▁the ▁need ▁for ▁improved ▁anti - air craft ▁( AA ) ▁def ences ▁became ▁apparent , ▁and ▁a ▁programme ▁of ▁converting ▁existing ▁T A ▁units ▁was ▁pushed ▁forward . ▁On ▁ 1 ▁October ▁ 1 9 3 8 , ▁ 2 6 4 ▁B ty ▁was ▁separated ▁from ▁ 6 6 th ▁Field ▁Brigade , ▁converted ▁to ▁the ▁heavy ▁anti - air craft ▁( H AA ) ▁role , ▁and ▁expanded ▁into ▁a ▁full ▁brig ade ▁as ▁ 8 0 th ▁( B erk shire ) ▁Anti - A ircraft ▁Brigade , ▁organ ised ▁as ▁follows : ▁ ▁Regiment al ▁Head quarters ▁( R H Q ) ▁at ▁Ye oman ry ▁House , ▁Reading ▁▁ 2 4 9 ▁( B erk shire ▁R HA ) ▁AA ▁B atter y ▁at ▁Reading ▁▁ 2 5 0 ▁( Read ing ) ▁AA ▁B atter y ▁at ▁Reading , ▁raised ▁ 1 ▁October ▁ 1 9 3 8 ▁▁ 2 5 1 ▁( B uck ingham shire ) ▁AA ▁B atter y ▁at ▁Sl ough , ▁raised ▁ 1 ▁November ▁ 1 9 3 8 ▁▁ 2 5 2 ▁( City ▁of ▁Oxford ) ▁AA ▁B atter y ▁at ▁Oxford , ▁raised ▁ 1 ▁November ▁ 1 9 3 8 ▁ ▁( The ▁remainder ▁of ▁ 6 6 th ▁Field ▁Brigade ▁at ▁Br istol ▁became ▁ 7 6 th ▁( G lou c esters hire ) ▁AA ▁Brigade .) ▁ ▁World ▁War ▁II ▁ ▁M obil isation ▁The ▁new ▁regiment ▁( RA ▁brig ades ▁were ▁red