Conn 30H Burkle Duo-Bore Medium
Date: 1940. Owned by Craig Koltes
The 30H was a "duo-bore" instrument, with a bore of 0.494" and 0.507". In Conn terms, this is approximately a #2¾ and a #3¼ bore. It was produced from 1934 to at least 1949. Judging from the 32H Large model Duo-Bore, it may have been produced from 1934 to 1958.
What Conn said in 1938:
These two [30H and 32H] new models were built especially for the theatre, dance, and other large organizations, where great power and volume are paramount. Designed by and named for "Jake" Burkle, dean of Conn experimental engineers, and considered by him to be two of the best he has ever built. Incorporate tapered bore throughout bell, tuning slide, bell taper, slides and hand slide bow. This design, together with new construction bell, produces great flexibility, plenty of bright tone of robust quality, just the right amount of resistance, exceptionally accurate intonation, and amazing ease of response. Every register is of same beautiful quality, the top register being unusually good. Players are surprised at the ease with which high F and the G above bass clef are obtained. Narrowest slides and longest slide bearing on outside slides of any Conn trombone, giving light, fast slide action. Slide lock, bell lock, standard bell 7 and 7½ inches. Bb. Price includes plush-lined case. Selected by such representative stars as Ernie Passoja, high note king, CBS, Chicago, formerly with Horace Heidt; "Mike" Martini, first trombone with Vincent Lopez; Frank Perry with Red Nichols' Orchestra; Harry Kite, first chair with Ace Brigode; Herbert Foll with Stan Myers, Guy Boswell of Cleveland Symphony; Vincent Grande, NBC, N. Y.; and Carroll Martin, great first chair, NBC, Chicago.
What Conn said in 1950:
The Burkle models are popular in in large organizations where great power and volume are paramount. Have [sic] unique tapered bore through bell, tuning slide, bell taper, hand slides and hand slide bow. This design produces big tone, accurate intonation and ease of response, especially in top register, making Burkles favorites of high note kings.
Narrow, light slides for fast execution. Two bore sizes: medium, 7-inch bell, 30H; large, 7½-inch bell, 32H. Both with long slide bearing for smooth 7th position, bell lock, slide lock, balancer, tuning in bell.