[ducretet]

Hello,
I recently purchased a 511. No speaker.
Speaker 211 is hard to find. And in good condition.
Could it work with the RCA 100-A ?. This speaker is easily found on ebay.

[Ron Ramirez]

Yes, it will work with any high impedance speaker. Or, by using an output transformer of suitable impedance, say, 2000 or 3000 ohms input inpepdance, you could then use it with any modern speaker.

[ducretet]

Thanks Ron. He knew the subject of the modern speaker. But, I like to keep the antique look as much as possible.
I had doubts that it could work properly with the RCA 100-A.

[Ron Ramirez]

Understood. Both the RCA and Philco speakers are high impedance - I don't remember the exact numbers, but somewhere around 2000 ohms impedance - and either will work with the 511.

Philco 211 Series speakers used pot metal parts, and as a result, most are now inoperative. On the other hand, the RCA 100 series of speakers (100, 100-A, 100-B, 103) were made with better materials and are often still good.

Be aware: the RCA speakers have a "Tone Filter" that filters out the low notes, so it will sound much like a horn speaker (all treble, no bass). Not that the Philco speakers were any better (they weren't).

[RodB]

I had the same situation with the 514 I restored. Used a 70V line transformer from Parts Express and an 8 ohm speaker mounted in a RCA 100 enclosure. Worked great. Here's the link to the transformer:
https://www.parts-express.com/70V-10W-Li...er-300-040
There's a 2000 ohm tap on the primary.

[Ron Ramirez]

Cool, thanks for the link. It's certainly cheap enough. The frequency response of that transformer isn't "high fidelity" (100 to 12,000 Hz) but quite adequate for a 511 Series radio. Hmmm...I have an empty 211 series speaker housing, and a Mandarin Red 512 with no speaker... 

[ducretet]

Perfect!!! Thanks

[RodB]

Ron, here's a photo of the one I did. The transformer mounted in the back. Wasn't difficult to put together.