Obi Wan would surely be proud.  If I can ever repay you with some small deed (perhaps saving your life, for example) please do not hesitate to ask.  I will be renaming my kids "Teemuk" for sure.  A million thanks.

pj

yeah, i'm waiting to hear back from crate w/part# and schematic.  the ONLY markings on the transformer are two stickers.  one has an SLME #, the other says, "High Pot Tested".  i can't find any references to any crate part#'s.

thanks allgood.  the rectifier turns it into dc.  and, not sure if i lost pt or not.  no pwr when i used the bulb limiter.  i'd previously posted that i'd checked everything but the caps.  but, now i'm in doubt as to my checking proceedures (read: sequence).  so, i'm back to square one.  but, won't make that mistake again.  also getting a lot of practice w/the iron.

so, a 48v ct, 3A pt would work, wouldn't it?  that would be 144VA (RMS).  wouldn't that come out to @ 50-60W to the speaker?  would that do it?  or too low?  why?

pj

i'm trying to understand power transformers. this is from the hammond 270bx.

"The 270 Series power transformers use the convenient 4 hole above chassis "X" type bell end mounts. Each unit features a 115 VAC, 60 Hz primary and two secondary filament windings, one 5.0V for tube rectifiers, plus a 6.3V for heater filaments. Leads are a minimum of 6" in length. Class A insulation (105ºC). These transformers are conservatively rated and CSA certified. VA: 95, Secondary RMS: 300-0-300, DC mA: 100, Fil. #1 Rectifier: 5.0V/2A, Fil. #2 Heater: 6.3V/3.0A."

115VAC, 60Hz primary = what it needs from the wall (mains) to go.
300-0-300 secondary = one tap will be +300VDC, another -300VDC, and the center is neutral.  600VDC across the entire secondary.
100mADC is secondary current flow = 30W of power to the speaker?
                    [300VDC*.1ADC=30W]
95VA = apparent power the amp is making?

am i understanding that right? CT is center-tapped meaning the leads come off the secondary winding wire in the middle of the wire?  like if you straightened it out.  so this transformer is a 3 phased, CT power transformer?

it has taken me 3 days to pull all of these "ideas" together b/c i can't find anywhere that explains this all in layman's terms (ie. the 270bx needs input of 115V @60Hz to make 300V out which will be a replacement for a 30W amp).  or maybe: X model transformer goes into  Zwatt amp, and here is why.

however, i have learned a lot of other things:  did you know that money does not grow on trees?  i never knew that.

pj

ok, i put my amp (crate gx600h) back together and set up my lightbulb current limiter.  I used a 75W bulb.  When I threw the switch, the light came on AND...nothing.  no lights no heat, just nothing.  the light glowed like i'd expect a 75W bulb to do.  no dimming or change.  so, i now take a look at the pwr transformer.  i guess it is just bad.  now I have to figure out what it is so i can get a new one.

btw, in my studies of the workings and chinese that is "transformer lingo" i came across this page.  this guy doesn't assume you know anything beyond ohm's law.  it's a pretty good read:  short and direct.
http://www.etasys.com/Main/ABCs/CalcVAWATTS.asp

pj

roger that.

i appreciate that, joe.  i p/u this crate g600 off ebay.  for $15 i couldn't pass it up!  seller said it was "blowing fuses".  i've gone thru and checked all the resistors, transistors, fets, opamps, and diodes w/a dmm.  everything read like it was supposed to.  i could see where some kind of fluid made its way into the -6db jack.  two resistors right behind that jack showed burn signs on the board.  but, the meter showed them right on.  i haven't gotten the hang of testing caps just yet.  oh, and the ground prong on the plug had been pulled out!  my next step is going to be trying to run it w/the limiter and see if anything glows.

pj

thank you, master teemuk.  just wanted to be sure before i made myself the ground!

pj

i know this is an ignorant question.  in the light bulb current limiter, where are the ground wires connected?

http://www.diyguitarist.com/PDF_Files/AmpCurrentLimiter.pdf

pj