Where to Source - 100k 3W Carbon Comp Resitor?

[selloutrr]

Where?

I need a Dozen.

[diagrammatiks]

try

http://www.apexelectronic.com/

or apexjr

[selloutrr]

Thank you I'll PM him,

Looking at the website it seems the allen bradley carbon comp resistors max out at 2W. I've found this to be true searching on the internet as well which leads me to ask.

Are we sure they made 3 watts and we aren't just guessing on the schematic? Most clones are using other types of resistors due to the trouble sourcing them.

[selloutrr]

Ohmite and Allen Bradley have not in the past and currently do not offer a 3W resistor....

[ToneMerc]

Ohmite and Allen Bradley have not in the past and currently do not offer a 3W resistor....

Allen Bradley did make 3 & 4 watts CC models. I have a few of the 3W industrials.

TM

[selloutrr]

Ohmite and Allen Bradley have not in the past and currently do not offer a 3W resistor....

Allen Bradley did make 3 & 4 watts CC models. I have a few of the 3W industrials.

TM

I might be missing something but the Data sheets confirm they don't exist.

The 3W and 4W resistors have heat sinks built into them. They are not the correct style of CC resistor used in TW builds. The correct body style is not available above 2W.

The best you can do would be a RCR42 2W 100k @ +/- 5% 750V keeping with the correct body style.

[diagrammatiks]

I think that might be true.

I think the issue might be whether people are off-handily referring to the mil-spec wattage or a general use wattage since those allen bradleys were mil-spec parts.

The 2watt mil specs could be referred to as a 3watt part.

I have some carbon comps that are the size of a medium sized mallory150 cap but I think those are still 2watt.

surplus sales only lists up to 2 watts as well.

http://www.surplussales.com/Resistors/R ... onComp.htm

they are pricier then the others though.

[Noel Grassy]

I bought a sack of 2W A/B carbon comps and they look for all the world to
be the same size as the ones in Francesca. I too couldn't find any 3W CC
types when I was sourcing parts so I gambled on the 2W resistors. I'm glad
to see this being addressed here. Especially by folks with access to OEM's
data sheets.

Noel Grassy.

[Cliff Schecht]

The discrepancy for me lies in the size of a 2W CC resistor compared to a 1W, 1/2W, 1/4W, etc.. Below is a pic for reference (this is Steve aka ApexJr's pic).

This starts with 1/8W, then 1/4W, then 1/2W, 1W and finally 2W resistors. I used to think these big ones were 3W as well but this size IS 2 Watts. Someone might have been mistaken when they made the Express BOM or accidentally hit a "3" instead of a "2" but as far as I can tell (seems you guys agree), nobody made a 3W carbon comp resistor in this size. I haven't seen any mil-spec 2W-sized CC resistors labeled as 3W in my years of collecting parts.

Who said it was a 3W part anyways? I'm pretty sure I settled on this Wattage being incorrect and I personally just use 2W resistors in my Express with no issues.

[img:533:456]http://honeybeeamps.files.wordpress.com ... stors1.jpg[/img]

[selloutrr]

The idea of the 3W comes from the Franchesca gut shot that is labeled. Later that was the basis for the schematics and just assumed to be correct.

[Cliff Schecht]

Yeah those are clearly 2W guys consistent with the pics I posted and everything else discussed in this thread. I wonder how many other people have been smashing their heads against the wall trying to find 3W CC resistors (like selloutrr ). I know I spent a good month or so digging through ALL of the carbon comp resistors in the EE stockroom when I was building my first Express and never found any labeled 3W (at least at that size). Every resistor I've seen that size was either in a 2W bin, in a bag labeled 2W or it was clearly written on the resistors body with higher precision parts (e.g. I've got some 56k 2W CC resistors white font on the body, otherwise they are standard shape/size/color with value bands). In other words, I learned the hard way that these resistors do not exist, at least not in the form that the Francesca picture implies.

[M Fowler]

I looked through my stock of NOS cc and did not find any 3W but the data sheets shown from AB do show 3W cc.

I wouldn't worry about it and just use the 2 watters.

Mark

[selloutrr]

the AB 3W CC have a heat sink. It's a hybrid resistor.

everything else above 2W is wire wound.