Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Graetz 4R-216 Electrostatic Tweeter Replacement
#1

Hello all,

I've just started restoration on a RCA 5QR73PX (Graetz 4R-216 in disguise) that has a pair of electrostatic tweeters that don't seem to work; no sound from either.  I'm looking at replacing them with regular paper cone tweeters.  What I need is a plan on rewiring to the output transformer (diagram below).  I'm thinking that the separate secondary can be disconnected from the B+ and used for driving the tweeters and a crossover.  Otherwise, they can be connected to the main speaker through a 3 mfd crossover.
   
#2

Instead of buying paper cone tweeters, why not buy piezo tweeters and save yourself all the bother? You can find them at reasonable prices on ebay.
#3

Hi Mike. I've considered that but all the ones I've seen have one inch openings. This has 2-1/4 inches so I would have to make an adapter. I'm keeping that as a plan B.
#4

Hi Rod,

A quick search on eBay found these, not exact, but could easily be mounted to the existing board with just some new screw holes...

here's one

and...
another choice
and...

and another

and this, which is even closer...

and still another

As the old saying goes, "Seek and ye shall find." I knew about this source for these because I was looking for some tweeters to use when I get around to building a cabinet for my Scott 800B

Hope this saves you some time and effort.



Mike
#5

Yes, that last one should fit fine. (phit phine?) Thanks so much.
#6

Hello Rob,
I also Find Parts Express a great source for speakers and I added a tweeter to my General Electric Console it really improves the sound .
Sincerely Richard
#7

Even if you replace them with something else the originals can usually be rebuilt so don't toss them. Apparently they have foam in them that goes rock hard so they will no longer tweet.
Regards
Arran




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 16B Parts
I think the chassis is painted.morzh — 08:13 PM
Philco 38-2 Automatic Tuning
Honestrly, the original is quite acceptable and, it seems to me, can be cleaned.morzh — 08:11 PM
Philco 41-608 changer coupler
Mondial left a thread about remanufacturing thois type coupler.morzh — 08:09 PM
IF can wire size and Rubber mounts?
Are you talking about rewinding or rewiring? For rewiring, meaning runnin wires to the coil from other components, the ...morzh — 08:08 PM
12' Philco
I wonder who would be able to "no stoop" with this one.morzh — 08:05 PM
IF can wire size and Rubber mounts?
Hello PHORUM members, I am still working on restoration of my PHILCO 37-640.  I want to start with rewiring the IF ca...georgetownjohn — 06:32 PM
Philco 41-608 changer coupler
I am working on a Philco 41-608 with the gear-driven changer.  The coupling (#35-2220) between the motor assembly and th...alangard — 06:29 PM
Gilfillan Brothers Car Radio?
There is a Mission Bell model 19/19A that could be what you’re looking for, Riders vol 4. It has the tube line-up of: 0Z...Joe Rossi — 05:01 PM
Looking for verification of correct schematic.
Definitely 870044RossH — 01:12 PM
12' Philco
Wonder if the chassis was big too.daveone23 — 12:38 PM

[-]
Who's Online
There are currently 1576 online users. [Complete List]
» 4 Member(s) | 1572 Guest(s)
AvatarAvatarAvatarAvatar

>