1. AM-7027 Up Converter-Amplifier
CECOM LAR Tropo Operation Course
AM-7027 Up Converter-Amplifier
CECOM LAR Course
Logistics Assistance Division
Fort Monmouth, New Jersey
In this class we will discuss the AM-7027 Up Converter Amplifier.
Up Converter

2. CECOM LAR Tropo Operation Course
PURPOSE
Converts the Local Oscillator 4.47 to 5.07 GHz signal and the nominal 70 MHz IF carrier to produce a Transmit frequency from 4.4 to 5.0 GHz.
Recap slide
Please note that the AN/TRC-170(V)2 system has two (2 ea.) Up Converters installed and the AN/TRC-170(V)3 system has one (1 ea.) Up Converter installed.
Up Converter

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Block Diagram
1. J9: The input from the Local Oscillator frequency (LO) 4.47 to 5.07 GHz from the Transmit Frequency Synthesizer is applied here.
2. J10: Is the nominal 70 MHz Intermediate Frequency (IF) from the Transmit Tropo Modem is applied here.
3. A1 RF Assembly: Receives two major inputs. The first input is the Local Oscillator (LO) Frequency and the second input is from the Transmit 70 MHz IF carrier. The signals are mixed together and the difference SHF frequency of (4.4 to 5.0 GHz) is routed to the A3.
4. A3 Filter Assembly: The first section rejects out of band spurious responses and maintains the bandpass frequency. Has a bandwidth of 7 MHz and is manually tuned at 5 MHz increments.
5. A2 Intermediate Power Amplifier Assembly: Has one input from the A3 module and four outputs. The signal is then amplified to a 1-watt output and routed through a directional coupler and then out to A3 Filter assembly.
6. A3 Filter Assembly: Filters the RF signal from the A2 module. This signal is sent through a directional coupler and out to the RF OUTPUT connector on the front panel. This coupled signal is also sent to the A3 CR1 RF Detector.
7. A4 BITE CCA: illuminates the front panel summary when any alarm is detected in the Up Converter. Logic inputs from the Down Converts and the HPA will inhibit the up converter output signal by 40 dB. When a RF Inhibit fault occurs, LED DS2 will illuminate.
Up Converter

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IF & RF Signal Flow
Now lets discuss the IF and RF Signal Flow of the Up Converter.
Please refer to F
1. J9: The Local Oscillator frequency (LO) 4.47 to dBm is provided by the Transmit Frequency Synthesizer.
2. J10: The70 MHz Intermediate Frequency 0 dBm is provided by the Transmit Tropo Modem.
3. A1 RF Assembly: Receives two major inputs. The first input is the Local Oscillator (LO) Frequency and the second input is from the Transmit 70 MHz IF carrier. The signals are mixed together and the difference SHF frequency of (4.4 to 5.0 GHz) is routed to the A3 module.
4. A3 Filter Assembly: The first section rejects out of band spurious responses and maintains the bandpass frequency. Has a bandwidth of 7 MHz and is manually tuned at 5 MHz increments.
5. A2 Intermediate Power Amplifier Assembly: Has one input from the A3 module and various outputs. The signal is then amplified to a 1-watt output and routed through a directional coupler and out to A3 Filter assembly.
6. A3 Filter Assembly: Filters the RF signal from the A2 module. The signal is then sent through a directional coupler and then out to the RF OUTPUT connector on the front panel. The coupled signal is sent to a detector for monitoring purposes to maintain a constant output.
Up Converter

5. Operational Mode Signal Flow
CECOM LAR Tropo Operation Course
Operational Mode Signal Flow
Now lets discuss the Operational Mode Signal Flow of the Up Converter.
Please refer to F
1. BITE CCA A4: The A4 CCA receives a logic signal from the HPA to determine if the LOS or Tropo mode is to be utilized. In the LOS Mode the output is +27 dB(501mw) and in Tropo Mode the output is +24 dBm (251 mw). The Line receiver passes this logic signal to the AGC circuitry and to the A3 RF Level Control CCA A1. Here the correct reference level is selected and sent to the AGC circuitry. Here the proper voltage is determined and sent to the Voltage Variable Attenuator AT1 on the RF Assembly A1 and AR1 on the A2 module. The output of Filter A3, and the IPA Assembly A2 are controlled by the BITE A4 CCA.
2. RF Assembly A1: The Voltage Variable Attenuator AT1 is a voltage controlled device used to establish the desired output level of the RF Assembly A1.
3. IPA Assembly A2: The voltage feedback through the BITE CCA A4 is applied to the variable attenuator A2AR1 device. This variable attenuator is used to establish, and maintain the desired output level of the A2 Module.
Up Converter

6. RF Output Control Signal Flow
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RF Output Control Signal Flow
Now lets discuss the RF Output Control Signal Flow of the Up Converter.
Please refer to F
1. Filter Assembly A3: An RF output sample 30 dB down from RF output is provided by the A3 Directional Coupler DC1, and detected by RF Detector A3CR1. The RF output voltage level is sent to the AGC circuitry on the A4.
2. BITE CCA A4: The A4 CCA receives the RF Reference Voltage and is applied to the AGC circuitry. The AGC circuit compares the RF Output level with the selected Reference level to produce a Voltage Variable Attenuator (VVA) control output voltage to the A1 and A2 modules to control and maintain constant RF output levels.
3. RF Assembly A1: The incoming VVA signal controls the Voltage Variable Attenuator AT1. The Variable Attenuator AT1 is a voltage controlled device used to establish the desired output level of the A1 module.
4. IPA Assembly A2: The incoming VVA signal controls the Voltage Variable Attenuator on the AR1 Power Amplifier module. The Variable Attenuator is a voltage controlled device used to establish the desired output level of the IPA A2 module.
Up Converter

7. RF Inhibit & BITE Circuitry Signal Flow
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RF Inhibit & BITE Circuitry Signal Flow
Now lets discuss the RF Inhibit and BITE Circuitry Signal Flow of the Up Converter. Please refer to F
1. RF INHIBIT CIRCUITRY
a. BITE CCA A4: Receives logic signals from the Down Converter or HPA to have the output attenuated by 40db as required. These logic signals are applied to the RF Inhibit Logic circuitry that sends a RF Inhibit signal to the A1. The RF Inhibit LED DS2, is activated during this condition. Also, all other LEDs are activated during this condition. There are 5 things that will cause a RF Inhibit condition and they are; VSWR fault in the Klystron, Antenna VSWR fault, High Reflected Power, Down Converter Input Overload, and switching between LOS & Tropo will cause a temporary inhibit.
b. RF Assembly A1: AT1 receives the RF Inhibit signal from the BITE CCA A4 to have the output of the Up Converter attenuated by 40db as required.
2. BITE CIRCUITRY:
a. RF ASSEMBLY A1: The A1 will send a low logic level to the BITE CCA A4 when the output level of the A1 drops below the proper output level or a RF Inhibit signal is sent from the Down Converter or HPA.
b. IPA Assembly A2: Will send a low logic level to the BITE CCA A4 when any of these three conditions occur; RF Inhibit, RF Drive missing from the Transmit Tropo Modem, or RF output missing from the IPA Assembly A2.
c. BITE CCA A4: detects fault signals from the Up Converter assemblies and activates the LEDs on this CCA and the Summary LED on the front panel.
Up Converter

8. BITE CCA Lamp (LED) displays per fault conditions
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BITE CCA Lamp (LED) displays per fault conditions
Now lets discuss the BITE CCA Lamp (LEDs) conditions that will cause these LEDs to activate on the BITE CCA A4.
1. Normal Operation: all LEDs are off.
2. RF inhibit: will cause all of the fault LEDs to be on. Condition is not considered a fault related to the Up Converter.
3. RF Drive missing or faulty RF Assembly A1: will cause the following LEDs to be on.
a. Summary
b. RF Assy Output
c. IPA Assy Output
4. RF Output from IPA missing or low and a faulty IPA Assembly A2: will cause the following LEDs to be on.
b. IPA Assembly Output
5. RF output from Filter missing or faulty Filter A3: will cause the Summary LED to be on.
6. RF level over threshold at A1 CR3 will cause the RF Assembly output LED to be on.
Up Converter

9. Controls and Indicators
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Controls and Indicators
1. RF OUTPUT connector - Output is fed to the High Power Amplifier for amplification in the TROPO mode and in LOS Mode the RF transmission passes through the HPA (without amplification) to the antenna.
2. FREQUENCY adjustable filter - Tuned to the transmit operating frequency. Has a bandwidth of 7 MHz and is marked in 5 MHz increments.
3. SUMMARY FAULT red LED indicator - Indicates a fault in one of the Up-Converter sub units, or an RF inhibit fault has occurred.
Up Converter

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Component Location
Now lets discuss the Component Location for the Up Converter. Please refer to slide # 10 above.
A1 RF ASSEMBLY: Mixes/Amplifies 70 MHz IF input from the Transmit Tropo Modem, and the Local Oscillator 4.47 to 5.07 GHz from the transmit side of the dual frequency synthesizer to produce a difference SHF frequency operating in the range of 4.4 to 5.0 GHz.
A2 INTERMEDIATE POWER AMPLIFIER (IPA): Is the final Amplifier in the LOS mode and an intermediate amplifier in the Tropo mode.
A3 FILTER ASSEMBLY: Is a multi-channel band pass filter with a bandpass of 7 MHz, and is marked in 5 MHz increments.
A4 BITE CCA: Reports internal faults to the Alarm Monitor and lights the summary alarm LED on the front panel. In conjunction with the A3-A1 (Reference level control module) controls the output of the IPA for LOS or HPA mode of operation, also reduces the output power of the IPA if, an RF inhibit is received from the (Down Converters RF Overload) or from the (HPA High VSWR). The BITE CCA also has internal fault LEDs on it that light when a failure of the subassemblies occur, DS1indicates an IPA Low Power Fault, DS2 indicates a RF inhibit fault and DS3 indicates a RF Assembly Fault.
Up Converter

11. Up Converter AM-7027Rear Panel
CECOM LAR Tropo Operation Course
Up Converter AM-7027Rear Panel
Now lets discuss the rear view of the Up Converter AM-7026.
Please refer to slide # 11 above.
Connector Jack Nomenclature
J Power DC Voltages Input
J U/C RF Inhibit from D/C 1 & 3 Input Fault Alarms
Output
J U/C RF Inhibit from HPA 1 & LOS – TROPO Mode
Select Input
J U/C RF Inhibit from HPA 2 Input * Only used in V2
J Local Oscillator (LO) from XMIT Synthesizer Input
J MHz IF from Transmit TROPO Modem Input
GND Ground Connection
J7 Only used in V2 and is the up-converter RF inhibit input from HPA 2
Up Converter

12. CECOM LAR Tropo Operation Course
Summary
The Up Converter Amplifier takes the 70 MHz IF output of the Tropo Modem and the output of the Transmit Frequency Synthesizer (LO), and then develops the 4.4 to 5.0 GHz SHF frequency for transmission.
Recap slide
Q: What is the purpose of the Up Converter?
A. The Up Converter Amplifier takes the 70 MHz IF output of the Tropo Modem and the output of the Transmit Frequency Synthesizer (LO), and then develops the 4.4 to 5.0 GHz SHF frequency for transmission.
Q: What is the power output level of the Up Converter in the Tropo mode of operation?
A. +24 dBm +/- 1dB
Q: What Circuit Card or Module sends the Voltage Variable Attenuator (VVA) signal to the A1 and A2 modules?
A. The BITE CCA A4.
Q: What module mixes the 70 MHz and the Local Oscillator signal together?
A. The RF ASSEMBLY A1
Up Converter