1G resistors

[Khron]

Just a quick question for you good people here:

Does anyone know of a somewhat reliable (and if possible, affordable) source for 1Gohm resistors? Preferably in Europe  ;D

I found some on eBay, but only in 3-5watt (read: HUMONGOUS) sizes/ratings  :-X Damn pricey, too...

 

[ln76d]

Farnell / Newark got them probably other molochs like mouser digikey got them too.
Those are not so cheap resistors :-\

 

[Khron]

The only decent-sized (250mW) resistors Farnell have are 8.36eu and 27.60eu A PIECE 

Good call on Mouser though - they've got some at 0.619eu a piece ;D

http://fi.mouser.com/ProductDetail/TE-Connectivity/RGP0207CHK1G0/?qs=sGAEpiMZZMsPqMdJzcrNwlDepD%252blwznyoKugq%252bfXem0%3d

 

[0dbfs]

I ordered a bunch of those from US mouser a while ago @ $0.82/ea and they work great. Small (like a 1/8W size) and certainly not $0.04/ea but not $4.- or more...

Cheers,
jb

 

[Khron]

I don't mean to sound too sour, but you guys "across the pond" ARE quite better catered for, in many areas ;D

But at least for now, i'm just glad i (or "we"?) found SOME more decently-priced ones And they've got 4k+ in stock...

 

[benqbasic]

I don't mean to sound too sour, but you guys "across the pond" ARE quite better catered for, in many areas ;D

But at least for now, i'm just glad i (or "we"?) found SOME more decently-priced ones And they've got 4k+ in stock...

Try living at the bottom of the world.  ;D

http://nz.mouser.com/ProductDetail/TE-Connectivity/RGP0207CHK1G0/?qs=%2fha2pyFaduhkrdcbzNk6CHQ1bfgoVndRtlEgfJiN2nuM8RBuTFoG3A%3d%3d
I have used these from mouser but i wait till i have over $200 worth for the free shipping.

 

[baadc0de]

http://www.banzaimusic.com/Mini-Mox-1G-0-25W.html

http://www.banzaimusic.com/Dale-1G-1W.html

pick your poison

 

[ln76d]

Try living at the bottom of the world.  ;D

Try to live in the middle of nowhere ;D

For now i have ordered parts from +/-20 different countries, 3 continentes

 

[SGare]

Farnell / Newark got them probably other molochs like mouser digikey got them too.
Those are not so cheap resistors :-\

What a great word to describe mouser "MOLOCHS" :

Thumbs up for that!

Moloch has been used figuratively in English literature from John Milton's Paradise Lost (1667) to Allen Ginsberg's "Howl" (1955), to refer to a person or thing demanding or requiring a very costly sacrifice.

 

[ln76d]

Moloch has been used figuratively in English literature from John Milton's Paradise Lost (1667) to Allen Ginsberg's "Howl" (1955), to refer to a person or thing demanding or requiring a very costly sacrifice.

Exactly, but in some countries of eastern europe it is colloquially used to describe some of monumental (for example) buildings, statues or other things.

 

[Pip]

1 Gig resistors are hard to find in stock everywhere. Also not used for that much that I'm aware of so the tend to be pricey. How many are you looking to buy?

 

[bruce0]

I just bought some from Mouser $0.75 quantity 1 http://www.mouser.com/Search/ProductDetail.aspx?R=RGP0207CHK1G0virtualkey20420000virtualkey279-RGP0207CHK1G0, they are nice and small too.

 

[ln76d]

I just bought some from Mouser $0.75 quantity 1 http://www.mouser.com/Search/ProductDetail.aspx?R=RGP0207CHK1G0virtualkey20420000virtualkey279-RGP0207CHK1G0, they are nice and small too.

Looks nice, but i would not used them for some projects - 10% tolerance (1G is really hard to measure) means in worse scenario +/-0.1Gohm which is huge difference. 350ppm coefficient isn't the best also.

 

[bruce0]

I only end up using them as leak resistors to charge a mic capsule.  Do you think I should worry about the tolerance or temperature drift in those applications?

 

[ln76d]

I only end up using them as leak resistors to charge a mic capsule.  Do you think I should worry about the tolerance or temperature drift in those applications?

It depends on concrete circuit and a philosophy of building electronic circuits.
In my case i like to always have most accurate values of parts and a stable low noise circuit.
Of course, I do not condemn other options, this is only my way of build.
Since i only doing electronics for my use and for example saving 1$ on a one part will not save 1000000$ like in mass production - i always prefer to pay little bit more and be satisfied
In your case maybe it will doesn't matter or maybe it does
I would have to check it out and compare two different resistors in one circuit, for example 1% and 10% with different ppm and other parameters.
And that's why i'm buying more accurate value parts for my projects. I don't need to check anything and I have peace of mind The devil is in the details 
Even if the part will change it own parameters in case of soldering or temparature change or any other factor -  it always will be more accurate than the 10% tolarance with all mentioned factors.
I know very well that in theory of designing circuits in many cases most of parts could have tolerance 20% or more, but this mostly focused on production, where costs are priority.

 

[bruce0]

In this case, the 1G resistor is just used to leak a little current to allow a charge to build up between the capsule diaphragm and backplate.  The key is to have that current be low enough so that changes in the charge are NOT corrected, so higher values are ok, and 10% low would be fine.

A bad thing would be if the resistor had a lot of noise somehow with that low current, and somehow are a result it inserted a signal onto the capsule.  I don't really understand resistor noise (shot and johnson-nyquist), and how it effects this circuit.

If anyone knows, I am happy to learn...

In any case at $11 bucks a resistor for the ones earlier in the article... I thought these were worth mentioning.

Here is an example schematic of where the 1G might be used.

 

[ln76d]

There's a many type of noise in resistors

Thermal noise
Shot noise
Avalanche noise
Flicker noise
Transit-time noise
Burst noise

It's everything for detailed calculation if you have adequate manufacturer specification, but what for? And the other parts? Tubes, silicon amplifiers, transistor and diodes, capacitors, transformers, coils? Since i'm not insane (i think..) i prefer to bought better part I'm using mostly vishay (beyschlag and draloric), vitrohm, dale etc. resistors. 0,1-2% tolarance 1-50ppm, low noise etc. Sometimes when i need some kind of dirt i using old carbon comps from allen bradley 

 

[bruce0]

Ok, but does anyone know whether the value, ppm drift, and noise specs matter with the Big Ugly circuit (previously posted)?

I just was wondering if the PPM and Tolerance made a difference in the noise level an matching of the Mic. 

I am pretty sure the circuit is insensitive to value and if so the 10% tolerance doesn't seem to matter.  And I thought the PPM spec was a temperature related value drift, and again the circuit is insensitive to that value.

But I don't know whether that circuit is sensitive to the resistor noise, and whether there is a significant noise difference between the types of resistors.

If it was 10 cents vs $1 it wouldn't much matter.  But if it is $0.75 vs $11 then you gotta wonder whether $33 more put in the capsule might make a bigger difference than in the leak resistors.

Economics is partly how sane people make tradeoffs 

 

[Phrazemaster]

Hi gang, just a question. I've read a lot about resistors (and am NOT the expert!). But from what I have read, metal oxide resistors tend to have more noise than metal film.

I am building a U47 clone and I need a couple of high-meg resistors, 100Meg and 200Meg. I found these:

http://www.mouser.com/ProductDetail/Ohmite/SM102032006FE/?qs=%2fha2pyFadujPwEibQbxGT%2fiO0j4Vf5N8bs7DI52P8G%252bkmWppDU14IA%3d%3d

However they appear to be metal oxide - the title "slimMox" leads me to believe that they are metal oxide. The datasheet says they are "low resistor noise" but I don't want to screw around with the capsule/backplate caps for this mic.

I also found these:

http://www.mouser.com/ds/2/427/fhv-230664.pdf

But I don't know what "thick film planar" resistors really means - they are Vishay so probably pretty good. I like how the Ohmites look - cool blue!

I am just tempted to get some caddocks http://www.mouser.com/ProductDetail/Caddock/MK632V-100M-1/?qs=sGAEpiMZZMu61qfTUdNhG4L4uVYDhklnzn%252b%252b0eX%2fJc4%3d

I don't really mind spending an additional $20-$30 for the mic - heck the mic mechanical kit from FleA cost over $1300.

So my question is, what do you think of using any of these? I'm just hesitant to try the metal oxide stuff because of what I've heard. Then again maybe at this level they are all metal ox?

 

[HellfireStudios]

I've used Ohmites in my C12 and U47 clones. Theye are pricey, but they have never given me any problems.

-James-