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

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

Issue with rebuilt 38-690 audio transformer
#14

Read my post above.

Start your check with pulling the rectifier and checking the AC outs.
Power down.
Then measure the load across the rectifier output, check if short is present.
If not, put rectifier in, put the loads (speakers) in, power up, briefly see if the DC develops and where it goes, once reached about 500V it should go down a bit and stabilize. Watch for smoke.
Power down AND watch the DC going down. If very slow, you have no load. If fast (second or few) - OK.

Once this is OK, start measuring voltages.
Check the transformers' continuities, check speakers.

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.


Messages In This Thread
RE: Issue with rebuilt 38-690 audio transformer - by morzh - 06-30-2015, 04:28 PM



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 944 online users. [Complete List]
» 2 Member(s) | 942 Guest(s)
AvatarAvatar

>