Hard Time

File: 082696_d50030_081.txt
Page: 081
Total Pages: 101
     b.  Static Electricity.  Wind and blowing sand/dust can cause static
buildup on antennas.   This can seriously degrade performance of receiving
systems.   Insure that all unused antenna cables are properly terminated.   If a
repetitive high pitch whine followed by snaps and pops are experienced,  insert
a *T" connector in the antenna transmission line.   Bridge the unused connection
with a 5,000 ohm, or greater, resister to blead the static to ground.   Wind
Loading of Antennas and Towers in Sandy Soil.    Guy anchors tend to pull loose
during high winds.   Oversize anchors may be required (bury spare tire,
55 gallon drums filled with sand, etc.   - the larger the better).

     c.  Microwave Communication Fading.  Wide day/night temperature changes may
cause evening and morning fading.   Fading may last for an hour or more.
Antennas should be installed to facilitate rapid adjustment to counter fading
where operational requirements dictate.   Space diversity ant~nnas, when
available, will help.

     d.  Ducting Over Sand and Water.  This phenomena can affect normal line of
sight communications and radar systems by bending signals over the radio
horizon.   The effect can range from being a curiosity to causing serious
interference and operational difficulties.   Changing operating frequencies and
antenna orientation may help.

13.   We have had extensive experience with the AB-1309/ThC Antenna Mast Sys-
tem.   The following are some observations and lessons learned:

     a.  The AB-1309/TRC can be erected in deep sand to a height of 29 feet.
(lower mast section only in vertical position) without guying if the footings
for the antenna mast trailer are stable.   The area of the footings should be
increased by placing steel plates or planking underneath the trailer jacks to
improve stability.   Since high winds can be expected during ODS, the mast
should not be extended beyond 29 feet without guying.   The tongue of the
trailer should be pointed into the wind to minimize lateral forces on the
trailer.

     b.  "Dead man  anchors can be used with guys in the sand.  Use a spare tire
or other large object and bury 4-6 feet deep.    The guy wires should be checked
frequently to insure uniform and proper tension.   Anchors should also be
checked often for any sign of becoming uprooted.

14.   The POC for items 5 - 13 above is Michael J. O'Connor, Electronic Proving
Ground, DSN 521-8012, Commercial (602) 533-8012.

15.    Burns from contact from metals.   Skin contact with metal at low
temperatures (below -10 degrees F) can result in frostbite and in high
temperatures can result in burns.   Anticontact gloves (NSN~84l5-00-227-
1220) are used in low temperatures to provide for dexterity for short
periods and prevent injury.   These gloves are light and thin but have
leather palm and finger protection which may make them useful in ODS
applications.
         POC is LTC. Karl R. Woodruff, Commander CRTC, DSN (317) 363-1990
or COM (907) 873-1990.

16.   Low humidity causing static electricity.   Low humidity conditions
can cause static electricity in both areas.   Tests have shown that thc


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