Thanks!
Thanks to Steve Uhrig and Randy Dow for providing this information.
IC-R10 Receiving Enhancements
The ICOM R10 portable communications receiver comes with a very short broad
band, untuned whip antenna. This antenna works well for receiving signals that
meet or nominally exceed the threshold sensitivity of the receiver.
The R10 was designed with significant RF signal amplification so as to be
effective with short untuned antennas at most of the radios' operating
frequencies. This design, however, is like a two edged sword; the radio is
excellent for picking up very weak signals, but distorts easily with stronger
nearby signals if mitigating practices are not utilized.
The R10 performance can be enhanced by connecting it to an external antenna,
especially if this antenna is designed for the intended listening frequency and
provides gain if required. Short untuned whip antennas (rubber ducks) are very
inefficient; they reduce signal strength by at least 5 dB. Although the R10
comes with a rubber duck it is not intended to provide satisfactory reception
over the entire tuning range of the radio.
Although the R10 is designed to operate down to 0.5 MHz, the small untuned whip
antenna provided may have difficulty providing the 1.6 uV signal level needed
at the radio for good AM reception. This may be true for all low and medium
band frequencies. If the station is too far away (weak signal), an antenna
better suited for that frequency will help considerably, such as a tuned long
wire, dipole, etc. If the station is very near (very strong signal), a signal
level attenuator may be required to keep the radio from overloading.
The R10 is a top of the line handheld communications receiver with specs
exceeding most similar non-ICOM units. The above information is provided to
increase the listening enjoyment and capabilities of R10 owners.
Comment From Steve Uhrig
People should be using more attenuators and fewer preamps. Many times a signal
that seems too weak is actually overloading the receiver, or a large antenna is
picking up a lot of adjacent channel crap that is killing the front end.
Putting bigger and bigger antennas on only exacerbates the problem. Symptoms of
overloading are similar to symptoms of insufficient signal. Very astute
professionals will know the difference, others should experiment.
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