I hope to modify an old 1968-70 Turner Model 253 communications/paging microphone for a blind ham radio operator by replacing its original dynamic cartridge with a more modern, wider range, better sounding, yet LOW COST microphone cartridge. My question is about the type of cartridge I should select.
The Turner 253 is a desk microphone with a closed head shell. And therein lies the rub: I worry it will choke off or impair the full potential of the replacement cartridge by failing to provide the usual auditory vent to the side and rear of the cartridge. The original cartridge sounds rather narrow range and boxy, like when one pinches his nose and speaks through a megaphone. I hope the replacement cartridge minimizes that effect and provides a more natural sounding response. Um ... ahem ... at least that is the plan. I attach a photo of the original microphone for reference. I also attach images of inexpensive cartridges under consideration.
I could just experiment and see what gives, but I would like to a) minimize messing with the original parts as it is not my microphone, and b) I wish to learn a bit as I proceed. His transceiver works best with a dynamic cartridge, opposed to any type of condenser capsule. The original cartridge has closed sides and rear, so it picks up only from the front, which is, I suppose, why it comes in a completely closed head shell - and yet, it sounds anemic, hollow, and boxy and reverberates terribly.
Please advise if I have not provided enough information to generate a productive discussion. While I might guess what might work best, I seek advice before I drive off half cocked.
Any traction? Thanks in advance. James
The Turner 253 is a desk microphone with a closed head shell. And therein lies the rub: I worry it will choke off or impair the full potential of the replacement cartridge by failing to provide the usual auditory vent to the side and rear of the cartridge. The original cartridge sounds rather narrow range and boxy, like when one pinches his nose and speaks through a megaphone. I hope the replacement cartridge minimizes that effect and provides a more natural sounding response. Um ... ahem ... at least that is the plan. I attach a photo of the original microphone for reference. I also attach images of inexpensive cartridges under consideration.
I could just experiment and see what gives, but I would like to a) minimize messing with the original parts as it is not my microphone, and b) I wish to learn a bit as I proceed. His transceiver works best with a dynamic cartridge, opposed to any type of condenser capsule. The original cartridge has closed sides and rear, so it picks up only from the front, which is, I suppose, why it comes in a completely closed head shell - and yet, it sounds anemic, hollow, and boxy and reverberates terribly.
Please advise if I have not provided enough information to generate a productive discussion. While I might guess what might work best, I seek advice before I drive off half cocked.
Any traction? Thanks in advance. James
