[AMRadio] 117Z6GT question

[gwt]

I have a question for the list.
I'm repairing an old am radio that uses at 117Z6GT as a rectifier. I 
have the radio working again, but I notice when I turn it on that the 
117Z6 filaments glow really bright for a couple of seconds. Then settle 
down to what you would expect to see, a red glow.
I don't have any experience with this tube, or how it should act at turn on.
It what I'm seeing a normal condition?
Thanks,
George KE4HJ