'PF' designation for raised resistor

[g1]

Working on a GL series Allen & Heath mixer. A few resistors are stood off from the circuit board, they are marked PF on the schematic to designate this.
Just curious as to what the PF is an abbreviation for. (in supply rails for headphone amp)

[The Dude]

Maybe they meant FP as in flame proof? Misprint?

[g1]

I had thought that too. But they have the exact same parts elsewhere that are not stood off and no schematic designation. And they look like very standard resistors.

[Jazz P Bass]

Phenolic resin coating?
https://link.springer.com/article/10...209-009-0050-1

[Jon Snell]

If you are refering to R90-93 & R97-100 they are fire proof just in case of numpties plugging something silly into the headphone socket and killing the headphone output transistors. And yes, it has happened!

[Greg Robinson]

Are the leads on those resistors formed to maintain their height above the board? Maybe "pre-formed"?

[Enzo]

Hey, I like that one.^^^^

[Chuck H]

Are the leads on those resistors formed to maintain their height above the board? Maybe "pre-formed"?

I thought on it. But all I came up with was "probably fine". I'm going with "pre formed" though.

[g1]

Are the leads on those resistors formed to maintain their height above the board? Maybe "pre-formed"?

Pre-formed seems to be it. The leads are kinked to stand them off the board a few mm.
Jon Snell , they are definitely not special 'flame-proof' type, but they are stood off the board to perform that function (for reasons you mentioned). GL2200, R33-36, R107 & R108.

[Delta362]

PF as pre-formed sounds very reasonable. While these aren't a necessity, I do have and use a set of these to make nice, consistent lead forms.

https://hakkousa.com/chp-pnr-30-d-lead-forming.html

[Mick Bailey]

Those lead formers are nice. Saves playing around with needle-nose pliers.