Not necessarily… responses back to dispatch should be using the repeater, regardless of which town/city was talking. You should hear everything, regardless of where they are in the county… it they can “hit” the repeater, you will hear them. It’s when the fire units are using the simplex frequencies (commonly referred to as fire ground (FG), fire tac or fire talk, that require they be close to you.
There are commonly two types of transmissions when you listen to a conventional repeater system, simplex and duplex. Simplex uses one frequency and it’s referred to a “going direct”. It’s unit to unit, be it a handheld or mobile radio. The range is limited to how much power they have and the antenna used. So, you can assume the handheld radio won’t cover as much distance between units… the mobile radios run higher power and have better antennas on the VHF and UHF bands. Your county uses VHF. A duplex system adds a repeater into the mix by using two frequencies, I will call them channel A and channel B, an input frequency and an output frequency. All units transmit on channel A and recieve on channel B. The repeater recieves on channel A and rebroadcasts on Channel B instantaneously. Now, take that repeater to a very high spot within the county, a mountain top or a high building and run it at a higher power level than the mobiles and handhelds and you’ve dramatically increased the range.
Now, all I’ve written here is going with my assumption that only initial dispatches are repeaterized (duplex) and the responding units routinely switch over to another frequency (which is the single channel simplex, no repeater in the mix, once they tell dispatch they are responding. The fire units take care of the call, switch back to the repeater and inform dispatch the incident is over and they are returning to their station. They may say something like “Engine 305 returning, available for other calls or not available (they have to get fuel or repack the hose bed, etc). One last point… after the responding units have signed on the air with dispatch and switched to the secondary simplex frequency, at least one unit still needs to be able to hear dispatch should dispatch have additional info for them… like when a person is not accounted for and may be trapped inside a building, etc. so, the incident commander (IC) either has two radios, one listening on the dispatch frequency and another on the incident channel or a multi channel radio that scans both. Again, this may or may not be the way your county works. It’s just my best guess as to why you don’t hear some transmissions. There also is another possibility… some departments use a digital method of acknowledging dispatches where the responding unit just pushes a button that activates a “canned” message. The message may simply be programmed to read “Engine 305 responding” but it’s sent in a digital format and sounds like berapp, rapid firing tones. Dispatch has a “code reader” that scrolls the message on a screen. No voice audio is transmitted.
Again, asking the dispatch center to help you understand exactly how their system works will help you understand why you hear or don’t hear everything. You could also go to the RR Forums and look for regional forums which are listed by state and pose your question there. Doing so will probably get you someone who knows this system. But you should ask the administrator of this page to transfer you to the regional state forums page as RR does not like duplicate postings on additional boards. I’ve never asked to have that done so I’m no help on how you transfer your post.
