Resistors as Chokes
Displaying 1-3 of 3
| Jun 9th 2015, 18:01 | |
wd6ejnTotal Topics: 0 Total Posts: 0 |
When I was a kid I had a project that used resistors as self wound chokes, I know a bout the power of resistor but does the value of the resistor effect the permiabillity of the choke? |
| Jun 9th 2015, 18:20 | |
W1VTSuper Moderator Total Topics: 0 Total Posts: 0 |
The resistive materials that I can think of, namely carbon and nichrome, are non-magnetic, but who knows what you might find at the hamfest. I would measure it if I had any doubts about it. Preferably at the frequency of interest--an antenna analyzer is a readily available tool for doing this. Zack Lau W1VT ARRL Senior Lab Engineer |
| Jun 9th 2015, 21:23 | |
wd6ejnTotal Topics: 0 Total Posts: 0 |
I'm trying to make a low pass filter for a very tinny high impedance high gain microphone preamp (stereo hearing aid Ramsey Electronics) that I am specially building for a senior lady here and she also says it picks up too much back round noise rather then who she is speaking with, here's another problem! how do I add a third microphone to make it noise cancelling,,,L-R ? using home made low pass filter? I wound these coils on 100-400k 1/4 watt resistors each coil is around 1k of resistance and a bout 1/4 of an each round. to make three series coils or six for both channels. There seems to be a very small attenuation of the higher but not much. I think I may have created a business here as another senior may want one! The only way to check this is to substitute a coil for an existing one in an existing circuit and listen on a sw receiver as my mfj analyzer bit the dust a long time ago I added some iron by making e-cores out of used magnetic business cards, so it seems to work in the audio range, I just use a paper circle cutter. Oh! I now stick all my resistor projects to rare earth magnets instead of placing in a cheap box or pill bottle....I hope this doesn't do any thing or damage the resistor. Although quite large, I'm now winding coils on surplus 1 watt resistors, this seems to have knocked the frequency down, now I have a boom box amp. |
Displaying 1-3 of 3
