1930 Rickenbacker amp tube layout ?

[zephyrblau]

hey all;
i've tried the Rick site & gotten nothing substantial. i'm trying to figure out what the tube layout is in my ca. 1930 Rick amp. in the attaches pix, the tube on the left i'm pretty sure is the rectifier. the only thing i know is that it's *not* a type 80 nor 83. (i have both of those in other units) it is a 4 pin device. the tube in the middle is a type 47 (for some odd reason i have another w/ clear markings) the tube on the right is a type 53 (enough of the original marking remains) the tube in the back has smoked glass so trying to compare internals is out. the base is marked Tung Sol 12. any help greatly appreciated.
best
jerry

[Enzo]

If two if the pins are wired directly to the power transformer HV winding, then it is a rectifier. It is a 4 pin but not an 80 or 83? How did you decide it was not one of those? About the only other tube of that base in a rectifier is a 5Z3, I think. And though the tube in there now might not be an 80, can you say for sure it was not originally?

Pull the tubes and look at the sockets, a lot of old tube sockets actually had the intended type number stamped in the center.

Look at the socket wiring, you can usually figure out what type of tube went there, then look up what tubes share that base wiring pattern. Circuits haven't changed that much, the high value resistor to B+, the cathode resistor is more or less 1/10 the plate resistor. Pentodes will have the screen wired and bypassed. etc.

[Rob Mercure]

Jerry,

You probably know this but the 47 is a power pentode and the 53 is a "dual power triode" so right off I would suspect that one of these is the wrong tube . Or the 53 is being used to drive a PI transformer and you've got two 47s as a PP output. But then would require at least one other tube for a preamp - so how many tube in total does the amp have (how many tube sockets)? Hmmm, 'nother possibility is the opposite - the 47 is driving a PI tranny and 53 is your PP output - then your mystery tube would be the preamp and since most signal pentodes of that time used a plate cap probably a triode. How many pins does your mystery tube have?

Note: I attempted to post this about 2 hours ago but for some reason I got some sort of a "security violation error" - whatever that is - and at the time Enzo had not posted. 'Tis strange.

Rob

[Marc]

I had one of these in my shop a few months ago and I'm pretty sure it was a 47, 53 and an 80 in the the tube line up...I'll see if I noted it anywhere.

Marc

[Enzo]

Hi.

[zephyrblau]

If two if the pins are wired directly to the power transformer HV winding, then it is a rectifier. It is a 4 pin but not an 80 or 83? How did you decide it was not one of those? About the only other tube of that base in a rectifier is a 5Z3, I think. And though the tube in there now might not be an 80, can you say for sure it was not originally?

Pull the tubes and look at the sockets, a lot of old tube sockets actually had the intended type number stamped in the center.

Look at the socket wiring, you can usually figure out what type of tube went there, then look up what tubes share that base wiring pattern. Circuits haven't changed that much, the high value resistor to B+, the cathode resistor is more or less 1/10 the plate resistor. Pentodes will have the screen wired and bypassed. etc.

guys... sorry to seem mute. for some reason i'm not getting notices about updates to the thread.
Enzo;
i have no idea what was in *any* socket originally that's why i was asking for a tube chart. i have a type80 in my '36 Philco radio & a type 83 in my Hickok 752A. it's neither of those. given the fact that it's "only" a rectifier, subbing another tube is probably safe (current handling, etc. notwithstanding) i'll have to pull the chassis & investigate further. no sockets are marked.
thanks
jerry

[zephyrblau]

Jerry,

You probably know this but the 47 is a power pentode and the 53 is a "dual power triode" so right off I would suspect that one of these is the wrong tube . Or the 53 is being used to drive a PI transformer and you've got two 47s as a PP output. But then would require at least one other tube for a preamp - so how many tube in total does the amp have (how many tube sockets)? Hmmm, 'nother possibility is the opposite - the 47 is driving a PI tranny and 53 is your PP output - then your mystery tube would be the preamp and since most signal pentodes of that time used a plate cap probably a triode. How many pins does your mystery tube have?

Note: I attempted to post this about 2 hours ago but for some reason I got some sort of a "security violation error" - whatever that is - and at the time Enzo had not posted. 'Tis strange.

Rob

hi Rob;
the mystery tube is a 5-pin type. closer inpspection under a strong light indicates that the mystery tube (from what i can see of it) and the type 47 are very similar, if not identical. slight variations in the mica etc. owing to different manufacturers (?)
again, i'll need to pull the chassis to investigate further / confirm.

jerry

[Enzo]

OK, but my question remains, if we have no idea what was in the sockets originally, how did we rule out the 80? All things considered, to me it would be the most likely candidate.

Are you saying that the tube in there NOW is not an 80? Because it doesn't look like another 80 you have elsewhere? Tubes of the same type are not always shaped the same, and different brands of a tube type even have different looking innards. For example: line up a selection of all the brands of 12AX7 on the market today and compare their innards. But even if this tube is a 5Z3 or something, the original still could have been an 80. Especially when the other tubes in it were most likely from the two-digit number series.

Did we look at the tube sockets themselves to see if type numbers were printed in the center of each?

If you are near Lansing, Micchigan, bring it by and we can draw up a schematic for it in a half hour or so. There won't be that many types to choose from that will work in those sockets.

[zephyrblau]

I had one of these in my shop a few months ago and I'm pretty sure it was a 47, 53 and an 80 in the the tube line up...I'll see if I noted it anywhere.

Marc

Marc;
that would be a big help! i trust that was a 4-tube unit?
thanks!
jerry

[zephyrblau]

OK, but my question remains, if we have no idea what was in the sockets originally, how did we rule out the 80? All things considered, to me it would be the most likely candidate.

Are you saying that the tube in there NOW is not an 80? Because it doesn't look like another 80 you have elsewhere? Tubes of the same type are not always shaped the same, and different brands of a tube type even have different looking innards. For example: line up a selection of all the brands of 12AX7 on the market today and compare their innards. But even if this tube is a 5Z3 or something, the original still could have been an 80. Especially when the other tubes in it were most likely from the two-digit number series.

Did we look at the tube sockets themselves to see if type numbers were printed in the center of each?

If you are near Lansing, Micchigan, bring it by and we can draw up a schematic for it in a half hour or so. There won't be that many types to choose from that will work in those sockets.

understood. i was editing my original post re; socket markings while you were posting above. unfortunately (for purposes of your offer) i'm on the left coast. would it help if i post digi pix of the chassis?

[Enzo]

Ah. May I suggest that going back to edit posts won't get the new information to most of us. I for one rarely look back at the previous posts to see if they changed. I'd just report new data in a later post. Think of it as a conversation.

STart with Marc's 47, 53, and 80. Look up the base diagram and put them on a page of paper. Now trace out the circuit. Does it make sense with those tubes? Is this going to be any more complex than a 5E3?

Sure we'd love to see pix.