Code:
zsh-4.3.9[t]% awk '
quote> END { if (r ~ v) print r }
quote> /^\*\*\*/ {
quote> if (r ~ v) print r
quote> f = 1; r = ""
quote> }
quote> f { r = r ? r RS $0 : $0 }
quote> ' v='\\** PBX TYPE:ID6' test1.txt
****** PBX TYPE:ID6 PBX-id: L14 polled on 011409 133905 00 >>>>>>
L14,2009-01-14 13:36:00.000,64,38772, ,18905238433,E,38772, , ,052,046,N,00, ,2009-01-14 13:36:00.000, , ,0, ,0,0,0,0,0,0,0,0,0,0,0,14486634
L13,2009-01-14 13:37:00.000,0, , ,1448845,E, ,052,016, , ,IN,00, ,2009-01-14 13:37:00.000, , ,0, ,0,0,0,0,0,0,0,0,0,0,0,14486636
L21,2009-01-14 13:36:00.000,60, , ,38883,E, ,000,003,052,017,$1,00, ,2009-01-14 13:36:00.000, , ,0, ,0,0,0,0,0,0,0,0,0,0,0,14486638
L12,2009-01-14 13:37:00.000,20, , ,38300,E, ,052,018, , ,IN,00, ,2009-01-14 13:37:00.000, , ,0, ,0,0,0,0,0,0,0,0,0,0,0,14486640
L28,2009-01-14 13:32:00.000,302,38843, ,1890017722010,E,38843, , ,001,156,N,00, ,2009-01-14 13:32:00.000, , ,0, ,0,0,0,0,0,0,0,0,0,0,0,14486642
L14,2009-01-14 13:34:00.000,168, , ,38945,E, ,000,007, , ,IN,00, ,2009-01-14 13:34:00.000, , ,0, ,0,0,0,0,0,0,0,0,0,0,0,14486644
L16,2009-01-14 13:35:00.000,108,1448805, ,1890018498124,E,1448805, , ,001,138,N,00, ,2009-01-14 13:35:00.000, , ,0, ,0,0,0,0,0,0,0,0,0,0,0,14486646