Can anyone answer why #45 tubes are so rare? Is it because they were superceded by pentodes and had a shorter commercial life?

I am looking for a replacement #45 and it is either expensive or non-existent.

Thanks
Lou

45s are highly sought after because people like how they sound (triode output). They are fairly common on eBay in ST form, and aren't too expensive in that form.

Most tubes haven't been manufactured in years. Eventually they will all be expensive and rare, especially if people go nuts about certain ones (such as the 35Z5, which once was extremely common).

T.

There is a replacement available from Bill Turner, here in St. Louis. Check this link.
Terry F

http://www.dialcover.com/tubes.html

Thanks for the inputs - I was not sure. The tube replacement site is very interesting.

I do have sources for #45s - just needed some backup to justify the expense ( as if I wasn't going to buy them!!).

Lou

:There is a replacement available from Bill Turner, here in St. Louis. Check this link.
:Terry F
:
:http://www.dialcover.com/tubes.html

If the 45 is just weak, I wouldn't replace it. It will probably work fine.

2A3s are similar to a 45, but they are still being made. However, the ckt would need to be modified to supply the 2A3's higher filament current and a different bias point.

Bill Turner's 45 sub seems like a bargain at $20 - if you don't mind the appearance of a metal tube perched on top of a socket adapter.
Doug

:Thanks for the inputs - I was not sure. The tube replacement site is very interesting.
:
:I do have sources for #45s - just needed some backup to justify the expense ( as if I wasn't going to buy them!!).
:
:Lou
:
::There is a replacement available from Bill Turner, here in St. Louis. Check this link.
::Terry F
::
::http://www.dialcover.com/tubes.html

One more thought.

I wouldn't think of buying a NOS 45, except for investment purposes ;>) Tested used ones should be fine.
Doug

Hi

Might be able to buy weak 45's. Even weak ones work well in most old radios. They don't have much use to the audio crowd.

Norm

:One more thought.
:
:I wouldn't think of buying a NOS 45, except for investment purposes ;>) Tested used ones should be fine.
:Doug

Thanks Guys:

I am just in the middle of restoring a Steinite Cathedral Radio. This is a four tube ( three 24As, one 45, one 80) TRF set with LOTS of GAIN. I have the chassis working perfectly and now its' time for the cosmetics. An excellent performer.

In my undertanding, this company was around for a number of years before the Depression, and then failed. They only made ONE cathedral, which makes this rare!! (And FUN).

Lou

:Hi
:
: Might be able to buy weak 45's. Even weak ones work well in most old radios. They don't have much use to the audio crowd.
:
:Norm
:
::One more thought.
::
::I wouldn't think of buying a NOS 45, except for investment purposes ;>) Tested used ones should be fine.
::Doug

Here is information to build an adapter to substitute a type 1619 for a 45 tube:

http://www.oldradiodata.com/radio-tips.html

Radiodoc
*******************

:Thanks Guys:
:
:I am just in the middle of restoring a Steinite Cathedral Radio. This is a four tube ( three 24As, one 45, one 80) TRF set with LOTS of GAIN. I have the chassis working perfectly and now its' time for the cosmetics. An excellent performer.
:
:In my undertanding, this company was around for a number of years before the Depression, and then failed. They only made ONE cathedral, which makes this rare!! (And FUN).
:
:Lou
:
::Hi
::
:: Might be able to buy weak 45's. Even weak ones work well in most old radios. They don't have much use to the audio crowd.
::
::Norm
::
:::One more thought.
:::
:::I wouldn't think of buying a NOS 45, except for investment purposes ;>) Tested used ones should be fine.
:::Doug

Good info, Doc.

The 1619 is evidently the metal tube that Bill Turner uses for his 45 replacement.

The 1619 filament draws 2A compared to 1.5A for the 45. So, the power transformer winding will run a bit hotter, particularly if the original ckt uses two 45s in push-pull, which was pretty common.

I have no doubt that a 1619 would work fine in replacement of a 45. However, I note from the RCA tube manual differences that might warrant tweaking the grid bias or cathode resistor?

The 1619 is pretty tall, but I wonder if it could be put into globe or ST glass envelope for appearance sake? If not, it ought to fit into one of those jumbo globe envelopes like some 80s had.
Doug
Doug

:Here is information to build an adapter to substitute a type 1619 for a 45 tube:
:
:http://www.oldradiodata.com/radio-tips.html
:
:Radiodoc
:*******************

:Can anyone answer why #45 tubes are so rare? Is it because they were superceded by pentodes and had a shorter commercial life?
:
:I am looking for a replacement #45 and it is either expensive or non-existent.
:
:Thanks
:Lou

One reason 45 tubes are rare is because there were lots of circuits printed in Ham radio magagines throughout the late '30s through the 40's about building transmitters using them. I have also seen a lot of them in signal generators used by dad and son service outfits.

45s did have a fairly short commercial life, but there were plenty of them being made during the 1930s since the radios that used them were less than ten years old. However during the war when tubes were hard to get, dealers' stocks were largely depleted. As soon as the war ended, no one wanted to maintain the 1929 consoles any longer, so dealers wouldn't have restocked as many 45s as they once did. Also, the 45s had a shorter life that the 24As or 27s, so any surviving radios are likely to contain weak 45s. The result is fewer 45s compared to other tubes of the same era. 50s (and 10s) had the same problems, even more so, since so few radios used them to begin with.

I've been hesitating making this post.

I don't recommend it, but probably an inexpensive source for good used 45s is buying a radio, like an AK-55, with two 45s, and then re-selling the AK-55, missing its two 45s. Sad but true.

Because of ignorance, many old radios sell for less than the value of their tubes.

But, there are always shysters that will strip an old radio of its more valuable tubes, sell the tubes separately, plug in "untested" duds, and sell the radio "as-is," because they have "no way to check it."

For this reason, and others, I've vowed not to buy any more 45s, used or NOS. (And I'm sitting on two NOS 45s, in boxes.) If necessary, I'll come up with a substitute, even with a socket adapter.
Doug

Boy:

That practice is LOW.

I do have an AK 55 chassis that has two 45's but I am restoring that unit.

Interesting - I did not know people would stoop this low!!

Thanks for the education!!

Lou

:I've been hesitating making this post.
:
:I don't recommend it, but probably an inexpensive source for good used 45s is buying a radio, like an AK-55, with two 45s, and then re-selling the AK-55, missing its two 45s. Sad but true.
:
:Because of ignorance, many old radios sell for less than the value of their tubes.
:
:But, there are always shysters that will strip an old radio of its more valuable tubes, sell the tubes separately, plug in "untested" duds, and sell the radio "as-is," because they have "no way to check it."
:
:For this reason, and others, I've vowed not to buy any more 45s, used or NOS. (And I'm sitting on two NOS 45s, in boxes.) If necessary, I'll come up with a substitute, even with a socket adapter.
:Doug

I have lots of 45 and 245 (same tube 245 has large glass globe)..that I bought as a lot many years ago...that I want to part with..All tubes test good..I just have to much of this crap and need to start getting rid of it...Let me know if interested

:Boy:
:
:That practice is LOW.
:
:I do have an AK 55 chassis that has two 45's but I am restoring that unit.
:
:Interesting - I did not know people would stoop this low!!
:
:Thanks for the education!!
:
:Lou
:
::I've been hesitating making this post.
::
::I don't recommend it, but probably an inexpensive source for good used 45s is buying a radio, like an AK-55, with two 45s, and then re-selling the AK-55, missing its two 45s. Sad but true.
::
::Because of ignorance, many old radios sell for less than the value of their tubes.
::
::But, there are always shysters that will strip an old radio of its more valuable tubes, sell the tubes separately, plug in "untested" duds, and sell the radio "as-is," because they have "no way to check it."
::
::For this reason, and others, I've vowed not to buy any more 45s, used or NOS. (And I'm sitting on two NOS 45s, in boxes.) If necessary, I'll come up with a substitute, even with a socket adapter.
::Doug

I refuse to buy 'crap' from anyone. Thanks for the offer.

:I have lots of 45 and 245 (same tube 245 has large glass globe)..that I bought as a lot many years ago...that I want to part with..All tubes test good..I just have to much of this crap and need to start getting rid of it...Let me know if interested
:
::Boy:
::
::That practice is LOW.
::
::I do have an AK 55 chassis that has two 45's but I am restoring that unit.
::
::Interesting - I did not know people would stoop this low!!
::
::Thanks for the education!!
::
::Lou
::
:::I've been hesitating making this post.
:::
:::I don't recommend it, but probably an inexpensive source for good used 45s is buying a radio, like an AK-55, with two 45s, and then re-selling the AK-55, missing its two 45s. Sad but true.
:::
:::Because of ignorance, many old radios sell for less than the value of their tubes.
:::
:::But, there are always shysters that will strip an old radio of its more valuable tubes, sell the tubes separately, plug in "untested" duds, and sell the radio "as-is," because they have "no way to check it."
:::
:::For this reason, and others, I've vowed not to buy any more 45s, used or NOS. (And I'm sitting on two NOS 45s, in boxes.) If necessary, I'll come up with a substitute, even with a socket adapter.
:::Doug

I would not sell to you Darlene/AKA= Steve in colorado..Go try to get free caps from someone else

:I refuse to buy 'crap' from anyone. Thanks for the offer.
:
:
:
::I have lots of 45 and 245 (same tube 245 has large glass globe)..that I bought as a lot many years ago...that I want to part with..All tubes test good..I just have to much of this crap and need to start getting rid of it...Let me know if interested
::
:::Boy:
:::
:::That practice is LOW.
:::
:::I do have an AK 55 chassis that has two 45's but I am restoring that unit.
:::
:::Interesting - I did not know people would stoop this low!!
:::
:::Thanks for the education!!
:::
:::Lou
:::
::::I've been hesitating making this post.
::::
::::I don't recommend it, but probably an inexpensive source for good used 45s is buying a radio, like an AK-55, with two 45s, and then re-selling the AK-55, missing its two 45s. Sad but true.
::::
::::Because of ignorance, many old radios sell for less than the value of their tubes.
::::
::::But, there are always shysters that will strip an old radio of its more valuable tubes, sell the tubes separately, plug in "untested" duds, and sell the radio "as-is," because they have "no way to check it."
::::
::::For this reason, and others, I've vowed not to buy any more 45s, used or NOS. (And I'm sitting on two NOS 45s, in boxes.) If necessary, I'll come up with a substitute, even with a socket adapter.
::::Doug