The AM Forum

I recently acquired an SX-28.  It  came with a tube adapter in place of the 5Z3 amp tube.  I want to find out what tube this could possibly be.  It had markings at one time on the tube, but they are long gone.  It is a 5 pin tube with one pin being quite a bit smaller than the other 4. It is a round, globe top, with straight sides, no taper. There is no marking on the adapter other than RCA.  Any ideas?
Thanks,
Benny - W5TYZ

How about a picture of what you are talking about.

The 5Z3 is a 4 pin rectifier tube and sometimes hard to find. Adapters were made to convert the 4 pin socket to the more common 5 pin rectifier socket so that a 5U4 rectifier tube could be used.

Further, manufacturers have designed solid state plugin replacements for the 5U4 rectifier tubes that could plug into those adapters.

Yes please take a picture of the tube and also the pins on the base.

The 5U4 etc. have all pins the same size.

Could it be a type 84 or 6Z4? It is totally not appropriate, but is a large-ish T5 pin base full wave rectifier.

Here is a datasheet:
https://bunkerofdoom.com/tubes/syl43/DATA/1943/P208.GIF

Almost all rectifiers close to being appropriate for that set will have a 4 pin base like the 5Z3 or an octal base (though not all pins may be populated in those and the 5U4 indeed usually has 5 pins populated).

Thanks guys for the input...I'll post a picture tomorrow.

Benny - W5TYZ

https://fairradio.com/?s=5z3

15 bucks Fair Radio put the right tube in this is a cheap price

I am not having any luck at posting shots of the tube in question.  I have resized the shots, but they still will not post.  So I am still trying to work this out.
Benny - W5TYZ

Whatever you did bombed the entire thread.

To attach a photo, you create or reply to a message and below the boxed text area on the left is the word "Attach" You click Browse and select to find the photo on your computer to attach

I've shown below the allowable .extensions that you can attach

Attach:    (more attachments)
Allowed file types: txt, rtf, doc, mp3, wav, pdf, jpg, jpeg, gif, mpg, png, xls, docx
Maximum attachment size allowed: 5000 KB, per post: 3

As an example, I click Browse; find the picture in whatever directory and click on it. File name will appear to the right of the Browse field.

I did everything you posted....More than once.  I even reduced the pictures using a re-sizer program that I have been using for quite a while, without any problems until today.  I dunno what is going on.  I post photos all the time on other web sites.  I'll try again, maybe tomorrow.

Benny

If you can post the same pictures on some other site, you can always just point to them here.

He sent me the pix, and now knows what is what.

It is a HB adapter to use a 5U4GB in a 5Z3 socket.

73DG