Double Horn Thumb Valve Function

Just got a double horn (this one: www.amazon.co.uk/dp/B0012INK88/ref=cm_sw..._api_i_8R97DbHGJJGMR ) and it came naturally as F (without thumb valve). Is there a way I can change it so I don't have to press thumb valve for B Flat side and have to press for the F side?

Any help would be appreciated,
Eddie

contact me @ <frugalhorn@gmail.com> and we'll exchange some pics on how to make your horn "Stand in Bb".
Bruce Tubbs (and my blog link, below...)
tubbshornstudio.wordpress.com/

If the photo of the product you've linked to is correct, you'll see that the linkage on the change valve (the one operated by the thumb) attaches to the rotor mechanism by a screw which goes into one of two holes. Simply unscrew the linkage and re-attach it using the other hole.

You are a life(/finger)saver! Saw the screw you meant right away and it now works perfectly! Thanks so much! Just a shame I got so used to putting my thumb down now!

Eddie