Rhotheta RT-8556 User manual

User Manual
Installation and Operating
Ramptester
for
RT-400, RT-500-M, RT-800
Radio Direction Finders

RT-8556 Ramptester User Manual
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Edited by:
RHOTHETA Elektronik GmbH
Kemmelpark
Dr.-Ingeborg-Haeckel-Str. 2
82418 Murnau
Germany
Tel.: [phone] - 0
Fax: [phone] - 15
Internet: www.rhotheta.de
E-Mail: [e-mail]
Copyright © RHOTHETA Elektronik GmbH
All rights reserved
-Issue: 2020/10/27 [Rev 1.00a]
-Document-ID: 12-9-1-0023-3-1-60
Note
The manufacturer reserves the right to make modifications to the product described here at
any time and without previous information.

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Content
1Safety Instructions ..................................................................................... 4
1.1 Legend of Signal Words .........................................................................................................................4
1.2 Basic Safety Instructions ........................................................................................................................5
2EU Declaration of Conformity.................................................................... 5
3General Description ................................................................................... 6
4Equipment for Test On-Site ....................................................................... 6
5Test Procedure ........................................................................................... 7
5.1 Test Preparation .....................................................................................................................................7
5.2 Bearing Accuracy Measurement ..........................................................................................................10
5.3 Bearing Sensitivity Measurement .........................................................................................................12
5.4 Audio Test.............................................................................................................................................14
6Product Disposal ...................................................................................... 16
6.1 Disposal within the European Union.....................................................................................................16
6.2 Disposal outside the European Union ..................................................................................................16
7List of abbreviations ................................................................................ 17

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1 Safety Instructions
RHOTHETA Elektronik GmbH is constantly trying to keep the safety standard of their
products up to date and to offer their customers the highest possible level of safety.
RHOTHETA products are designed and tested in accordance with the valid safety
regulations. The compliance with these standards is continuously monitored by our quality
assurance system.
This product is tested and left the factory in perfect technical and safety-relevant condition. To
maintain this condition and to ensure safe operation, the user must pay attention to all
instructions and warnings given. For any questions regarding these safety instructions,
RHOTHETA Elektronik GmbH can be contacted at any time.
The observance of the safety instructions will help to prevent personal injury or damage
caused by all kinds of dangers. This requires that the following safety instructions must be
read carefully and understood before using the product, as well as observed when using the
product. The additional safety instructions such as for protecting persons appear in relevant
parts of the product documentation and must also be paid attention to.
In addition, itisthe responsibility ofthe user to use the product appropriately. The
RT-8556 ramptester may not be used in any way that results in personal injury or property
damage.
The use of this product other than its designated purpose or in disregard of the instructions of
the manufacturer is the responsibility of the user. The manufacturer takes no responsibility for
the misuse of the product.
The manufacturer is not liable beyond the scope of legal rules!
1.1 Legend of Signal Words
Note
This symbol designates tips or additional notes that must be paid attention to and make
work easier.
Caution
Means that ignoring the instructions may lead to property damage or loss of data.
Warning
Means that ignoring the instructions, there may be a danger to health or life.

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1.2 Basic Safety Instructions
Caution
Read and observe the following instructions, warnings and safety guidelines from
the manufacturer!
•At all times, the local or national safety and accident prevention regulations must be
observed.
•When installing or operating with the product, always follow the manufacturer's instructions.
•Only place the product on appropriate locations.
•Do not expose the product to environmental conditions (heat, humidity, wind load etc.) that
exceed the specified conditions in the manuals.
•Use only the manufacturer prescribed components and/or use only recommended
materials and do not change them. Any other use or unauthorized modifications to the
product will void the authorization to operate it.
•Connect only approved accessories kits or additional equipment.
•Ensure that the connections with information technology equipment, e.g. industrial
computers, comply with the IEC 62368-1 standard that applies in each case.
•The product may only be opened by authorized service personnel.
2 EU Declaration of Conformity
Hereby RHOTHETA Elektronik GmbH declares that the product RT-8556 Ramptester
(Basic Equipment) is in compliance with the essential requirements and other relevant
provisions of:
•Directive 2011/65/EU on the restriction of the use of certain hazardous substances in
electrical and electronic equipment
The full text of the Declaration of Conformity can be found at:
http:// www.rhotheta.com
The EU Declaration of the Optional Equipment is on request available at RHOTHETA
Elektronik GmbH or directly at the manufacturer of the Optional Equipment.

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3 General Description
The RT-8556 ramptester is aDF (direction finder) performance measurement equipment
designed for quick test and maintenance of the RT-400, RT-500-M, and RT-800 radio
direction finder systems (RDFs). The ramptester consists of the antenna measurement
device (ramptester itself) and an optional RF signal generator, which allows tests on any
desired frequencies in the RT-8556 defined frequency range. The antenna measurement
device allows the bearing testing in 45° steps and can be simply attached to the
RT-400/RT-500-M/RT-800 AU (antenna unit). Thus, the RT-8556 ramptester provides an
extensive and convenient performance test of the direction finder installed on a vessel,
which includes the bearing accuracy, bearing sensitivity and audio modulation tests on
every customer desired frequency channel.
4 Equipment for Test On-Site
Device under test is the RT-400 / RT-500-M / RT-800 direction finder.
•Antenna unit (AU)
Basic Equipment:
•RT-8556 ramptester
(antenna measurement device)
•RF cable
•User manual
•Test protocol template
Optional Equipment:
•RF Signal Generator
-PN RT-14400WP
-Freq: 35-4400 MHz
-Level: -80 to +10dBm
-Battery, charging circuit
-Cables
-Carrying case

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5 Test Procedure
5.1 Test Preparation
•Assemble the ramptester in two steps:
1. Connect the measuring ring of the ramptester to the handle tube at the position
of the groove and fix the parts with the knurled screws.
2. Then screw the two dipole radiators into the corresponding threads.
•Mount the ramptester on the DF antenna unit.
Basically,the three guide pieces (brackets) must be on top.

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Standard mounting: Upside-down mounting:
1. Loosen the knurled screws in the three guide pieces of the measuring ring and
push the guide pieces outwards.
2. Loosen the knurled screw on the clamping piece. Impose the ramptester on the
antenna unit (AU).Pull on the handles ofthe clamping piece (it has a built-in
spring) and release as soon as the clamping piece is placed under the antenna
ring. Turn the measuring ring so that the locking piece of the clamping piece is
at the180° position and the dipole antenna is at the 0° position.
locking piece
0° mark
handles of
clamping piece

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3. Press the three guide pieces (brackets) against the antenna and tighten the
knurled screws.
4. Now you can turn the measuring ring on the handle tube and the ramptester
remains fixed to the antenna, the locking function of the clamping piece allows
exact 45°-steps.
•Ensure that the DF is switched on (for the audio test (s. 5.4) use either the
external speaker or connect the DCU to the audio system ofthe vessel).
•Connect the RT-14400WP generator - or another signal generator that fulfills the
requirements ofthe test procedure - with theramptester.
RF-signal feeding

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5.2 Bearing Accuracy Measurement
Test Procedure: Bearing Accuracy
Nr. Procedure Setting
1 Set the DF frequency to the desired frequency.
2 Set the signal generator frequency to the measurement frequency.
Depending on purchased frequency
options available on the DF, RHOTHETA
recommendstesting of following
frequencies. Additional frequencies can be
tested on demand.
VHF Air Band 121,500 MHz
VHF Maine Band 156,800 MHz
Military Air Band 243,000 MHz
COSPAS-SARSAT 406,025 MHz
3 Set the generator level. -30 dBm
4 Set the generator modulation.
AM = OFF
FM = OFF
5 Adjust the ramptester to the 0° Position.
6
Rotate the ramptester to each azimuth position and note the bearing results in the test
protocol.
7 Chose the next frequency and start with the first step.

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Protocol: Bearing Accuracy Measurement (Example)
Nr. Description Limits Result Passed Result Passed
1 Frequency -- 121,500 MHz 156,800 MHz
2 0° Position 350° … 10 ° OK OK
3 45° Position 35° … 55 ° OK OK
4 90° Position 80° … 100 ° OK OK
5 135° Position 125° … 145 ° OK OK
6 180° Position 170° … 190 ° OK OK
7 225° Position 215° … 235 ° OK OK
8 270° Position 260° … 280 ° OK OK
9 315° Position 305° … 325 ° OK OK
10 Frequency -- 243,000 MHz 406,025 MHz
11 0° Position 350° … 10 ° OK OK
12 45° Position 35° … 55 ° OK OK
13 90° Position 80° … 100 ° OK OK
14 135° Position 125° … 145 ° OK OK
15 180° Position 170° … 190 ° OK OK
16 225° Position 215° … 235 ° OK OK
17 270° Position 260° … 280 ° OK OK
18 315° Position 305° … 325 ° OK OK
Note
Other frequencies can be tested according to the test procedure. The see test protocol
template can be adopted appropriately.

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5.3 Bearing Sensitivity Measurement
Test Procedure: Bearing Sensitivity
Nr. Procedure Setting
1 Set the DF frequency to the desired frequency.
2 Set the DF squelch level.
(The output of the RF Generator should be set OFF)
5% above the
noise level
3
Set the signal generator frequency to the desired frequency and switch off all
modulations (AM = OFF, FM = OFF)
Depending on purchased frequency
options available on the DF, RHOTHETA
recommendsthe testing of following
frequencies. Additional frequencies can be
tested on demand
VHF Air Band 121,500 MHz
VHF Maine Band 156,800 MHz
Military Air Band 243,000 MHz
COSPAS-SARSAT 406,025 MHz
4 Adjust the level of the RF generator and set the output ON. -50 dBm
5
Adjust the ramptester to the 0° position and wait until the bearing
value has been stabilized. Note the bearing result.
0°
-50 dBm
6
Adjust ramptester to the 90° position and wait until the bearing value
has been stabilized. Note the bearing result.
90°
-50 dBm
7 Adjust the level of the RF generator and set the output ON. -60 dBm
8
Adjust the ramptester to the 0° position and wait until the bearing
value has been stabilized. Note the bearing result.
0°
-60 dBm
9
Adjust the ramptester to the 90° position and wait until the bearing
value has been stabilized. Note the bearing result.
90°
-60 dBm
10
Reduce the signal generator level until no bearing is displayed. Note
the generator limit level.
Note
Before starting the test, make sure that the noise level is not higher than the signal level.

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Protocol: Bearing Sensitivity Measurement (Example)
Nr. Description Limits Result Passed Result Passed
1 Frequency -- 121,500 MHz 156,800 MHz
2 0° Position; PGen = -50 dBm 350° … 10 ° OK OK
3 90° Position; PGen = -50 dBm 80° … 100 ° OK OK
4 0° Position; PGen = -60 dBm 340° … 20 ° OK OK
5 90° Position; PGen = -60 dBm 70° … 110 ° OK OK
6
DF Receiving OFF level
(Note generator RF level)
-- -- --
7 Frequency -- 243,000 MHz 406,025 MHz
8 0° Position; PGen = -50 dBm 350° … 10 ° OK OK
9 90° Position; PGen = -50 dBm 80° … 100 ° OK OK
10 0° Position; PGen = -60 dBm 340° … 20 ° OK OK
11 90° Position; PGen = -60 dBm 70° … 110 ° OK OK
12
DF Receiving OFF level
(generator level)
-- -- --
Note
Other frequencies can be tested according to the test procedure. The see test protocol
template can be adopted appropriately.

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5.4 Audio Test
Test Procedure: Audio Test
Nr. Procedure Setting
1 Set the DF and the signal generator (if it provides modulation) to the desired
frequency. Adjust the ramptester to any position.
Depending on purchased frequency
options available on the DF,RHOTHETA
recommendsthe testing of following
frequencies. Additional frequencies can be
tested on demand.
VHF Air Band 121,500 MHz
VHF Maine Band 156,800 MHz
Military Air Band 243,000 MHz
COSPAS-SARSAT 406,025 MHz
2
Set the generator modulation depending on the used frequency and set the output on
ON.
Amplitude modulation for the VHF air band or military band
AM: 60%
AF: 800 Hz
FM: OFF
Frequency modulation for other frequencies
FM: 3 kHz
AF: 800 Hz
AM: OFF
3 Set the generator on the appropriate level. -30 dBm
4 Set the DCU volume. 50%
5
The 800 Hz tone should be hearable loud and clear (external speaker or out of the audio
system of the vessel).

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Protocol: Audio Test (Example)
Nr. Description Limits Result Passed Result Passed
1 Frequency -- 121,500 MHz 156,800 MHz
2 Audio output loud and clear OK OK
3 Frequency -- 243,000 MHz 406,800 MHz
4 Audio output loud and clear OK OK
Note
Other frequencies can be tested according to the test procedure. The see test protocol
template can be adopted appropriately.

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6 Product Disposal
6.1 Disposal within the European Union
Product Disposal
Product labeling according to EN 50419
At the end of product life, this product may not to be disposed together with normal household
waste. Even disposal via the municipal waste disposal collection for electrical and electronic
equipment is not permitted.
The correct disposal of this product helps to protect the environment and prevent any
potential damage to the environment and human health, which can occur due to improper
handling of the product.
•Therefore, carry out the inoperative device, an electronics recycling.
or
•The RHOTHETA Elektronik GmbH takes back all products that are subject to the
requirements of the WEEE Directive (2012/19/EU) of the European Union to supply
these products to professional disposal.
6.2 Disposal outside the European Union
For proper disposal of used electronic equipment in accordance with the respective national
regulations in countries outside the European Union please check it with your dealer or the
local authorities.

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7 List of abbreviations
Abbreviation
Meaning
Remarks
AM
Amplitude Modulation
AMD
Antenna Measurement Device
AU
Antenna Unit
CP-SS, C-S
COSPAS-SARSAT System
DCU
Display & Control Unit
DF
Direction finder
Deg
Degree (° = 60' )
ELT
Emergency Locator Transmitter
FM
Frequency Modulation
GND
Ground
GPS
Global Positioning System
ID
Identification
IP
Ingress Protection rating
IP67
LAN
Local Area Network
LCD
Liquid Crystal Display
LED
Light-Emitting Diode
MOB
Man-Over-Board
MSSI
Maritime Mobile Service Identity
Ship's Ident. No.
NF
Audio Frequency
NMEA (0183)
National Marine Electronics Association
Interface standard
PLB
Personal Locator Beacon
PS RAM
Averaging Random Access Memory
PTT / SBS
Push-To-Talk / Self Bearing Suppression
RAM
Random Access Memory
RF
Radio Frequency
Rx
Receiver
S/N
Signal to Noise
SAR
Search And Rescue
SNR
Signal to Noise-Ratio
SQL
Squelch
TFT
Thin Film Transistor (see also LCD)
Tx
Transmitter
V
VTS Version
AU-Variant V
VDC
Volts of Direct Current
VTS
Vessel Traffic Service