Hammond 158M specs.

[EarWorm]

I see that the TRIAD C7-X is a popular choice as a filter choke in the Crack it being 270 Ohms, but I'm having trouble with the specs of the Hammond 158M which is a sometimes alternative choice.

The problem I have is with the published specs for the Hammond 158M found on many seller sites and the specs for the Hammond 158M on the Hammond Manufater's site.

http://www.hammondmfg.com/153.htm

Parts Express, Mouser, Angela, Digikey, all list the Hammond 158M as having 262 Ohms. However the Hammond site states that the Hammond 158M is 195 ohm.

I sent an email to Hammond asking them what the specs for the Hammond 158M are.  195 or 262 ohm?

This was the reply. "Calculated DCR for 158M is 188.98ohms ±15%.".

Am I missing something?

also according to this chart from Hammond the Hammond 159M is rated at 256 Ohm, as it is also on seller sites.   

Are folks using the 159M in Crack amps?

[Paul Birkeland]

I would suspect that the Hammond website is correct.

The difference in DCR will not be that big of a deal, but if you want to be closer to spec, consider the 157M.

[bjorgens]

They are not 262 ohms.  I know because I ordered a couple from mouser, measured, then returned them. . Mouser's specs are mistaken

Bryan

[Doc B.]

It's not at all unusual for DCR specs to change over time on an inductor or transformer that has been in production for years. Always worth getting the latest info right from the manufacturer.

[bjorgens]

Yep... Lesson learned, and Mouser was very accommodating.

B

[EarWorm]

How important is the inductance rating?  Is there a difference between 10H and 15H choke rating, or does it not matter much since the real benefit is how much better a choke is for smoothing than resistors and a 5H difference isn't of consequence?

[Doc B.]

The short answer is not much. The best answer is model it in PSUD and see how much difference it makes. PSUD can be a little intimidating the first time you use it but for free software it is a great modeling tool.