top hat diodes & other mystery parts

[Frankenamp]

I got a load of "vintage electronic tube parts" on flea bay and while sorting the parts (seeing how far the CC resistors have drifted) and thoroughly annoying the wife by spreading hundreds of resistors all over the table with sticky notes '68' '390' '475k'... Got distracted by some funny looking diodes that say GE m124j779-4  552  with the diode symbol (arrow pointing to the 'brim' of the 'hat') several google searches later all I found out was that they were top hat diodes, and that the numbers didn't match standard nomenclature. almost two 3x5 drawers full the thingies. Any ideas as to what they are and what they can be used for?

Bakelite (?) diodes "+6718+188" & "x122j177-2"

found a couple of HV rectifiers Sylvania ECG-118 & a JJ-650 both obsolete, and another that looks like a barber pole the black & white pattern makes reading the print impossible. and a drawer full of belfuse (?) chemical fuses

[sluckey]

Tophat was a common style a long time ago. The arrow points to the cathode. They were used in standard rectifier circuits and were made in a wide variety of voltage/current ratings. Some were rated at 50PIV. Others were rated 100, 200, 500, 800PIV. And there were some zeners that used the tophat style too. If your diodes have no standard number, ie, 1Nxxx, theres likely no way to determine the ratings, unless you have a variable voltage/current source and use it to blow up a few. Too much trouble for a cheap diode IMO.

Google for "GE m124j779" turns up M124J779-1 NTE Equivalent NTE116 1A 600V rectifier... 0.79 EACH
Could be your diode?

[Frankenamp]

Could very well be, Thanks! I plugged in various iterations into Google AVG and Yahoo and didn't get squat. There were a few 1N1695 (.6A,400v) going for three bux a pop on fleabay (there go my plans of makin' it big there...) I guess a couple in series (a'la Leo) will work? If that is the case, those and the dozen or so 1N4007's I already had should keep me rectified for a while at least. I spent several evenings with unmarked drawers of CC & metal film (?) resistors... still have a fair ways to go. Then there's the capacitors (mostly ceramic)  three drawers full, and leeetle glass diodes that I'll need a loupe to read.

(back to introducing Mr. Resistor to Mr. Meter- I'm really liking the little J-hook grabber-thingie, much easier)