Lafayette HA 600 Service Manual

Page 1

Model HA-GOO

(Stock No. 99-2595WX)

"mm

mm

.x. ~ .1.»

I" an.

SOLID STATE
AMATEUR AND SHORTWAVE
RECEIVER

INSTALLATION AND OPERA TING MAM/Al

Page 9

DIPOLE ANTENNA

A dipole or doublet antenna will give excellent results, especially on amateur bands. A 75 ohm
coaxial cable transmission line should be used to connect the antenna to the receiver as shown

in Figure 513. Since the dipole antenna provides optimum performance only at a given frequency,
it should be cut to the length for the most used band of frequencies. The overall length of the
dipole antenna may be determined by using the following formula:

468
Frequency in Megacyc les

= L (Length in feet)

For example: If operation is desired on 3.5 Me (the low end of the 80 meter amateur band), the
length of the antenna should be approximately 134 feet as determined by the formula.

468
- : A roximatel 134 feet.
3.5 Mc Pp y
Since the dipole antenna displays directional properties broadside to its length, it should be ori-
ented in such a manner that maximum signal pick-up can be obtained from the desired direction.
An antenna height of 30-50 feet is recommended for good reception of weak signals.

OPERATION

TUNING

The main and band spread tuning dials are calibrated in megacycles and contain markings through-
out the dial to simplify tuning. The major amateur radio bands are contained in the 1.6-4.8,
4.8-14.5 and 10.5-30 megacycle scales. The location of each amateur band is indicated by a
small circled letter or letter and number that appears near the amateur band frequencies on the
main tuning dial. These amateur band markings may be found on, or near 4.0, 7.0, l4, 2?. and

30 megacycles on the main tuning dial. The BAND SELector must be set to the range or band of
frequencies desired to be tuned.

Bandspreading on the amateur bands is carried out by initially setting the bandspread pointer to
100 on the Logging Scale and the main tuning pointer directly over the circled letter (or letter
and number) for the band to be tuned. The tuning range of the calibrated bandspread dial to be
used is indicated by the corresponding letter (or letter and number) to the left and right-hand
side of the bandspread scale. 0n the 40 meter amateur band it will be noted that the hand is split
between two markings (B1 and B2). B1 and B2 together cover the full range of frequencies on
the 40 meter band (7.0 to 7.3 MC) -- Bl from 7.0 to 7.145 Mc, B2 from 7.145 to 7.3 Mc. Thus,
if the main tuning pointer is set over Bl, the bandspread scale to be used is the one marked B1.
In turn, when the BAND SELector is set to the desired band, and the main tuning pointer is set
to a letter (or letter and number) marking, the tuning is accomplished solely with the BAND
SPREAD control on the appropriate scale.

For tuning other than the amateur radio bands, the PIA-600 may also be operated as a general
coverage shortwave receiver. On the shortwave bands radio stations are found transmitting
from all over the world. Many of these stations provide English-language broadcasts; however
there are also stations transmitting in different foreign-languages. The frequencies on which
most shortwave broadcast stations operate are found in the two upper bands of your receiver.
The majority of shortwave broadcast stations operate within certain internationally assigned
groups of frequencies or "bands.