Internal VHF antenna

[n1chu]

The Unication G5 pager is a dual band receiver that uses an internal VHF or UHF antenna, depending upon which version is chosen. (There are two versions, VHF/700-800MHz or UHF/700-800MHz.) the 700-800MHz antenna is a small stubby external antenna.

The pager has a hot receiver, I’ve heard it related to “commercial grade” and from what I’ve read and actually heard, it is in fact a commercial grade in quality and performance. So I finally scrapped up enough cash to get one of my own. I have the VHF/700-800MHz version. The fist thing I did once I got it programmed was to compare it to the SDS100 and a BCD325P2 on the VHF band. I was impressed with its performance. But it got me thinking about how they get an internal antenna to work as good as it does on the G5… and wonder why scanner manufacturers haven’t offered the same on their handheld units? If they did, both VHF and UHF antennas would be inboard and just the 800MHz band would have an external antenna, a lot shorter than the multi-band antennas currently used. Obviously, it’s a question of cost, but I’m guessing design also plays a large part in it. Maybe it’s just not all that practical?

My experience with handheld radio antennas are primarily related to amateur radio. And since those antennas are also used for transmitting, they need to be positioned away from the circuitry so the radiated RF doesn’t interfere or damage the radio. But scanners and pagers don’t transmit. So, why isn’t it practical to have internal antennas like the G5 has?

 

[kruser]

The G5's internal antenna is just a solid wire antenna only a couple inches in length maybe. It's very inefficient and relies upon the fact that the users the G5's are intended for will be working in areas where the signal levels are generally good for the UHF or VHF secondary band.
In my case, the G5 will not detect the VHF sites I monitor at all using its internal antenna. I must supply the secondary band radio in my G5 with an external antenna signal fed thru the contacts on the bottom of the G5. I use the amplified charging base for this as it has an external antenna jack on it that will feed signals to the G5's primary and secondary inputs.
I can take a portable scanner or commercial portable and tune the VHF sites the G5 will not hear, the sites come in just fine on the portables that have decent flexible VHF antennas on them.

 

[hill]

My G5 works rather well for monitoring the Virginia statewide TRS STARS when staying there for work.

It does sometimes have issues inside the hotel if staying on first floor with this radio system not really built out for in building coverage. Even the end users like State Police use mobile repeaters (extenders in the old days) to provide coverage when out of the vehicle with the way the system was designed.

Overall the G5 works well from the internal antenna VHF. I used all band scan and receives ham repeaters, marine radio and some VHF public safety better than I expected on the internal antenna.

 

[n1chu]

The G5's internal antenna is just a solid wire antenna only a couple inches in length maybe. It's very inefficient and relies upon the fact that the users the G5's are intended for will be working in areas where the signal levels are generally good for the UHF or VHF secondary band.
In my case, the G5 will not detect the VHF sites I monitor at all using its internal antenna. I must supply the secondary band radio in my G5 with an external antenna signal fed thru the contacts on the bottom of the G5. I use the amplified charging base for this as it has an external antenna jack on it that will feed signals to the G5's primary and secondary inputs.
I can take a portable scanner or commercial portable and tune the VHF sites the G5 will not hear, the sites come in just fine on the portables that have decent flexible VHF antennas on them.

Interesting. It’s not some electronic magic at work here, it’s simply a matter of location. The closer to the transmit site, the stronger the signal. And of course, as it is with all receivers, we try to improve on their performance… usually starting by adding a more efficient antenna.

 

[n1chu]

My G5 works rather well for monitoring the Virginia statewide TRS STARS when staying there for work.

It does sometimes have issues inside the hotel if staying on first floor with this radio system not really built out for in building coverage. Even the end users like State Police use mobile repeaters (extenders in the old days) to provide coverage when out of the vehicle with the way the system was designed.

Overall the G5 works well from the internal antenna VHF. I used all band scan and receives ham repeaters, marine radio and some VHF public safety better than I expected on the internal antenna.

Thanks for the input. I agree with your findings and am happy with the G5 performance also.