Welcome to Australia's only Vintage Radio and Television discussion forums. You are not logged in. Please log in below, apply for an account or retrieve your password.
Australian Vintage Radio Forums
  Home  ·  About Us  ·  Discussion Forums  ·  Glossary  ·  Outside Links  ·  Policies  ·  Services Directory  ·  Safety Warnings  ·  Tutorials

Tech Talk

Forum home - Go back to Tech talk

 Centre tapped 6.3 volt heater winding.
« Back · 1 · Next »
 Return to top of page · Post #: 1 · Written at 3:19:37 PM on 19 April 2024.
Bowler's Gravatar
 Location: Bongaree, QLD
 Member since 26 October 2018
 Member #: 2308
 Postcount: 81

Good Afternoon all, can somebody explain the necessity to provide a centre tapped heater winding in a valve radio. bowler


 
 Return to top of page · Post #: 2 · Written at 7:52:55 PM on 19 April 2024.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5303

The general idea relates to hum cancelation it is most common on sets where it has a filament rather than a heater and its an AC filament.

It is however, not unusual on some heater tubes; However, it should be noted that the heater tubes will only be grounded via that centre tap.

A fact of life is that you can get hum modulation at the Mixer and sometimes from heater to cathode leakage.


 
 Return to top of page · Post #: 3 · Written at 10:31:39 AM on 22 April 2024.
Bowler's Gravatar
 Location: Bongaree, QLD
 Member since 26 October 2018
 Member #: 2308
 Postcount: 81

Thanks Marcc, your reply was most informative . bowler


 
 Return to top of page · Post #: 4 · Written at 10:06:24 AM on 4 May 2024.
6A8G's Gravatar
 Location: Wellington, NZ
 Member since 24 July 2009
 Member #: 517
 Postcount: 63

& don't forget if your transformer doesn't have a centre tap you can manufacture one by installing a 100-ohm resisistor from each side of the winding to ground. A rating of one watt is sufficient.
-JR.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
6A8G.

 
« Back · 1 · Next »
 You need to be a member to post comments on this forum.

Sign In

Username:
Password:
 Keep me logged in.
Do not tick box on a computer with public access.