1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Test Equipment

Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Threaded Mode
RCA WV-98c
morzh
Odobenus rosmarus
******
Posts: 16,507
Threads: 572
Joined: Oct 2011
City: Jackson State, Province, Country: NJ
#31

11-10-2024, 09:22 PM
strange. It should have more even to the GND, and the GND is 1M to the case.
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.
Find
daveone23
Member
***
Posts: 98
Threads: 21
Joined: Jun 2024
City: tampa State, Province, Country: florida
#32

11-11-2024, 08:30 AM
Are you saying if I measure ohms from the ground lead to case it should be 1m ohms? That low resistance tells me there is a leak to ground, right?
(This post was last modified: 11-11-2024, 09:03 AM by daveone23.)
Find
morzh
Odobenus rosmarus
******
Posts: 16,507
Threads: 572
Joined: Oct 2011
City: Jackson State, Province, Country: NJ
#33

11-11-2024, 08:47 AM
Well, in the sch you provided (there is something missing at the very bottom, but I think it is GND), the sole connection to the case shown is the 1M resistor R31, which is used to bring the case and the GND under the same potential.
Unless I am missing something.

Of course there is a cap across that R31. And it could be bad. Or, again, we are missing something.
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.
Find
daveone23
Member
***
Posts: 98
Threads: 21
Joined: Jun 2024
City: tampa State, Province, Country: florida
#34

11-11-2024, 09:17 AM
I guess I need to look at r31 and C7.


Attached Files Image(s)
   
Find
morzh
Odobenus rosmarus
******
Posts: 16,507
Threads: 572
Joined: Oct 2011
City: Jackson State, Province, Country: NJ
#35

11-11-2024, 09:25 AM
That too.
There might be other things.
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.
Find
daveone23
Member
***
Posts: 98
Threads: 21
Joined: Jun 2024
City: tampa State, Province, Country: florida
#36

11-11-2024, 04:28 PM
Interesting readings, r31 common ground to case bounced to 1meg on analog meter, r31 common to case bounced to 1meg. R31=1meg.  Across c7, which is common to case with a parallel resistor = 40k ohms steady.
(This post was last modified: 11-13-2024, 11:41 AM by daveone23.)
Find
daveone23
Member
***
Posts: 98
Threads: 21
Joined: Jun 2024
City: tampa State, Province, Country: florida
#37

11-11-2024, 06:40 PM
My resistance readings are not even close. Worried about pins 1 and 6. Even though they are off, the meter works on dc 50v and higher.
(This post was last modified: 11-13-2024, 11:41 AM by daveone23.)
Find
morzh
Odobenus rosmarus
******
Posts: 16,507
Threads: 572
Joined: Oct 2011
City: Jackson State, Province, Country: NJ
#38

11-11-2024, 07:20 PM
>>r31 common ground to case bounced to 1meg on analog meter, r31 common to case bounced to 1meg.

Would you re-read and correct?
This does not make sense.
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.
Find
morzh
Odobenus rosmarus
******
Posts: 16,507
Threads: 572
Joined: Oct 2011
City: Jackson State, Province, Country: NJ
#39

11-11-2024, 07:21 PM
Check all your caps. Even ceramics. I am not sure what is going on.
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.
Find
morzh
Odobenus rosmarus
******
Posts: 16,507
Threads: 572
Joined: Oct 2011
City: Jackson State, Province, Country: NJ
#40

11-13-2024, 10:24 PM
Just occurred to me: what if you have a power transformer leak? From a, say, secondary to the case. If it is bolted to teh case.
Not sure how to better check it.
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.
Find
daveone23
Member
***
Posts: 98
Threads: 21
Joined: Jun 2024
City: tampa State, Province, Country: florida
#41

11-14-2024, 09:46 AM
Thats a good thought but the secondary does go to ground via R30 27k resistor.
Find
morzh
Odobenus rosmarus
******
Posts: 16,507
Threads: 572
Joined: Oct 2011
City: Jackson State, Province, Country: NJ
#42

11-14-2024, 10:26 AM
Yes.....it would connect GND to case, and you do have 1MOhm.....

I am not sure how the wiper has resistance to the case.
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.
Find
daveone23
Member
***
Posts: 98
Threads: 21
Joined: Jun 2024
City: tampa State, Province, Country: florida
#43

11-15-2024, 03:56 PM
From now on iam using an analog meter. R31 removed is 1 meg and c7 .01 but chassis to common is 600k. Why is that?
Find
morzh
Odobenus rosmarus
******
Posts: 16,507
Threads: 572
Joined: Oct 2011
City: Jackson State, Province, Country: NJ
#44

11-15-2024, 04:22 PM
Are you saying the Chassis to GND became LESS when you removed the R31?
And we are sure the C7 and other caps are not leaking?
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.
Find
daveone23
Member
***
Posts: 98
Threads: 21
Joined: Jun 2024
City: tampa State, Province, Country: florida
#45

11-15-2024, 05:57 PM
Yep, hunting down the source. Will get back to you. Thanks
Find
« Next Oldest | Next Newest »




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
PT 6 chassis screws size???
Have this done except for missing chassis screws. It looks like 1 inch 6/32 sheet metal screw may work but can anyone s...bridkarl — 10:32 PM
Philco model 38 code 121 not receiving signal.
Hello Stormlord, Well done on rewinding that coil it turned fairly good for your first one. Sincerely Richardradiorich — 09:12 PM
Philco model 38 code 121 not receiving signal.
Well here it is. It ain't pretty, but hopefully it'll work. I checked it with my DMM on continuity and it keeps and r...Stormlord5500 — 08:56 PM
Philco 42-345 Restoration/Repair
Yes, 57 is an electrolytic cap that should be 12 mfd 400 volts according to the parts list from the Phorum library schem...RodB — 06:01 PM
Philco 42-345 Restoration/Repair
Looks like if I am reading it correctly it looks like the silver capacitor#57 that appears to be a replacement is of a l...osanders0311 — 05:09 PM
Philco model 38 code 121 not receiving signal.
Thanks Arran. Yeah this plastic is pretty thin. It's a little thinner than the original stuff. It kinda reminds me of p...Stormlord5500 — 04:37 PM
Testing a speaker and output transformer Trutone A2-G
The equivalent of one short turn is basically the same as that of a shorted load. If it is the primary's turn, then the ...morzh — 03:53 PM
Testing a speaker and output transformer Trutone A2-G
I've never had an output transformer become shorted, the failure mode is usually an open primary, or in a center tapped ...Arran — 03:52 PM
Philco model 38 code 121 not receiving signal.
As long as the plastic sheeting isn't too thick, I think that the thickness of photographic film would be just about rig...Arran — 03:19 PM
Philco model 38 code 121 not receiving signal.
Well why not! :lol:Stormlord5500 — 03:14 PM

[-]
Who's Online
There are currently 970 online users. [Complete List]
» 2 Member(s) | 968 Guest(s)
AvatarAvatar

>
  1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Test Equipment