Phonoland

I recently bought this Grundig majestic, It's an 1960 model and the radio and speakers work great. The only problem I've been having is with the record player. It spins at the right speed, and brings it's arm over correctly, however, when the need hits the record it produces an awful high-pitch squeal. I can hear the music beneath it though. I bought a new needle, but that seemed to have no effect. I was going to buy a new cartridge for it but all I could find was an Astatic aftermarket replacement. Before I went out and spent $80.00 on it I thought I would see if anyone knew whether this would fix it. Also is there anything else it could be?
Thanks!

That might be acoustic feedback from the speaker to the pickup. Try turning the volume down.