https://www.radioreference.com/db/browse/ctid/305
HFD has approx 25 TGs on the HartLink TRS
HFD only has 2 TG on the CLMRN system
so apparently - HFD main channel is on a TRS - but all the 'Fire
Incidents' channels are used in the conventional mode - with patches
back to the HartLink TRS
Cambridge MA FD operates in a similar way - most channels are on the
TRS - but the 2 primary FG channels are conventional - with patches
back to the TRS (and to UHF also)