In several of my All American Five sets, the original 35L6 or 35A5 tube was replaced with a 50L6 or 50A5. I imagine this was an attempt to reduce the filament voltage on all of the tubes to increase life. Does anybody know if this was a common practice, and have an opinion as to whether a possible lack of performance offsets the benefit? The only problem that I have found is that the set takes a much longer time to warm up.

Stop by my radio restoration page some time!
http://www.verinet.com/~park7963/radio.html

: In several of my All American Five sets, the original 35L6 or 35A5 tube was replaced with a 50L6 or 50A5. I imagine this was an attempt to reduce the filament voltage on all of the tubes to increase life. Does anybody know if this was a common practice, and have an opinion as to whether a possible lack of performance offsets the benefit? The only problem that I have found is that the set takes a much longer time to warm up.

: Stop by my radio restoration page some time!
: http://www.verinet.com/~park7963/radio.html
I don't know if this was common practice or not, but
back in those days the line voltage regulation was not
always so good. They probably used 50xx to prevent
burnout from surges. Unless the tubes are fresh, you
will probably have poor performance at normal line
voltage. These days, I don't think I would worry about
voltage problems and just go ahead and use the correct
tubes. If your overall performance is down, don't
forget that the input sensitivity will drop several db
which will cause poor reception and noise. You may not
even know it until you see how well it works with the
right tubes.

: : In several of my All American Five sets, the original 35L6 or 35A5 tube was replaced with a 50L6 or 50A5. I imagine this was an attempt to reduce the filament voltage on all of the tubes to increase life. Does anybody know if this was a common practice, and have an opinion as to whether a possible lack of performance offsets the benefit? The only problem that I have found is that the set takes a much longer time to warm up.

: : Stop by my radio restoration page some time!

: : http://www.verinet.com/~park7963/radio.html

: I don't know if this was common practice or not, but

: back in those days the line voltage regulation was not

: always so good. They probably used 50xx to prevent

: burnout from surges. Unless the tubes are fresh, you

: will probably have poor performance at normal line

: voltage. These days, I don't think I would worry about

: voltage problems and just go ahead and use the correct

: tubes. If your overall performance is down, don't

: forget that the input sensitivity will drop several db

: which will cause poor reception and noise. You may not

: even know it until you see how well it works with the

: right tubes.

NEW NEW NEW NEW NEW NEw
The 50xx were very common and cheaper thats the reason you are finding them in the older sets
Danny

:: : In several of my All American Five sets, the original 35L6 or 35A5 tube was replaced with a 50L6 or 50A5. I imagine this was an attempt to reduce the filament voltage on all of the tubes to increase life. Does anybody know if this was a common practice, and have an opinion as to whether a possible lack of performance offsets the benefit? The only problem that I have found is that the set takes a much longer time to warm up.
:
:
:
:: : Stop by my radio restoration page some time!
:
:: : http://www.verinet.com/~park7963/radio.html
:
:: I don't know if this was common practice or not, but
:
:: back in those days the line voltage regulation was not
:
:: always so good. They probably used 50xx to prevent
:
:: burnout from surges. Unless the tubes are fresh, you
:
:: will probably have poor performance at normal line
:
:: voltage. These days, I don't think I would worry about
:
:: voltage problems and just go ahead and use the correct
:
:: tubes. If your overall performance is down, don't
:
:: forget that the input sensitivity will drop several db
:
:: which will cause poor reception and noise. You may not
:
:: even know it until you see how well it works with the
:
:: right tubes.
:
:NEW NEW NEW NEW NEW NEw
:The 50xx were very common and cheaper thats the reason you are finding them in the older sets
:Danny
:
:
:

Back then the line voltage was 105-115vac .
With today's 125vac... a 50L6 is a safe bet... and all the filaments will last longer.

This was apparently common practice. I have the 1960 edition of "Tube Caddy, Tube Substitution Guidebook" by H. A. Middleton. This books gives "direct substitutions only" that should give what are called "good" or "excellent" results.
Both of the substitutions that you have mentioned as giving "good" results.

:In several of my All American Five sets, the original 35L6 or 35A5 tube was replaced with a 50L6 or 50A5. I imagine this was an attempt to reduce the filament voltage on all of the tubes to increase life. Does anybody know if this was a common practice, and have an opinion as to whether a possible lack of performance offsets the benefit? The only problem that I have found is that the set takes a much longer time to warm up.
:
:Stop by my radio restoration page some time!
:http://www.verinet.com/~park7963/radio.html

All I get is an error msg when I try to go to that site you listed.