Luiton LT-298 User manual

Luiton LT-298
SERVICE MANUAL

-TECNNICAL CHARACTERITICS
LUITON LT-298 ( config: E d d2 EU EC PL,without ASQ )
1-GENERAL:
-Multiconfiguration(E,d,d2,EU,EC,U,PL)
-E ⇒40 channels AM/FM 4W (from 26,965Mhz to 27,405Mhz)
-d ⇒80 channels FM 4W (from 26,565Mhz to 27,405Mhz)
12 channels AM 1W (from 27,005Mhz to 27,135Mhz)
-d2 ⇒40 channels FM 4W (from 26,565Mhz to 27,405Mhz)
12 channels AM 1W (from 27,005Mhz to 27,135Mhz)
-EU ⇒40 channels FM 4W/AM 1W (from 26,965Mhz to 27,405Mhz)
-EC ⇒40 channels FM 4W (from 26,965Mhz to 27,405Mhz)
-U ⇒40 channels FM 4W (from 26,965Mhz to 27,405Mhz)
40 channels FM 4W (from 27,60125Mhz to 27,99125Mhz)
-PL ⇒40 channels AM/FM 4W (from 26,960Mhz to 27,400Mhz)
Ch-annel step
-10KHz
-Class of emission
-AM(A3E)/FM(F3E)
-Power supply
-13,2V (from10,8V to 15,6V)
-Antenna impedance
-50Ω
-Dimensions(in mm)
-115(L)x150(H)x38(D)
-Weight
-0,8Kg
2-TRANSMISSION:
-Frequency allowance
-±300Hz
-Transmission interference
-Inferior to 4nW(-54dBm)
-Audio frequency response
-From 300Hz to 3kHz in AM/FM
-Emitted power in the adjacent channel
-Inferior to 20µW
-Microphone sensitivity
-Inferior to 10mV
-Current drain
-1,7A(in transmission mode with modulation)
-Modulated signal distortion
-Inferior to 2%

3-RECEPTION:
-Maximum sensitivity at 20dB sinad
-0,5µV(-113dBm) AM/FM
-Audio frequency response
-From 300Hz to 3kHz in AM/FM
-Adjacent channel selectivity
-Superior to 60dB
-Frequency image rejection
-Superior to 60dB
-Intermodulation response
-Superior to 54dB
-Maximum audio power
-5W
-Squelch sensitivity
-Threshold 0,2µV(-120dBm)/Tight 1mV(-47dBm)
-Current drain
-500mA nominal/800mA maximum

ALIGNMENT PROCEDURE
LUTION LT-298
* VCO/PLL PORTION
- Alignment procedure
- Test points
- Frequencies chart
* TRANSMITTER
- Alignment procedure
- Test points
* RECEIVER
- Alignment procedure
- Test points
Test equipement required
Frequency counter 200 Mhz HF Generator
DCVolmeter BFVolmeter
Distortiometer HFVolmeter
Wattmeter - Dummy load Osilloscope
FM linear detector
AF generator Load 8 Ω
Sinad meter
Conditions of Measurements on HF Generator
Reception
AM mode: Level - 107 dBm Frequency 1 KHz with 80% of modulation.
FM mode: Level - 107 dBm Frequency 1 KHz with 1,2KHz of deviation.
Transmission
Frequency1 KHz 30mV.

ALIGNMENT VCO/PLL
1 - Alignment procedure(13,2V;configuration“PL”)
STEP CONDITION ADJUSTMENT REMARKS OF ADJUSTMENT
1 FM(PL)
TX mode
Channel 19
Connecting a voltmeter to test
TP6,to reach 2.2V±0,2V.
2 FM(PL)
RX mode
Channel 19
Connecting a voltmeter to test
TP6,to reach 2.2V±0,2V
3 FM(PL)TX/
RX mode
Channel 1
Connect a voltmeter to TP6,and check:
Rx Channel 1=1.8V±0,2V
Tx Channel 1=1.8V±0,2V
4 FM(PL)
RX mode
Channel 19
Connect a frequency counter to R23
37,880MHz.
5 FM(PL)TX/
RX mode
Channel 1 to 40
or 1 to 80(d)
Connect a frequency counter to R23,and
check frequencies.

- FREQUENCY LIST (PL)
CH Channels
Frequencies
(MHz)
VCO
Frequencies
(MHz)
126,96037,660
226,97037,670
326,98037,680
427,00037,700
527,01037,710
627,02037,720
727,03037,730
827,05037,750
927,06037,760
10 27,07037,770
11 27,08037,780
12 27,10037,800
13 27,11037,810
14 27,12037,820
15 27,13037,830
16 27,15037,850
17 27,16037,860
18
27,170
37,870
19 27,18037,880
20 27,20037,900
21 27,21037,910
22 27,22037,930
23 27,25037,950
24 27,23037,930
25 27,24037,940
26 27,26037,960
27 27,27037,970
28 27,28037,980
29 27,29037,990
30 27,30038,000
31 27,31038,010
32 27,32038,020
33 27,33038,030
34 27,34038,040
35 27,35038,050
36 27,36038,060
37 27,37038,070
38 27,38038,080
39 27,39038,090
40 27,40038,100

- FREQUENCY LIST (CE,E,EU)
CH Channels
Frequencies
(MHz)
VCO
Frequencies
(MHz)
126,96537,655
226,97537,665
326,98537,675
427,00537,695
527,01537,705
627,02537,715
727,03537,725
827,05537,745
927,06537,755
10 27,07537,765
11 27,08537,775
12 27,10537,795
13 27,11537,805
14 27,12537,815
15 27,13537,825
16 27,15537,845
17 27,16537,855
18 27,17537,865
19 27,18537,875
20 27,20537,895
21 27,21537,905
22 27,22537,915
23 27,25537,945
24 27,23537,925
25 27,24537,935
26 27,26537,955
27 27,27537,965
28 27,28537,975
29 27,29537,985
30 27,30537,995
31 27,31538,005
32 27,32538,015
33 27,33538,025
34 27,34538,035
35 27,35538,045
36 27,36538,055
37 27,37538,065
38 27,38538,075
39 27,39538,085
40 27,40538,095

- FREQUENCY LIST (U)
CH
CEPT
Channels
Frequencies
(MHz)
VCO
Frequencies
(MHz)
1 26,965 37,665
2 26,975 37,675
3 26,985 37,685
4 27,005 37,705
5 27,015 37,715
6 27,025 37,725
7 27,035 37,735
8 27,055 37,755
9 27,065 37,765
10 27,075 37,775
11 27,085 37,785
12 27,105 37,805
13 27,115 37,815
14 27,125 37,825
15 27,135 37,835
16 27,155 37,855
17 27,165 37,865
18 27,175 37,875
19 27,185 37,885
20 27,205 37,905
21 27,215 37,915
22 27,225 37,935
23 27,255 37,955
24 27,235 37,935
25 27,245 37,945
26 27,265 37,965
27 27,275 37,975
28 27,285 37,985
29 27,295 37,995
30 27,305 38,005
31 27,315 38,015
32 27,325 38,025
33 27,335 38,035
34 27,345 38,045
35 27,355 38,055
36 27,365 38,065
37 27,375 38,075
38 27,385 38,085
39 27,395 38,095
40 27,405 38,105

- FREQUENCY LIST (U)
CH
ENG
Channels
Frequencies
(MHz)
VCO
Frequencies
(MHz)
1 27,60125
38,30125
2 27,61125
38,31125
3 27,62125
38,32125
4 27,63125
38,33125
5 27,64125
38,34125
6 27,65125
38,35125
7 27,66125
38,36125
8 27,67125
38,37125
9 27,68125
38,38125
10 27,69125
38,39125
11 27,70125
38,40125
12 27,71125
38,41125
13 27,72125
38,42125
14 27,73125
38,43125
15 27,74125
38,44125
16 27,75125
38,45125
17 27,76125
38,46125
18 27,77125
38,47125
19 27,78125
38,48125
20 27,79125
38,49125
21 27,80125
38,50125
22 27,81125
38,51125
23 27,82125
38,52125
24 27,83125
38,53125
25 27,84125
38,54125
26 27,85125
38,55125
27 27,86125
38,56125
28 27,87125
38,57125
29 27,88125
38,58125
30 27,89125
38,59125
31 27,90125
38,60125
32 27,91125
38,61125
33 27,92125
38,62125
34 27,93125
38,63125
35 27,94125
38,64125
36 27,95125
38,65125
37 27,96125
38,66125
38 27,97125
38,67125
39 27,98125
38,68125
40 27,99125
38,69125

- FREQUENCY LIST (d)
CH Channels VCO CH Channels VCO
D Frequencies Frequencies D Frequencies Frequencies
(MHz) (MHz) (MHz) (MHz)
1 26,965 37,66541 26,565 37,265
2 26,975 37,67542 26,575 37,275
3 26,985 37,68543 26,585 37,285
4 27,005 37,055 44 26,595 37,295
5 27,015 37,71545 26,605 37,305
6 27,025 37,72546 26,615 37,315
7 27,035 37,73547 26,625 37,325
8 27,055 37,75548 26,635 37,335
9 27,065 37,76549 26,645 37,345
10 27,075 37,77550 26,655 37,355
11 27,085 37,78551 26,665 37,365
12 27,105 37,80552 26,675 37,375
13 27,115 37,81553 26,685 37,385
14 27,125 37,82554 26,695 37,395
15 27,135 37,83555 26,705 37,405
16 27,155 37,85556 26,715 37,415
17 27,165 37,86557 26,725 37,425
18 27,175 37,87558 26,735 37,435
19 27,185 37,88559 26,745 37,445
20 27,205 37,90560 26,755 37,455
21 27,215 37,91561 26,765 37,465
22 27,225 37,93562 26,775 37,475
23 27,255 37,95563 26,785 37,485
24 27,235 37,93564 26,795 37,495
25 27,245 37,94565 26,805 37,505
26 27,265 37,96566 26,815 37,515
27 27,275 37,97567 26,825 37,525
28 27,285 37,98568 26,835 37,535
29 27,295 37,99569 26,845 37,545
30 27,305 38,00570 26,855 37,555
31 27,315 38,01571 26,865 37,565
32 27,325 38,02572 26,875 37,575
33 27,335 38,03573 26,885 37,585
34 27,345 38,04574 26,895 37,595
35 27,355 38,05575 26,905 37,605
36 27,365 38,06576 26,915 37,615
37 27,375 38,07577 26,925 37,625
38 27,385 38,08578 26,935 37,635
39 27,395 38,09579 26,945 37,645
40 27,405 38,10580 26,955 37,655

ALIGNMENT TRANSMITTER
1- Alignment procedure(13,2V;configuration”PL,EU”)
STEP CONDITION ADJUSTMENT REMARKS OF ADJUSTMENT
1 AM(EU)
Channel 20
VR2(LOW) Connect a wattmeter to jack
antenna, adjust VR2 to reach 1W on
the wattmeter.
2 FM(PL)
Channel 20
VR1(HI) Connect a wattmeter to jack
antenna, adjust VR1 to reach 4W on
the wattmeter.
3FM(PL) Mod
30 mV 1
KHz CH 20
VR3(DEV) Adjust VR3 to reach +/- 2KHz of
deviation.
4AM(PL) Mod
30 mV 1
KHz CH 20
VR6(AMC) AdjustVR6 to reach +/- 60% of
modulation.
5AM(PL) Mod
30 mV 1
KHz CH 20
VR5ALC) Adjust VR5 to reach +/- 90% of
modulation.
3FM(UK)
Channel 1
JP4 shorted the pin into the C22
there, then look at the first
channel frequency
transmitter,27.60125MHZ

ALIGNMENT RECEIVER
1 - Alignment procedure(13,2V;configuration”PL”)
STEP CONDITION ADJUSTMENT REMARKS OF ADJUSTMENT
1 AM(PL) Channel
20 Middle
volume level.
No squelch active
T1-T2-T3
T4-T5
Connect HF generator to jack antenna
adjusted at ( –107dBm 1KHz 60%),
connect sinad meter to jack EXT speaker
and adjust coils for maximum sensitivity(
≥20dB sinad).
2 FM(PL)Channel
20 Middle
volume level
No squelch active
Connect HF generator to jack antenna
adjusted at ( –107dBm 1KHz 1,2KHz
Dev),connect sinad meter to jack EXT
speaker and adjust sensitivity( ≥20dB
sinad).
3 AM(PL) Channel
20 Middle
volume level
No squelch active
RV2(S-METER) Connect HF generator to jack antenna
adjusted at ( –67dBm 1KHz 60%) and
adjust RV2 so that the 4th led is
lighting.
4 AM(PL) Channel
20 Middle volume
level
Squelch
maximum
clockwise
RV4(SQ) Connect HF generator to jack antenna
adjusted at ( –47dBm 1KHz 60%) and
adjust VR4 so that the signal is
audible .
5 AM(EU,E)
Channel 20
Middle volume
level
Squelch maximum
counterclockwise
(ASQ)
VR1(ASQ) The microphone in hand in the middle of
ASQ open,Then radio PTT LED will light
green,AM status, 1K / 80% will signal
open -107DB, adjust VR1 so that the
squelch open

LUITON LT-298
COMPONENT LAYOUT

TP6
R23
VC1
VR2
RV1
JP4
VR4
VR6
VR5
RV2
VR1
VR3
JP4
T1
T2
T4
T5
T3

LUITON LT-298
BLOCK DIAGRAM