background image

Axcera-430A FCC Type Acceptance Report                                 Operational Description 

February 2004 

  8-3 

8.4. System Overview 

 
The 430B (1303854) is made up of the trays and assemblies listed in Table 8-1. 

Table 8-1. 430B Major Trays and Assemblies 

 

MAJOR ASSEMBLY 

DESIGNATOR 

TRAY/ASSEMBLY NAME 

DRAWING NUMBER 

A2 

AC distribution panel 

1265-1600 

A4 

VHF exciter 

1070901 

A6 and A7 

Two VHF amplifier trays 

1301169 

A8 

VHF combiner assembly 

1219-1006 

A9 

Bandpass filter assembly 

1067297 

A12 

Remote interface assembly 

1083510 

 
The (A4) VHF exciter can operate using either the baseband audio and video inputs 
alone or, if the (optional) 4.5-MHz composite input kit is purchased, the 4.5-MHz 
composite input or the baseband video and audio inputs to produce a diplexed, 
modulated, and on-channel frequency aural RF output. The switching is 
accomplished by a relay on the sync tip clamp/modulator board that uses a baseband 
select to control a relay that chooses either the 4.5 MHz generated from the baseband 
inputs or from the 4.5-MHz composite input. 
 
To operate the transmitter with the (optional) 4.5-MHz composite input kit using 
baseband inputs, the baseband video must be connected to J1 or J2; the baseband 
audio must be connected to the proper input jack; and a baseband select must be 
connected from J7-6 and J7-7. To operate the transmitter with the (optional) 4.5-MHz 
composite input kit using the 4.5-MHz composite input, the 4.5-MHz composite input 
must be connected to J1 or J2 and the baseband select must be removed from J7-6 
and J7-7. 
 
The RF output of the VHF exciter is split two ways in (A5) the 2-way power splitter 
assembly (ZFSC-2-2). The outputs of the splitter feed the two (A6 and A7) VHF 
amplifier trays that amplify the RF signals to approximately 300 watts each. The 
outputs of the two VHF amplifier trays are combined in (A8) the VHF combiner that 
provides approximately 600 watts peak of sync output. The 600-watt output is 
connected to (A9) a bandpass filter assembly. The bandpass filter is tuned to provide 
the high out-of-band rejection of unwanted products. The filtered signal is connected 
to A9-A5, a coupler assembly that provides a forward and a reflected power sample to 
the visual/aural metering board in the VHF exciter. The forward sample is processed to 
provide peak detected visual and aural power output samples to the transmitter 
control board in the VHF exciter. The reflected power sample is also peak detected and 
wired to the transmitter control board. The transmitter control board connects the 
visual, aural, and reflected power output samples to the front panel meter to monitor 
the system.  
 
In the VHF amplifier tray, a forward power sample and a reflected power sample from 
the 4-way combiner board are connected to the dual peak detector board, single 
supply. This board provides peak-detected forward samples to the amplifier control 
board and supplies the samples to the front panel meter of the tray.  
 

 
 

Содержание 430B

Страница 1: ...FCC TYPE ACCEPTANCE REPORT 430B 1000 WATT HIGH BAND VHF TRANSMITTER AXCERA LLC 103 FREEDOM DRIVE P O BOX 525 LAWRENCE PA 15055 0525 USA 724 873 8100 FAX 724 873 8105 www axcera com info axcera com...

Страница 2: ...4 3 4 2 4 Video Frequency Response 4 3 4 2 5 RF Sideband Response 4 4 4 2 6 Audio Modulation 4 6 4 2 7 AM and FM Noise 4 7 4 3 Occupied Bandwidth 4 7 4 4 Conducted Spurious Emissions 4 9 4 5 Radiated...

Страница 3: ...oard 7 11 7 2 12 3 Composite 4 5 MHz Filter Board 7 11 7 2 12 4 Optional 4 5 MHz Bandpass Filter Board 7 12 7 2 12 5 IF Carrier Oven Oscillator Board 7 12 7 2 12 6 Sync Tip Clamp Modulator Board 7 12...

Страница 4: ...Axcera 430B FCC Type Acceptance Report ID Label Location Info February 2004 1 1 1 ID LABEL LOCATION INFO 1 1 Front Panel FCC Label 1 2 Rear Panel Manufacturer s Label...

Страница 5: ...Axcera 430B FCC Type Acceptance Report ID Label Location Info February 2004 1 2 1 3 Front view Axcera 430B Transmitter with FCC ID Label 1 4 Rear view Axcera 430B Transmitter with Manufacturer s Label...

Страница 6: ...Axcera 430B FCC Type Acceptance Report External Photos February 2004 2 1 2 EXTERNAL PHOTOS 2 1 Front view complete Axcera 430B Transmitter...

Страница 7: ...Axcera 430B FCC Type Acceptance Report External Photos February 2004 2 2 2 2 Rear view Axcera 430B Transmitter rear top of cabinet...

Страница 8: ...Axcera 430B FCC Type Acceptance Report External Photos February 2004 2 3 2 3 Rear view Axcera 430B Transmitter rear bottom of cabinet...

Страница 9: ...Axcera 430B FCC Type Acceptance Report External Photos February 2004 2 4 2 4 Output Bandpass Filter Assembly...

Страница 10: ...Axcera 430B FCC Type Acceptance Report Schematics February 2004 3 1 3 SCHEMATICS The schematics for the Axcera 430B system are provided as separate PDF files...

Страница 11: ...at the output connector This level was used to establish a reference on the spectrum analyzer Next the aural power was turned on and adjusted to 10 dB below the visual power The following operating p...

Страница 12: ...ion was accurately measured to be 87 5 while maintaining a depth of modulation at blanking Next the video was adjusted for modulated staircase and the differential phase and gain were measured and rec...

Страница 13: ...n one step of the 5 step staircase This is a video to peak noise ratio of 125 42 dB or using the standard conversion factor of peak to RMS noise of 14 dB about 64 dB S N rms Observing the video at the...

Страница 14: ...4 18 MHz 1 0 dB 4 5 MHz 20 dB 4 75 MHz 30 dB 5 0 MHz 44 dB Figure 4 3 Graph of Detected Video Frequency Response 4 2 5 RF Sideband Response The RF sideband response was recorded using the test setup s...

Страница 15: ...5 50 250 1 0 175 75 500 4 0 176 00 750 4 1 176 25 1000 4 0 177 25 2000 4 0 178 25 3000 4 4 179 25 4000 4 0 179 75 4500 9 180 00 4750 24 180 25 5000 50 175 00 250 0 5 174 75 500 4 0 174 50 750 4 6 174...

Страница 16: ...TION 100 Hz 0 25 0 12 0 09 0 06 1000 Hz 0 28 0 15 0 09 0 07 5000 Hz 0 31 0 16 0 12 0 09 15000 Hz 0 39 0 23 0 24 0 12 While maintaining 25 KHz deviation the audio input frequency and level were varied...

Страница 17: ...sts and solid lines were used for the FM tests with the following results AM noise 56 dB FM noise 69 dB 4 3 Occupied Bandwidth Using the test setup in Figure 4 6 with the transmitter operating at maxi...

Страница 18: ...Axcera 430B Type Acceptance Report Test Report February 2004 4 8 Figure 4 7 Channel Occupied Bandwidth Figure 4 8 Aural Carrier Occupied Bandwidth...

Страница 19: ...al Carrier None observed 262 25 Image Aural Carrier None observed 221 00 Local Oscillator None observed 166 25 9 MHz Product None observed 170 75 4 5 MHz Product 69 179 75 Aural Carrier 10 175 25 Visu...

Страница 20: ...he second and third harmonic frequencies of the transmitter and all of the signals received were maximized by antenna orientation and their absolute levels were recorded With these various antennas an...

Страница 21: ...tting antenna increases this by 1 64 to 1 64 x 2 32 w m2 If a dipole receive antenna of area 1 64 x 2 4 is used to receive the signal the received level would be 320 mw 25 dBm The receive levels at 36...

Страница 22: ...rolled chamber and the temperature was varied from 30 C to 50 C The chamber was slowly heated and the frequency was measured at 10 C increments up to 50 C The oscillators were allowed to stabilize at...

Страница 23: ...20 0 061 0 032 0 371 10 0 057 0 031 0 305 0 0 043 0 025 0 243 10 0 023 0 014 0 135 20 0 0 0 0 0 0 30 0 026 0 031 0 274 40 0 055 0 057 0 511 50 0 083 0 070 0 643 Table 4 12 Frequency Stability Versus...

Страница 24: ...x Demodulator 10656 43 Bird Power Meter 278801 1000C Bird 1000W Power Meter VHF Element 8892 300 Bird 50 Termination 2867 7L12 Tektronix Spectrum Analyzer 804392 5253B Hewlett Packard Frequency Counte...

Страница 25: ...Axcera 430B Type Acceptance Report Users Manual February 2004 5 1 5 USER S MANUAL The user s manual for the Axcera 430B system is provided as separate Word and PDF files...

Страница 26: ...Axcera 430B FCC Type Acceptance Report Internal Photos February 2004 6 1 6 INTERNAL PHOTOS 6 1 Top view Exciter Tray...

Страница 27: ...Axcera 430B FCC Type Acceptance Report Internal Photos February 2004 6 2 6 2 Top view 600 watt Amplifier Tray...

Страница 28: ...t 3 way splitter VHF amplifier pallets 3 way combiner Power supply Output filter assembly Bandpass filter with traps VHF coupler VHF splitter combiner assemblies 7 2 Tune up Information The 430B trans...

Страница 29: ...et for a 25 kHz deviation with a balanced audio input of 10 dBm If the reading is at not the correct level adjust balanced audio gain pot R13 on the aural IF synthesizer board as needed to attain the...

Страница 30: ...d by the ALC reference This is normally due to excessive attenuation in the linearity signal path or the IF phase corrector signal path or because jumper W3 on J6 is in the Manual ALC Gain position DS...

Страница 31: ...IF linearity correction function consists of three non linear cascaded stages each having magnitude and threshold adjustments or cut in points on the ALC board The threshold adjustment determines at...

Страница 32: ...entiometer on each VHF amplifier tray fully CCW Switch the transmitter to Operate and adjust the gain pot on each tray for 25 Output Power Adjust the phase control CW on the left VHF amplifier tray If...

Страница 33: ...ual Power position turn the power adjust pot to 20 Check that the jumper is in Manual on the VHF filter amplifier board 1064252 Reverse the cables on A9 A5 J3 and J4 and adjust R39 on the visual aural...

Страница 34: ...ing current for the amplifier boards is adjusted with no RF drive applied S1 should be in the Auto AGC position for the normal operation of the transmitter Connect a dummy load with a rating of a leas...

Страница 35: ...the subassembly section of this manual for more information The board has approximately 14 dB of gain and the output is typically 45 dBm 7 2 11 7 3 Way Splitter Board This board contains no tuning ad...

Страница 36: ...meter in the Reflected Output Power position to a 100 reading using R53 the reflected power meter adjust on the AGC control board Adjust the reflected output power to a 20 reading using R5 on the AGC...

Страница 37: ...d to the video input jack J1 or J2 loop through connections and the baseband audio to the proper baseband audio input on the rear of the tray For balanced audio input connect TB1 1 TB1 2 and TB1 3 GND...

Страница 38: ...counter to J1 and check for 50 kHz which is the aural phase lock loop PLL reference 7 2 12 6 Sync Tip Clamp Modulator Board To align this board 1 Determine if jumper W4 on jack J3 is present Jumper W...

Страница 39: ...demodulator to the horizontal input of the waveform monitor using a 250 kHz low pass filter An oscilloscope can be used in place of a waveform monitor C Set the controls of the demodulator to the fol...

Страница 40: ...serve the visual frequency response with the spectrum analyzer set at 1 dB division Tune R63 and C30 the IF frequency response adjustments for a flat frequency response 0 5 dB 18 While still monitorin...

Страница 41: ...jack J3 on the rear of the tray Follow the procedures in the stereo generator instruction manual for matching the level of the generator to the exciter Use R17 to adjust the composite audio gain 7 Che...

Страница 42: ...ly 7 2 12 9 IF Phase Corrector Board See Section 7 2 4 of this chapter for the system alignment procedures for the IF phase corrector board The signal level into the board should be approximately the...

Страница 43: ...d in A14 the channel oscillator assembly 1145 1202 To align the board 1 Connect the main output of the channel oscillator J1 to a spectrum analyzer tuned to the crystal frequency and peak the tuning c...

Страница 44: ...f the FSK identifier board is applied to J3 of the IF attenuator board As the bias applied to J3 increases and decreases the amplitude of the aural IF signal that enters the board at J1 and exits at J...

Страница 45: ...without the proper equipment The filtered output connects to J1 of the board and is amplified by U1 to a nominal 8 dBm visual and 2 dBm aural level by adjusting R9 The output at J2 is fed to J4 on the...

Страница 46: ...annel Output Power Visual 250 to 1000 watts peak sync front panel adjustable Aural 100 watts average Maximum Power Rating Visual 1000 watts peak visual Aural 100 watts average aural Power Consumption...

Страница 47: ...Nominal Power 100 watts Impedance 50 ohms Connector Type N Aural Input Impedance 600 ohms Level 0 to 10 dBm Amplitude vs Frequency Response 75 microseconds pre emphasis 0 5 dB Audio Harmonic Distorti...

Страница 48: ...put kit using the 4 5 MHz composite input the 4 5 MHz composite input must be connected to J1 or J2 and the baseband select must be removed from J7 6 and J7 7 The RF output of the VHF exciter is split...

Страница 49: ...r plug with a jumper between pins 23 and 24 is connected to jack J11 on the back of the tray The jumper plug must be connected to A12 J9 when the optional remote interface panel is used This jumper pr...

Страница 50: ...lected Power Visual Power Aural Power video level or audio level Audio 0 to 100 kHz Reads the audio level 25 kHz balanced or 75 kHz composite on the 0 to 10 scale Will indicate baseband audio if it is...

Страница 51: ...is pushed In Automatic the video fault command from the ALC board will control the operation of the transmitter The transmitter will switch to Standby after a slight delay if the input video is lost...

Страница 52: ...rd f IC A sample of the intercarrier signal that is taken from the sample jack on the aural IF synthesizer board f s A sample of the channel oscillator output that is taken from the sample jack of the...

Страница 53: ...Reflected Output Power 10 AGC Voltage Reads the AGC level of the tray 1 to 2 VDC Power Supply Reads the voltage from the switching power supply 28 VDC Switch S1 Meter Current Uses switch S2 to indica...

Страница 54: ...DESCRIPTION Phase A7 R2 Adjusts the phase of the RF output by approximately 70 Gain A6 R3 Adjusts the gain of the RF output when the amplifier control board is in the AGC mode Table 8 9 VHF High Band...

Страница 55: ...er for normal operation 1176 1038 the jumper jack should be used Remote Control Commands Transmitter Standby Disable J9 9 Contact closure Transmitter Standby Operate Rtn J9 10 Transmitter Operate Enab...

Страница 56: ...emote Metering Visual Output Power J9 1 Visual Output Power Rtn J9 2 1V full scale at 1k source resistance Aural Output Power J9 3 Aural Output Power Rtn J9 4 1V full scale at 1k source resistance Ref...

Страница 57: ...al block TB1 that connects to the 220 VAC The AC distribution panel contains four circuit breakers that supply the AC to the rest of the transmitter The input AC is connected to the main AC circuit br...

Страница 58: ......

Отзывы: