Acom International 1000 사용자 설명서 - 페이지 10
{카테고리_이름} Acom International 1000에 대한 사용자 설명서을 온라인으로 검색하거나 PDF를 다운로드하세요. Acom International 1000 17 페이지. External radio frequency power amplifier
페이지 인쇄We recommend that you tune-up at the center frequencies of the preferred frequency band. First select the band switch (never with RF applied!). Then
use table 4-1 in order to achieve an approximate preset for both TUNE capacitor and LOAD capacitor knobs:
b) Selecting the plate-load True Resistance Indicator (TRI) tuning aid.
You may select TRI scale in three different ways:
- By pressing simultaneously for a moment the PREV+NEXT buttons. This will insert a 6dB attenuator between the driver and the amplifier's input (the
ATT LED will light), so you'll not need to reduce the drive power during tuning. Press PREV+NEXT buttons momentarily again to switch the attenuator
off the input and to return to the old screen. If you use any of PREV or NEXT buttons only, the attenuator would be switched off too, but the information
screen would change to respectively previous or next.
- By pressing repeatedly either PREV or NEXT button (whichever is nearest), until you reach the TRI scale. This will not insert the attenuator, so you'll
have to use less than 20W drive (unless the amplifier is nearly correctly tuned), otherwise the next step would be executed automatically:
- By simply applying a normal working (50-60W) drive power, while the amplifier is not yet tuned. This will automatically invoke the TRI tuning aid and
will insert the input attenuator (the ATT LED will light) after one second. The attenuator will be switched off, and the old screen will be returned
automatically, after you release the PTT shortly. If you have achieved meanwhile a nearly good tuning, the attenuator would not be inserted again. If
the old screen was the same (TRI, selected manually earlier), you'll then be able to precisely tune the amplifier also at nominal power, without
changing drive at all. Use this hint to shorten the tuning process duration.
c) Tuning Procedure.
While a continuous (CW) signal at the desired frequency is still applied:
- Look at the upper scale (forward power); obtain maximum power using the upper (TUNE) knob;
- Look at the lower (Load Cap) scale and turn the lower (LOAD) knob in order to center the triangle marker at the "!"
mark.
- Release the PTT shortly in order to disable the attenuator, then repeat both steps at nominal power. Always finish by
peaking with the TUNE knob.
N O T E
Appearance of an arrow on either left or right TRI scale edges means that the LOAD knob is too far from the proper
position. To correct for this, turn the LOAD knob to the prompted direction until the triangle marker appears inside the
scale field.
i
-----!-----
>----!-----
no marker:
marker is far left:
use TUNE knob
turn LOAD knob
for max.P
pointer to right
to get any marker
until marker inside
Exhibit 8
Band, MHz
Tune Knob Dial
1.8-2
3.5-4
7-7.3
10.1-10.2
14-14.35
18-18.2
21-21.45
24.9-25
28-29.7
50-54
TABLE 4-1. APPROXIMATE TUNING PRESET
iiii
iiiiiiiii
marker is far right:
turn LOAD knob
pointer to left
until marker inside
Fig. 4-1. Using TRI tuning aid
Load Knob Dial
75 - 50
75 - 45
50 - 30
77 - 60
43 - 40
73 - 66
12 - 10
32 - 30
55 - 45
26 - 24
61 - 63
54 - 52
44 - 17
35 - 33
79 - 81
47 - 49
46 - 20
36 - 32
40 - 15
16 - 12
iiiiii
-----!----<
-----!---v-
marker inside:
turn LOAD knob
slightly left
to center it
10 -17
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-----v-----
LOAD is tuned:
turn TUNE knob
to peak Forward
Power & finish.
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