I have ebjoyed the comments in the forum more than anything I have come across for awhile. Thanks to all.
I have found a transformer from an ancient radio in my junk box that will fit nicely in the old chassis. It is from the old days when my enthuiasm was running high. In the fifties. Anyway.
I measured the open circuit voltage and all the windings measure about 10% high. I used a digital MM and I am getting confused as to just what the readings mean. PP,RMS? The line voltage at my bench reads 123.5 AC on the digital meter. Now the service literature for the Crosley says there should be 630 VAC across the diodes of the 5Y3. Loaded? Like I tried to say the transformer HT winding read 740 VAC OC. The service literature also says the circuit voltages were to be taken with a 1000 ohms/volt MM. When I say the voltages are high I mean higher than the Crolsey service lit. says I need. Am I confusing myself unnecessarily? Too:
I worry about the inrush current when I install any transformer in this radio. My friend thinks this is a valuable antique (In spite of trusting me with it's vitals)I hesitate to garf it all up. But would not some type of surge protector be a good idea for this?
The wiring looks to be frail and as manufactured, I think in the thirties, seems to me totally unprotected. Not to mention a fire hazard.
Any thoughts on this would be appreciated.
Cheers to all.
Ivan Copas

Your digital multimeter will be reading close to RMS value. There are other mutlimeters available that read true RMS. Your digital multimeter does not load the circuit down as much as a 1000 per volt multimeter. Yours most likely will have close to 1 million (meg) ohm loading. The readings you are getting from the line voltage and power transformer are normal. Old radio work will not always yield precision measurements 10-20% tolerance is typical. Old pointer type meters typically had at best 3% acuracy. Enjoy the hobby, if you don't understand something ask the question. What I have found is there are many people willing to share what they have learned. This old radio hobby is so much more relaxing than working on modern electronics and computers.
MRO

I re-read your comments about the power transformer you found. Bring your voltage up slowly with a variac. Make sure your filter capacitors are new and you don't exceed the voltage ratings. Pay special attention to the initial surge voltage. Your rectifier tube will warm up before the rest of the tubes so the DC voltage will peak initially on power up. You will want to replace the other capacitors in this set. Leave the mica capacitors alone.
MRO

If you are replacing the power transformer, it is entirely possible that the replacement transformer doesn't have the same voltages as the old one. If it came from a different radio, the other radio may have different requirements. 740 volts divided by 2 will give you 370 volts. What you need to do is install a suitable 10 watt wire wound resistor between the rectifier cathode and the B+ wiring which leads to the radio circuits. The voltage after this resistor should be the voltage you would originally find at the rectifier cathode. This voltage will not be accurate until the rest of the radio is warmed up and is loading down the resistor.

When the resistor is not loaded down, the voltages imposed upon the electrolytics will be excessive. Be sure that your present electrolytics are rated for at lest 400 WVDC. If not, replace with 400 or 450 WVDC electrolytics. Be sure that all other condensers within the set are rated for at least 400 WVDC.

Regarding fraying wires, the wires coming out of the transformer may be sleeved with heat shrink. Better yet, purchase some beautiful cloth covered hook-up wire in all of the colors available from www.tubesandmore.com. Then splice on the appropriate colors inside the transformer (end bells removed). Throw away the old wires. Be sure that you made a chart for the new wires, if any of them don't match the original color code. Place heat shrink over each wire and leave it long enough so that it goes all the way from where each wire enters the paper wrapping of the transformer, to the hole in the end bell where the wires pass through. Thread the wires through the bell and reassemble the transformer. Your transformer now has fresh wiring.

If any of the other wiring in the radio is in terrible shape, replace it, too, or cover bad spots with heat shrink tubing. If a wire is only stiff, leave it alone. It'll be fine sitting under the chassis where noone disturbs it. If a wire is in dangerous shape, attend to it!

There are in-rush current limiters available. My RCA color bar-dot-crosshatch generator came equipped with one in 1957 (it has a solid state rectifier). I do not see them as a necessity for most equipment with tube rectifiers, especially if the rectifier is filamentary. Filamentary rectifiers warm in a very uniform manner, and cool almost instantly when the switch is turned off. They afford much electrolytic protection, and they afford their own protection, because the cathode is almost never fully warmed when the electrolytics are first charging up (which makes for a lot of current that the rectifier must handle). Tubes which keep their cathodes hot for quite a while, like the 6X5, tend to flash over when the set is turned off warm and then back on right away. The electrolytic charge-up overloads the tube. Most of my AC radios (if not all) have filamentary rectifiers. I use them quite often and have no trouble with overloads or breakdown.

Thomas