A Audio and hi-fi forum. AudioBanter.com

Go Back   Home » AudioBanter.com forum » rec.audio » Vacuum Tubes
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

rarity of LF and HF adjustable coils, coil forms, etc.

Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old April 2nd 21, 08:50 AM posted to rec.audio.tubes
Big Bad Bob
external usenet poster
Posts: 366
Default rarity of LF and HF adjustable coils, coil forms, etc.

There seems to be a general LACK of non-N.O.S. and
non-ripped-out-of-gear RF coils for LF and HF band, ESPECIALLY the coil
forms needed to wind your own, particularly ADJUSTABLE ones.

If you're into antique radio restoration this could be a SERIOUS problem!

I _HAVE_ seen sources for ferrite [and most likely powdered iron as
well] core material as ferrite rods, though. There are also toroidal
ferrite beads of an appropriate length that would work.

So getting cor ematerial isn't the problem. It's the COIL FORM that is
the problem!

I think I have a solution involving a 3D printer, nylong screws and
nuts, and those ferrite rods of various dimensions.

Here's the basic plan: Using a ferrite or powdered iron core of a
reasonably correct size, construct a coil form around it that could work

* IF transformer inside of a can
* Peaking or resonant circuit inside or outside of a can
* ratio detector transformers

you'd use a 3D printer to make an appropriate coil form with the right
inside/outside diameter

You'd attach some kind of adjusting yoke, or make it part of the 3D print

You'd use nylon screw and nuts to make the adjustment stem

You'd glue a nut onto the core, and then attach [and glue] the nylong
screw to it

Now you have an adjustable inductor, one that may even fit in the
original can [if there is one], which you can wind yourself as necessary
using standard available coil wire.

This is all DO-able, and might solve the problem of HYPER-EXPENSIVE
N.O.S. parts and (generally) unavailable coil forms.

(aka 'Bombastic Bob' in case you wondered)

'Feeling with my fingers, and thinking with my brain' - me

'your story is so touching, but it sounds just like a lie'
"Straighten up and fly right"

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Low-Output MC Coils [email protected] High End Audio 6 July 15th 06 11:10 PM
QLogic Q-Forms Accord 01/(99/02) opinions wanted Ethan Car Audio 0 August 27th 04 01:13 AM
Voice Coils MarkZimmerman Tech 3 July 10th 04 04:09 PM
Proproduction forms? T. Day Pro Audio 0 November 19th 03 07:01 PM
dual coil vs single coil JohanWagener Car Audio 9 July 18th 03 09:12 PM

All times are GMT +1. The time now is 09:11 PM.

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Copyright 2004-2022 AudioBanter.com.
The comments are property of their posters.