power transformer problem??? maybe

[yunger]

i just wired up the filament pins on my tube sockets, being very attentive to polarity on the preamp tubes. when i soldered the 6.3v wires from the transformer to the filament pins, i rechecked and i had no resistance (.3r exactly) between pins 4/5 & 9 of a 12ax7. i disconected the transformer wires and tested them. i heard the continuity buzzer from my multimeter!

is there supposed to be continuity between the two green 6.3v wires??

the transformer was not bad a day ago when it was in another amp. all i did different was twist the wires. could i have damaged the transformer or am i just being paranoid? i'm afraid to power it up and find out for myself.

[tubeswell]

i just wired up the filament pins on my tube sockets, being very attentive to polarity on the preamp tubes. when i soldered the 6.3v wires from the transformer to the filament pins, i rechecked and i had no resistance (.3r exactly) between pins 4/5 & 9 of a 12ax7. i disconected the transformer wires and tested them. i heard the continuity buzzer from my multimeter!

is there supposed to be continuity between the two green 6.3v wires??

OK think about this. In those pre-amp tubes the filament goes from pin 4 to pin 9 and then from pin nine back to pin 5, so whichever way you hook then up on your meter you should get continuity. Otherwise the filament is broken.

Further than that, you should even get continuity between both ends of the 6.3V winding. In addition, with a 12AX7 in there you will get a DC resistance reading of the two circuits (filament and PT secondary) in parallel (which would be three wires in parallel if pins 4 and 5 were wired together), so the DC resistance will read lower than if measured individually.

[Enzo]

The 6v winding of your transformer is very heavy wire. A transformer winding is nothing more than wire wrapped around the core. SO when you measure resistance of the 6v winding, all you are doing is measuring the resistance of the wire. it will usually have less that an ohm resistance.


It's fine.

[yunger]

i should have mentioned that there were no tubes in any sockets. it is a new build in an existing chassis with existing pt.

Further than that, you should even get continuity between both ends of the 6.3V winding.

that's what i wanted to hear. i assumed there would be more resistance in the winding. on with the build.
thanks.

[yunger]

The 6v winding of your transformer is very heavy wire. A transformer winding is nothing more than wire wrapped around the core. SO when you measure resistance of the 6v winding, all you are doing is measuring the resistance of the wire. it will usually have less that an ohm resistance.


It's fine.

i do like confirmation. i'll try to keep my anal-retentive tendancies in check as much as possible for the remainder of the build. thanks.