The base model ran at 180 MHz, and the two higher end models ran at 200 MHz and 240 MHz. Thus, the different models were referred to as the 3400c/180, 3400c/200, and 3400c/240.
The base model operated at 180 MHz, while the higher-end models ran at 200 MHz and 240 MHz. These different models were designated as the 3400c/180, 3400c/200, and 3400c/240.