Vectronics VEC-101K - Manual (Page 22)

VEC-101K Owner's Manual Shortwave Converter Kit
20
Connecting to your car’s AM receiver:
Receiver requirements: The output of the converter is designed for receivers
covering the standard AM broadcast band—540 kHz to 1600 kHz. Since the
receiver is being used a “tunable IF.” (the shortwave stations are tuned across
the receiver’s dial) it must meet certain requirements. The receiver must be well
shielded, and require an external antenna to hear signals on the broadcast
band. This is because we don’t want AM band broadcast signals competing with
the shortwave signals. The ideal receiver is a car radio. They are well-shielded
(to keep out ignition noise) and will only receive signals when an external
antenna is attached.
Connecting the converter to the car receiver and antenna: Auto receivers use
very short antennas that are very reactive (offer a poor match) at the broadcast
band frequencies. The antenna cable is a special very-high impedance coax.
Using standard 50 or 75-ohm cables would severely attenuate the received
signals. Connecting cables between the VEC-101K and auto receiver can made
from sections of automotive antenna extension cables. Radio Shack carries
these in different lengths. Most automotive radios use Motorola
TM style antenna
jacks and plugs. (Some newer vehicles use a new miniaturized style.) You will
need to make up interconnecting cables to mate with the RCA fittings on the
VEC-101K. The cables must be long enough to permit the antenna lead to reach
the converter’s location, and for the converter output to reach the receiver
antenna input connector.
Cable A
Cable B
Female Motorola
Male Motorola
Male RCA
h
Male RCA
To car antenna To J1
to car radio To J2
Cable A: Cable A is used to extend the existing automotive antenna lead to
reach the converter enclosure. One end is a Motorola female connector to mate
with the male connector on the antenna cable. The other end of the cable is
terminated with a solder-on RCA male connector to mate with jack J1 (antenna)
on the VEC-101K. The cable can be made by cutting the male connector off of