This is pretty much my setup. One receiver locked on the county's P25 system, one "dedicated" to CHP and another for everything else. Ideally you only want desired signals to pass through an amplifier which is why I filter AM & FM broadcast radio before the amp. However, I do feed the full range of the amp's outputs to all receivers. The signals are all present at all radios, then, for example, if there's an incident I can repurpose receivers for whatever channels are involved.
I have the same idea in mind. Right now I have three radios and I'm going to go for a fourth. My office sits out enough from the San Bernardino Mountains that if there's a forest fire I should be able to hear the front of the mountain which is where they usually start. If they go down the Victorville side they don't usually last long because the sun doesn't preheat that side of the mountain. That's what a fireman friend of mine told me anyway.
My plan is to get the Austin Spectra and the 4 ft tall extension mast that's the most to make it like a base station antenna. It will just barely fit in my office under the ceiling. I found a small Christmas tree stand that should be big enough to support it without being overly big. I suppose I could sprinkle a little presents around it anyway. Lol.
If the Spectra works and improves CHP reception then I'll stop there. I know I can get the P25 system. I normally listen using the VHF repeaters so now I'm having trouble programming the P25. I don't know if I am supposed to use the mountain simulcast or use the individual ones like Strawberry and I think it's Heaps Peak and then there's Big Bear or Forest Falls which I'm not sure I can get anyway. I know not to expect perfection from inside an office.
I will try the all band preamp that's been recommended. I had previously mentioned that I could put in a variable attenuator and some thought I was talking about dialing out the noise figure. Not at all. I was talking about dialing back the gain so that if I were to get the preamp that has 20 dB gain I could dial it back so that it's just enough and not too much.
If all that doesn't work, my second plan was to get a Larson VHF low band mobile antenna and another Austin 4 foot extension with the NMO on it. I'd use that on just CHP. I can then throw in a duplexer or a triplexer and split the two antennas off. For that matter I could put in a third VHF antenna but that's going to start costing me a hell of a lot of money.
So I'll start with just the Austin Spectra and go from there. I don't expect to be able to hear the firefighters or the search and rescue guys on their handhelds anyway. I see by the database that on the new P25 system search and rescue has a whole set of frequencies now. But I know from talking with them that they've always had them and the 800 radios work like crap. So they switch to their VHF stuff. That I know I can pick up. I do a lot of hiking up there.
