Posts: 961
Threads: 39
Joined: Feb 2015
City: Roseville, MN
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.
Posts: 1,824
Threads: 114
Joined: Jul 2014
City: Sneedville, TN
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.
(This post was last modified: 06-11-2021, 04:30 PM by
mikethedruid.
Edit Reason: reword.
)
Posts: 961
Threads: 39
Joined: Feb 2015
City: Roseville, MN
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.
Posts: 1,824
Threads: 114
Joined: Jul 2014
City: Sneedville, TN
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
(This post was last modified: 06-11-2021, 10:05 PM by
mikethedruid.
Edit Reason: spelling
)
Posts: 961
Threads: 39
Joined: Feb 2015
City: Roseville, MN
Yes, that last one should fit fine. (phit phine?) Thanks so much.
Posts: 1,583
Threads: 99
Joined: May 2008
City: Omak
State, Province, Country: WA
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
Posts: 4,686
Threads: 51
Joined: Sep 2008
City: Sandwick, BC, CA
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