LM1881 resistors

[dorrington]

Does the wattage of the resistor matter in the LM1881 circuut?

Also, my local radio shack does not sell 680kohm resistors.  Is there a suitable replacement?  I was thinking using two 330k and two 10k in series, but thats a bit bulky.  Would a 470k suffice?

Lastly, can the LM1881 Rset ground be tied in with the composite video ground?

Thanks

[NFG]

1. As long as the resistor's wattage is rated higher than necessary you're ok.

2. Smack your RadioShack manager for being useless.  I don't recommend using the wrong value, but I haven't tried it so I dunno if it'll work.

3. All grounds are the same.

[Born A Trumpet]

It's perfectly ok to use two or more lower ohm resistors in series, but I would make sure they add up to the recommended value, nothing less, unless you want to accidentally burn random components.
It is also possible to add multiple resistors in parallel, though it is much more complicated. The reciprocal of the overall resistance equals the sum of the reciprocals of the resistors added in parallel. If you have no idea what i'm talking about (A horrible explanation) then look it up. It's probably not necessary but can be useful if you have a resistor of a higher resistance than is needed.
Both of these methods, of course, take up more space and are a complete waste of time if you have a resistor of the needed value, so excuse my rambling...

[dorrington]

so for this application (ps2 rgb), 1/8 watt should be OK, no?

[fragment]

I used three 220kohm resistors and it worked fine. Resistors just add up when connected in series. I wouldn't recommend going lower however.


Erik