#16
|
||||
|
||||
Quote:
See tuner type ( 175-###) & compare with with manual to be sure it has the right mix/osc tube. Do not sub, may work but not right. Turn channels. You should see & hear loud static crashes. If you do odds are the tuner is dead. If you dont its the IF's. While running pull one IF tube at a time. Example: Pull 1st if no effect Pull 2nd IF & you see & hear things. This means the 3rd is OK & probably the 2nd is bad. This is all crude signal injecting & with practice it can show you a lot in seconds to narrow things down. You can also do tube tapping. Lightly tap tubes & see if it pops back in. When the set is all fixed you can also tap them. This can find int shorting tubes & dirty sockets. Oh yes the hum may or may not be related. Consider it a second problem for now & ignore it for now. 73 Zeno LFOD ! |
#17
|
||||
|
||||
Moved all 3 of them one at a time starting from the back and no changes at all. Also turning the channels doesn't do anything either.
__________________
cedmagic.com |
#18
|
||||
|
||||
If you did that with the set on, then there are a few things I could see it being: an AGC issue, bad video detector diode, loss of B+ to the IF system.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#19
|
||||
|
||||
Set was working when tossed. I doubt the 7 or 8 months of sitting i
outside in the junk pile did it any good. I wanted to try and save it but at the same time, space is limited and I really don't want to put much into it. Not sure what to do at this point.
__________________
cedmagic.com |
#20
|
||||
|
||||
I'm just wondering if the mixer/osc is wrong. It's supposed to have a 6EA8 but the one I have in there has the numbers rubbed off so I can't tell. If I look through my lot and can not find a 6EA8, what is a suitable sub?
__________________
cedmagic.com |
Audiokarma |
#21
|
||||
|
||||
6GH8, possibly a 6U8A and 6CQ8 (odd!) as well. Each tube has it's idiosyncrasies, so the sub manuals always have the asterisk or a foot note.
One manufacturer actually made a dual marked 6EA8/6GH8 - but they were short lived, as no other manufacturer jumped on the bandwagon.. http://www.smcelectronics.com/DOWNLO...SUB%201980.PDF
__________________
Brian USN RET (Avionics / Cal) CET- Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit! |
#22
|
||||
|
||||
A life saver as always. I'll check and see if I have any of those.
__________________
cedmagic.com |
#23
|
|||
|
|||
The correct tube numbers for the tuner should be stamped on the tuner. Most Zenith tuners have this. scrape all the tubes pins with a small flat head screw driver. And hit the tube sockets with Deoxit or some kind of cleaner. It's a pita to do, But if the chassis was outside, all of the sockets Will need to be cleaned.
|
#24
|
||||
|
||||
Tried two subs and still the same. Maybe capacitor issue now? Component level. Issues mentioned earlier.
__________________
cedmagic.com |
#25
|
||||
|
||||
Worked on it for the last 3 hours. Caps all check good. Finally did get the static sound along with tuner activity but still hear hum sound and cannot get a pic on screen. Moved if tubes around and changed to different locations. Not sure what else I can do with the resources I have.
__________________
cedmagic.com |
Audiokarma |
Thread Tools | |
Display Modes | |
|
|