FT7800R.pdf

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1、Dual Band FM Transceiver FT-7800R Technical Supplement Introduction This manual provides technical information necessary for servicing the FT-7800R Transceiver. Servicing this equipment requires expertise in handling surface-mount chip components. Attempts by non-qualified persons to service this eq

2、uipment may result in permanent damage not covered by the warranty, and may be illegal in some countries. Two PCB layout diagrams are provided for each double-sided circuit board in the transceiver. Each side of thr board is referred to by the type of the majority of components installed on that sid

3、e (“leaded” or “chip-only”). In most cases one side has only chip components, and the other has either a mixture of both chip and leaded components (trimmers, coils, electrolytic capacitors, ICs, etc.), or leaded components only. While we believe the technical information in this manual to be correc

4、t, Vertex Standard assumes no liability for dam- age that may occur as a result of typographical or other errors that may be present. Your cooperation in pointing out any inconsistencies in the technical information would be appreciated. Specifications . A-1 Exploded View check with your dealer. A-1

5、 B-1 Exploded View realignment should not be done until after the faulty component has been replaced. We recommend that servicing be performed only by au- thorized Vertex Standard service technicians who are ex- perienced with the circuitry and fully equipped for re- pair and alignment. Therefore, i

6、f a fault is suspected, con- tact the dealer from whom the transceiver was purchased for instructions regarding repair. Authorized Vertex Stan- dard service technicians realign all circuits and make com- plete performance checks to ensure compliance with fac- tory specifications after replacing any

7、faulty components. Those who do undertake any of the following alignments are cautioned to proceed at their own risk. Problems caused by unauthorized attempts at realignment are not covered by the warranty policy. Also, Vertex Standard must reserve the right to change circuits and alignment procedur

8、es in the interest of improved performance, with- out notifying owners. Under no circumstances should any alignment be attempt- ed unless the normal function and operation of the trans- ceiver are clearly understood, the cause of the malfunc- tion has been clearly pinpointed and any faulty compo- ne

9、nts replaced, and the need for realignment determined to be absolutely necessary. Required Test Equipment The following test equipment (and thorough familiarity with its correct use) is necessary for complete realignment. Correction of problems caused by misalignment result- ing from use of improper

10、 test equipment is not covered under the warranty policy. While most steps do not re- quire all of the equipment listed, the interactions of some adjustments may require that more complex adjustments be performed afterwards. Do not attempt to perform only a single step unless it is clearly isolated

11、electrically from all other steps. Have all test equipment ready before be- ginning, and follow all of the steps in a section in the or- der presented. ?Regulated DC Power Supply: adjustable from 11.5 to 16 VDC, 10 A ?RF Signal Generator with calibrated output level at 500 MHz ?Frequency Counter: 0.

12、1 ppm accuracy at 500 MHz ?AF Signal Generator ?SINAD Meter ?Oscilloscope ?Spectrum Analyzer ?Deviation Meter (linear detector) ?AF Millivoltmeter ?AF Dummy Load: 8-Ohm, 5 W ?DC Voltmeter: high impedance ?Inline Wattmeter with 5% accuracy at 500 MHz ?50-Ohm non-reactive Dummy Load: 50 watts at 500 M

13、Hz ?VHF/UHF Sampling Coupler Set up the test equipment as shown below, and apply 13.8 VDC power to the transceiver. E-1 Power Supply 13.8 VDC Pin 5 EXT SP Frequency Counter Deviation Meter Inline Wattmeter 50-ohm Dummy Load RF Sampling Coupler RF Signal Generator 8-ohm Dummy Load SINAD Meter AF Sign

14、al Generator Alignment Alignment Preparation & Precautions A dummy load and inline wattmeter must be connected to the main antenna jack in all procedures that call for transmission, except where specified otherwise. Correct alignment is not possible with an antenna. After complet- ing one step, read

15、 the following step to determine wheth- er the same test equipment will be required. If not, re- move the test equipment (except dummy load and watt- meter, if connected) before proceeding. Correct alignment requires that the ambient temperature in the repair shop be the same as that of the transcei

16、ver and test equipment, and that this temperature be held constant between 68 C and 86 F (20 C 30 C). When the transceiver is brought into the shop from hot or cold air it should be allowed some time for thermal equaliza- tion with the environment before alignment. If possible, alignments should be

17、made with oscillator shields and circuit boards firmly affixed in place. Also, the test equip- ment must be thoroughly warmed up before beginning. Notes: Signal levels in dB referred to in alignment are based on 0 dB = 0.5 V (closed circuit). Entering the Alignment mode Alignment of the FT-7800R is

18、performed using a front- panel software-based procedure. To perform alignment of the transceiver, it must first be placed in the “Align- ment Mode,” in which the adjustments will be made and then stored into memory. To enter the Alignment mode: 1.Press and hold in the MHz(PRI) key and the Hyper Memo

19、ry 5 key while turning the radio on. Once the radio is on, release these two keys. 2.Press the front panel keys in the following sequence. MHz(PRI) ? TONE(HM/RV) ?LOW(ACC) ? BAND(SET) ? V/M(MW) ? SCAN(SEL) ? S.SCH(ARTS) 3.Press and hold in the key to cause “A-0 REF.xxH” to appear on the display, thi

20、s signifies that the transceiver is now in the “Alignment mode.” PLL Reference Frequency 1.Tune the frequency to 435.050 MHz, then set the Trans- mit Power Level to “LOW.” 2.Press the BAND(SET) key while pressing and hold- ing in the key, if needed, to set the Alignment parameter to “A-0 REF.xxH.” 3

21、.Press the PTT switch to activate the transmitter, and adjust the DIAL knob while pressing and holding the key, if needed, so that the counter frequency read- ing is 435.050 MHz (100 Hz). RF Front-end Tuning 1.Connect the DC voltmeter to TP1010 on the MAIN Unit, then inject a 439.050 MHz signal at a

22、 level of +10 dB (with 1 kHz modulation 3.5 kHz deviation) from the RF Signal Generator. 2.Tune the frequency to 439.050 MHz. 3.Press the BAND(SET) key while pressing and hold- ing the key to set the Alignment parameter to “A-1 TUN.xxH.” 4.Adjust the DIAL knob while pressing and holding in the key,

23、if needed, so that the DC voltmeter reaches maximum deflection. The FT-7800Rs RF Front-end has a broad bandwidth. Therefore, prior to adjustment you must adjust the DIAL knob to set the frequency to the middle of the band, in step 2, so you can set peak in the DC voltmeters deflection in the center

24、of the RF passband. 5.Tune the frequency to 145.050 MHz. 6.Inject a 145.050 MHz signal at a level of +10 dB (with 1 kHz modulation 3.5 kHz deviation) from the RF Signal Generator. 7.Adjust the DIAL knob while pressing and holding in the key, if needed, so that the DC voltmeter reaches maximum deflec

25、tion. As in the previous sec- tion, be sure to set the DIAL knob for the center of the band prior to making this adjustment. MAIN UNIT TEST POINTS E-2 TP1010 Alignment TX Power Output 1.Tune the frequency to 440.050 MHz, then set the Trans- mit Power Level to “LOW.” 2.Press the BAND(SET) key while p

26、ressing and hold- ing in the key to set the Alignment parameter to “A-2 PWR.xxH.” 3.Press the PTT switch to activate the transmitter, and adjust the DIAL knob while pressing and holding in the key, if needed, so that the wattmeter reading is 5 Watts (0.5 Watt). 4.Increase the Transmit Power Level to

27、 “MID2.” 5.Press the PTT switch to activate the transmitter, and adjust the DIAL knob while pressing and holding in the key, if needed, so that the wattmeter reading is 10 Watts (0.5 Watt). 6.Increase the Transmit Power Level to “MID1.” 7.Press the PTT switch to activate the transmitter, and adjust

28、the DIAL knob while pressing and holding in the key, if needed, so that the wattmeter reading is 20 Watts (0.5 Watt). 8.Increase the Transmit Power Level to “HIGH.” 9.Press the PTT switch to activate the transmitter, and adjust the DIAL knob while pressing and holding in the key, if needed, so that

29、the wattmeter reading is 40 Watts (0.5 Watt). 10. Tune the frequency to 146.050 MHz, then set the Trans- mit Power Level to “LOW.” 11. Press the PTT switch to activate the transmitter, and adjust the DIAL knob while press and holding the % key, as needed, so that the wattmeter reading is 5 Watts (0.

30、5 Watt). 12. Increase the Transmit Power Level to “MID2.” 13. Press the PTT switch to activate the transmitter, and adjust the DIAL knob while pressing and holding in the key, if needed, so that the wattmeter reading is 10 Watts (0.5 Watt). 14. Increase the Transmit Power Level to “MID1.” 15. Press

31、the PTT switch to activate the transmitter, and adjust the DIAL knob while pressing and holding in the key, if needed, so that the wattmeter reading is 20 Watts (0.5 Watt). 16. Increase the Transmit Power Level to “HIGH.” 17. Press the PTT switch to activate the transmitter, and adjust the DIAL knob

32、 while pressing and holding in the key, if needed, so that the wattmeter reading is 50 Watts (0.5 Watt). TX Deviation 1.Tune the frequency to 440.050 MHz, then set the Trans- mit Power Level to “LOW.” 2.Press the BAND(SET) key while pressing and hold- ing in the key to set the Alignment parameter to

33、 “A-3 DEV.xxH.” 3.Inject a 1 kHz audio tone at a level of 80 mV (20 dBm) from the Audio Generator. 4.Press the PTT switch to activate the transmitter, and adjust the DIAL knob while pressing and holding in the key, if needed, so that the deviation meter reading is 4.2 kHz (0.2 kHz) (EXP Version: 4.5

34、 kHz (0.2 kHz). 5.Tune the frequency to 146.050 MHz, then set the Trans- mit Power Level to “LOW.” 6.Press the PTT switch to activate the transmitter, and adjust the DIAL knob while pressing and holding in the key, if needed, so that the deviation meter reading is 4.2 kHz (0.2 kHz) (EXP Version: 4.5

35、 kHz (0.2 kHz). DCS TX Deviation 1.Tune the frequency to 440.050 MHz, then activate the DCS with a “023” DCS code, and set the Transmit Power Level to “LOW.” 2.Press the BAND(SET) key while pressing and hold- ing in the key to set the Alignment parameter to “A-4 DSC.xxH.” 3.Press the PTT switch to a

36、ctivate the transmitter (with no microphone input), and adjust the DIAL knob while pressing and holding in the key, if needed, so that the deviation meter reading is between 0.50 kHz and 0.60 kHz. 4.Tune the frequency to 146.050 MHz, then activate the DCS with a “023” DCS code, and set the Transmit

37、Power Level to “LOW.” 5.Press the PTT switch to activate the transmitter (with no microphone input), and adjust the DIAL knob while pressing and holding in the key, if needed, so that the deviation meter reading is between 0.50 kHz and 0.60 kHz. E-3 CTCSS TX Deviation 1.Tune the frequency to 440.050

38、 MHz, then activate the CTCSS Encoder with a “100 Hz” tone, and set the Transmit Power Level to “LOW.” 2.Press the BAND(SET) key while press and holding the key to set the Alignment parameter to “A-5 CTC.xxH.” 3.Press the PTT switch to activate the transmitter (with no microphone input), and adjust

39、the DIAL knob while pressing and holding in the key, if needed, so that the deviation meter reading is between 0.65 kHz and 0.75 kHz. 4.Tune the frequency to 146.050 MHz, then activate the CTCSS Encoder with a “100 Hz” tone, and set the Transmit Power Level to “LOW.” 5.Press the PTT switch to activa

40、te the transmitter (with no microphone input), and adjust the DIAL knob while pressing and holding in the key, if needed, so that the deviation meter reading is between 0.65 kHz and 0.75 kHz. Center Meter Sensitivity 1.Tune the frequency to 440.050 MHz. 2.Press the BAND(SET) key while press and hold

41、ing the key to set the Alignment parameter to “A-6 CNTL/V.” 3.Inject a 1 kHz audio tone at a level of +10 dB from the Audio Generator. 4.Press the LOW(ACC) key while press and holding the key. S-Meter Sensitivity 1.Tune the frequency to 440.050 MHz. 2.Press the BAND(SET) key while press and holding

42、the key to set the Alignment parameter to “A-7 SM L/V.” 3.Inject a 440.050 MHz signal at a level of 5 dB (with 1 kHz modulation 3.5 kHz deviation) from the RF Signal Generator. 4.Press the LOW(ACC) key while pressing and hold- ing in the key. 5.Increase the RF Signal Generator output level to +23 dB

43、. 6.Press the V/M(MW) key while pressing and holding in the key. 7.Tune the frequency to 146.050 MHz. 8.Inject a 146.050 MHz signal at a level of 5 dB (with 1 kHz modulation 3.5 kHz deviation) from the RF Signal Generator. 9.Press the LOW(ACC) key while pressing and hold- ing in the key. 10. Increas

44、e the RF Signal Generator output level to +23 dB. 11. Press the V/M(MW) key while pressing and holding in the key. 12. Tune the frequency to 230.050 MHz. 13. Inject a 230.050 MHz signal at a level of 5 dB (with 1 kHz modulation 3.5 kHz deviation) from the RF Signal Generator. 14. Press the LOW(ACC)

45、key while pressing and hold- ing in the key. 15. Increase the RF Signal Generator output level to +23 dB. 16. Press the V/M(MW) key while pressing and holding in the key. 17. Tune the frequency to 850.050 MHz. 18. Inject a 850.050 MHz signal at a level of +3 dB (with 1 kHz modulation 3.5 kHz deviati

46、on) from the RF Signal Generator. 19. Press the LOW(ACC) key while pressing and hold- ing in the key. 20. Increase the RF Signal Generator output level to +31 dB. 21. Press the V/M(MW) key while pressing and holding in the key. DC Voltmeter 1.Set the power supply voltage to 13.8 VDC. 2.Press the BAN

47、D(SET) key while pressing and hold- ing in the key to set the Alignment parameter to “A-8 BAT SC.” 3.Press the SCAN(SEL) key. To close the Alignment mode, just press and hold in the PWR switch for 0.5 seconds (to turn the power off). The next time the transceiver is turned on, normal operation may r

48、esume. Alignment E-4 F-1 MAIN Unit Circuit Diagram 4.3 dB +1.4 dB +18.8 dB +15.5 dB 0.81 V 0.30 V 1.37 V 8.56 V 8.57 V 0.69 V 4.94 V 4.75 V 1.10 V 1.48 V 0.50 V +15.9 dB 0.98 V 1.56 V 0.43 V 5.83 V 8.83 V 0.15 V (+15.8 dB) (+0.8 dB) (6.2 dB) 0.97 V 2.22 V 8.13 V 0.32 V 8.53 V 0.70 V 2.92 V 0.71 V 4.

49、69 V 8.70 V 0.71 V 0.78 V (8.6 dB) 9.2 dB (3.55 V) 3.30 V (3.25 V) 3.62 V (11.45 V) 11.23 V (12.60 V) 12.54 V (xxx): Freq. = 146.05 MHz xxx: Freq. = 440.05 MHz (xxx): Freq. = 146.05 MHz xxx: Freq. = 440.05 MHz 45.05 MHz (+21.6 dB) +21.0 dB 45.05 MHz (+12.3 dB) +11.6 dB 0.83 V 0.13 V 4.94 V 2.22 V 0.82 V0.71 V 0.11 V 0.23 V (12.73 V) 12.76 V 2.09 V 0.68 V 1.23 V 4.72 V 0.69 V 45.05 MHz (+23.4 dB) +22.6 dB Q1023 Pin 1: 4.79 V Pin 4: 4.81 V Pin 8: 0.65 V Pin 10: 4.81 V 1.89