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The SG-230 is supplied with 9 feet of cable standard. SGC has two standard
lengths of antenna extension cable available in the event you need to mount
the cable farther than 9 feet from the transmitter. A 25 foot extension cable is
available (SGC Part # 54-61) as is a 50 foot cable (SGC Part # 54-62).
If you need to install the antenna coupler more than 50 feet from the trans-
mitter site, up to 2 extension cables may be used for a total of 75 or 100 feet.
However, SGC does not recommend installing the Smartuner more than 100
feet from the transmitter because two losses must be considered.
¥ The first loss in long distance installations is normal attenuation of the
radio signal coming from the antenna to the radio via the coax. As you may be
aware, the longer the coaxial cable run, the higher the loss will be. The
amount of loss is dependent on frequency. At 2 MHz, the loss is approximately
.5 dB, while at 30 MHz the loss in 100 feet of coaxial cable is over 2 dB. This
means that a 100 watt transmitter would actually deliver about 70 watts to the
antenna after running through 100 feet of coax at 30 MHz.
If you are seeking the utmost performance at 30 MHz and you can not avoid a
run of 100 feet, or longer, we recommend using a larger low loss type of coax
such as RG-8 (foam dielectric) or Belden type 9943 coax. Both of these will
reduce attenuation to under 1 dB per hundred feet. You should be aware that
this heavier cable is less easy to work and may be quite expensive.
¥ The second loss which must be considered is the losses in the DC power,
lock/reset and indicator control lines. At any distance other than the 9 foot
cable which is supplied by SGC, we recommend that the DC voltage at the
antenna coupler be measured. This is because if the coupler voltage drops
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA 98005 USA
P.O. Box 3526, 98009 Fax: 425-746-6384 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: [email protected] Web site: http://www.sgcworld.com
© 1998 SGC Inc
SG-230 Manual
Smartuner mounted inside a plastic waste
basket to protect it from extreme heat and
heavy icing. This type of enclosure is widely
available in all countries.
Long wire antenna