[SOLD] (20) Ohmite 2ohm new-old stock 11" 225w power w/tap bands, brackets - Page 1
Forum section: electronics / general

author: Cliff Matthews
author_rank: Unknown
timestamp: December 02, 2016, 01:24:14 am
content: I have 20 new-old stock (vintage 1977) power resistors for sale in original boxes. They are about 11" long and in good condition. If more pictures are needed, please advise. I can divide the lot at 5 for $60, 10 for $95 US, or all 20 for $175. I will pay for shipping within most places in North America. (perhaps a little more for SA, EU and Brexit area)**Edit: With brackets. PayPal is preferred. Shipping <20lbs. Approx 18"x16"x14" Insurance included, PM me if you have questions. thanks for all replies folks!

author: Cliff Matthews
author_rank: Unknown
timestamp: December 07, 2016, 04:31:34 pm
content: Maybe the price is too high? Or maybe I need to break the shipping quantity down a bit... any ideas?

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 07, 2016, 06:26:06 pm
content: http://www.electronicsurplus.com/ohmite-d225k2r0-resistor-ceramic-2-ohm-225w-adjI don't think your price is too high, but it's just not something you keep in a drawer because it may become handy one day. So you are looking for a buyer that needs a lot of these but didn't buy them already. That is a niche market...

author: Cliff Matthews
author_rank: Unknown
timestamp: December 09, 2016, 12:32:46 pm
content: Price and quantity adjusted, shipping is expensive these days..

author: ruairi
author_rank: Frequent Contributor
timestamp: December 09, 2016, 08:28:20 pm
content: Do you know if these are non-inductive? I'm guessing not. I'm interested for amplifier testing but would prefer a non-inductive load.If you have a data sheet please post it.Thanks,Ruairi

author: Cliff Matthews
author_rank: Unknown
timestamp: December 10, 2016, 07:47:53 pm
content: Quote from: ruairi on December 09, 2016, 08:28:20 pmI would think for AF it's minimal. I see audio-file forums commenters say there's little diff between these and the double-wound Ayrton-Perry type. Maybe some think the cancelling presents other issues with damping, phase or hell knows what, I don't know..

author: fcb
author_rank: Super Contributor
timestamp: December 10, 2016, 07:55:19 pm
content: BREXIT area: Great Britain hasn't left the EU yet, nothing has changed..

author: mtdoc
author_rank: Super Contributor
timestamp: December 10, 2016, 08:24:35 pm
content: PM sent

author: Cliff Matthews
author_rank: Unknown
timestamp: December 10, 2016, 11:48:07 pm
content: Quote from: fcb on December 10, 2016, 07:55:19 pmSorry, didn't really intend on trolling-up anyone's ire.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 11, 2016, 02:39:36 am
content: Quote from: ruairi on December 09, 2016, 08:28:20 pmFYI, the inductive (L/R) time constant of this type of resistor is on the order of 100kHz. You will observe the inductance in power switching circuits, where it's not usually a big deal anyway (e.g. RCD snubber load resistor) unless it is (e.g. RC damper), but not at audio frequencies.To a certain extent, you can reduce the inductance by placing a copper tube down the center, or around the outside (of course, you can't do that while keeping the adjustment track usable!).FYI, approx. $10/ea is fair value for these parts, and vintage is as good as new. It's made of metal and glass, it simply doesn't age.Tim

author: Cliff Matthews
author_rank: Unknown
timestamp: December 11, 2016, 02:55:22 am
content: Quote from: T3sl4co1l on December 11, 2016, 02:39:36 amFor my future info, can that just be copper water pipe? Does it need to be grounded?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 11, 2016, 03:00:29 am
content: If it's the right size. You've got the resistors, you measure it!You can even cement them in place, and add cooling water... (but still don't go much over the ratings, because of thermal expansion and conductivities).Grounding doesn't matter, unless you're worried about capacitance from the winding, through the tube (which BTW is a ceramic like steatite, only a modest dielectric constant).Tim