Etherwave 3 Pi Inductors

Posted: 3/3/2022 11:17:08 PM
20ola02

Joined: 3/3/2022

Hi, 

Im currently looking for some 3 Pi inductors, but as I have read on the forum this is no easy task! 
I found some stores that claimed they had them. 
Im not sure if these are legit. Except infinity-semiconductor, they have a bad rep for just taking the money. 

Here is a list for those who is interested:

https://www.chip1.com/search?partno=6306-RC 
https://www.infinity-semiconductor.com/product/Bourns,Inc_6306-RC.aspx 
https://no.component-world.com/product/Bourns,Inc/6306-RC.html
https://www.peawo.com/Bourns/6306-RC--95220190.html

The question is: 

Does anyone know of a safe and reliable store that selles the three values 2.5, 5 and 10mH? 
Or does some of these stores look legit?
Is there someone on the forum who is willing to sell me some? 
Or is it even possible to make these myself? 

Looking forward to your answers!

Posted: 3/4/2022 1:37:05 AM
oldtemecula

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014


I think you should study these 10 MH inductors. Each side is 10 MH, separate them. The antenna circuit just needs to resonate, then tune it to maximum voltage slightly lower in frequency than the pitch oscillator frequency. They also have dual 2.5 MH which can be 5 MH


I dedicate my computer programming skills today to profit from the stock market which funds my self-funded local food pantry, Café Temecula of 25 years. The past three years have been challenging. My daily stock updates are real, unlike all the make believe or 95% of mostly fake stock trading forums out there. This is my "magnum opus"  TheGame PDF

Posted: 3/5/2022 7:09:36 PM
JPascal

From: Berlin Germany

Joined: 4/27/2016


Hi,
could you tell something about your project? If you want to build a diy theremin, in the majority of cases you can use solid ferrite or ferrite powder core coils.
For example a german supplier: https://www.reichelt.de/index.html?ACTION=446&LA=2&nbc=1&q=festinduktivit%C3%A4t%20mh

Air cored coils are able to guarantee a low temperature dependency, if in addition a suitable oscillator circuit is at the start.They will probably no more be available on the common electronic market.

Posted: 3/8/2022 3:59:12 PM
glenlivet

Joined: 7/18/2020

I was a heavy user of these devices once upon a time.

There are three values of Pi-wound inductors used in the Etherwave.
3- 10mH, J.W Miller P/N 6306/Hammond Mfg P/N 1535-G
1- 5mH, J.W Miller P/N 6304/Hammond Mfg P/N 1535-D
2- 2.5mH, J.W Miller P/N 6302/Hammond Mfg P/N 1535-B

I hate to be the bearer of bad news but the inductors you are looking no longer exist in production.
When Bourns acquired J.W. Miller circa 2006 they dropped them like a hot potato. Hammond Manufacturing
discontinued them about four years ago when their offshore manufacturer (no doubt India or China) no longer wanted to produce them.
Of course Hammong Mfg. never bothered to send out a last buy notification like most electronics manufacturers they just dropped them
cold turkey and left all of their customers that were using them in production holding the proverbial excrement covered end of the stick.
I even spoke to the product manager at Hammond Mfg. HQ in Canada who told me they were going to start producing them again in their
Canada facility but "somebody threw out the specialized lattice coil winding machine needed to wind them. I was all over the world trying to
find a custom winding shop to make them for me in quantity but nobody ever got back to me. I would hate like hell to be in the business of
manufacturing terrestrial radio equipment these days! This is no doubt the reason that Moog dropped the Etherwave.
 


Posted: 3/19/2022 2:55:45 PM
20ola02

Joined: 3/3/2022

I think you should study these 10 MH inductors. Each side is 10 MH, separate them. The antenna circuit just needs to resonate, then tune it to maximum voltage slightly lower in frequency than the pitch oscillator frequency. They also have dual 2.5 MH which can be 5 MHI dedicate my computer programming skills today to profit from the stock market which funds my self-funded local food pantry, Café Temecula of 25 years. The past three years have been challenging. My daily stock updates are real, unlike all the make believe or 95% of mostly fake stock trading forums out there. This is my "magnum opus"  TheGame PDF

Thanks for the reply, I bought a pair of the 10mH version. By separating them do you mean physically or electrically i.e one side floating/not connected to anything? If you mean physically separating them, what should i use, a diamond saw or a normal hacksaw? 

Hi,
could you tell something about your project? If you want to build a diy theremin, in the majority of cases you can use solid ferrite or ferrite powder core coils.
For example a german supplier: [color=#428bca]https://www.reichelt.de/index.html?ACTION=446&LA=2&nbc=1&q=festinduktivit%C3%A4t%20mh
[/color]

Air cored coils are able to guarantee a low temperature dependency, if in addition a suitable oscillator circuit is at the start.They will probably no more be available on the common electronic market.


Yes it is a diy theremin project. Trying to replicate the offical EW PCB by using photos online, almost done with that. 

I was a heavy user of these devices once upon a time.
There are three values of Pi-wound inductors used in the Etherwave.
3- 10mH, J.W Miller P/N 6306/Hammond Mfg P/N 1535-G
1- 5mH, J.W Miller P/N 6304/Hammond Mfg P/N 1535-D
2- 2.5mH, J.W Miller P/N 6302/Hammond Mfg P/N 1535-B

I hate to be the bearer of bad news but the inductors you are looking no longer exist in production.
When Bourns acquired J.W. Miller circa 2006 they dropped them like a hot potato. Hammond Manufacturing
discontinued them about four years ago when their offshore manufacturer (no doubt India or China) no longer wanted to produce them.
Of course Hammong Mfg. never bothered to send out a last buy notification like most electronics manufacturers they just dropped them
cold turkey and left all of their customers that were using them in production holding the proverbial excrement covered end of the stick.
I even spoke to the product manager at Hammond Mfg. HQ in Canada who told me they were going to start producing them again in their
Canada facility but "somebody threw out the specialized lattice coil winding machine needed to wind them. I was all over the world trying to
find a custom winding shop to make them for me in quantity but nobody ever got back to me. I would hate like hell to be in the business of
manufacturing terrestrial radio equipment these days! This is no doubt the reason that Moog dropped the Etherwave.

That is interesting, weird how they stopped when there seams to be a demand for them.

Posted: 3/19/2022 4:54:49 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

"That is interesting, weird how they stopped when there seams to be a demand for them."  - 20ola02

It's par for the course.  Looking to the open market to supply critical Theremin parts (coils, cases, etc.) is a sucker's game.  That's just the way it is.

Posted: 3/24/2022 9:18:26 PM
glenlivet

Joined: 7/18/2020

"That is interesting, weird how they stopped when there seams to be a demand for them."  - 20ola02It's par for the course.  Looking to the open market to supply critical Theremin parts (coils, cases, etc.) is a sucker's game.  That's just the way it is.

When JW Miller and Hammond MFG were making these parts their use in theremins was probably the furthest thing from their minds. The great bulk of these devices probably ended up as plate chokes in the final amplifiers of tube type transmitting equipment- which no doubt is also the reason for their disappearance.

musicfromtheether.com

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