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DELCO 4052 ACDC (was 43 tubes)
#16

To bypass? You mean to improve rectification so it would not wait 'till the tube is hot??

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.
#17

Yup Will get your B + up where it needs to be till you can get a 25Z5.
Is your hum coming from the p/s? Or the amp? I find that a 6B7 is a
pretty high gain tube (there is one in the green radio that you saved
mister kitty from certain death). I'd check to see if it was shielded.
Terry
#18

Oh it is shielded.

The hum only is present when the station is heard, otherwise no. So not really PS nor it is the amp.
Will try alignment.

I have another 25Z5.

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.
#19

Well

Tried to align. In the process found more bad soldering.
It roared when peaked, hummed and overall behaved badly. Reception was the same - lots of hum.

Eventually I decided to do what I wanted to since the first day of looking at it. My number one suspect was cap C3.
It is supposed to go to the B- but somehow was connected to .... the Hot plug pin.
Kirk!!!! Icon_twisted
Kirk swore all the caps including this were connected this way. I trust the fella.

I connected it to B-.....then realigned it and now it works quite acceptably.

I still want to see if there are more bad connections by tapping and probing but it is more than I hoped for for today.

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.
#20

Mike;
  You were not kidding, that schematic is an absolute mess, whomever did the drafting had no clue how to depict the connections. One thing that I also can't stand is when they list parts as C4 or R15, and then a corresponding parts list, rather then writing in the values on the schematic, so you have to keep going back and forth between the list and the diagram to figure out that C4 is a .01 uf 450 vdc cap or that R15 is a 120K Ohm resistor. This is where I say a blessing to the late Chester Carlson for inventing the photo copier, and then run off three copies of a diagram so I can write all over them. It also doesn't help having to repair a set after Kirk got the B+ and B- mixed up.
Regards
Arran
#21

(04-07-2016, 10:51 PM)Arran Wrote:  One thing that I also can't stand is when they list parts as C4 or R15, and then a corresponding parts list, rather then writing in the values on the schematic, so you have to keep going back and forth between the list and the diagram to figure out that C4 is a .01 uf 450 vdc cap or that R15 is a 120K Ohm resistor.

Philco is guilty of the same Icon_smile ; not only that but they do not even use C or R ref designator, they simply enumerate position numbers, anything's a number, field coil, cap, transformer or resistor.

Kirk did not go as far as to mix B+ and B-. He has successfully learned that this is a real No-no.
I even suspect that maybe that radio was handled by someone before. Two electrolytics missing, and the field coil voltage simply would not develop without it. Kirk knows better. Icon_lol

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.
#22

Wow! What fun! Don't ya just love it when "someone" has been monkeying around inside something before you get ahold of it. Might want to be sure he gets another tick on his electrocution counter Icon_lolno Glad you got it running right Mike. It's really a mess when the schematics are screwed up. Ok, maybe Kirk DIDN"T do it, but he looks so guilty. Especially in pajamas!!

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
#23

Icon_lol

Times I have been electrocuted in 2021
As of 1/01/2021
AC: 4 DC: 1
Last year: 6
#24

Tried to put it in the cabinet yesterday, stopped playing. More bad connections. Tookit out. What I thought before to be some tube socket issue (twist the chassis or touch a tube, playing stops) turned out to be one bad solder on the osc coil a wire looped over another, floded with solder but moving freely) abd then wgen I touched another wire on another coil it just came off, so reworked that one too.
Seems to cure the " don't touch me" chassis problem.
Not putting it back to cabinet - have no knobs and the shafts are not protruding requiring the knobs with "necks" otherwise cannot tune.

The field coil wire was on its last leg where it goes in the coil, had to pour hot glue over.

Works fine after that. Reception is good across the dial.


PS. Terry, I rechecked the 25Z5, it is in fact strong, both halves show better than middle of the green zone. I am tempted to shunt the cap that is the B+ (the other one is strictly the field coil) with a reversed diode to keep it from repolarising but it seems it stopped going into -25V and now is about -1V.


PPS. Tried that original 43 with HK short. It works but the radio hums VERY loudly. Two other tubes, one with the short that disappeared (tests good now) and one that came today, no short upon the test, both have zero hum.
So, as I expected, short does affect things in radios that have no separate winding for the heaters (like here, ACDC with filament string).
Possibly might work fine in transformered radios but...I doubt 25V heater tubes were used in those.

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.
#25

(04-08-2016, 07:30 AM)Madmurdok Wrote:  Wow! What fun! Don't ya just love it when "someone" has been monkeying around inside something before you get ahold of it. Might want to be sure he gets another tick on his electrocution counter Icon_lolno Glad you got it running right Mike. It's really a mess when the schematics are screwed up. Ok, maybe Kirk DIDN"T do it, but he looks so guilty. Especially in pajamas!!

I'd check for finger prints...

Joe

Matthew 16:26 "For what does it profit a man if he gain the whole world, yet lose his own soul?"
#26

I replaced the caps only one by one with photos so you cant blame me.
Me=Innocent Icon_mrgreen

Me

Times I have been electrocuted in 2021
As of 1/01/2021
AC: 4 DC: 1
Last year: 6
#27

Are you sure those weren't porn photos you were looking at while replacing caps? Icon_lol while in pajamas, looking guilty?

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.
#28

No.... Maybe...

I also got your call message but have been on Daddy duty so I missed it.
Me

Times I have been electrocuted in 2021
As of 1/01/2021
AC: 4 DC: 1
Last year: 6
#29

For the sake of the implied children I hope by them you meant the little radios.
Or do people trust you with actual live little bumans? Icon_lol

Don't try to recap them.

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.




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