Posts: 16,213
Threads: 562
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Two things.
1. Make sure your switch is clean and provide good contact across all ranges. It is S2 Range switch.
2. I don't think this is it (I think only the lower dual triode is involved for DC, as for everything else), but just in case, have the tubes been checked?
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: 97
Threads: 20
Joined: Jun 2024
City: tampa
State, Province, Country: florida
Tubes and resistors are fine. R22 measures 9k so iam not sure if that could be the issue.
Posts: 16,213
Threads: 562
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Switch. Check the switch. Make sure it makes good contacts. Clean if necessary, Deoxit D or any contact cleaner (be careful and don't spray it all around).
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: 97
Threads: 20
Joined: Jun 2024
City: tampa
State, Province, Country: florida
I cleaned and checked the sw2 switch, its fine. Has to be something in the .5v to 15v circuit. Iam going to check the ac operation.
Posts: 97
Threads: 20
Joined: Jun 2024
City: tampa
State, Province, Country: florida
No ac function. Pegs the meter to the left, no adjustment.
Posts: 16,213
Threads: 562
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
If I had it in front of me, I would triy to trace the signal on one of the non-working functions.
Try to trace and highlite at least one non-working path.
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: 97
Threads: 20
Joined: Jun 2024
City: tampa
State, Province, Country: florida
At this point, there is no input, just internal voltages
Which are incorrect and not sure what they should be.
Posts: 16,213
Threads: 562
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Those will probably depend on teh switch combination.
Could you list some that you see, their values and what they should be (if you know correct values)?
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: 97
Threads: 20
Joined: Jun 2024
City: tampa
State, Province, Country: florida
Check out this crazy zero pot operation. Touching it drives it crazy. Its rubber tipped. Also the 6al5 has no negative voltage on it.
https://www.dropbox.com/scl/fi/gnvltn9la...fvikk&dl=0
Posts: 16,213
Threads: 562
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
If this is R22, check the voltage on the wiper (86V).
If this is R33, see if the lower pin indeed connected to GND, the wiper is indeed wipes, and if the pot 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: 97
Threads: 20
Joined: Jun 2024
City: tampa
State, Province, Country: florida
I measured the wiper of r22 , 95vdc.
(This post was last modified: 11-10-2024, 05:14 PM by daveone23.)
Posts: 16,213
Threads: 562
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
The resistor you are touching at the video, is it R22 or R33?
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: 97
Threads: 20
Joined: Jun 2024
City: tampa
State, Province, Country: florida
R22, but it doesnt do that all the time. Strange. What do you think of the 95 voltage. I guess its close.
Posts: 16,213
Threads: 562
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Yes, it is close. It is a solid state diode rectifier, so the voltage won't depend much on the load, as would with tube rectifier.
However the behavior is strange.
Also, see if this pot,s case (and so the shaft) should be grounded through the fron panel, and somehow it is not.
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: 97
Threads: 20
Joined: Jun 2024
City: tampa
State, Province, Country: florida
Case and shaft go to case. Center wiper of r22 has 3kohms to case.
Users browsing this thread: 1 Guest(s)
|
|
Recent Posts
|
|
B&K 1077B no video
|
| Hello Tim,
I would if it's a leaky Capacitor So are all 3 of those B- voltages low then ?
Sincerely Richardradiorich — 01:55 AM |
|
B&K 1077B no video
|
| I found a schematic and think I have the problem traced down to the minus power supply. I have very low voltages that go...TV MAN — 12:41 AM |
|
RCA 15X
|
| I'd try replacing the bulb first and if that doesn't do it, then change the 35Z5 and see if the problem goes away.NostalgiaRadioTime — 12:28 AM |
|
B&K 1077B no video
|
| Hello Tim,
I have that exact unit in my shop too plus a Sencore unit there are times I like one or other !!.
Sincerely...radiorich — 11:07 PM |
|
RCA 15X
|
| Everthing goes at once, maybe it's the cold weather, I have had 2 dial strings break and no my little RCA is having dial...Paul Philco322 — 10:26 PM |
|
Philco 91 Schematic
|
| Hi Dan,
I can't explain this specific resistor but I have seen the use of a switch to apply B+ voltage to screen gri...RodB — 09:36 PM |
|
6TPZ and 5TPO Radio Help
|
| I suspect it's been repaired before.
And I suspect whoever repaired it, wanted to re-use old transistors' pin stubs in o...morzh — 09:24 PM |
|
B&K 1077B no video
|
| Thanks Rich! I'll take a look and see what he has. I know there's more modern equipment to be had, but this one I know a...TV MAN — 09:11 PM |
|
B&K 1077B no video
|
| Hello Tim,
Here is a link to restoration of one on Phil's old radios site !
Sincerely Richard
bk1077bradiorich — 09:01 PM |
|
6TPZ and 5TPO Radio Help
|
| I'm a little befuddled on this one. Should X5 and X4 be tied together like this? It looks like someone added this at so...R3Sons — 07:33 PM |
|
Who's Online
|
| There are currently no members online. |
|
 
|
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
