Posts: 16,312
Threads: 569
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Terry answered it all.
#4 says "without the rectifier". The rectifier IS the 80 tube so it means, without it.
Also in #1 you tested everything, field coil and the output xfmr primary, so all is good. The output secondary always shows as zero (zero means short, not opsn) and it is OK.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
This is perfect, now I get it. I'll be back this week with the results of the other tests. Thanks again, guys.
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
Update:
The filament continuity test was easy enough, so I did that and everything seemed to pass. However, my replacement bulb for my tester came today and I decided to test everything following the booklet instructions: one of my 24s failed the cathode short test. Of course it had to be the really cool, old Philco branded globe style which is probably original. Additionally, my 27 tube technically passed, but in the final test, the needle was in the "?" area, so guessing that one is iffy.
I know I at least have a bad 24, so I'll need one of those.
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
Posts: 16,312
Threads: 569
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
? Area still works, just get the 24A.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
Ok
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
I'm finally back after getting sidetracked by work and vacation.The new tube came, so I figured I'd run these tests; results are below:
80 filament voltage: 5.4v
71A filament voltages: 5.5v
27 filament voltage: 2.7v
24 filament voltages: 2.7v
These above look more or less ok from the charts.
Plate voltage test for 80 (#6 from list): I got 364 at pin 2 and 366 at pin 3. (I think I may have done this test wrong, I'm thinking I was supposed to probe pins 2 and 3 together like in the filament voltage test rather than place - probe to chassis and + probe to pin 2 or 3... if so let me know and I'll re-do)
The B+ test at tube 80 (#7 from the list) gave me 272v.
Plate voltages (#8)
27: 101 (chart says should be 120)
24: 215, 215, and 95 (chart says they should be 250, 250 and 35)
71A: 203 and 217 (chart says they should be 215)
Any thoughts?
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Measure the dc voltage from pin 3 of each of the 71's to the chassis. Should see some -voltage there on both unless the interstage transformers secondary is open.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
Ok, will do that tonight!
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
Ok, one reads -8.7 the other reads +0.7 and when I touch the probe to it, the speaker crackles and the hum gets louder.
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Seems like 1/2 of your interstage transformer is open. This is why the plate voltage on your 71's isn't more even, one tube has no grid bias and it's causing the plate to draw more current. Just to confirm measure the resistance from each 71 grid back to the center tap of the transformer. Should see a fairly low resistance 1K or less.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 06-19-2017, 10:18 PM by Radioroslyn.)
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
That makes sense as I've read on other threads those are problematic on this model. By "grid" you mean pin 3 again, right? I'll check resistance tonight. Thanks again, Terry.
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
(This post was last modified: 06-20-2017, 11:52 AM by WallaceRoger.)
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
> By "grid" you mean pin 3 again, right?
Yup
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
Ok, one of them is 3k, the other is 7.2M. That sounds like a problem : ) The center tap is the wire that connects to point 1 on the filter can, right?
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
Posts: 7,294
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 203
Threads: 20
Joined: Feb 2017
City: Orland Park
State, Province, Country: Illiinois
Ok, thanks Terry.
Greg
"We are here to laugh at the odds and live our lives so well that Death will tremble to take us."
Users browsing this thread: 13 Guest(s)
|
|
Recent Posts
|
|
91H Code 126 Restore
|
| Just to make it more confusing here is another model 91 schematic that doesn't show parts with dotted lines in that spot...Arran — 10:37 PM |
|
Atwater-Kent 84, restoration.
|
| The wires were desoldered from the can, and the capacitors checked. All checked at 0.102 uF, which is correct.
So the c...morzh — 09:41 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| Arran
Yours probably then the H speaker, same as mine.morzh — 08:39 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| Mike;
I would like to have a look at the speaker in my model 96, but the set is packed into a corner in the basement. ...Arran — 08:04 PM |
|
91H Code 126 Restore
|
| Thanks Arran,
I'm convinced the power cord is good but have a nice repro plug for it. Would it be prudent to add a fus...RealRider — 07:28 PM |
|
91H Code 126 Restore
|
| As I was studying this schematic I was wondering what does this dotted line means? I haven't traced it out yet.
An o...RealRider — 07:22 PM |
|
91H Code 126 Restore
|
| When it comes to the cloth covered power cords, if they are not frayed, and are flexible, and if I can bend one without ...Arran — 06:21 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| Could be. The central cylinder is OK, but the sides are...well. What's done is done.
I wonder if some standard bobbine w...morzh — 06:02 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| Mike;
As I was saying it doesn't look like they used much of a bobbin for the field coil, not like a Magnavox one wou...Arran — 05:49 PM |
|
Atwater-Kent 84, restoration.
|
| This AK84 was bought, I think, last fall.
For a whopping $100.
It has been, according to the seller, restored.
As I go ...morzh — 05:48 PM |
|
Who's Online
|
| There are currently no members online. |
|
 
|
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
