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K2 - RF choke identification

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sergio t. ruiz

K2 - RF choke identification

let me start out with the fact that i am colorblind..

this isn't too bad for resistors, as i can always use an ohmmeter to
verify..

but for rf chokes, this is killing me..

i usually ask my son and wife to help me sort them, but this time,
even they are having alot of trouble sorting them out..

it looks like we have them all sorted out but one..

RFC 15 does have a tan body, but it is the same size as the other
100uH choke, as the builder note talks about this..

the one remaining i cannot ID is RFC10.. it is supposed to have a
green body, and marked brown black red..

the last one i have is VERY small, and marked green-brown-green..

it is very tiny, which makes sense, as the value is alot smaller..
but the colors are not even close..

anyone have any ideas?

thanks!

73 de kb8qpt

___
peace,
sergio
photographer, journalist, visionary
www.coffee-black.com

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JT Croteau

Re: K2 - RF choke identification

On 8/23/07, sergio <[hidden email]> wrote:
> the last one i have is VERY small, and marked green-brown-green..

Sergio, I had the same problem. What you have here on this component
is a resistor. It is R116 and 5.1 MOhm. Stick it on an ohm meter and
see.

It took me awhile to identify all the chokes. I feel your pain.

--
JT Croteau, N1ESE - Manchester, NH
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Brett gazdzinski-2

RE: K2 - RF choke identification

In reply to this post by sergio t. ruiz

You can buy a DMM that measures inductance.
I have a wavetech meterman model that was under $100.00
that does capacitance from many micro farads to pico farads,
inductance from henrys to micro henrys, frequency
to 10 Mhz, plus all the other usual DMM stuff.

I also ran into problems with some chokes, on a green
body the colors don't show well, and the DMM told me
what was a choke and what value it was.

Its also great to measure vari cap settings in homebrew
stuff, and to identify what value those big chokes are
that I use for the big tube transmitters, the inductance
of coils used in the homebrew receivers, even the range
of slug tuned coils....

Well worth the investment is you do a lot of electronics...

Brett
N2DTS

>
> let me start out with the fact that i am colorblind..
>
> this isn't too bad for resistors, as i can always use an ohmmeter to
> verify..
>
> but for rf chokes, this is killing me..
>
> i usually ask my son and wife to help me sort them, but this time,
> even they are having alot of trouble sorting them out..
>
> it looks like we have them all sorted out but one..
>
> RFC 15 does have a tan body, but it is the same size as the other
> 100uH choke, as the builder note talks about this..
>
> the one remaining i cannot ID is RFC10.. it is supposed to have a
> green body, and marked brown black red..
>
> the last one i have is VERY small, and marked green-brown-green..
>
> it is very tiny, which makes sense, as the value is alot smaller..
> but the colors are not even close..
>
> anyone have any ideas?
>
> thanks!
>
> 73 de kb8qpt
>
> ___
> peace,
> sergio
> photographer, journalist, visionary
> www.coffee-black.com
>
>
> _______________________________________________
> Elecraft mailing list
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>
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>

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Don Wilhelm-4

Re: K2 - RF choke identification

I finally broke down an purchased the AADE L/C meter after I got tired
of doing the calculations required when using my homebrewed K6OLG LC
Tester (the AADE meter is based on that LC Tester). I believe it is a
bit more trustworthy for small values than the typical DMM with
capacitance and inductance measurement capability, but if all you have
is the DMM, it can be a big help. Some DMM LC measurements can be quite
accurate, but I would not trust the exact measurements on a DMM until it
has proven its worth - give it +/- 20% uncertainty until you prove it is
more accurate - and remember that the leads contribute to stray
inductance and capacity too, so your measurement fixture can be a big
factor when measuring small values.

73,
Don W3FPR

Brett gazdzinski wrote:
> You can buy a DMM that measures inductance.
> I have a wavetech meterman model that was under $100.00
> that does capacitance from many micro farads to pico farads,
> inductance from henrys to micro henrys, frequency
> to 10 Mhz, plus all the other usual DMM stuff.
>
>
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David Pratt-2

Re: K2 - RF choke identification

In reply to this post by Brett gazdzinski-2

I can recommend the Almost All Digital Electronics L/C meter Model IIB,
available as kit at $99.95.
http://www.aade.com/lcmeter.htm

It can be built in a couple of hours and works a treat.

73

David G4DMP

In a recent message, Brett gazdzinski
<[hidden email]> wrote ...
>You can buy a DMM that measures inductance.
>I have a wavetech meterman model that was under $100.00
>that does capacitance from many micro farads to pico farads,
>inductance from henrys to micro henrys, frequency
>to 10 Mhz, plus all the other usual DMM stuff.

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Brett gazdzinski-2

RE: K2 - RF choke identification

In reply to this post by Don Wilhelm-4

In most cases, I don't think you need to be more than
in the ballpark, at least when identifying parts.

My cheap meter reads 14 pico farads with nothing
hooked up, and has no null knob.
I just ADD 14 pico farads to the small values.
A 1 pico farad cap reads as 15....

Inductance seems much better, and I don't often need
to know the exact value of parts, just a ballpark or comparison
to other parts (to find matching parts), or a range.

I often compare known value new parts with old or unknown
parts to get the values close enough.

A real LC meter would be nice, and they sell them cheap
also, but you get what you pay for.

If you need a DMM, or have a limited test equipment budget,
it might pay to get one that measures inductance and capacitance,
even if its not precise...

Brett
N2DTS

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Don Wilhelm
> Sent: Friday, August 24, 2007 8:50 AM
> To: [hidden email]
> Subject: Re: [Elecraft] K2 - RF choke identification
>
> I finally broke down an purchased the AADE L/C meter after I
> got tired
> of doing the calculations required when using my homebrewed K6OLG LC
> Tester (the AADE meter is based on that LC Tester). I
> believe it is a
> bit more trustworthy for small values than the typical DMM with
> capacitance and inductance measurement capability, but if all
> you have
> is the DMM, it can be a big help. Some DMM LC measurements
> can be quite
> accurate, but I would not trust the exact measurements on a
> DMM until it
> has proven its worth - give it +/- 20% uncertainty until you
> prove it is
> more accurate - and remember that the leads contribute to stray
> inductance and capacity too, so your measurement fixture can be a big
> factor when measuring small values.
>
> 73,
> Don W3FPR
>
> Brett gazdzinski wrote:
> > You can buy a DMM that measures inductance.
> > I have a wavetech meterman model that was under $100.00
> > that does capacitance from many micro farads to pico farads,
> > inductance from henrys to micro henrys, frequency
> > to 10 Mhz, plus all the other usual DMM stuff.
> >
> >
> _______________________________________________
> Elecraft mailing list
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> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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>
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> Elecraft web page: http://www.elecraft.com
>

Brett gazdzinski-2

RE: K2 - RF choke identification

In reply to this post by David Pratt-2

But it only does small values....

I often need to measure caps to 100 mf, chokes to
50 henrys....

Brett
N2DTS

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of David Pratt
> Sent: Friday, August 24, 2007 9:28 AM
> To: [hidden email]
> Subject: Re: [Elecraft] K2 - RF choke identification
>
> I can recommend the Almost All Digital Electronics L/C meter
> Model IIB,
> available as kit at $99.95.
> http://www.aade.com/lcmeter.htm
>
> It can be built in a couple of hours and works a treat.
>
> 73
>
> David G4DMP
>
> In a recent message, Brett gazdzinski
> <[hidden email]> wrote ...
> >You can buy a DMM that measures inductance.
> >I have a wavetech meterman model that was under $100.00
> >that does capacitance from many micro farads to pico farads,
> >inductance from henrys to micro henrys, frequency
> >to 10 Mhz, plus all the other usual DMM stuff.
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

Don Wilhelm-4

Re: K2 - RF choke identification

In reply to this post by Brett gazdzinski-2

Brett,

You are absolutely correct - when identifying parts the meter does not
have to be accurate, a relative measurement will do fine. My point is
that one must realize the fact that all such DMM capacitance/inductance
measurements can be subject to these inaccuracies. Use what you have,
but use it intelligently - 'technician, know your tools' (and their
limitations).

73,
Don W3FPR

Brett gazdzinski wrote:
>
> In most cases, I don't think you need to be more than
> in the ballpark, at least when identifying parts.
>
>
>
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Sam Morgan

Re: K2 - RF choke identification

In reply to this post by David Pratt-2

David Pratt wrote:
> I can recommend the Almost All Digital Electronics L/C meter
>
snip
while we are going along this route,
I also have an LCRZ meter I will highly recommend...
the M3 LCRZ meter was an easy assemble
and has exceeded all my hopes and expectations
http://www.m3electronix.com/saleslcr.html

try it you'll like it <g>

usual disclaimer....
just a very satisfied customer
--
GB & 73's
KA5OAI
Sam Morgan
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