How much tubing to trim?

[Tubajug]

Any rough guesstimates on how much tubing to trim on a 1918 H.N. White King Eb to get it up to modern pitch? It's got a nice long tuning slide, so there's plenty to cut off, I was just wondering if anyone had a guess as to where to start?

I'm going to eventually use it for another project, but in the meantime I'd like to at least get up to modern pitch and see if it's useable as an Eb for now.

Here it is after the first round of Tarn X and baking soda:

[Dan Schultz]

Pull out the main slide until the horn is XXcents flatter than what you want to raise the pitch.

[Tubajug]

Thanks guys, that's much simpler than I anticipated. I was hoping to avoid multiple attempts at cutting, soldering, unsoldering, cutting....

[aqualung]

You can do this by yourself, with or without another player, and with or without a "tuner".

Get another (same key) horn that is at the pitch you want. Pull the tuning slide until it is in tune with your horn.
The amount you pull is the amount you want to cut.