IF transformers - UK Vintage Radio Repair and Restoration Discussion Forum

LA9CHA Thorvald · 27th Sep 2020, 8:57 pm

Hello, anybody who can tell me which are the primary and secondary coils (upper or lower) in an IF transformer (with "silvered mica" disease)? The transformer is used in vintage battery radios with 96 series 7-pin valves.

Davewantsone · 28th Sep 2020, 2:10 pm

In a standard 470kHz IF can with a quarter inch tuning slug, the top coil is the primary.

LA9CHA Thorvald · 30th Sep 2020, 11:31 am

Hello Dave and many thanks for answer. I have to mention that in my case the IF freq is 460kHz, and the slugs are ca. 1/2" OD. The valves are for the 91 series, not 96!(sorry). Assume that the orientation of the coils are the same!

27th Sep 2020, 8:57 pm	#1
LA9CHA Thorvald Pentode Join Date: Dec 2019 Location: Egersund, Norway Posts: 208	IF transformers Hello, anybody who can tell me which are the primary and secondary coils (upper or lower) in an IF transformer (with "silvered mica" disease)? The transformer is used in vintage battery radios with 96 series 7-pin valves.

28th Sep 2020, 2:10 pm	#2
Davewantsone Hexode Join Date: Dec 2011 Location: Wigan, Greater Manchester, UK. Posts: 291	Re: IF transformers In a standard 470kHz IF can with a quarter inch tuning slug, the top coil is the primary.

30th Sep 2020, 11:31 am	#3
LA9CHA Thorvald Pentode Join Date: Dec 2019 Location: Egersund, Norway Posts: 208	Re: IF transformers Hello Dave and many thanks for answer. I have to mention that in my case the IF freq is 460kHz, and the slugs are ca. 1/2" OD. The valves are for the 91 series, not 96!(sorry). Assume that the orientation of the coils are the same!