Old Resistor Chart - Printable Version

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+--- Thread: Old Resistor Chart (/showthread.php?tid=22425)

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Old Resistor Chart - David - 04-25-2021

Printed this out a few years ago, just found the Pdf have no idea of the  source.

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RE: Old Resistor Chart - mikethedruid - 04-25-2021

Thanks ! Shouldn't be called "Old" though, since it covers ALL the common markings right up to the newer 4+1 band markings on the newest 1% resistors. The old system most commonly seen was known as the "BED" system, which stands for "body, end, dot." The body is the first digit, the end, is the second digit, and the dot is the number of zeros following the two digits. Sometimes there was a second end in silver or gold indicating 10% or 5% tolerance. I always get a kick out of those who call the dot, or third (or fourth) band "multiplier." The color corresponds to the number of zeros you draw after the initial digits. Example: brown black orange, brown is 1, black is 0, orange is 3, so three zeros, hence 10,000 ohms. LOL ! I think some folks just like to sound all high fallootin' when it's really very simple.

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RE: Old Resistor Chart - Jimradio - 04-26-2021

Thanks for the post, I printed it.

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RE: Old Resistor Chart - Raminc - 10-23-2023

Thanks great info. Saved

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RE: Old Resistor Chart - Tim Tress - 01-03-2024

Unfortunately, it doesn't include the IRC "BT" series of resistors, used heavily by Philco and other manufacturers in the 1935-42 period. They are tubular insulated types, but are coded with the body-end-dot scheme. Another type which turns up occasionally is the Micamold insulated resistor, made in both carbon and wire wound versions. Those have the colors arranged in a series of dots, with one dot shaped like an arrow to indicate the direction to be read. They look like mica capacitors, but their bodies are very slender.

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RE: Old Resistor Chart - Chas - 01-03-2024

Tim

Quote:Unfortunately, it doesn't include the IRC "BT" series of resistors, used heavily by Philco and other manufacturers in the 1935-42 period. They are tubular insulated types, but are coded with the body-end-dot scheme.

I found this at WRH:

Quote:BT AND BW 10% INSULATED TYPES Type BT Filament Carbon. Exceed rigid MIL -R -11 sped- Type BW Wire Wound. Will withstand 50% to 100% specifications. Withstand 50 -100% overloads for short overloads with little or no resistance change. Values periods. RETMA -coded. Sizes: BTR, 1 xß'; BTS, clearly indicated by standard RETMA color coding. 11 x .Ç; BTA, 23,6x%"; BTB, 1%x3'. Figure in Type Sizes: BW -%, 1%204"; BW -1, 1 %x %'; BW -2, 1 %x No. indicates wattage rating. 24'. Figure in Type No. indicates wattage rating.

Copy/paste of WRH OCR docs often results in strange conversions of fractions

https://www.worldradiohistory.com/hd2/IDX-CATALOGS/IDX/Allied-Catalogs/Allied-Catalog-1956-OCR-Page-0108.pdf

The Black & White artists drawings of this type of resistor do seem to indicate code with the familiar color bands.
I got a quite a few of these from a local distributor when they closed, all banded.
Yet, I have come across early axial resistors that ARE bed code. Again, a few are in my resistor inventory.

Sadly, I had some 5# of NOS BED dog bone resistors, all were found to be some 35% high  

I gave them away marked as bad at a recent radio meet. I dare not use them as they would change value with current applied...

Now if I could just find a stash of Allen-Bradley or Ohmite

Getting more difficult to find old parts at Yard Sales and Ham radio fleas. WW-II surplus is no longer seen anywhere. Even tube radio has all but disappeared. It's been 3 years since I was able to buy a wooden 40's table radio for $10 at a flea.

Chas

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RE: Old Resistor Chart - poulsbobill - 01-08-2024

I have been having problems pullong up old pdf's from our site lately. This one today wont work for me Old Resisitor Markings.pdf from post #1.

ANy ideas?

Thanks

Bill

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RE: Old Resistor Chart - Chas - 01-08-2024

I was able to download just 2 minutes ago I now have the file...

Here is a re-post:



I suggest you delete cookies for Phorum and can check your browser for spam client if it is rejecting attachments...

Chas

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RE: Old Resistor Chart - morzh - 01-08-2024

Both old and new postings worked with me downloading.

Cookies? Security?

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RE: Old Resistor Chart - radiorich - 01-08-2024

Hello Chas,
Yes, I am there with you "Now if I could just find a stash of Allen-Bradley or Ohmite"
Allen-Bradley made some great resistors I do havwe some old stock laying around .

I hear you about finding surplus parts at yard sales nope just new chinese made junk .

Sincerely Richard

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RE: Old Resistor Chart - poulsbobill - 01-08-2024

Hmmmm still no go i get....

This site can’t provide a secure connectionphilcoradio.com sent an invalid response.
Try running Windows Network Diagnostics.
ERR_SSL_PROTOCOL_ERROR

So did that said could not find any problems. i am using the old portal will try the new one.

just updated to the new look ( whoa lots of blue) still wont download.

tried to download from a google search still no luck says the error i get above...in firefox too now i just checked wont work.

made sure site was in trusted zone in ie options....still no workie

Bill

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RE: Old Resistor Chart - radiorich - 01-08-2024

Funny Bill
It works for me I downloaded it !

Sincerely Richard
P.S. how is the weater at that end of the state ?

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RE: Old Resistor Chart - radiorich - 01-08-2024

Hello Bill ,
Do want me to email the chart to you ?

Sincerely richard

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RE: Old Resistor Chart - poulsbobill - 01-09-2024

Thank you i pm'd you me email addy

Thanks

Bill
Still odd -- i can download pdf's from any other site but this one.

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RE: Old Resistor Chart - poulsbobill - 01-09-2024

Thank you. Got it. Looks good

Bill

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