Capacitor marking question

[JHow]

Okay. Dumb question time. Am I interpreting these cap markings right? It looks like "1m0", am I right that this means 1,000uF? These are the power supply filter section in a Randall rm-12-2 mixer of about 1977 vintage. I don't have a schematic.

[Enzo]

Maybe. 1977 seems early to me for the term millifarad to be in use. Even today, nanofarad is often not used, we tend to stick to micro and pico. Today we have multifarad caps as common things, so millifarads seems reasonable enough, but that is now. Then again, those folks could have been prescient.

On the other hand, I don;t know what else it could mean. 1977 is way too late to see M for micro, and a 1uf cap in the power supply doesn;t make sense.

You could measure one.

No cap meter? Pull one and use a large resistor in series with the cap across a supply voltage, and see how long it takes to charge. Calculate C from the RC time constant.


Ask Randall for a schematic.

[g1]

Was thinking the same thing. '77 seems early for millifarad terminology but seems the only option. I never saw Mf used till the late '90s, on a meter that had a cap. tester. First thought a cap tester that only went to 2 microfarads was pretty useless, then realized it was a big M.
Now farads are becoming more common, back then it was unimaginable. First big cap I ever saw was 1F in the early Panasonic DAT (SV-3500 in late 80's?). It was only a couple volts but they used it to unload the tape if there was a power outage. Remember getting into a big argument with a technology student who just wouldn't accept it was possible to build a 1F cap. Had to bring in the schematic & parts list to prove it but of course he welched on the bet.

[Enzo]

Ah geez, now I'm getting all nostalgic again. Next thing you know, I'll start crying at chick flicks...

When I was learning in the 1950s, "1 farad" was nothing more than a theoretical concept used in electronic definitions. No one would make one, it would fill the room. And perhaps be too much for that rectifier tube in the corner. Nowdays multifarad caps are used in place of batteries in some applications.


Hell, it was tough enough for me to learn to say picofarad instead of micro-microfarad or uuf.

[jmaf]

I think they look about the right size for 1000uF x 35V no?

I heard from a wise old man that the reason for not using mF instead of 1000's of uF is that they'd be nicknamed the MF caps.

[Gtr_tech]

Hell, it was tough enough for me to learn to say picofarad instead of micro-microfarad or uuf.

I've heard the term "Mickey-Mouse farad" too....

[JHow]

Ask Randall for a schematic.

This worked. Randall's schematic says "1,000uF 50V".