Just a comment.

Even such a thing as a small 1/2-watt resistor has distributed R, L and C.

L and C can be calculated from physical dimensions.

A resistor can be treated as a helically-loaded transmission line in exactly
the same way as a helically-loaded antenna. If the frequency is high enough
the radiation resistance can be taken into account.

Just calculate the input resistance of the line with a short circuit at the
other end and the job is done. The performance of dummy-load resistors can
be determined in the same way.

If you (in the plural) are unable to do this then you are unworthy to call
yourselves engineers. Whatever happened to your education? ;o)

----
Reg

I've used these as a dummy load and they work
fine even at 440mhz..
http://www.ohmite.com/catalog/pdf/tah_tch_series.pdf
Mouser sells them..
http://www.mouser.com/catalog/620/415.pdf

Hope this answers your question..

-Pete

James Bond wrote:
are metal film resistors wirewound or not? I've been trying to find this one
out. Someone who I know says they're not so are suitable for RF but Maplin
catalog seems to say they are.


someone please help!

dr. x

On Mon, 29 Nov 2004 13:40:16 GMT, Pete D wrote:

I've used these as a dummy load and they work
fine even at 440mhz..
http://www.ohmite.com/catalog/pdf/tah_tch_series.pdf

I notice they say "very low inductance" but it would be nice to have a
figure!!!
--

"What is now proved was once only imagin'd." - William Blake, 1793.

I use them with no issues that I know of.

Perhaps someone else has the mathematical and physical explanation.

I measured a few with my LC meter in the L mode and was unable to measure
any L.


"James Bond" wrote in message
...
are metal film resistors wirewound or not? I've been trying to find this
one
out. Someone who I know says they're not so are suitable for RF but Maplin
catalog seems to say they are.


someone please help!

dr. x


---
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"Brian - KB9BVN" wrote in message
nk.net...
I use them with no issues that I know of.

Perhaps someone else has the mathematical and physical explanation.

I measured a few with my LC meter in the L mode and was unable to measure
any L.

"James Bond" wrote in message
...
are metal film resistors wirewound or not? I've been trying to find this
one
out. Someone who I know says they're not so are suitable for RF but Maplin
catalog seems to say they are.

someone please help!

dr. x

Just a simple explanation. Not a comprehensive review. I do not know what
meter, nor the circuit.

Your depending on the circuit in your meter.
Some Inductance measurement circuits need the resistive component to be
canceled out (balanced by a bridge) to read the inductance. It doesn't mean it
has no inductance, only that he resistance values is much higher than the
reactance of the inductor. Therefore the meter sees the resistance only.

To make it even worse, not all MF resistors are inductive.