Spectracom 8225 Installation Manual

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8225 Antenna

TSAT Dome Antenna

Type

Active

Frequency

1575.42+/- 15 MHz (L1)

Temp Range

-30 to 85 C

-40 to 85 C

Gain

30dB

N/A

Connector

N type, female

12-pin round

Diameter

3.50 in. (8.9 cm)

3.74 in. (9.5 cm)

Weight

6.8 oz. (191 g)

5.4 oz. (154 g)

Model 8225 GPS Outdoor Antenna Installation Guide

Rev D, June 2012

/ PN 8225-5000-0050

Spectracom provides one of two different standard GPS antennas with certain GPS-equipped products, including the Model 8225 (1) antenna and the T SAT dome antenna (2) (the produc t num ber of which varies depending on the board-level timing product with which it ships). Each antenna is shipped with a mast and clamps for affixing the antenna to an appropria te structure. The antenna c omponents thems elves ar e simply screwed together ( the appropriate components are threaded). Refer to the installation instructions herein for proper positioning of your GPS antenna.

NOTE: A free-standing base is sold separately. Contact Spectracom to

order a Model base for your antenna mast.

The Model 8225 is an active G PS antenna tuned to rec eive 1575.42 MHz L1 band satel lite transmiss ions. The received signals are passed thr ough a narrow bandp ass filter and a pream plifier within the ante nna. The active an tenna circuitry provides 30dB of gain and requires +5 VDC at 27 milliamps (provided by a Spectracom G PS receiver over the antenna cable).

The TSAT dome antenna/receiver is is an active GPS antenna/receiver operating on the 1575.42 MHz L1 band . It provides continuous tracking with an update rate of 1 Hz and generates a pulse-per-second (PPS) output synchronized to UT C within 15 nanoseconds. It also outputs a serial protocol at RS-422 levels. The rec eiver requir es +5 VDC at 50 m illiam ps (provided b y a Spectracom board-level product over multi-conductor cable).

Specifications

Installing the Antenna

The GPS antenna m ust be insta lled outd oors with a n unobstruc ted vi ew of the sky (to 20° elevati on from the horizon). An u nobstruc ted line of sight to t he sky allows the antenna to locate and track the maximum number of satellites throughout the day. Installations with obstructed views may still prove functional, but the equipm ent may experience reduced rec eption quality or be unable to track sim ultaneously the maximum number of satellites. Mak e sure the antenna is installed so mewhere that it will n ot be buried in loose or dr ifting snow, or obstructed by grow ing foliage. Whenever possible, a void placing the GPS antenna in close proximity to broadcast antennas.

To connect the antenn a, run the antenna cab le through the mast if des ired or feasible (4, 8), into the antenna slot up through the end of the mast if not feasible (5), or simpl y to the antenna dom e (9). The 8225 ante nna connection is made inside the ho using and the c ollar s cre wed dow n to sec ure it (3-6). T he TSAT dome antenna is screwed in (7-9).

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Spectracom Model 8225 GPS Antenna Installation Guide Rev D, June 2012 / PN 8225-5000-0050

Antenna Cable for Outdoor Antenna

When using the Model 822 5 GPS outdoor antenna, Spec tracom recommends using LMR-400 (or equivalent) lo w loss type cable for the GPS antenna cable. To simplify the installati on process, Spectracom offers GPS cable assemblies terminated with Type N Male connectors. Standard lengths are 25, 50, 100, 150 and 200 feet.

If the antenna cable is purchased loc ally, select c oax suitab le for outdoor use. Consider the cable's weather ability, temperature range, UV resistance, and attenuation characteristics.

Do not allow the antenna c able to be placed in stand ing water, as water m ay permeate through the coax jack et over time. O n flat roof installati ons, the c oax can be suspended b y cable ha ngers or placed in s ealed PVC conduit. Apply a weather proofing sealant or tape over all outdoor connections.

Installation of a surge pr otection de vice in the an tenna line is recomm ended to protect the GPS receiver and connected devices from lightning damage. Spectracom offers the Model 8226 Impulse Suppressor to shunt potentially damaging voltages on the antenna coax to ground. Note the Model 8226 surge suppressor is only com patible with the Model 8225 GPS antenna. It is not compatible with the TSAT dome antenna.

Cable Lengths

For the Model 8225 antenna, the maximum recommended antenna cable length, when installed without a preamplifier, is 300 feet of LMR 400 or equivalent cable with a maximum attenuation (loss) of 16 dB (Figure 2-1).

When selecting alternate antenna cable sources, the attenuation characteristics at the GPS frequency of 1575.42 MHz must be known. To ensure optimum receiver performance, the total antenna cable attenuation must not exceed 16 dB regardless of cable length. Cable attenuation of greater than 16 dB requires the use of a Model 8227 Inline Amplifier (Figure 2-2).

Model 8224 GPS Splitter

The GPS Antenna Spl itter, Model 8224, is designed for use with an existing antenna/cable setup. It eliminates the need and expense for a second antenna/cable run when two synchronization systems are desirable. The Model 8224 should be installed indoors.

Model 8226 Impulse Suppressor

Spectracom recom mends the us e of a n inline c oaxial protector f or all pro ducts with an outside antenna. Spectracom offers the Model 8226, Impulse Suppressor, to protec t the receiver from damaging vo ltages occurring on the antenna coax. Voltages exceeding the impulse suppresser trip point are shunted to the system ground. The Model 8226 is designed to withstand multiple surges.

Two LMR-400 field-installable N type connectors are provided with the Model 8226 to splice in the surge suppressor wherever it must be plac ed. Ho wever , the r ecom m ended m ethod to avoid havin g to c ut the anten na c able is to d eterm ine the desired location of the Mode l 8226 ahead of tim e and then order two lengths of pre-terminated cabl es instead of just one long cable that spans the entire distance between the antenna and the Spectracom GPS Receiver. Mount the suppressor indo ors, pref erably where th e coax enters the b uilding. I nstall the sup pressor on a gr ounding p anel or bulkhead as shown in Figure 2-3. Refer to the Model 8226 Manual for proper installation.

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Spectracom Model 8225 GPS Antenna Installation Guide

Spectracom

Model

Model 8225

Install impulse

5 Foot Cable included

300’ Maximum

400’ Maximum 21 dB Maximum

450’ Minimum, 700’ Maximum (24 dB Minimum, 37 dB Maximum

Rev D, June 2012 / PN 8225-5000-0050

Spectracom offers a grounding kit that includes grounding cable, clamps, mounting bracket and ground plane. The Spectracom Part Number for this kit is 8226-0002-0600. Contact our Sales department for additional information.

2-1: Cabling without Inline Amplifier

(LMR 400)

16 dB Maximum

suppressor between the antenna and the amplifier whenever possible

8226

8227

GPS Receiver

(LMR 400)

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Figure 2-1: Cabling with Inline Amplifier

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Spectracom Model 8225 GPS Antenna Installation Guide Rev D, June 2012 / PN 8225-5000-0050

Figure 2-3: Model 8226 Impulse Suppress or

Model 8227 GPS Inline Amplifier

An inline amplifier is required whenever GPS antenna cable lengths cause greater than 16 dB attenuation. The Model 8227 GPS Inline Amplifier, shown in figure 2-4 extends the maximum cable length. The Model 8227 provides 20 dB of gain and is powered by the GPS Receiver.

Figure 2-4: Model 8227 Inline Amplifier

Two LMR-400 field-installable N type connectors are provided with the Model 8227 to splice in the amplifier wherever it must be placed. However, the recommended method to avoid having to cut the antenna cable is to determine the desired location of the Model 8227 ahead of time and then order two lengths of pre-terminated cables instead of just one long cable that spans the entire distance between the antenna and the GPS receiver unit.

A five foot N type connector cable is also supplied with the Model 8227 to allow it to be installed after the Model 8226 surge suppressor. The Model 8227 should always be installed after the surge suppressor to prevent lightning or surge damage to the preamp.

Refer to the Model 8227 Manual for proper installation.

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Spectracom Model 8225 GPS Antenna Installation Guide

Document Revision History

Rev

ECN

Description

Date

2213

Document created to include both the 8225 and the TSAT dome antenna, obsoleting Man8225.

2452

Included additional installation information.

C 2702

Updated address information.

October 2011

2984

Specification corrections & document maintenance.

June 2012

Rev D, June 2012 / PN 8225-5000-0050

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