A quick review/reminder on OLD resistors
A quick review/reminder on OLD resistors
As a review for some, or some new info for others, I thought I'd review the coding scheme for the really old "dog bone" style resistors you may come across--typically in your 1930s era sets.
Just remember this little saying of mine: "Chances are you've been working on that radio too long, it's probably time for BED".
B.E.D. Body End Dot The trick to the secret code
Here's the first example:

Sorry for the lack of color clarity, but you have a majority of the body colored brown, and end painted black and an Orange dot
So, using the trick of BED; body= brown end= black dot= orange.
Remember your resistor color codes?
Brown = 1
Black = 0
Orange= 3
1 0 3
10000
10,000 or 10k ohm resistor is what we have here.
Next one;

We have a red painted body, a yellow blob in the middle and the end that has been dipped in black....
Okay, so what do we have here? (Besides an old resistor
)
(Quiz time)....
Just remember this little saying of mine: "Chances are you've been working on that radio too long, it's probably time for BED".
B.E.D. Body End Dot The trick to the secret code

Here's the first example:

Sorry for the lack of color clarity, but you have a majority of the body colored brown, and end painted black and an Orange dot
So, using the trick of BED; body= brown end= black dot= orange.
Remember your resistor color codes?
Brown = 1
Black = 0
Orange= 3
1 0 3
10000
10,000 or 10k ohm resistor is what we have here.
Next one;

We have a red painted body, a yellow blob in the middle and the end that has been dipped in black....
Okay, so what do we have here? (Besides an old resistor

(Quiz time)....

Dr. Radio- Member
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Re: A quick review/reminder on OLD resistors
20K???
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Bill Cahill- Admin
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Re: A quick review/reminder on OLD resistors
I believe that would be 200K
Joe T.
Joe T.
jtauser- Member
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Re: A quick review/reminder on OLD resistors
I can never remember how to read those things. I always have to ask. Now I know WHO to ask. Thanks, Doc.
Regards
WC
Regards
WC
Wildcat445- Member
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Re: A quick review/reminder on OLD resistors
Dang. I was half asleep. Thanks.
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Bill Cahill- Admin
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Re: A quick review/reminder on OLD resistors
Thanks for sharing that! At least I won't be caught off base when I need to evaluate one of those types.
75X11- Member
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Re: A quick review/reminder on OLD resistors
Now for the answer to our quiz:
"We have a red painted body, a yellow blob in the middle and the end that has been dipped in black..."
Body = Red which = 2
End = Black which = 0
Dot= Yellow which = 4
So....
204
200000
If you said 200,000 OR 200K You would be correct
PART II
Another thing that throws many for a loop is the use of "M" on old schematics. "M" is the Roman Numeral for 1000. It was not until later "k" was adopted meaning "kilo" or 1000. Today we take for granted M means million. Here lies the problem....
Many times those old "un-updated" '30s era schematics show resistance such as 10M or 100M. This almost always spells confusion for the newbies.
100 million ohms is pretty darn high for a radio circuit??!!!
100 thousand (100k) is not. M=1000 in these cases.
It's another thing you pick-up as you learn.
Just an FYI or review.
"We have a red painted body, a yellow blob in the middle and the end that has been dipped in black..."
Body = Red which = 2
End = Black which = 0
Dot= Yellow which = 4
So....
204
200000
If you said 200,000 OR 200K You would be correct

PART II
Another thing that throws many for a loop is the use of "M" on old schematics. "M" is the Roman Numeral for 1000. It was not until later "k" was adopted meaning "kilo" or 1000. Today we take for granted M means million. Here lies the problem....
Many times those old "un-updated" '30s era schematics show resistance such as 10M or 100M. This almost always spells confusion for the newbies.


It's another thing you pick-up as you learn.
Just an FYI or review.

Dr. Radio- Member
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