A few years ago contacts on 134GHz were on 134.920, which was the closed to Sam suggested frequency of 134.926, that could be derived from an Elcom synthesiser.
Now we have moved to 134.400 as it easier to get to, from a number of synthesisers. As Barry said, if that is paired with 134.840 as an LO, then the IF is 440MHz. It also allows 134.84 to be used as an alternative paired frequency for TX. From early attempts at mixing, to use SSB. Generally all distance QSOs, have been made by keying the oscillator, so in CW. Although most power is derived by separate TX/ RX (>1mW)