passive LC delay line design help

[diggy fresh]

I'm experimenting with something similar to a Hammond roto scanner.

i need to compute a passive delay line of 500ns, 1ms. Not sure yet about impedance requirement but should be driveable by normal line level stuff and picked up by line input.

i dont mind the number of components, i have a lot of small 1mh inductors and dont mind winding some, (idealy they'd be much smaller than the 500mh hammond uses.

I'm no EE, so i'm kinda confused with all the formulas made mostly for rf stuff..


Anybody can help?
i'm not fluent in simulations yet but if you guys know a good calculator it would help, i'm having problems interpreting the results i get using the calculators i found.

Thanks
regards

 

[abbey road d enfer]

I'm experimenting with something similar to a Hammond roto scanner.

i need to compute a passive delay line of 500ns, 1ms.

Most passive delay lines don't have constant delay. Their nominal delay is within a restricted range.

Not sure yet about impedance requirement but should be driveable by normal line level stuff and picked up by line input.

i dont mind the number of components, i have a lot of small 1mh inductors and dont mind winding some, (idealy they'd be much smaller than the 500mh hammond uses.

If this value is correct, with the 5.6nF capacitors, the response is somewhat flatt-ish up to 6kHz, but delay is a maximum of about 0.9ms (55us per tap) somewhat constant up to 1kHz but quite varaiable after that (-70/+300%).
For the intended purpose, delay accuracy is not a requisite

nybody can help?
i'm not fluent in simulations yet but if you guys know a good calculator it would help, i'm having problems interpreting the results i get using the calculators i found.

A calculator won't be any help, because they are intended for well-constrained fequency response, which is not the case for the vibrato effect in the Hammond organs.
A simulator, such as LTspice, is what you want.


With 1mH inductors, you would need 2.8uF capacitors, a very low source impedance capable of driving 20 ohms, because that's the correct load.
With 10mH inductors, you would need 0.28uF caps, load the thing with about 200 ohms and you could drive it from a beefy output stage.

 

[diggy fresh]

Thanks Abbey! This clears up a few things for me.
here's one version of the hammond delay line and scanner

caps are 22nf and inductor supposedly 500mh. I'm guessing the impendance is way higher.

i'll try it in Ltspice!

 

[abbey road d enfer]

caps are 22nf and inductor supposedly 500mh. I'm guessing the impendance is way higher.

IDK what you mean by that.
The delay line is driven by a 1.8kohm source and loaded with about 14-30 kohm.