[Guest]

Mounted below the big honking speaker of my 37-116 are three devices that, at first glance, appear to be tweeters (about 6" or so in diameter), but aren't. They have no wiring attached; in fact, they don't have terminals. They just have a rubber-looking strap running from one side of the frame across the center point of the cone (and attached there) and on over to another point on the frame. Are these things resonators or what?

Thanks, guys.
Jim

[Ron Ramirez]

Passive radiators.

Philco's name for them at the time was "Acoustic Clarifiers."

A couple of pages explaining their use:

http://en.wikipedia.org/wiki/Passive_radiator_(speaker)

http://www.diysubwoofers.org/prd/

(edited by site admin to correct link)

[Guest]

Thanks, Ron. When I was composing that post, the term "passive radiator" was lurking somewhere way back in my vocabulary but I just couldn't seem to locate it. So "resonator" had to suffice.

Jim

[PTurney]

Hi everyone,

It's been a while since I've posted here, but I do check in every day!

Just thought you may be interested in the original patent filed by Philco for their acosutic clarifiers. http://www.google.com/patents?id=4KdBAAA...dq=2059929

Hit the "Read this patent" to see the patent (then scroll up to see the associated figures).

The layout of these devices shown in the patent of course corresponds to the 1936 model 116X, but the principles apply to other sets using them also.

Google patents is a gold mine of info on old radios & it's totally free. I've spent hours searching through...

Paul http://www.tuberadioland.com

[Ron Ramirez]

Hi Paul

Welcome back. VERY neat link! Thanks for providing it.

[Guest]

Hello Paul,

Thanks for the patent link to Google. It should prove to be useful. And thanks very much for all the links on your Web site!

Jim