UHF Whip Antenna 5/8, 5
dB
, NMO
JAVAD GNSS
www.javad.com
Rev.1.5 June 26, 2017
Specifications are subject to change without notice
L
Electrical Specifications:
Frequency
406-430 (p/n 99-587303-01)
430-450 (p/n 99-587304-01)
450-470 (p/n 99-587305-01)
450-455 (p/n 99-587305-20)
455-460 (p/n 99-587305-30)
460-465 (p/n 99-587305-40)
465-470 (p/n 99-587305-50)
Gain
5 dBd (7.15 dBi)
VSWR*
< 1.5:1
Impedance
50 Ohms
Radiation Pattern
Omni directional
Power Rating
200 W
Mechanical Specifications:
Radiator
Stainless steel
Matching coil
Silver plated enclosed coil
Base
ABS, chrome plated brass
Length
39" maximum
Weight
0.51 lbs (0.23 kg)
Mounting
NMO type
COMTELCO
Technical Specification
A1845A,B A1845AS,BS
________________________________________________________________
406-512 MHz 5dB Gain
BASE LOADED MOBILE ANTENNA
High Performance:
A full 5dB gain is achieved in this
premium antenna by featuring a 5/8 wave over 5/8 wave
whip with a base loaded matching coil. It has a power
handling capacity of 200 watts.
Stylish and Durable:
This antenna is manufactured
using the finest corrosion resistant materials and finishes
available. The base is triple plated chrome brass with an
insert molded low loss coil form and a spring loaded
contact. The silver plated phasing coil is fully enclosed to
insure years of dependable service. It is available in both
brite and black finish.
Weatherproof:
O ring seals and overlap construction
keep moisture out of the antenna.
Economical:
These base loaded antennas feature a
great price to performance ratio.
Standard Mounting:
All Comtelco base loaded
antennas mate with the standard TAD/NMO type mount.
ELECTRICAL SPECIFICATIONS:
FREQUENCY RANGE:
406-512MHz
GAIN:
5dB
IMPEDANCE:
50 ohms
POWER RATING
:
200 watts
VSWR:
<1.5:1
RADIATION PATTERN:
Omni directional
MECHANICAL SPECIFICATIONS:
RADIATOR:
Stainless steel
MATCHING COIL:
Silver plated enclosed coil
BASE:
ABS, chrome plated brass
CONTACT:
Spring loaded contact
LENGTH:
39" maximum
WEIGHT:
< 1 lb.
MOUNTING:
Standard TAD/NMO type
Ordering Information:
FREQUENCY
BRITE
BLACK
406-430MHz
A1845A-06
A1845B-06
430-450MHz
A1845A-30
A1845B-30
450-470MHz
A1845A-50
A1845B-50
470-490MHz
A1845A-70
A1845B-70
490-512MHz
A1845A-90
A1845B-90
To order with shock spring add suffix S to the part
number.
Example:
A1845AS-50 or A1845BS-50
Vertical Pattern
90
60
30
0
330
300
270
240
210
180
150
120
406-430 MHz
430-450 MHz
450-470 MHz
Frequency,
MHz
CUT WHIP
Frequency,
MHz
CUT WHIP
Frequency,
MHz
CUT WHIP
inches
cm
inches
cm
inches
cm
405.0
13 7/16
34.2
430.0
12 5/16
31.3
450.0
11 5/8
29.5
406.0
13 1/4
33.7
432.5
11 15/16
30.3
452.5
11 3/8
28.9
410.0
12 5/8
32.0
435.0
11 1/2
29.3
455.0
11 3/16
28.4
412.5
12 1/2
31.7
437.5
11 1/8
28.3
457.5
10 15/16
27.8
415.0
12 3/16
31.0
440.0
10 11/16
27.2
460.0
10 3/4
27.3
417.5
11 15/16
30.4
442.5
10 7/16
26.5
462.5
10 9/16
26.8
420.0
11 5/8
29.6
445.0
10 1/8
25.8
465.0
10 5/16
26.2
422.5
11 1/2
29.2
447.5
9 15/16
25.2
467.5
10 1/8
25.7
425.0
11 3/16
28.5
450.0
9 5/8
24.5
470.0
9 7/8
25.1
427.5
10 9/16
26.9
430.0
10 7/16
26.6
WHIP CUTTING INSTRUCTIONS
The whip should be cut to the length that corresponds to the de-
sired frequency you expect to operate on. In most cases it is de-
sired to cut the whip a bit longer than the chart and make final ad-
justment by moving the whip in the adapter. Please note that the
lengths given in the chart are the total length of the antenna whip.
Each antenna is supplied with a whip that is trimmed to operate
at the lowest frequency. To adjust for a higher frequency you must
cut an appropriate amount from the bottom of the whip. Adjust-
ment of the exact frequency can be made by moving the cut whip
up or down in the adapter and checking the lowest VSWR.
Coil assemblies are factory tuned and sealed. No adjustment should be attempted on them. All frequency adjustments
should be made by trimming the whip. As a rule, you should be able to obtain a VSWR of 1.5 to 1. If you are unable to
accomplish this, a check for correct whip length and proper mounting condition is recommended.
1) Using hexagon wrench unscrew two screws at the base
of the antenna and remove the antenna whip.
2) Cut the end opposite the antenna’s top in accordance
with the table.
3) Clean 15 mm of the paint for good contact.
4) Insert the cleaned end of the antenna whip into the base
and tighten two screws.
5) After cutting the antenna do not forget to write down the
frequency on the label, if it is available.
6) After cutting, measure the antenna VSWR.
All cuts made on antennas
with phasing coils should
be made on the bottom rod
only. Measure the length of
the rod cut from the lower
edge of the phasing coil to
the end of the whip.
*At tuned frequency
