Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: shujinko on March 01, 2013, 11:14:19 AM
-
Hi all,
My tubes ain't glowing. I did leave it on the other day by accident so I thought the switch connection might be bad, but it seems to be okay. I've tried two different sets of tubes and same results for both. Getting some odd readings on the multimeter for DC connections. This is a standard Crack kit (no Speedball). Hopefully you guys can help me out? I'm heading out of town for the weekend so I won't be back until Monday, but I appreciate your responses.
AC
Switch = 120
Transformer 1-2 = 120v
Transformer 4-5 = 6.3v
Transformer 6-7 = 175v
Transformer 9-10 = 175v
DC (using terminal 12 for ground)
The following 244v readings start at around 244v, drop over the course of a few seconds to around 220v, and then they jump back up to 244v.
1 = 244v
2 = 244v
3 = 0
4 = 244v
5 = 244v
6 = 0
7 = 0
8 = 0
9 = 0
10 = 0
11 = 0
12 = 0
13 = 244v
14 = 0
15 = 244v
20 = 0
21 = 244v
Tubes
A1 = 0
A2 = 0
A3 = 0mv, climbs to 400mv, then drops back to 0.
A4 = 0
A5 = 0
A6 = 244v
A7 = 0
A8 = 0mv, climbs to 400mv, then drops back to 0.
A9 = 0
B1 = 244v
B2 = 0mv, slowly climbs to 400mv, then drops back to 0.
B3 = 0
B4 = 0mv, slowly climbs to 400mv, then drops back to 0.
B5 = 244v
B6 = 0
B7 = 0
B8 = 0
EDIT: I checked all my soldering connections and everything looks okay...
-
Power transformer terminals 4/5 heat the tubes, they go to pins 7/8 on the octal socket and pins 4,5/9 on the 9 pin socket.
If neither tube lights up, I'd suspect a break in the wires going from power transformer terminals 4/5 to the octal socket.
-
If the tubes are not heating all other voltages will be very high or zero. Paul, of course is getting you right to the problem.
-
Thanks for your responses. I'm back in business now. I'm not sure exactly what was wrong, but I poked and prodded the tube connection points downstream from transformer terminals 4 and 5 (they all seemed well soldered and sturdy), and after some initial static, it seems to have done the trick. Thanks again.
-
Sometimes a wire gets nicked right at the point where it meets the stripped jacket, and that weak point later breaks just inside the insulation where you don't see it. That will often result in an intermittent connection since the insulation sort of holds the broken wire together. Could be that one of the heater wires is like that. You might try a little more wire wiggling to see if the problem comes and goes.