ElroyJetson
Getting tired of all the stupidity.
I've noticed that some people seem to prefer the shortest, stubbiest antennas they can find for their UHF and 800 MHz portable radios, and then they complain that their radios don't seem to have a lot of range.
I've done some testing using P7100IP portable radios with the FCC menu feature turned on, and verified
the calibration of the built-in signal strength meter against calibrated signal generators, and then used
the radios with different antennas to determine how they perform differently.
The difference can be greater than you might imagine.
For the 800 MHz radios, here are my findings:
The standard 3" whip antenna with yellow coded bands on the tip of it will be considered to be
the standard of measurement. This is the generally supplied antenna with an 800 MHz M/A-Com
portable radio.
Some people use the "spots" Larsen antenna of the very short and stubby variety in place of the
regular antenna. Though this antenna is undeniably smaller, it also is a poor performer, relatively
speaking. Trying one out showed that it exhibits 3 dB less sensitivity than the standard antenna,
which means that the system the radio is listening to is being heard with only HALF the signal strength.
A 100 watt repeater with the stubby antenna is equal to a 50 watt repeater with the regular antenna.
The transmit performance of the portable radio suffers in exactly the same manner. Set the radio for
an honest three watts to the regular antenna, put a stub antenna on, and it's like you turned the power
down to 1.5 watts with the regular antenna. This antenna reduces your effective working range by
a respectable amount. I do not recommend it for anyone who will ever go into an area of poor coverage
and must rely on his radio.
There is also an infrequently used high gain whip antenna, which is my personal favorite. It looks like a
longish UHF whip antenna. It gives 3 dB of gain over the standard 3" whip antenna. That means that
the 100 watt site repeaters now seem to be 200 watts. The radio has better coverage, receiving and
transmitting both. The 3 watt output now looks like 6 watts out of a standard antenna. And the
antenna is quite flexible and should not be annoying to you. This antenna is not the same as the
elevated feed dipole, which is long but only the last 2 inches are skinny and flexible. That antenna is
hardly any better than the 3" whip antenna, but it is more susceptible to breakage.
Most people wouldn't care much about portable radio antennas and their performance, but I do as I
move all around the county a few times a week. And I like to be sure that an apparent difference in
performance is a REAL difference, not imagined.
If anyone is interested in getting these antennas, I can give you the part numbers and MAY be able to
obtain them for you.
Elroy
I've done some testing using P7100IP portable radios with the FCC menu feature turned on, and verified
the calibration of the built-in signal strength meter against calibrated signal generators, and then used
the radios with different antennas to determine how they perform differently.
The difference can be greater than you might imagine.
For the 800 MHz radios, here are my findings:
The standard 3" whip antenna with yellow coded bands on the tip of it will be considered to be
the standard of measurement. This is the generally supplied antenna with an 800 MHz M/A-Com
portable radio.
Some people use the "spots" Larsen antenna of the very short and stubby variety in place of the
regular antenna. Though this antenna is undeniably smaller, it also is a poor performer, relatively
speaking. Trying one out showed that it exhibits 3 dB less sensitivity than the standard antenna,
which means that the system the radio is listening to is being heard with only HALF the signal strength.
A 100 watt repeater with the stubby antenna is equal to a 50 watt repeater with the regular antenna.
The transmit performance of the portable radio suffers in exactly the same manner. Set the radio for
an honest three watts to the regular antenna, put a stub antenna on, and it's like you turned the power
down to 1.5 watts with the regular antenna. This antenna reduces your effective working range by
a respectable amount. I do not recommend it for anyone who will ever go into an area of poor coverage
and must rely on his radio.
There is also an infrequently used high gain whip antenna, which is my personal favorite. It looks like a
longish UHF whip antenna. It gives 3 dB of gain over the standard 3" whip antenna. That means that
the 100 watt site repeaters now seem to be 200 watts. The radio has better coverage, receiving and
transmitting both. The 3 watt output now looks like 6 watts out of a standard antenna. And the
antenna is quite flexible and should not be annoying to you. This antenna is not the same as the
elevated feed dipole, which is long but only the last 2 inches are skinny and flexible. That antenna is
hardly any better than the 3" whip antenna, but it is more susceptible to breakage.
Most people wouldn't care much about portable radio antennas and their performance, but I do as I
move all around the county a few times a week. And I like to be sure that an apparent difference in
performance is a REAL difference, not imagined.
If anyone is interested in getting these antennas, I can give you the part numbers and MAY be able to
obtain them for you.
Elroy
