Ok, I just boxed up my HP-2 and am prepared to send it back... all ready to go actually. I've had the hp-2 about a week and read a lot on it and watched videos etc. But I was never able to pick up local police, fire, ems...pretty much zero emergency services in my area. I have an external antenna so reception was not an issue. So I ordered an sd card for my area from scanner master thinking maybe they could sort it out. nope. I have the android app scanner radio pro and I does pick up all local emergency channels. So what gives? Am I missing something on the scanner? fyi I am in Galveston county, Texas.
Besides making sure that you have the correct service types for what you want to monitor, your other problem, using an HP-2, is simulcast.
TxWARN P25, the regional trunked system used by almost all public service agencies (Law Enforcement, Fire, EMS) in the greater Houston metro area, including Galveston County, has a large number of simulcast sites. While the HP-2 is a decent scanner, it is not designed to deal with simulcast. The only scanners that are designed with simulcast systems in mind are Uniden's SDS100 & SDS200.
Whoever is providing the feed you are accessing is using a scanner, or other hardware, that can monitor the system and resist issues related to simulcast systems. He or she might be using one of the SDS series scanners, a Unication pager, one of the BlueTail receivers, or using one or more SDR dongles & a PC. Alternately, they may be lucky to located somewhere that is not impacted as severely with simulcast.
Simulcast is extremely location specific. If you are very close to one of the transmit towers, the strong signal may override conflicting signals from other transmitters. Of, a set of taller buildings potentially could block signals from all but one of the sites, allowing reception.
Simulcast Distortion - The RadioReference Wiki
In your case, when dealing with simulcast, having an external (rooftop) antenna might make matters worth. Instead, try using just the antenna that came with the scanner, or remove the antenna & only use a paper clip.