-2016, 01:29 PM)Radioroslyn Wrote: Just as an aside try measuring the resistance 35Z5 out of it's socket, pins 2,3,and 7 should show a low resistance to each other. The pilot lamp get it's power from a tap in the 35Z5 heater (pin3) if there is no resistance from pin 3 to 2 or 7 the lamp won't light but the power supply will make HV. Don't know if an open tap will show on the tube tester. This may solve your pilot lamp issue.
Gl
Terry
Thanks. I will do that when I get home today.
While I'm at it. Let me put up a couple of photos to see if things look right. I think someone did some work on this before it came to me....or the factory wiring is different from what I understand the schematics to mean...anyway.
This is the 35Z5:
[Image: http://i.imgur.com/9vEJIRq.jpg]
Now first excuse the sloppy solder job. That will be cleaned up.
What seems odd is that the power and bulb wire are supposed to attach to pin 2 according to the schematic, but is jumpered over to pin 4 with that wire and there's that other wire attached to pin 2 that goes off to something I can't recall. I'll have to check that when I get home, but I can't see that anything else is supposed to attach to that pin according to the schematic. Everything else looks logical compared to the schematic. Is this normal?
And when it comes to the switch this is how I received it:
[Image: http://i.imgur.com/w8rmDFI.jpg]
What I "think" is odd is how the switch is "grounded"/jumpered/wired to pin 8 of the 12SQ7 tube. If that is supposed to be the ground wire for that switch shouldn't it be attached to pin 1? That obviously looks like the ground since that wire running off of it is attached directly to the chassis.
(This post was last modified: 06-13-2016, 04:26 PM by Tgace459.)
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
What I "think" is odd is how the switch is "grounded"/jumpered/wired to pin 8 of the 12SQ7 tube. If that is supposed to be the ground wire for that switch shouldn't be attached to pin 1? That obviously looks like the ground since that wire running off of it is attached directly to the chassis.
http://www.nostalgiaair.org/pagesbymodel...007583.pdf
Pin 8 of the 12SQ7 is one of the two pins connected to the heater it goes to the off/ on sw and is also B-. B- is floating in this set (not connected to the chassis as it would present a shock hazard). Chassis ground is connected to B- though C20 and R11 they provide a rf ground for the tubes shield on pin 1 of the metal tubes.
Check ur PM box.
Terry
(This post was last modified: 06-13-2016, 04:59 PM by Radioroslyn.)
Posts: 130
Threads: 25
Joined: Apr 2016
City: Buffalo NY
Thanks. That's why I don't change anything before consulting people who know more than I.
Since I'm still a newb at this, I stick to the newb rules of changing out the electrolytic caps, trying a start-up then doing a cap at a time vs shotgunning all the caps. Is there any advantage to changing out the rest of the caps at this point?
And let me throw this out there too. When I got this radio the pilot lamp was blown. I picked up a bulb at radio shack and it fits and lights up when I run a 9v through it. Is it possible that the bulb is "wrong" or could be part of my problem?
(This post was last modified: 06-13-2016, 05:12 PM by Tgace459.)
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Yes, C-14,16,20,11,and 12.
When caps are leaky or shorted they can cause excessive
current flow lowering the HV among other things.
The burned out lamp could be from C-13 being shorted.
Hey wait just a minute! There's no lamp in the circuit!
Perhaps someone added it and miss wired it.Lamp
goes to pin 2 and 3 of the 35Z5 tube. The lamp socket
must be isolated from the chassis.
Terry
(This post was last modified: 06-13-2016, 05:33 PM by Radioroslyn.)
Posts: 130
Threads: 25
Joined: Apr 2016
City: Buffalo NY
(06-13-2016, 05:25 PM)Radioroslyn Wrote: Yes, C-14 looks like it's missing,16,20,11,and 12.
When casps are leaky or shorted they can cause excessive
current flow lowering the HV among other things.
The burned out lamp could be from C-13 being shorted.
Hey wait just a minute! There's no lamp in the circuit!
Perhaps someone added it and miss wired it.
Terry
The schematic im using shows it...if you go back to page 1 there is a link to it.
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Interesting, Riders doesn't show the lamp. So we back to c13 was shorted and took out the lamp or the heater tap is open.
Terry
Posts: 130
Threads: 25
Joined: Apr 2016
City: Buffalo NY
(06-13-2016, 05:44 PM)Radioroslyn Wrote: Interesting, Riders doesn't show the lamp. So we back to c13 was shorted and took out the lamp or the heater tap is open.
Terry
Something odd...
The schematic you showed me has no lamp, but a resistor running off of the plate (and back to the negative blade of the plug? I think?). I have a resistor attached to the plate and to Pin 3 as you see in the photo.
The schematic I'm using shows the lamp...but no resistor. I have a lamp AND a resistor. Is this set-up right?
(This post was last modified: 06-15-2016, 09:30 AM by Tgace459.)
Posts: 130
Threads: 25
Joined: Apr 2016
City: Buffalo NY
What has me stumped for now is why the 35Z5 wont light up (pilot lamp or tube). I can light the bulb from the pins with a 9V and 2,3 and 7 show continuity between themselves. I'm getting voltage when I turn it on. But the bulb and tube stay dark....
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Sound like a bad heater in one of your tubes. Remove tubes, Measure resistance from pin 2 to pin 7 on all except on the 'SQ7 it's 7 and 8. Should show low resistance.
Terry
(This post was last modified: 06-15-2016, 10:04 AM by Radioroslyn.)
Posts: 130
Threads: 25
Joined: Apr 2016
City: Buffalo NY
Thanks! Think I may have found a or THE culprit....no 2-7 continuity on the 12SK7.
(This post was last modified: 06-15-2016, 01:52 PM by Tgace459.)
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Drop in another 12SK7 and that will get the heaters going again.
GL
Terry
Posts: 130
Threads: 25
Joined: Apr 2016
City: Buffalo NY
Have one coming tomorrow hopefully.
Thanks for taking the time to answer my questions. It helps in more ways than one. Like understanding schematics better. Now that I look at the schematic I feel like a complete newb for not figuring that out for myself. The circuit goes through all the heaters so obviously if one is open the circuit isn't complete.
(This post was last modified: 06-15-2016, 03:48 PM by Tgace459.)
Posts: 599
Threads: 24
Joined: Jan 2014
City: Edmonton AB CA
Did I miss something here, I thought you had voltages on all of the tubes? That would be impossible if the filaments were not lighting up. Were the tubes lighting up and then they stopped?
Gregb
Posts: 130
Threads: 25
Joined: Apr 2016
City: Buffalo NY
That was it!
Now I just have the antenna issue to figure out. The back with the antenna was toast on this thing.
The voltage thing. Looking back at the readings I posted it looks like some of the 2 and 7 pin readings were low (or non-existent) while others were giving readings. The voltage readings on the other pins I cant explain. I was still getting them as recently as yesterday.
(This post was last modified: 06-17-2016, 09:37 AM by Tgace459.)
Users browsing this thread: 5 Guest(s)
|
Recent Posts
|
New member
|
Hello jeff,
Welcome aboard !
Sincerely Riochardradiorich — 06:53 PM |
New member
|
Good picture,
When was it taken? You don't look in it like a guy who has a teenage son :)morzh — 06:13 PM |
New member
|
Love the pic! I'm southern IL, so wouldn't be much help and Bob Anderson is very good on those, but lives in Chicago are...TV MAN — 05:25 PM |
Philco 40-120C Filament Wiring
|
:thumbup:klondike98 — 04:56 PM |
Philco 40-120C Filament Wiring
|
With these values I think you are OK; the Cmax for this tube is 40uF.
Your Vbb could rise a bit, but probably not too mu...morzh — 04:53 PM |
Philco 40-120C Filament Wiring
|
BTW, someone had replaced the original 20uF/20uF filter cap with a 47uF/33uF cap. Do you think these values are safe on ...bluecap — 04:33 PM |
Philco 40-120C Filament Wiring
|
You're correct. I was misinterpreting the key position. I now know where it is, and things are making sense. I appreciat...bluecap — 04:29 PM |
Philco 40-120C Filament Wiring
|
I think Morzh has a good thought. Check the key position. The under chassis diagram in the Philco info shows an “H” for ...klondike98 — 04:25 PM |
Philco 630csx power cord
|
Yes, the third wire goes to the stud on the side and is separate from the other two.
I've usually used cloth covered ...Tynwald — 03:09 PM |
New member
|
Have you tried Alabama Historical Radio Society?
They possibly could recommend someone.
I remember a name of Dee Hanes...morzh — 03:08 PM |
Who's Online
|
There are currently 4802 online users. [Complete List] » 3 Member(s) | 4799 Guest(s)
|
|
|
![>](https://philcoradio.com/phorum/images/bootbb/asb/right_arrow.png)
|