Speaker Polarity Tester w/ AD8302 Phase Detector Module

A simple Speaker Polarity Tester you can build that utilizes an AD8302 Phase Detector Module, two 2N3904 transistors and just a few other components.
The schematic can be downloaded from the following folder at:
Speaker Polarity Tester
drive.google.com/drive/folder...
A great resource for reference below:
How to Test Speaker Polarity & Does Speaker Polarity Matter - Audio University
audiouniversityonline.com/spe...
Thanks for watching and subscribing to my channel on vintage radio repair and other related circuits.
#restoreoldradios

[@RestoreOldRadios]

I made one change to the circuit to improve the sensitivity from the pick-up coil; 10K ohm resistor changed to 1K ohm. The schematic has been denoted. Don

[@aa1ww]

The AD8302 is such a nice component. Because of its wide bandwidth, it makes the core of a versatile HF/VHF/UHF LC meter. Thanks again for your your focus on tools as well as on restoration.

[@RestoreOldRadios]

Jeff, I appreciate it. I need to explore the other possibilities you noted as well. All the best. Don

[@rciancia]

Don - that is a very cool device. I love your inventions very much - it shows how forward thinking you are... excellent !!!!

[@RestoreOldRadios]

Much appreciated Ron. It gave me something new to try on a cold winter day as well. I’m thinking the solution (with a few circuit changes) could be used on IF transformers and loudspeakers with humbucking coils as well. Best, Don

[@roncaruso931]

Thanks for uploading. I will build mine.

[@RestoreOldRadios]

Ron, thanks for watching and I hope your build goes well. Best, Don

[@jp040759]

VERY COOL

[@RestoreOldRadios]

jp - thank you, I appreciate you watching. All the best. Don

[@apexmcboob5161]

Hi Don, great idea. Can you clarify please, is the pickup coil used inductively or acoustically? Thanks.

[@RestoreOldRadios]

Thanks for watching and reaching out. It’s an inductive solution. I did play around with a microphone too, but got much better results using the inductive telephone pick-up coil. Hope this helps. Best, Don

[@davido.hamilton3254]

Hello Don...thank-you for all you do! Would you please explain what's wrong with just using a 1-1/2 volt 'A' cell across the voice coil and see whether the cone moves 'out' or 'in'? Thus any 'parallel' speakers will be in phase with the 1st. one if done the same way. Thanx. David O.

[@RestoreOldRadios]

David, the 1-1/2V battery solution works great as you described/noted. My design is better suited for speaker(s) in an enclosure or alike where a visual inspection of the cone movement under test is not possible/practical. Thanks for reaching out and your kind words. All the best. Don

[@davido.hamilton3254]

@@RestoreOldRadiosBless Your Bunions! Don.