Chapter 3 - Connecting your radio
13
CHAPTER 3
CONNECTING YOUR RADIOS
The following paragraphs outline installation procedures for interconnecting your transceivers
and the KAM. Prior to actually connecting the cables, you should determine if the internal jumpers
K-1, K-2, K-5 or K-7 require repositioning to accommodate your system.
Jumpers are appropriately labeled on the PC board. Refer to the parts location diagram in this
manual for help in locating them. Also refer to the assembly and disassembly section for informa-
tion on obtaining access to the interior of the unit.
K-1
VHF EQUALIZATION – This jumper is provided to alter the equalization characteristics of the VHF
modem. With no jumper installed on the 3-pin header, full equalization is effected. With the jump-
er connecting the center post and the post marked 1, there is no equalization. With the jumper
connecting the center post and the post marked 2, partial equalization is in effect. Testing has
shown that most VHF transceivers require that the input audio signal be fully equalized for best
performance. This unit is shipped with the jumper placed on ONLY ONE of the posts effectively
"OFF" so that full equalization is in effect. Should you wish to operate the KAM in a hard wire pack-
et line, no equalization should be in effect.
K-2
AFSK OUTPUT - VHF – This jumper is provided to alter the VHF AFSK output level. The LO position
sets an AFSK output level from the KAM at 10 mV. The HI position sets an AFSK output level of
50 mV. Both levels are peak-to-peak values. In general, transceivers requiring a pre-amplified mi-
crophone will require the HI level AFSK output from the KAM. Removing the jumper entirely will
provide the maximum possible output level of approximately 1.7 V. Should you require an inter-
mediate value of AFSK modulation signal, it may be obtained by replacing resistor R-12 with the
appropriate value chosen from the following chart. If you change R-12 to obtain an intermediate
value, place K-2 in the HIGH position. This unit is shipped from the factory with the jumper in the
LO position.
R-12 Value AFSK Output Level
470 Ω 24 mV
2.2 kΩ 106 mV
6.8 kΩ 290 mV
22 kΩ 680 mV
47 kΩ 1000 mV
K-3
VHF TIMER – This jumper is provided to DISABLE the VHF "watch dog" timer. The timer is disabled
if the jumper is installed. Time-out of the KAM will occur after approximately 2.5 minutes un-key-
ing the VHF PTT line. This unit is shipped with the jumper NOT CONNECTING the jumper posts;
therefore, the timer is in effect.
K-4
HF-TIMER – This jumper is provided to DISABLE the HF "watch dog" timer. The timer is disabled if
the jumper is installed. Time-out of the KAM will occur after approximately 2.5 minutes un-keying
the VHF PTT line. This unit is shipped with the jumper NOT CONNECTING the jumper posts; there-
fore, the timer is in effect.
K-5
AFSK OUTPUT - HF – This jumper is provided to alter the HF AFSK output level. The LO position
sets an AFSK output of 100 mV. The HI position sets an AFSK output level at 500 mV. Both levels
are peak-to-peak values. In general, transceivers requiring a pre-amplified microphone will also re-
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