Various arrangements are presented for recording broadcast television programming. A tube is obtained having an axially-extending first portion and a tube form which extends transversely from the first portion. Thus, as one of the charge levels passes above its corresponding charge threshold recharge needs may become equal commencing simultaneous recharge at the latter porting of system recharging. The tongue and groove engagement provides added rigidity to the retaining system, as well as preventing air from bypassing the filters retained within each frame.