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Antenna cable:
Antenna co-ax cable is the critical component in antenna system performance
that is almost always overlooked and is most likely to be of poor or medium
grade when an antenna purchase is made. When a cellular antenna is made, the
biggest and most expensive part of the purchase should be the co-ax cable. High
grade low loss cable for high frequency communications is expensive when
compared to co-ax cable used in lower frequency communications, however from
the outside it looks the same and to most people, "a cable is a cable".
Most name brand cellular antennas use RG58 or RG174 RF co-ax cable and
even though this cable is acceptable when used in lower frequency
communications, like CB radio, this grade of cable is mediocre for the high
frequency bands used in cellular communications. An RG58 cable that is 15 ft
long and with a connector on each end will have a loss of 4 dB or greater in the
Cellular 800 Mhz band and upwards of 8 dB of loss in the 1900 Mhz PCS band.
A smaller RG174 cable will have a loss of 6 dB or greater in the Cellular 800 Mhz
band and upwards of 12 dB of loss in the 1900 Mhz PCS band. Antennas with
these cables are useful in the 800 Mhz Cellular band but virtually useless in the
PCS band.
To overcome cable losses, the engineers at Smoothtalker designed a quadshielded
solid center conductor cable to replace RG58 with less than 1.8 dB loss
at 800 Mhz and less than 3.25 dB loss in 1900 Mhz and a smaller dual-shield
cable to replace RG174 which has less than 3.5 dB loss at 800 Mhz and less
than 7.2 dB loss in 1900 Mhz. Smoothtaker antennas are only sold with
Smoothtalker high performance co-ax cable. Cheap co-ax cables are signal
killers.
Example of how cable loss affects power: 3 watts of power (from a booster) equals 34.8 dBm. A Smoothtalker booster model BST850 is designed and rated
to deliver 3 watts (34.8dBm) to the end of the Smoothtalker cable, which includes
1.8 dB loss. If a lower grade antenna cable is used that has an additional loss of
3 dB, then the power that reaches the antenna is reduced from 34.8 dBm (3
watts) to 31.8 dBm which equals 1.51 watts. The output power is cut in half and
the range of the cellular phone is reduced drastically.
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