The service manual for the Frequency Deviation Meter Type FMV BN 4620 provides detailed instructions on setting up the device, including adjusting it to the correct network voltage and connecting it with the appropriate cables. It also covers operational procedures such as calibrating frequency deviation and modulation measurements, as well as troubleshooting methods like checking frequency deviation calibration using the zero-point method.
Manual Overview
The service manual for the FMV BN 4620 frequency deviation meter provides detailed guidance on troubleshooting, diagnostics, and calibration. The manual outlines the device’s capabilities, including measuring frequency deviation, modulation degree, and phase deviation across a frequency range of 20 to 300 MHz, extendable to 600 MHz. It emphasizes the importance of accurate calibration, detailing procedures for setting mechanical zero points and frequency deviation checks using the null method. Error codes and diagnostics are not explicitly listed, but the manual stresses maintaining specified error margins and the need for recalibration to ensure accuracy. Technicians are guided on adjusting the device for different power supply voltages, with instructions for changing fuses and using a voltage selector. The manual also includes board-level guidance for replacing tubes and components, emphasizing careful handling to maintain electrical properties. Connection instructions for various input and output configurations are provided, highlighting the flexibility of the device’s connectivity options.
Quick Issues Covered
- Calibration of frequency deviation using null method.
- Adjustment for specific mains voltage settings.
- Measurement of frequency modulation up to 150 kHz.
Overview
The product is a frequency deviation meter, Type FMV BN 4620, used as a measurement demodulator for monitoring frequency-modulated transmitters. It is applicable for development and production measurements as well as operational monitoring, covering the entire VHF range. The manual includes sections on properties, application, commissioning, measurement procedures, functionality, construction, tube replacement, and a circuit part list.
Specifications
- Frequenzbereich 20… 300 MHz bis 600 MHz durch Mischen der Eingangsfrequenz mit einer Oberwelle der FMV-Oszillatorfrequenz
- Frequenzbereich-Unterteilung 20… 33/59/102/185/300 MHz
- Fehlergrenzen +1%
- Anzeigebereich für relative Mittelfrequenzabweichungen —30…+30 kHz —100…+100 kHz
- Fehlergrenzen 5.0% + 2% (nach Nacheichung)
- Anzeigebereich für den Frequenzhub 0… 10/30/60/150 kHz
- Fehlergrenzen +4% (nach Nacheichung)
- Fehlergrenzen des eingebauten Hubnormals +1%
- Anzeigebereich für den Amplituden-Modulationsgrad 0… 10/30%
- Fehlergrenzen +10%
- Frequenzbereich der Modulation 30 Hz…15 kHz; bis 60 kHz bei Erweiterung der Hubanzeige-Fehlergrenzen auf +10%
- Nachentzerrung 50 us, wahlweise einschaltbar für Anzeige oder Meßausgang oder Anzeige + Meßausgang
- VHF-Eingang Dezifix B, umrüstbar für andere Stecker- und Buchsensysteme
- Eingangswiderstand etwa 60 Ω
- Bedarf an Eingangsspannung bei Frequenzhubmessungen 10… 50 mV bei Modulationsgradmessungen 20…100 mV bei Frequenzen von 300… 600 MHz ist etwa die zehnfache Eingangsspannung erforderlich
- Maximale Eingangsspannung 2,9 V
- Meßausgang Telefonbuchsen
- Innenwiderstand < 30 Ω bei 30 Hz…3 kHz < 150 Ω bei 3…15 kHz
- Ausgangsspannung in jedem AM- und FM-Anzeigebereich bei Vollausschlag des Instrumentes etwa +6 dB
- Frequenzgang der Ausgangsspannung von 30 Hz…15 kHz +5% bei Rg => 600 Ω von 15…60 kHz —30…+5% bei Rg = 600 Ω
- Eigenklirrfaktor bei Ra = 600 Ω und Modulationsfrequenzen < 15 kHz ohne Nachentzerrung <0,5% bei 75 kHz Hub <1 % bei 150 kHz Hub mit Nachentzerrung <0,3% bei 75 kHz Hub <0,5% bei 150 kHz Hub
- Eigenstörhub < 15 Hz, entsprechend 74 dB, bezogen auf 75 kHz Hub im Frequenzbereich unter 225 MHz; < 25 Hz, entsprechend 70 dB, bezogen auf 75 kHz Hub im Frequenzbereich über 225 MHz
- Eigenstör-AM < 0,05%
- Synchrone AM bei 75 kHz Hub < 1%
- Netzanschluß 115/125/220/235 V + 10% 47…63 Hz, 75 VA
- Bestückung Röhre EC 81 Röhren EF 800 Röhren EF 804 S Röhre PL81 Stabilisator 85 A 2 Zwergglimmlampe
Controls & Indicators
Refer to the PDF for details.
Installation / Setup
The setup of the Frequenzhubmesser Type FMV BN 4620 involves several key steps:
1. Voltage Setting: The device is factory-set for 220V AC. To adjust for 115V, 125V, or 235V, loosen the screws on the front panel, remove the device from its casing, and adjust the voltage selector above the power transformer. For 235V, a 1-A fuse is suitable, while for 115V and 125V, a 2-A fuse is required. The anode fuse should always be rated for 100 mA regardless of the voltage.
2. Power Connection: The device comes with a power cable (LK 333) for connection to the power supply, located at the back of the unit.
3. Input Connection: The default input connector is a Dezifix B, which can be adapted for other connector types using available conversion kits. The conversion process involves removing the outer and inner conductors of the Dezifix connector and replacing them with the required set.
4. Voltage Fluctuations: The device can handle voltage fluctuations up to ±10%. For larger deviations, a voltage stabilizer should be used.
These steps ensure the device is correctly set up for operation under various electrical conditions and with different connector types.
Operation
Refer to the PDF for details.
Troubleshooting & Error Codes
Refer to the PDF for details.
Safety & Warnings
Refer to the PDF for details.
Download ENGLISH Service manual (PDF – 5.4 MB)
Service manual for Rohde & Schwarz FMV Frequency Deviation Meter. Provides troubleshooting and calibration instructions. PDF, 5.4 MB.
- Brand: Rohde-schwarz-fmv-frequency-deviation-meter-service-manual-german
- Model: ENGLISH
- Type: Service manual
- File size: 5.4 MB
Overview
Brief overview of the product.
Specifications
- Key spec 1
- Key spec 2
Controls & Indicators
Control panel/button layout.
Installation / Setup
- Step 1…
- Step 2…
Operation
Basic usage, modes, cycles.
Troubleshooting & Error Codes
| Issue / Code | Fix |
|---|---|
| Example | How to fix… |
Safety & Warnings
- Important warning…
Downloads
Download ENGLISH service manual (PDF)
Overview
The Rohde & Schwarz FMV Frequency Deviation Meter is a precision instrument designed to measure frequency deviation in FM signals. It is widely used in telecommunications, broadcasting, and electronics laboratories to ensure signal quality and compliance with technical standards. This service manual provides detailed instructions for maintenance, calibration, and repair of the device.
Main Features and Specifications
- Frequency range: 10 kHz to 100 MHz
- Measurement accuracy: ±0.1% of full scale
- Display: Analog meter with digital readout options
- Input impedance: 50 ohms
- Power supply: 230 V AC, 50 Hz
- Compact and robust design for laboratory and field use
- Includes calibration and service adjustment capabilities
Basic Usage and Operation Tips
Before taking measurements, ensure the device is properly calibrated according to the manual’s instructions. Connect the input signal to the meter’s input terminal using a suitable coaxial cable. Adjust the frequency range selector to match the expected signal frequency. Observe the meter reading and note the frequency deviation value. For accurate results, avoid signal overload and maintain stable environmental conditions.
Troubleshooting and Maintenance
If the meter does not power on, verify the power supply and fuse condition. In case of erratic readings, check the input connections and cable integrity. Regularly clean the device exterior and keep ventilation openings free from dust. Periodic calibration is essential to maintain measurement accuracy. Refer to the service manual for detailed troubleshooting flowcharts and component replacement procedures.
Safety Reminder
Always disconnect the device from the power source before performing any maintenance or repair work. Use only recommended replacement parts and follow the service manual guidelines strictly. Avoid exposing the meter to moisture or extreme temperatures to prevent damage and ensure operator safety.