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.

Closed Thread
 
Thread Tools
Old 18th Oct 2017, 10:20 am   #21
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: Push fit connectors for EHT/ RF, high current?

There's a calculator here for what it's worth:

http://chemandy.com/calculators/roun...calculator.htm

Lawrence.
ms660 is offline  
Old 18th Oct 2017, 10:30 am   #22
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,684
Default Re: Push fit connectors for EHT/ RF, high current?

Quote:
Originally Posted by astral highway View Post
Thanks Russell, it's helpful to see that effect quantified exactly for the design f.
You're welcome. There's a good section about skin effect losses in Terman and the equation for single round-section copper wire is on page 32. I believe Terman (Radio Engineers' Handbook) is available as a free download, if you haven't a copy. But it appears in the downloadable New England wire catalogue (Litz and winding Wire section) amongst other places.

https://www.newenglandwire.com/newt-catalog.pdf

More importantly, I guess you have to use what you've got, and that's that!
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline  
Old 18th Oct 2017, 5:42 pm   #23
Al (astral highway)
Dekatron
 
Al (astral highway)'s Avatar
 
Join Date: Nov 2006
Location: London, UK.
Posts: 3,496
Default Re: Push fit connectors for EHT/ RF, high current?

Quote:
Originally Posted by russell_w_b View Post
More importantly, I guess you have to use what you've got, and that's that!
Yes, it does come down to that. Otherwise it's overspend time - another £45 or so for some thicker stuff.

I have 2mm enamelled copper here, and as I'll hardly ever be operating in CW mode, except for bursts of a few seconds, I think it will be fine. Duty cycle will be between 10 and 25%, and it's already only in class C.

Also, if I'm going to be pulling loops out for tuning, 2mm is about the limit of workable, especially if twisted to 4mm!
__________________
Al
Al (astral highway) is offline  
Old 19th Oct 2017, 9:34 am   #24
Argus25
No Longer a Member
 
Join Date: Oct 2016
Location: Maroochydore, Queensland, Australia.
Posts: 2,679
Default Re: Push fit connectors for EHT/ RF, high current?

Quote:
Originally Posted by astral highway View Post
if I'm going to be pulling loops out for tuning, 2mm is about the limit of workable, especially if twisted to 4mm!
Astral highway, I would avoid twisting this 2mm wire. Bring a straight length out bent perpendicular to the former surface, make the loop and a straight section back in with another sharp bend to get the wire back into the correct position to keep winding. Have the straight sections leading to the loop touching each other and if you wanted you could solder them together on the straight section too (if the enamel was removed there) to stop the loop pulling apart as you continue to wind the coil.
Argus25 is offline  
Old 19th Oct 2017, 12:01 pm   #25
Al (astral highway)
Dekatron
 
Al (astral highway)'s Avatar
 
Join Date: Nov 2006
Location: London, UK.
Posts: 3,496
Default Re: Push fit connectors for EHT/ RF, high current?

Quote:
Originally Posted by Argus25 View Post
Astral highway, I would avoid twisting this 2mm wire...
Hey Argus25, I saw this just in time - I'm starting on the winding!

Thanks for your recommendation I will try that technique. The soldering idea is a good one, too, as I'm taking out individual turns and even a half turn, for fine tuning, towards the end of the winding.
__________________
Al
Al (astral highway) is offline  
Old 19th Oct 2017, 1:32 pm   #26
Guest
Guest
 
Posts: n/a
Default Re: Push fit connectors for EHT/ RF, high current?

A rather neat "turns selector" I saw years ago was two bits of copperclad PCB about an inch wide made into a clip. The insulation stopped shorting to adjacent turns and the width allowed high currents without overheating.
 
Old 21st Oct 2017, 12:13 am   #27
Al (astral highway)
Dekatron
 
Al (astral highway)'s Avatar
 
Join Date: Nov 2006
Location: London, UK.
Posts: 3,496
Default Re: Push fit connectors for EHT/ RF, high current?

Neat suggestion, MM. I like it; I might try that one, thank you
__________________
Al
Al (astral highway) is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 3:12 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.