Note that while it’s easy to determine which software version is loaded into the Model 45 a trip back to the factory is required to update it. The 8-bit micro- controller that provides the unit’s logic “horsepower” also includes internal FLASH memory. This nonvolatile memory is used to store the operating software (“firmware”). Re-programming this mem- ory requires using a specialized program- ming unit. While not outrageous in price, it still costs in the range of US$500. The pro- grammer uses a ribbon cable and socket to interface with a 6-pin “header” on the Model 45’s printed circuit board. And, as you would guess, once connected repro- gramming takes only a matter of seconds. But unfortunately the programmer is not something that would be found in a typical “field shop” or repair facility.
Two Units can be a TW-12B Replacement
Two Model 45 units with their 4-wire in- terface connectors linked in a crossover fashion can act as a universal 2-wire-to- 2-wire “bridge.” This should, in theory, create an updated and improved version of the venerable Clear-Com TW-12B unit. In this arrangement two independent
2-wire party-line intercom systems can function as one while still maintaining full electrical isolation.
The connection scheme is very simple, using just four male-female 3-pin XLR patch cords. The 4-wire outputs of the first Model 45 would be connected to the 4-wire inputs on the second Model 45; the 4-wire outputs on the second Model 45 would connect to the 4-wire inputs on the first Model 45. A 2-wire party-line intercom circuit would connect to each Model 45
