Heath Heathkit SB-104A, Manual

Page: 5 / 204

INTRODUCTION
The Heathkit Model SB-104A SSB and CW transceiver
covers the high frequency amateur bands from 3.5 MHz
through 29.7 MHz. It is entirely solid-state and delivers
approximately 100 watts to the antenna. However, it can be
instantly switched to ORP operation, in which case a
minimum of one watt is delivered to the antenna.
Broadbanding eliminates the necessity to "peak" circuits
within a band. All that is necessary is just to turn the Band
switch and select the desired frequency.
The frequency to which the Transceiver is tuned is elec­
tronically displayed, which eliminates the usual dial read­
out. A unique frequency counter is employed which in­
cludes a crystal-controlled time base. Very high accuracy
is maintained on all bands and any requirement for a
calibrator is therefore eliminated. A red window, which
provides subdued lighting and high visibility, covers the
frequency display, the panel meter, and a space for sta­
tion call letters.
The Vox Gain and Vox Delay controls are
conveniently
located on the front panel to facilitate adjustments for
operators who work both CW and SSB. Vax or PTT is
pushbutton-selected, and the AGC action can be switched to
fast, slow, or off. Provision is made for ALC input from an
amplifier, and relay contacts are available for switching an
amplifier between transmit and receive.
The Transceiver operates from a 13.8 VDC power input,
which can be furnished by a power supply or direct from a
battery. The panel meter can be switched to read supply
voltage or relative power output; in the receive mode,
when
ii
is switched to ALC, it acts as an S meter. The
Power Amplifier circuit board carries a special 1-year war­
ranty -see "Circuit Board Service Policy" on Page 2-45
for complete details.
1HHAT'HTT "
To align this Transceiver, you should have a volt-ohmmeter
with a high ohms-per-volt rating and a 50 ohm dummy load
capable of dissipating 100 watts of
power.
The following accessories are also available for use with this
Transceiver:
• An accessory noise blanker that can
be
installed to
reduce impulse type noise. A front panel switch is
included for this accessory.
• A very versatile accessory VFO. This instrument
includes a duplicate of the VFO in the Transceiver and
a switching circuit which permits you to transceive
with either the Transceiver or the accessory VFO, or
to transmit on either VFO and to receive on the other.
This instrument is particularly appealing to those
operators who communicate with stations operating
split-frequency.
• A narrow filter for CW operation. Space is provided
for it on the carrier generator/XTAL filter circuit
board.
• An AC-operated power supply, as well as a speaker
in a matching cabinet. The power supply can be
installed in the speaker cabinet.
Refer to the "Kit Builders Guide" for information on tools, wiring,
soldering, resistors, and capacitors.
1-3