Author Topic: Closer look at "double duty" Mushroom bases?  (Read 528 times)

Offline WEBellSystemChristian

  • Moderator
  • Hero Member
  • *****
  • Posts: 3421
  • Grandpa's 1955 Western Electric 500
Closer look at "double duty" Mushroom bases?
« on: June 29, 2016, 08:59:20 PM »
I saw this Black 500U on ebay. Even though it's an auction, I figured the high starting bid isn't exactly a 'steal', so it's probably not a big deal posting it here.

I always heard that Mushroom bases were labeled with P or P/U, the latter serving as "double duty" for the new U type. But I've never heard of a base strictly labeled with U before, like this one. Does anyone know why this is?

I would have figured the P/U designation came between the earlier P and later U models, but my 1959 U is labeled with P/U, while this one is a 1958. ???

www.ebay.com/itm/201613816069
Christian Petterson

"Whether you think you can or think you can't, you're right" -Henry Ford

Offline jsowers

  • Hero Member
  • *****
  • Posts: 1864
Re: Closer look at "double duty" Mushroom bases?
« Reply #1 on: June 29, 2016, 09:57:03 PM »
The 500P and 500U were both introduced about 1955 and the P/U designation didn't happen until 1959. I've never thought about it until now, but I've never seen a 500 P/U that was a 500P, meaning without the night light switch. They have all been 500Us.

I have two 500P phones and they are both marked 500P or P500 if you want to go in the order of the markings. I have an 12-58 500U that is marked 500U with no P, so I'm assuming that sometime in 1959 was when it changed to dual duty, using the 500P/U marking.

And no, we don't see many early 500U or 500P phones from before 1957. A 500U or P in one of the early dark colors is a rare bird indeed.

See the pics below for some examples of markings...
« Last Edit: June 29, 2016, 09:59:55 PM by jsowers »
Jonathan

Offline WEBellSystemChristian

  • Moderator
  • Hero Member
  • *****
  • Posts: 3421
  • Grandpa's 1955 Western Electric 500
Re: Closer look at "double duty" Mushroom bases?
« Reply #2 on: June 30, 2016, 12:46:22 AM »
The 500P and 500U were both introduced about 1955 and the P/U designation didn't happen until 1959. I've never thought about it until now, but I've never seen a 500 P/U that was a 500P, meaning without the night light switch. They have all been 500Us.

I have two 500P phones and they are both marked 500P or P500 if you want to go in the order of the markings. I have an 12-58 500U that is marked 500U with no P, so I'm assuming that sometime in 1959 was when it changed to dual duty, using the 500P/U marking.

And no, we don't see many early 500U or 500P phones from before 1957. A 500U or P in one of the early dark colors is a rare bird indeed.

See the pics below for some examples of markings...
I think I see where I went wrong here. I somehow thought that the P was an older Mushroom, and the U replaced it and included an on/off switch. Now I remember the H, which was basically an early P, but the U was introduced and, thus, the H designation was replaced by the P.

Makes sense now, sorry about that!
Christian Petterson

"Whether you think you can or think you can't, you're right" -Henry Ford