Rockola 1454 Speaker

Rob

You are correct, it is a piezo tweeter. Thanks for advice and info.

Best
Darrell

Hi All

New info. The new piezo speaker would not work, so I jumpered around the 20MFD 50 VDC capacitor and now I have the original 16 ohm Jensen speaker working as well as the 8 ohm Piezo speaker. Are there any advantages/disadvantages to by-passing the cap?

If I replace the cap should it be of the same size or would some other value work better?

There are two openings to the front of the unit, so, I could actually hook both horn tweeter speakers (original Jensen is 16 ohms and Piezo is 8 ohms) up if there is a safe way to do this without overloading the amp?

Appreciate your ideas on this.

Best
Darrell

Darrell,
STOP ! Remove that "jumper" ! That cap is there for a reason, jumping it WILL, blow your horn (Pun intended !).
It's probably an Non-polarized cap, and it's has probably become "open"--just replace it, and send the pizzo back.
Ron Rich

Ron

Disconnected. I have included a pictue of the old cap, which has a black line on one end, so I think it is polarized. It is rated 20MFD and 50 VDC. Best place to get one Mouser?

Nest
Darrell

Hi Darrell,
I can't tell from the photo-too burly---it may, or, may not be polarized. Older "paper caps" with a line like that, only indicated the "outside foil". If an "Electrolytic" type, yes--it is polarized. It also may have a "+" on the other end, where the wire is attached--if so, for sure it's an electrolytic. Usually that value is an electrolytic. "Best source" --I dono --You can probably pick-up an electrolytic at Rat Shack ( least they used to carry a [much smaller]22x63 which will work).
Ron Rich

Either Ron's suggestion or put two 47's (mfd) back-to-back. Radio Shacks around here (Manhattan) do have 10's and 22's non-pol.

Rob

Ron/Rob

Everthing I have read and seen says not to increase the size of UF/MFD, so since they no longer make a 20MFD you go to the next size 22UF is that how it works?

I cut the cap out and can not find any minus or plus sign anywhere on the cap so it has to be non-polarized.

Cannot get continuity so assume cap is open.

As I understand both of you, I am safe to use a 22uF 50VDC(or greater) as a replacement.

Best
Darrell

Darrell, you can 'go up" slightly w/no prob. 22 Is ok.

You can not test a capacitor with a continuity test. A cap blocks DC which is what a typical meter uses for test. In fact, if you did see a reading in that situation it would likely be a shorted cap.

Rob

Rob

Checked with Mouser and this is their reply:

"The best replacement is a 20uF 50V axial leaded film capacitor. Unfotunately , we don't have any in stock or on order. An alternate source may be Antique Electronic Supply aka tubesandmore.com. The stripe indicates the end the outside wrap is connected to. This should be connected to ground when next to a source of hum (tranformers, chokes, tubes). "

Local Radio Shack does not have anything close, so checking with Antique Electronic Supply as suggested.

Best
Darrell

Darrell, get two 47's, connect them can-to-can with the + leads connected to the speaker/amp as original. 16v-Up/each is fine as this will equal 32 volt total. This sort of thing is so non-critical there is no point in hunting around.

Rob