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Experimenting with radio frequencies (50-150 MHz) I found that parasitic inductance of resistor can cause problems. Reading about resistors technologies (THT) seams that the parasitic inductance of a resistor is mainly generated by their construction method instead of their material. In film resistor they cover a support with carbon or metal "films" than they cut an helix along the resistor to simulate a "wire" of known resistance. I found that old resistor were made by conductive powder pressed to form the resistor, those type of resistor are non inductive (no helix shaped conductor) but are bad in any other parameter. I will exclude wirewound resistors for cost reasons.

Because I cannot find precise information about the resistance vs frequency behavior of resistors what resistor could be used to make radio circuits without care so much about parasitic inductance?

EDIT: I found this article EDN. It is very interesting how Z changes increasing the frequency. Seams that resistors have around 14 nH of parasitic inductance so the "problems" will shows up to 100 MHz. Suggesting a test to measure the parasitic inductance of resistor should be a must but I don't want to open another question.

winny
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gino
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    The word is helix, not elix. – Hearth Jun 07 '23 at 15:10
  • Search "RF resistors", not "resistors". – DKNguyen Jun 07 '23 at 15:14
  • @DKNguyen already done, only one question about this topic but they mention SMT resistors (metal film) my question is specifically related to THT technology. If I understand the problem in the right way... is the "helix" shaped resistor that make the inductance (parasitic) and the "helix" is not present in SMT – gino Jun 07 '23 at 15:17
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    I meant when searching resistors to buy, not on SE. Normal SMT has a snaking meander which still has inductance and capacitance. – DKNguyen Jun 07 '23 at 15:17
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    the old resistors you're talking about are referred to as carbon composition resistors, incidentally. The modern equivalent is called ceramic composition, but they're fairly expensive. – Hearth Jun 07 '23 at 15:49
  • I designed a 88-108 MHz FM receiver around cheap THT metal oxide film resistors. Effort towards impedance matching had greater impact on performance than trying to optimize parasitics. Of course try to minimize leads, but that type of resistor should be sufficient at the lower end of your spectrum. – Yousif Alniemi Jun 07 '23 at 17:01
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    What **value** resistor? Self-capacitance likely dominates for high resistance, while self-inductance likely dominates for low resistance. – glen_geek Jun 07 '23 at 17:42
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    This is potentially a duplicate of https://electronics.stackexchange.com/questions/411069/passive-elements-at-high-frequency-parasitic-effects to which I just added some detail you may find useful, but since you want an answer about THT resistors specifically, probably better to keep this separate from that. – Tim Williams Jun 07 '23 at 18:31
  • @Hearth Are there even signal-type ceramic composition resistors? All the ones I've seen are really expensive and large snubber resistors. – DKNguyen Jun 07 '23 at 19:08
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    @DKNguyen I have no idea. They certainly are expensive, though. – Hearth Jun 07 '23 at 19:55

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