Audio Project Amplifier Speaker Loudspeaker Kit
diyAudio.com diyAudio Forums Archive > Top > Amplifiers > Tubes
 
How do I measure OPT impedance? - Click HERE for Original Thread
roundel325
I've got a pair of telefunken OPTs. They are marked:

P=10,000Gktc
s1=4
s2=8

My first problem is that I don't know what leads are 4 and 8 ohm. Secondly, the input side has 3 leads, so I'm wondering if "Gktc" somehow means "center tapped" in german, which would be great, because I'd rather use the 5k primary if there is one....

Any help is appreciated. Thanks.

-Jared
speaker
Some Telefunkens used a common, 4-5 ohm, and a negative feedback tap on the secondary side. Output from the feedback usually went to the front-end. You do not have 4 & 8 ohms hook-ups.

Your unknown tap on the primary side maybe a humbucker tap. Some Telefunkens ran all B+ through the output transformers and then stripped it off, out-of-phase and sent to main supply filtering for the rest of the radio. It was out-of-phase to reduce hum because the radio was SE.

Do you know what model they came out of?

speaker

Page generated in 0.018971920013428 seconds with 16 queries,
spending 0.00904727 doing MySQL queries and 0.00992465 doing PHP things.

Powered by: Search Engine Indexer and vBulletin
Copyright ©1999-2009 diyAudio.com