I typed in the stuff below in answer to a question on another list. Then I figured that the folks on this list might like to have it for their file cabinets. When I get time I'll put a web page wrapper around it.
I've also got the info on the part number prefix - like why a 36- part is a knob, why a 41- is a spring and a 66 is a tool. But that is going to be a lot of typing and I've got to be out of my house in a few weeks. Mike WA6ILQ At 07:27 AM 08/27/07, you wrote: >Howdy Folks, > >Has there been a list of the "T" designations posted >anywhere? I haven't figured out any rhyme or reason to the ones >on my equipment...I'm sure there's some logic there somewhere. >TLN-#### for example. > >Thanks, >Lar >K2JIA This is from a 1960s Mot Buyers Guide - as far as I know it disappeared after 1969, and was never published again. My library has three buyers guides from around 1962, 1965 and 1969. Things have changed in this numbering plan since the 60s but a lot of it is still accurate. 1st letter T=two-way radio product (i.e. Illinois plants) N=Portable product (i.e. Florida plants) S="Test Equipment, CCTV, traffic light equipment and other special products" 2nd letter A=antenna related but not duplexers, filters or feedline B=boxes or packaging kits (mostly used internally) C=control equipment (control heads, control panels, etc) D=drop ship items (i.e. stuff manufactured outside Moto, and shipped from the OEM plant to the end customer) E=service kits and conversion kits F=filters and duplexers G=panels (mostly metering panels) H=housings and cabinets J=coil kits K=cable kits L=misc non-categorized items M=Microphones P=power supplies and power supply related equipment R=receivers and receiver related S=speakers, earphones, and related T=transmitters U=unified chassis Other letters have been assigned since this list was printed in the 1960s. 3rd letter A= under 25mhz B=25-54 Mhz (yes, the buyers guide included 6m) C=72-76 Mhz (see note) D=144-174 Mhz E=400-470 Mhz (see note) F=890-960 Mhz N=not frequency dependent (like an audio-squelch board) (see note) C=was limited to the 72-76 USA assignment (one split) until the UK needed equipment for 66-89mhz land mobile in the early 70s, then it was widened to 66 to 88MHz. Some books say 60-99. In the USA the 60-66MHz range is television channel 3, the 66-72MHz range is TV channel 4, the 72-76MHz frequencies are used as "Operational Fixed / Repeater" frequencies (essentially commercial point-to-point links), 76-82MHz is TV channel 5, 82-88MHz is TV channel 6, and 88-108MHz is commercial FM broadcast. E was redefined downwards to 370mhz for certain military and spook equipment in the early 70s, and upwards to 490 and later to 512 as those frequencies were allocated. N is still used as not frequency sensitive even when there is some differences between wideband and narrowband equipment (like in the audio recovery circuitry in an low-IF / discriminator board). The numbers after the three letters are simply a design sequence number. One or two letters after the numbers are variations / revisions. Mike WA6ILQ
