Microphone; 2.6 Key; Rtty (Fsk); Ground - Kenwood TS-820 Operating Manual

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For antenna adjustments. th e transceiver may be loaded
lightly. using the TUN posi tion instea d of operating at full
power output. This will limit tube dissipation during adjust·
ments. and will also help to reduce interference on the fre·
quency In any case. do not leave the transmitter on f or very •
long at one time. Turn it on . i ust long enough to tune and
load. and get a field strength reading. Start out with the an-
tenna whip at about th e center of its adjustment ra nge. Set
the V FO to the desired operating frequency and then adjust
the PLATE control for a dip, and then the LOAD control.
Then observe the field strength reading. The field strength
meter may be set on top of the dash. on t he hood, or
at
an
elevated location some distance from the car.
Change the whip length a half inch. or so at a time. retune
the finals each time. and again check the field strength at the
antenna. Continue this procedure until the point of maxi-
mum field strength is found. This adjustment will be most
critical on 75 meters, somewhat less critical on 40, until on
10 meters the adjustment will be quite broad. After tuning
the antenna to resonance. the finals can be loaded to full po·
wer.
2.5
MICROPHONE
Attach the microphone connector to a suitable microphone
as shown in Figure 2. Be sure that the PTT switch of the mi-
crophone is separa te from the microphone circuit, as shown
in Figure 3.
It should be noted that a microphone with a 3P plug having
a common earth terminal cannot be used.
The microphone input is designed fo r high impedan ce (50k
ohms) microphones only. The ch oice of microphone is im-
portant for good speech quality. and should be given serious
considera tion. The crystal lattice filter in the transceiver pro-
vides all the restriction necessary on audio response. and
further restriction in the microphone is not required. It is
more important to have a microphone with a smooth. flat re··
sponse throughout t he speech range.
The microphone manufacture's instructions should be folio ·
wed in connecting the microph one cable to the plug. With
many microphones, the push-to-talk button must be pressed
to make the microphone operative. For PTI operation. this
feature may be disabled. if desired. by opening the micro-
phone case and permanently connecting the contacts which
control the microphone.
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The standard microphone sensitivity is within the range of
- 50 dB to - 60 dB. If a microphone having a higher sensi·
tivity is used. the ALC circuit will not function properly. In
this case. insert an attenuator as shown in the illustration at
right or connect a resistor ( 1 Ok ,...., 33k ohms) in parallel
with the c:apacitor 100 pF (C94) in the IF unit
(X48-l l 50-00) of the t ransceiver.
MIC
2.6 KEY
1 OkH to 331<:11
x
0
TS-820
M 1C Conn ector
If 0/11 operation is desired. connect a key to the KEY jack.
2.7 EXTERNAL SPEAKER AND
HEADPHONES
Receive audio output from the TS -820 is 1.5 watt at 4 to 16
ohms. The TS -820 has
a
built-in speaker. However. if an
external speaker is desired for fixed station or mobile opera·
tion. simply connect it to the SPEAKER jack on the real pa·
nel. The speaker may be any good
a
ohm permanent ma-
gnet type in the 4 il}ch or large size. The internal speaker is
disconnected when an external speaker is u sed.
Headphones should also be
a
ohms impedan ce. When the
headphones are connected to the front panel PHONES jack
the speaker is disabled.
2.8 RTTY ( FS K)
For RTTY operation. connect a teletypewriter to the
RTIY
KEY jack on t he rear of the transceiver. Since this jack is
connected to the switching circuit for shifting frequencies. a
relay should be inserted in the closed loop of the teletypew-
riter for keying operation.
2.9 GROUND
So preventing to receive an electric shock. TVI and SCI,
select a good. effective ground for installation and then con·
nect an earthing wire to the backside of GN D terminal. Use
a heavy earth line as big as possible. it is because short-line
wiring is regarded as most effective for operation.
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