User's Manual

ITCR Wayside User’s Manual
© 2013 Meteorcomm LLC. All Rights Reserved. Proprietary and Confidential
6 5/16/2013
Therefore, the wayside radio may not transmit on those channels or their 221 MHz
counterparts, 361-370 and 381-385. This corresponds to wayside frequencies,
220.8125, 220.8375, 220.9125, 221.8125, 221.8375, and 221.9125 MHz.
Please refer to Part 90 Subpart T and SRSP-512 for additional frequency use
restrictions in Canadian and Mexican border areas.
3.3 Wayside Radiated Power Limits
It is the responsibility of the licensee to comply with the effective
radiated power limits based on operating frequency, geographic location,
and effective antenna height set out in 47CFR Subpart T §90.701 et. seq.,
or Industry Canada SRSP-512 §6.3, as applicable.
Important: The following supplementary antenna system information discusses
means for the licensee to determine effective radiated power (ERP) and comply with
regulatory power limits.
Licensees must comply with the specific power and antenna height limitations for
fixed-antenna stations per §90.729 or SRSP-512 §6.3. Note that U.S. and Canadian
power limits vs. HAAT are not identical.
Licensees should note that all mobiles and also fixed installations transmitting
between 221 and 222 MHz must limit effective radiated power (ERP) to 50W or
10*log(50) + 30 = 47dBm PEP referenced to the 2.15 dBi gain of a dipole, unless
operating under a waiver of FCC rule §90.729(b) or SRSP-512 §6.3 as applicable. The
EIRP for this case is 49.15 dBm. Also note that the maximum ERP on FCC/IC channels
196-200 at 220.975 to 221.000 MHz is 2 watts.
The allowable transmitter peak envelope power output in dBm is determined by
subtracting the antenna gain in dBi from 49.15, then adding the loss from the
antenna feedline and connectors. If the result is greater than or equal to 44.85 dBm
= 14.85 dBW then the maximum power output of the Wayside transmitter can be
used. If the value is less than 44.85 dBm, then the transmitter output power must be
reduced to the calculated value.
Mobile Installation: As an example of a mobile installation, consider a vertical half
wave ground plane on a vehicle metal rooftop. In an ideal installation the antenna
gain = 2.4 dBd = 4.55 dBi. Ignoring connector losses, feedline loss is at least 0.6 dB