[morzh]

If someone knows for a fact whether it's allowed.

While inspecting the tubes in my 16 I found an 80 in place of 5Z3.
80 is 125mA while 5Z3 is 225mA tube.

So I decided to look into the other 16, same cathedral type  I bought for Peter from John Hagman.
It also has the 80.
Then I looked at the radio I got from Ron. The chassis is a different type, and there is also an 80 in there.

And, as the last resort, I looked into the 16X Kirk gave me about 2 years ago. Same. An 80 inside.

So, is it quite ok to use an 80 in there or will it struggle and so I then should buy a 5Z3?

[KCMike]

Mike you have so much more knowledge than I ever will of electronics that I don't know if this data base helps but it shows 80 as a sub for 5Z3 and mentions an 83 also.
http://www.nj7p.org/Tubes/SQL/Tube_query.php?Type=80

[GarySP]

Mike, just an observation on my part, but isn't the 125 mA the current draw for the heater in the tube?  If an 80 is identical in all other respects to a 5Z3 I would think the lighter draw on the transformer couldn't be a bad thing.  I am by no means an authority on the subject... just applying my view of common sense to the application.  I could very well be wrong.  Take care, Gary

[morzh]

Gary


No. The heater of the 80 is 2A. 5Z3 - 3A.


Mike

Thanks. It says though (as I understood it) that 5Z3 and 83 are substitutes for 80, not the other way around.
Also, even though 83 or 5Z3(which are almost the same) can work in place of 80 (the ratings are higher for both V and I-load) this is only possible if your transformer is capable of one extra Amp of filament current, as 80 draws only 2A while the other two draw 3A, so you spent 5W extra and stress your transformer a bit more.

[Ron Ramirez]

Mike (morzh)

The console versions of Model 16 put out 15 watts of audio (class AB) as opposed to 10 watts in the cathedrals & tombstones.

The console versions also run a higher B+ to get that extra output power.

That increases current draw as well...so the 5Z3 is required in console models while the 80 is good enough for cathedrals/tombstones.

If you compare a cathedral or tombstone chassis with a console chassis, the console chassis always has a physically larger power transformer.

[morzh]

Ron

Thanks. I was trying to make sense of the 5Z3 shown in basic version sch, and without knowing the exact power draw it is not simple. BTW even the console I gave, as I mentioned, has the 80. I guess if one does not crank up the volume all the way to scare out rodents, 80 was enough even in consoles.
The tombstone 16 also has the console chassis, right? The transformer is the horizontal version in it.

[morzh]

PS. Just viewed the sch...says 16-121 (which is what I have) uses 80 rectifier.
OK good, have tons of those.

[Ron Ramirez]

The tombstone 16 also has the console chassis, right?

Nope. The early tombstone (5-band) also uses the Code 121 chassis with an 80 rectifier. Later tombstones use the 4-band Code 125 chassis, also with an 80 rectifier.

5-band Code 122 (consoles) and chairsides (Code 123) use 5Z3 rectifiers, as do later 4-band consoles (Code 126) and chairsides (Code 127).

[morzh]

So yours was not the early tombstone? The chassis is very different from mine, including power transformer, RF coils etc.

[Ron Ramirez]

Isn't it a 4-band Code 125 set? It's been a while and I don't remember now.

(after looking at Phorum banner to refresh my memory)

Oh yes. That's the final version of the 16B tombstone, with shoulders. The last version of the 16B made before Philco introduced the 116B for the following sales year.

[Arran]

 The 80 and the 5Z3 are not interchangeable, a 5Z3 is like a four pin 5U4, an 80 more like a 5Y3/5Y4. I'm not sure about an 83V but an 83 is a mercury vapor rectifier so no to using one of those. Put a type 80 where a 5Z3 is supposed to go and it will live a short life, put a 5Z3 in place of an 80 and you might burn out the 5 volt winding on the transformer eventually. I don't know why all of the Philco 16/116 set don't use a 5Z3 rectifier, the RCA Victor model 143 did and it only has 8 tubes with push pull #42s in pentode connected class A, not triode connected class A-b (if the 16Bs had it?)
Regards
Arran

[codefox1]

You could just replace with a couple of ten cent diodes and be done with it. Just get 'em in right.

[morzh]

You could just replace with a couple of ten cent diodes and be done with it.  Just get 'em in right.

...and why would I do such a thing to a perfectly good 16?