Little Brown Job (1 Viewer)

Seen at Pulborough Brooks on Sunday evening. Sorry no pic. Haven't gone digital yet.

Size very small, I thought Goldcrest at distance though close up it was probably a little larger, but slim. Perched in a field hedgerow. Back, top of head and wings mid-brown with no markings. Breast and face buff, again no markings, except maybe a slightly darker eyeline.
Seen only from front and 1/4 each side.
Call repeated for about 10 mins and always identical, which I thought might help with BF birdcall Resource. Tried a number of obvious contenders but I can't find it. teeoo;teet;teet, each note about 1/2 sec and very consistent. Piercing, hard, clean tone
Any ideas?

phylloscopus collybita ........chiffchaff

Hi Paul,
I agree,most likely a Chiffchaff,but perhaps also a Willow Warbler:the latter can sound odd when just fledged.That said,juvenile Willow Warblers are usually yellower below than you describe your bird as being.
What colour were the legs?Usually(but not always!),they are pale orangey on Willow and dull(blackish,but actually a dark brown) on Chiffchaff.
Harry

Dark legs. I guess Chiffchaff is it. They are frequent at PB though usually larger than this and 'classic' chiffchaff call, so probably juv as you say. General appearance and voice certainly right.
Thanks guys.