UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Components and Circuits

Notices

Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

Reply
 
Thread Tools
Old 23rd Apr 2024, 5:27 pm   #1
mole42uk
Nonode
 
mole42uk's Avatar
 
Join Date: Aug 2010
Location: Resolven, Wales; and Bristol, England
Posts: 2,621
Default 0.04mH Choke?

I've a Pye 2010 car radio chassis that has this choke on the power supply cable. It's a little disgruntled at the moment but measures 0.04mH and 0.3ohms. It's close wound in 3 layers on a 5.16" x 1" piece of ferrite rod. I plan to make it better again but wanted to make sure that the measurements seem reasonable for this choke?
Attached Thumbnails
Click image for larger version

Name:	Choke.jpeg
Views:	152
Size:	70.4 KB
ID:	296788  
__________________
Richard

Index:
recursive loop: see recursive loop
mole42uk is offline   Reply With Quote
Old 23rd Apr 2024, 5:43 pm   #2
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,082
Default Re: 0.04mH Choke?

It looks like it may have been overheated, if so you could have shorted turns which will significantly reduce any measurable inductance.
__________________
I'm the Operator of my Pocket Calculator. -Kraftwerk.
G6Tanuki is offline   Reply With Quote
Old 23rd Apr 2024, 6:40 pm   #3
mole42uk
Nonode
 
mole42uk's Avatar
 
Join Date: Aug 2010
Location: Resolven, Wales; and Bristol, England
Posts: 2,621
Default Re: 0.04mH Choke?

Further investigation (I unwound it) reveals that much of the silk has burnt away, so any measurements will be meaningless. I counted the turns and will rewind in enamelled wire.
__________________
Richard

Index:
recursive loop: see recursive loop
mole42uk is offline   Reply With Quote
Old 23rd Apr 2024, 6:54 pm   #4
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 28,114
Default Re: 0.04mH Choke?

I wouldn't expect the inductance to be very critical.
paulsherwin is offline   Reply With Quote
Old 24th Apr 2024, 6:15 am   #5
mole42uk
Nonode
 
mole42uk's Avatar
 
Join Date: Aug 2010
Location: Resolven, Wales; and Bristol, England
Posts: 2,621
Default Re: 0.04mH Choke?

Quote:
Originally Posted by paulsherwin View Post
I wouldn't expect the inductance to be very critical.
I doubt it is, but it’s a curious little device and I’d like to rewind it just for interest. I’ve to measure the wire gauge and see if my stash of enamelled wire has anything suitable.
__________________
Richard

Index:
recursive loop: see recursive loop
mole42uk is offline   Reply With Quote
Old 24th Apr 2024, 6:58 pm   #6
John_BS
Octode
 
John_BS's Avatar
 
Join Date: Dec 2008
Location: Wincanton, Somerset, UK.
Posts: 1,786
Default Re: 0.04mH Choke?

Did you mean inches or cms in your first post?

J
John_BS is offline   Reply With Quote
Old 24th Apr 2024, 7:03 pm   #7
mole42uk
Nonode
 
mole42uk's Avatar
 
Join Date: Aug 2010
Location: Resolven, Wales; and Bristol, England
Posts: 2,621
Default Re: 0.04mH Choke?

Inches - the 5/16" got a little error.

Unfortunately I grew up in inches and was expected to convert to metric in the early '70's when taking 'O' levels in engineering subjects...I still haven't made a seamless transition.

Having rewound the device I measure ten times the impedance.
__________________
Richard

Index:
recursive loop: see recursive loop

Last edited by mole42uk; 24th Apr 2024 at 7:12 pm.
mole42uk is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 5:39 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.