36 watt project heater voltage issues

[menger]

im building a 36 watt tmb i have a transformer in my stash i pulled from a 4 el84 baldwin organ its giving me 296v hv, but the fil voltages are all wacked out im getting 17v from the heater taps is it possable to reduce this to usable voltage for tubes heaters?? or should i just locate a fil transformer any one know where to order a fil transformer im in the states mark

[stoo]

If that's unloaded voltage Maybe it'll come down to 12.6 when loaded. Then you can run 12 volt heaters for the pres and 2 el84s in series.

[morcey2]

Is your meter set to AC voltage and are you measuring across the winding? I know they're silly questions, but I've done the same things.

Matt

[menger]

i beleave im measure it right the tubes looks perfect as far as the glow but im reading 6.3 at each pin. i tried a 5.9k 7 watt resistor it knocked it down to 2.5 v i dont know if this will work or not? ill adjust till i get to 3.15 on last 12ax7 mark

[morcey2]

i beleave im measure it right the tubes looks perfect as far as the glow but im reading 6.3 at each pin. i tried a 5.9k 7 watt resistor it knocked it down to 2.5 v i dont know if this will work or not? ill adjust till i get to 3.15 on last 12ax7 mark

Is there any way you can post a gut shot? If the 5.9k resistor is inline in one of the heater legs, you'll only flow 1mA of heater current. If it's between the heater legs, it won't change the current enough to make a difference.

What kind of ground reference do you have for the heater winding? Does it have a center-tap or an artificial center tap (2 100-ohm resistors or something similar)? I'm positive that you're just dealing with a measurement problem and not actual voltage-weirdness.

Matt

[menger]

I beleave your right morcey theres 2 sets of windings, both ran heaters on the baldwin chassis 1 set is measuring 17.5 volts per leg when i first hooked them to the tubes heaters the tubes lit up like light bulbs white and bright, the second set is reading 34.5 volts per leg but are lighting the tubes up to look the way they should with proper voltage it is wierd, i do beleave this is a measuring issue, the second set of wires does indeed have a ct these wires are measuring 34.5 v but when i lift my meters leads off the pin it read 3.5v leaving me to beleave there heating the tubes properly. the pt is not heating up what so ever im recharging my camera but will post pix asap, yes i just tested again and they measure 34.5 then when i take the lead off the pin it reads 3.5 wierd mark[/b]

[57chevy]

Set your meter to measure AC voltage. Connect one meter probe to pin 4 of any EL84. Connect the other meter probe to pin 5 of the same EL84. What does the meter read?

[menger]

thank you for your replys ive figured it out i've got proper voltage on all heater, hears what my trouble was very simple very stupid of me. Theres 2 sets of wires i assumed were both for heater they were'nt 1 went to a reverb unit, that set of wires was ct, the other was not centertapped i hooked up the 100 ohm resistors and walaa good voltages on all heaters i was getting a wacked out reading as the wires were'nt referenced to ground now just too build the board should be easy sailing from here thanks for your replys ill post a pix a little later mark

[barryman]

Mark I think I have the same pt from a baldwin organ that was running (6)el84s & (5)12ax7s & a 5U4GB rectifier. I'm wondering if I can strip down this chassis to power the 36w (4)el84 amp that's on this site with some obvious modifications. I've been digging around for info but haven't found anything on how to measure all the values of the PT, what all the wires are etc. Can you (or anyone) point me in the right direction as far as keywords to search for, sites to research, reading material? Thanks!!