PS…
I remember one of Greg’s exercises in the book was a low A to A above the staff.. (impossible for me a year ago) similar to your idea John in last post of pedal a and then breath attacks..
just now done several of them..warming up with smaller jumps before low pedal note to A above the staff..another milestone day!

learning from today..
where as before I would take out my Jo Rai mute (is this what they call a Harman.. with the hole in the middle..) and replicate for 30 seconds the note /phrase before going back to trumpet..which did help to get better core to sound.. Today i just focused on 45 very easy seconds on the Jo Rai.. doing MUCH easier interval jumps../keeping this post relevant to the title./ not blowing at all hard.. .. (to “fool” my inner self1 if you like into thinking it’s easier than i hitherto understood…)then went back to trumpet and pedal a to A was coming out with minimum effort and sounding tip top!!
Thanks John.. and good luck with the move
steve