Hello. I recently found a 1630A Altec Dividing Network at a Thrift Store near here. Being a musician, I recognized that this piece of rack gear was probably useful or valuable and purchased it even though I have no idea what a dividing network is. I can't find any info on this piece of equipment. Can anyone tell me about it? I'd love to know what it does, when it was made, how much it might be worth, etc. It does turn on, but it's apparently missing some tubes in the back. Thanks for any help with this.