SGC develops, manufactures, and sells high performance single
sideband (SSB) communications equipment. Since 1971, the company has sold to the marine, military, aviation, and industrial markets
world wide. Over these years, SGC has earned an outstanding reputation for product reliability and for service after sale.
The company keeps pace with equipment options, engineering
developments, and design requirements. Its products are the most
competitive in the entire long distance communication market. SGC
equipment is presently being used by the United Nations for
inter-communications in developing countries throughout the world.
Many competitive racing vessels, as well as fishing boats, tugs, and
commercial craft are equipped with SGC equipment. In fact, an SGC
radiotelephone provided the only communications available on a past
Polar expedition by the National Geographic Society.
SGC also supplies U.S. government agencies, several foreign governmental agencies, and major petroleum companies through Asia
and latin America.
All SGC equipment is designed and manufactured in the USA. SGC
has qualified people ready to provide technical information, assistance in selecting equipment, and recommendations for any installation.
SGC welcomes your call to discuss your SSB requirements.
1 . 0F E AT U R E S1
2 . 0I N T R O D U C T I O N2
3 . 0S P E C I F I C AT I O N S4
4 . 0INSPECTION UPON RECEIPT5
5 . 0MODES OF OPERAT I O N5
6 . 0I N S TA L L AT I O N8
7 . 0SG-2020 APPLICAT I O N S1 2
8 . 0FRONT PA N E L1 7
9 . 0S E C O N D A RY SWITCH FUNCTIONS2 1
1 0 . 0POWER ON OPTIONS2 3
11 . 0BARGRAPH DISPLAY2 5
1 2 . 0FRONT PANEL CONNECTO R S2 6
1 3 . 0REAR PANEL CONNECTO R S2 7
1 4 . 0CIRCUIT DESCRIPTION2 9
1 5 . 0AM BROADCAST RECEPTION3 1
1 6 . 0QUICK TOUR OF USER CONNECTO R S3 3
1 7 . 0ALIGNMENT / TEST PROCEDURES3 6
1 8 . 0EXCITER VO LTAGE MEASUREMENTS3 9
1 9 . 0PCB LAYOUT AND SCHEMAT I C S4 5
2 0 . 0C ATALOG ITEMS6 6
Thank you for choosing the SGC Model SG-2020 transceiver. We
know that you have many options when choosing your communications equipment, and we are glad that your choice was SGC - an
American designed and manufactured product. SGC has been manufacturing HF transceivers and equipment form 1971. Our philosophy is to bring unique design innovations to the industry; products
that give superior performance and at very affordable prices.
The SG-2020 is by no means just another radio amateur product. It
is a professional, commercial grade transceiver, designed for a
whole panorama of HF users - amateurs, professionals and others.
The SG-2020 is the first in a series of new generation SGC products
based on the single I.F. frequency.
SGC introduced the first HF SSB which was mass produced for the
2
marine industry. This product included new features, such as wideband technology, all solid state and single conversion. This concept
led to the cutting edge technology behind the SG-2020 transceiver
with its intercept point at +18 dbm. Strong front end, single conversion, structured around an I.F. frequency of 60 MHz, provides for a
superior and outstanding receiver with an IF rejection of 90db.
Spurious frequencies typically generated by conventional multiple
conversion designs are virtually eliminated.
With a custom high performance SGC mixer, we keep the design
simple and of superior performance. We have eliminated interfering
circuitry found in other transceivers. An additional design goal was
to have a low stand-by current, below 400 mA, which would allow
this unique product to be used in many applications when others
could not.
The SG-2020 incorporates a very basic noise blanker circuit which
operates without compromising receiver performance and without
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
any additional current drain. This allows excellent receiver characteristics to be preserved along with long battery life. We believe
these benefits will be highly appreciated by operators in the field
and other portable operations.
The rugged transmitter section provides exceptionally clear, clean
audio, and provides excellent performance characteristics. The
amplifier has the stress power capability of 40 watts. In other
words, it is capable of producing 40 saturated watts in mid band
and therefore, a rating of 20 watts PEP is very conservative.
The SG-2020 is equal to the performance of only a very few transceivers available in today's market and which cost several thousand
dollars. We are very proud of this unit - its' features, performance
and price. You check it out and let us know what you think.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
General Operating modes:USB, LSB and CW
Receiver Frequency range:1.8 to 30.0 MHz, general coverage
(400 kHz to 1600 kHz with broadcast filter bypassed)
Transmit Frequency range:1.8 to 29.7 MHz (US Ham Bands only)
1.8 to 30.0 MHz (general coverage, export)
Operational Temperature
Range:-30 to +70º C
Operational Voltage Range:9 - 18 VDC
Microprocessor:MC68HC711E9
Frequency Stability:3 ppm per 10º C *(see example below)
Frequency Resolution:10 Hz
Frequency Display:100 Hz
RX / Tx Changeover:less than 10 ms
Memories:20 (factory pre-set, user definable)
Reflected Power Metering:built in
LCD:back light selectable
Keyer:fully adjustable IAMBIC mode 'B', 5 to 60 WPM
Memory Scan:Adjustable
Dimensions:2.75H x 6W x 7L
Approximate weight:4.4 lbs.
Microphone:fist, dynamic
Battery Volt meter:digital; front-panel controlled
RECEIVER
Sensitivity:better than .5µV for 10dB S/N+N
Intermodulation:+18 dbm 3rd order intercept
Selectable AF bandpass:100Hz to 2700Hz
Audio Output:1 watt RMS
AF distortion at nominal
output power:less than 3%
Internal Speaker:5 watts maximum, 4 ohms
Noise Blanker:pulse / ignition
RF Gain:front panel controllable
BFO:processor controlled
Total power consumption:less than 400 mA (receive only)
TRANSMITTER
Output Power:nominal 1.8-25 MHz 20 watts PEP
( above 25 MHz 12 watts min.)
Output Power Adjustment:front panel control 1 to 25 watts
RF Speech Processing:VOGAD baseband and rf clipping
Transmit Current consumption: 4 amperes, typical at 20 watts PEP voice
Transmit intermods, 20 watts:-28 dB or better
Specifications listed represent optimal conditions and are not subject to warranty. All
SGC products must be used with compatible equipment
*Example: at 14.2 MHz = 14.2 x 3 = 42.6 Hz; A total frequency drift of 42.6 Hz for a temperature change
of 10º C. If the ambient temperature changes from 20º to 30º C, there could be a drift of 42.6 Hz.
SGC reserves the right to modify specifications without notice.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
4.0INSPECTION UPON RECEIPT
Upon receipt, open the shipping carton and inspect your SG-2020
transceiver carefully for any signs of damage. After removing all
packing materials, check that all exposed controls move freely, and
that the enclosure has no dents or scratches. If you notice any
damage to the unit, document it completely and contact the shipping company immediately. Save all packing materials for possible future use.
4.1 INSTALLATION ACCESSORIES
Please check to see that the following items are included in your
shipping carton:
A quick-start information guide is printed on the inside of the SG2020 packing carton. Use this handy reference as soon as you
receive your SG-2020 unit.
5.0MODES OF OPERATION (USB, LSB, CW,
DATA, AM)
5.1VOICE (USB, LSB)
Voice communication is accomplished using either upper or lower
sideband. To display the current operating mode, press "BW".
The display will indicate the current mode and the bandwidth filter
setting. To change modes, press REV while holding the "BW"
button down. When operating in the ham bands, LSB is normally
used below 10 MHz, and USB is used above 10 MHz. The SG2020 will retain the operating mode and bandwidth settings until a
different frequency is chosen using one of the memory selections.
Favorite frequencies can be stored in any of the 20 memories,
including the mode and bandwidth settings.
Note: Voice operation will not function if the unit is in “CW” mode.
5
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
An external automatic antenna coupler can be automatically tuned
in SSB by momentarily depressing the "PBT" push button and
then pressing the push button on the microphone within 5 seconds.
This will insert the CW tone to allow the coupler to tune. The
SG-2020 will transmit a tone as long as the microphone push button is depressed. Once you release the push button on the microphone, the radio reverts to SSB with no tone and normal transmission can resume.
Note:Once ‘"PBT"’ has been depressed and released, you must
key the microphone with-in 5 seconds or the function will time
out. You may also escape this function by depressing any other
key, or by moving the main adjustment knob.
5.2CW MODE
The SG-2020 is designed for CW use with many special features.
To choose the CW mode, press and hold the "BW" button, and
momentarily press the REV button until “CW” appears on the disp l a y. Continue to hold the "BW" button while turning the main
tuning control knob to adjust the bandwidth for the desired filter
setting. Narrowing the bandwidth filter will allow clear reception
of CW signals in crowded bands. The bandwidth can be adjusted
down to a very narrow 100 Hz, however, 300 Hz should be adequate for clear CW reception. CW transmit can be accomplished
with paddle, keyer, or push button (PTT) on the microphone.
The SG-2020 is set to transmit at 650 Hz upper sideband tone.
Setting the dial frequency for the same receive and transmit frequency (Push Button "XCVE") will transmit a tone frequency of
650 Hz above the carrier frequency (upper sideband).
CW for optimum performance:
1. Set volume to maximum
2. Set RF gain for comfortable level
3. Reduce bandwidth to 600 Hz approximately
4. If interfering signals are present, use the past band tuning
to reduce interference
5. If further rejection is required, reduce bandwidth again to
as low as 100 Hz
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
This setup approach will allow any operator to get superb performance under all conditions or pile ups.
In CW the SG-2020 supports full break in and performs extremely
well. Also, in the electronic paddle mode, the break-in is supported, but has been modified to support the overwhelming demand
to extend some hold time after the last character and space, in
order to limit the fast back and forth TX-RX cycles.
Both modes are supported in the break-in mode as follows:
There are two front panel inputs for CW operation
(1) PAD - for built in keyer
(2) KEY - for straight key or external keyer
Only the “KEY” input provides the capability for full break-in. If
full break-in is desired with the keyer, use the external keyer
attached to the “KEY” input.
“KEY” input: Radio reverts to receive immediately when key is
released. This allows traffic to be heard between CW elements.
“PAD” input: Radio remains in transmit for space duration of CW
elements and only reverts to receive after a character is sent. This
allows for partial break-in.
Note: CW operation will not function if unit is in “USB” or LSB” mode.
5.3DATA MODES
The SG-2020 is also designed for various HF data transmission
modes, such as RTTY, NAVTEX, weatherfax, and packet. An HF
data modem is needed, such as the SG-7200. Connection to the
radio is through the microphone jack on the front panel, using
standard audio in, audio out, PTT, and ground. See section 19.2
for a diagram of these connections. Select either USB or LSB for
data transmission and adjust the bandwidth setting as described
above for clear data reception.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
Reception of AM broadcast and shortwave stations is very effective by using upper sideband or lower sideband. Choice of either
sideband will allow the user to avoid nearby interfering signals.
For additional information concerning the SG-2020’s broadcast filter and how to bypass it for broadcast reception in the 400 to 1600
kHz range, see section 15.1.
6.0INSTALLATION
6.0.1 EQUIPMENT LOCATION
The SG-2020 can be affected by strong nearby magnetic fields.
Therefore, be sure to place any AC supply or other source of
strong magnetic fields at least several inches away from the transc e i v e r. Additionally, it is of good practice to avoid locating the
unit on top of heat generating devices such as linear amplifiers.
6.0.2 ANTENNA CONSIDERATIONS
Successful operation of any station depends on providing a reasonably efficient and well matched antenna system. The SG-2020
expects a 50 ohm resistive impedance at the operating frequency.
The output load conditions are monitored by the SG-2020 to provide protection for the final amplifier ’s output transistors by automatically reducing power output when an impedance mismatch is
detected.
Despite this protection, the transmitter should never be activated
unless an antenna or dummy load is connected to the RF connector
located on the rear panel. Use 50 ohm coaxial cable with a proper
PL-259 plug to connect the transceiver to the antenna load. If the
SWR is too high to permit the desired performance, re-configure
your antenna system to include an automatic antenna tuner such as
the SG-231 or SG-230 between the transceiver and the antenna.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
6.0.3 GROUNDING THE RADIO
Under normal conditions the radio does not need to be grounded,
especially if a dipole antenna or an external coupler is used. In
preference and a general rule never ground the radio on the same
ground as the coupler, this will avoid harmful RF to come back to
the radio. If grounding of the radio is necessary, proceed as
described below:
Any of the four rear panel screws can be use to attach the ground.
1. remove the desired screw.
2. attach RF ground to ring lug (not supplied).
3. Re-install rear panel screw and ring lug.
6.0.4 FUSE (INTERNAL)
The SG-2020 has an internal self recovering 5 amp fuse. This fuse
is not visible and is mounted under the LPA PCB. The fuse will
recover within a few seconds after the short in the radio has been
removed.
6.1BASE STATION
The SG-2020 requires a power source of 9 to 18 volts DC, capable
of up to 5 or more amperes peak when operating at full transmitter
output power. A power supply with an output current rating of 1 or
more amperes will be sufficient if the SG-2020 is used in receive
mode only. Power supply voltages greater than 18 volts can damage the SG-2020 while voltages of less than 9 Volts may shut the
unit down. For base station operation, it is advised that a well filtered linear power supply with an output voltage of 12 to 18 VDC
be used for best performance. Avoid using switching supplies as
they may generate receiver noise and be less immune to RF environments during transmit.
Before connecting any power supply to the transceiver or AC line,
make sure that the supply is properly wired for the local line voltage and that the correct value of fuse is installed.
NEVER CONNECT AC OR DC ABOVE 18 VOLTS
DIRECTLY TO THE SG-2020
Make sure that the polarity of the power connections on the rear
panel is correct before turning on the transceiver.
9
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
This foot can be flipped up to raise the front of the radio 3 inches
above the desk level. Additional front flip feet can be ordered separately, catalog number 05-43.
6.1.2 DESK OR BASE MOUNTING (option 05-42)
10
To mount the SG-2020 in a secure installation, use the optional
mounting plate in the transverse or longitudinal position a s
described below:
A. Remove 3 screws in the bottom of the chassis.
B. Line up the mounting plate so the 3 holes match the
screw holes in the chassis.
C. Re-install the 3 pan head screws provided with the plate
to secure the radio to the mounting plate.
D. Secure the radio to a flat surface using four self-tapping
wood or sheet metal screws.
6.2MOBILE
6.2.1 POWER CONNECTION
(Negative Ground vehicles only)
The DC power cable for mobile installation should be made with
AWG #12 stranded copper wire. Please review all power supply
considerations throughout this manual and apply all recommenda-
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
tions as appropriate. The DC cable should be connected directly to
the vehicle battery, rather than to the ignition or accessory circuitry. Route the cable as far away from the ignition wiring and other
cables as possible. Keep the length of this cable as short as possible to minimize voltage drop losses.
• Do not plug in the DC power cable to the transceiver until the
proper connections are made to the battery; by convention, we recommend a RED cable lead to the POSITIVE battery terminal, and
a BLACK cable lead to the NEGATIVE battery terminal. Do not
rely on the vehicle chassis to provide the DC negative return path.
Make sure the battery terminal connections are tight and remember
to check them periodically to assure they remain tight and corrosion free.
• Measure the voltage across the battery terminal with the engine
running fast enough to show a charge. This voltage cannot exceed
18 Volts DC as that is the maximum allowable DC Voltage for the
SG-2020.
• Measure the voltage at the transceiver end of the cable and confirm that the proper voltage and polarity exist for the SG-2020.
The center position of the 3 contact connector is POSITIVE while
the left contact (facing the rear of the radio) provides the NEGATIVE connection to the radio.
• Insert the DC power cable connector into the mating connector
on the rear panel of the SG-2020, connect antenna coax to the
ANTENNA connector, and external speaker connection via the 3.5
mm stereo phone jack if desired.
6.2.2 ANTENNA CONNECTION
Please take a moment to review the base station antenna information in the previous section of this manual. An antenna tuner such
as the SG-231 or SG-230 is particularly desirable in a mobile
installation as short antennas typical of mobile installations usually
provide a hostile load impedance to any HF transceiver. Even if
the antenna is resonant near the operating frequency, the bandwidth
of such antennas is extremely narrow limiting operating frequency
agility.
11
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
Velcro mobile mounts (option 05-42) with peel-off adhesive are
supplied (to be installed by the operator). When using the velcro
mount, we recommend the use of a secure cable, which should be
attached between the radio chassis (or mounting plate) and the
vehicle for added safety. For a more secure and versatile installation, an optional pedestal mount system is also available from your
dealer.
Note: SGC assumes no liability for damage or injury which could occur in the
event of an accident or collision.
7.0SG-2020 APPLICATIONS
7.1.HAM GEAR VOICE
The SG-2020 is a multi-purpose ham radio, ideally suited for base,
mobile, or portable use. Because of its unique characteristics, it
will out perform many of its more expensive competitors in the
market place.
12
Low current consumption, both in receive and transmit allows this
equipment to operate when others will not. In addition, it can be
operated by simple “D” size drycell batteries. Its transmit characteristics with 20W output and adequate speech compression, allows
“on air” performance to be perceived as a 100W transceiver. The
simple but effective settings capability from the RF gain, pass band
tuning, and audio frequency band width allows the unit to operate
efficiently in any severe communication environment. This, combined with low intermodulation of + 18 dbm and the frequency
scanning feature, make this low cost transceiver ideal as a base station monitor.
The SG-2020 HF radio is unique as a portable product on the global market, because its outstanding performance, small size, quality,
and multi application capability.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
7.2HAM GEAR CW
In the development of this product, special attention was given to
design a product with excellent CW operation. Two key jacks are
provided; one for a straight key (mono jack) and the other for an
electronic keyer (stereo jack). The straight key allows the operator
full break in capability, and also the transmitter can be keyed by
using a separate foot switch or depressing the push button on the
microphone. The second jack is designed for operation with the
internal electronic keyer that preconditions the speed of the keying
from 5 to 60 words per minute. The software design is highly
sophisticated and has been acclaimed by many hard core CW operators. Power adjustment capability is provided from the front
panel; from 25 watts to below 1 watt. Accurate adjustment or reading from the indicator is not supported. At 5 watts the reading may
be within plus or minus 1 watt and 15 watts it maybe within plus or
minus 2 watts. Higher deviation in some instances may be recorded and the operator can set his own table for the particular radio.
Combining the proper use of audio level, RF level, passband tuning, audio frequency and bandwidth tuning, the CW operator will
enjoy superb CW communications world wide. From a home base
station or to the North Pole or the, Amazon jungle, the SG-2020
functions as a remarkable CW portable unit.
7.3HAM AND COMMERCIAL DATA COMMUNICATION
The SG-2020 is well suited for data communication especially if
operated with modern DSP data modems such as the SG-7200 or
SCS PACTOR. This provides a well balanced combination for
efficient data communication. Most DSP data modems have a 12
to 20 dB signal to noise ratio advantage over an analog modem;
therefore power output of 1 to 20 watts is more than sufficient to
provide reliable world wide communications. Future developments
of the SG-2020 will be available with external power and frequency adjustments to allow adjustment of both elements depending on
the signal quality.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
The SG-2020 will switch between receive and transmit in less than
10 milli seconds and is well suited for this type of data operation.
7.4MARINE
The SG-2020 is an ideal marine radio. Since it is not FCC type
approved for this operation, it should be used as an auxiliary hobby
radio. The low power requirements enable the unit to operate when
other equipment on board may not, (i.e. because of a power failure
or major accident at sea). In this situation it is perfectly legal to use
this radio for emergency transmission. Many marine radio nets
exist; the most popular frequency is 14.313 kHz and is run everyday. As an addition to your regular marine electronic equipment,
the SG-2020 will give you hours of enjoyment and provide additional safety on your boat. Depending on your cruising area and
habits, we recommend you program into the memory channels
some popular ship to ship marine frequencies (simplex) and some
US Coast Guard high seas frequencies. Appendix A is provided for
14
popular ham net frequencies and marine frequencies.
7.5AVIATION
The SG-2020 was also designed for aviation operation. It is not
FAA type approved for such use, and should be installed on a voluntary basis only. The SG-2020 fits the standard aviation panel
width which is under 6 1/4 inches. The units low power current
consumption will allow it to work when the rest of the electronic
gear in a small airplane may not. It is the perfect companion radio
to be operated in a single or double seated airplane from the jungles
of Brazil to Indonesia, and from Alaska to the icy Alps.
We recommended programming the preferred frequencies of the
operator for fast retrieval. The unit can also be locked so only these
channel frequencies are accessible to the operator. This is a practical way to insure that a casual operator calls on the proper frequency and mode settings.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
7.6COMMERCIAL USE
The SG-2020 is a practical radio for commercial applications,
because it can be programmed with only a few necessary channels
and then locked. The casual or unfamiliar operator can access only
these channels through the main tuning knob. Scanning can be easily accessed allowing perfect channel monitoring of only the channels in use. If only 3 frequencies are required for a normal network; we recommend entering the first operating frequency in the
first 8 memory channels 1 thru 8, then the second operating frequency in memory channels 9 thru 13, then the third frequency in
memory channels 14 thru 20 and locking the unit.Now when; the
operator depresses the MEM push button and rotates the main tuning knob then only the 3 preset channels will be accessible.
Scanning will automatically cover only these 3 frequencies.
Note: all memories must be frequency programmed and can not be
left empty. Also, the unit is not designed to lock out only a few
selective channels.
7.7POWER AMPLIFIER
The SG-2020 is fully compatible with our SG-500 watt amplifier.
Expected power from 3 to 18 MHz is not less than 450 watts and
not less than 300 watts on the extreme ends of the HF bands.
Only RF is required to control the SG-500. However any suitable
linear SSB amplifier can be used with the SG-2020 transceiver.
7.8MONITOR BASE STATION
The special receive and scanning characteristics of the SG-2020
combined with its very low cost allows several transceivers to be
used to monitor many different frequencies simultaneously. This
provides a flexible and versatile base system. One single, expensive HF radio may not provide the same performance, and its
power consumption may be restricted in some applications. The
SG-2020 is the most suited product for this type of application.
15
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: sgc@sgcworld.com Web site: http://www.sgcworld.com
8.0FRONT PANEL (see figure 2)
The following legend presents the PRIMARY function of each
individual control and indicator. Several controls have secondary
functions when used in conjunction with the spinner knob or other
buttons, as described in the SECONDARY SWITCH FUNCTIONS chapter of this manual.
8.1CONTROLS
Location of push buttons - (see figure 2)
All four main push buttons:FAST, MEM, BW, REV have been
designed and located for convenient one-hand operation.A few
users have complained that two hands are required and that the
push buttons are too close.Users should become familiar with the
use of one hand, using these push buttons and the main tuning
knob.
8.1.1 PWR
The PWR button turns the radio on and off. When turned on the
display will first show the serial number followed by SGC (SGC
will also be in CW sidetone), and then the DC voltage of the
power supply. Finally, the operating frequency will be displayed
and the transceiver is then ready for operation.
8.1.2 LIGHT
Pressing the LIGHT button turns the display backlight on and off.
Battery life when operating portable can be extended by turning
the backlight off when not needed.
8.1.3 SPEED
This button controls the speed of the internal keyer when operating
in the CW mode. Press and hold the SPEED button. The keyer
speed will be displayed in (WPM) words per minute. To adjust the
keyer to the desired speed, turn the main tuning knob while the
speed button is depressed, and adjust the speed to the desired rate.
The range of adjustments in 1 word increments from 5 WPM to 45
WPM, and 5 word increments from 45 through 60 WPM. The
speed is retained in the SG-2020’s non-volatile memory.
17
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The "PBT" button will activate passband tuning. The display will
show the passband offset in KHz. Turn the main tuning knob while
pressing the "PBT" button to change the passband tuning as
desired.
This will shift the IF passband relative to the BFO frequency. The
adjustment rate is from -1000 Hz to +300 Hz in 100 Hz steps.
Shown at left is the
e ffect of the passband
tuning. Assume the
bandwidth is set at 2.0
KHz. For lower sideband, all adjustments
are symmetrical in
relation to the upper
sideband.
Note:
Accurate calibration is not supported in Passband Tuning
8.1.5 NB (Noise Blanker)
This button controls the noise blanker. The LED above the NB button is lit when the blanker is activated. The noise blanker is
designed to provide modest blanking of impulse (ignition) type
noise without degrading the performance of the receiver. Normally
the blanker would remain in the off condition.
8.1.6 "XCVE" / RIT / SPLIT
The receiver is general coverage and can be tuned to any
frequency between 1.8 MHz and 29.7 MHz. The transmitter will
not operate if the frequency is set outside the amateur bands. Inside
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the amateur bands it is the operator's responsibility to transmit only
on modes and frequencies consistent with his or her class of license
and regional recommended band plan.
In the "XCVE" position the SG-2020 receives and transmits on the
same frequency.
Press the RIT(Receiver Incremental Tuning) button and the transmit frequency remains fixed while the receive frequency can be
varied. Push the REV button while in RIT and the transmit frequency will be displayed and can be tuned while the receive frequency remains fixed. (XIT-Transmitter Incremental Tuning)
Working Split: (receiving on one frequency while transmitting on a
different frequency)
Example: The DX station is listening up band by about 5 kHz.
1.Tune in the DX station while in "XCVE".
2.Press SPLIT.
3.Press and hold the REV button while tuning to listen for
other stations calling the DX station upband
(by about 5 KHz).
4.When you have found the DX station's listening frequency,
release the REV button and make your call. You will be
transmitting on his listening frequency and listening on his
transmitting frequency.
5.
Remember to switch off the SPLIT when moving for another QSO.
When changing from RIT to "XCVE" the RIT transmit frequency will
become the active frequency.
Note: Pressing the SPLIT button also serves to ‘lock’ the receive frequency.
8.1.7 FAST
By pressing the FAST button while turning the main tuning knob,
the tuning rate will be set to one of four different values: .1 kHz, .5
kHz, 1.0 kHz, or 10 KHz (see section 9.7). Normal tuning rate is .1
KHz in 10 Hz steps. This feature allows the operator to move to
different parts of the band quickly.
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P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
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The SG-2020 has 20 user accessible memories. The unit comes
from the factory with the memories preset to a few frequencies in
each amateur band for convenience. However, these preselected
frequencies may be changed by the operator at any time desired.
Press the MEM button and turn the main tuning knob to step from
one stored frequency to another. Tune to a new frequency using
the FAST button if the new frequency is some distance from the
previous one. Press the FAST button and hold while pressing the
MEM button. The new frequency is now stored in the current
memory.
It is possible to toggle between two frequencies through use of the
MEM button. For example, suppose you want to check a net frequency periodically while operating elsewhere on the band. Press
the MEM button and the frequency will change to the current memory frequency. Tune to a new frequency. If you press it once more
you will return to the last used frequency. Each time you press
MEM you will alternate between the current memory and the frequency last used.
The following frequencies have been preset as defaults into the
memory locations at the factory:
Note: Each memory retains the following parameters: receive freq u e n c y, transmit frequency, mode (USB/LSB/CW),
X C V E / R I T / S P L I T, bandwidth setting, and transmitter output
power. Memories can be retuned to the factory presets by pressing
MEM button while turning the power on.
Channel numbers are not
assigned, and therefore are not displayed.
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P.O.Box 3526, 98009 Fax: 425-746-6384 or 746-7173 Tel: 425- 746-6310 or 1-800-259 7331
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8.1.9"BW" (Bandwidth)
Press the "BW" button. The display will show the receiver bandwidth. Turn the main tuning control while pressing the "BW" button to change bandwidth. It is adjustable from 2.7 KHz to 100 Hz
in 100 Hz steps.
8.1.10 MODE SELECTION ("BW" + REV)
To display the current operating mode (USB / LSB / CW), press
"BW". To select another mode, hold "BW" and momentarily press
REV until desired mode appears on the display. Release "BW" to
return to frequency display.
8.1.11 RF GAIN
The RF knob controls the RF gain of the receiver. When receiving
extremely strong stations, it may be desirable to reduce the receive r’s RF gain by adjusting this control in the counter clockwise
direction. Normal position for this control is in its maximum or
fully clockwise position.
8.1.12 VOLUME
The VOLUME knob controls the AF gain of the receiver.
Maximum receive audio is when this control is in its fully clockwise position.
9.0SECONDARY SWITCH FUNCTIONS
9.1BARGRAPH MODE (CMD + LIGHT)
When pressing CMD and LIGHT simultaneously, the bargraph display toggles between 'full' bar display and 'peak' bar display.
9.2DC INPUT VOLTMETER (CMD + SPEED)
When pressing and holding CMD and SPEED simultaneously, but
momentarily, the LCD will display DC Input Voltage. The voltage
will be displayed until one of the following actions is performed:
a. move the tuning knob.
b. Initiate transmit while in CW mode.
c. depress any of the following keys:
21
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When pressing CMD and NB simultaneously, but momentarily, Tx
output power level is adjustable by rotating the main tuning knob.
Adjustment levels are made in increments of approximately one
watt, from 0 to 20 watts. To return to the frequency display, press
MEM. To enter this setting in the last recalled memory, press
FAST + MEM. Accurate calibration is not supported.
9.4MEMORY SCAN (CMD + MEM)
To initiate memory scan mode, press CMD and MEM simultaneously, but momentarily. The SG-2020 will begin scanning the 20
memories. To stop memory scan, press any button or transmit.
22
9.5FREQUENCY SCAN (CMD + "PBT")
To initiate frequency scan mode, first tune to the desired starting
frequency using the main tuning control. Pressing CMD and
"PBT" simultaneously begins the frequency scan. Blinking LED’s
will indicate the direction of the scan. To reverse the scan direction, press REV momentarily. To stop frequency scan, rock the
tuning knob back and forth.
9.6
ADJUST FREQUENCY SCAN VARIABLES (CMD + REV)
The following scan variables may be adjusted by the user by
pressing CMD and REV simultaneously but momentarily:
DWELL TIME: 0.1 thru 10 seconds, 0.1 second increments
Dwell: ‘d’ is displayed (Press MEM to enter).
PAUSE on DETECTION:
Pause: ‘P’ is displayed (Press MEM to enter).
DETECTION THRESHOLD: S1 thru S9, 1 'S' unit increment .
Threshold: ‘S’ is displayed (Press MEM to enter).
AUDIO BLANKING TIME: 0 - 1.28 seconds in 10 ms intervals
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Blanking: ‘b’ is displayed (Press MEM to enter).
FREQUENCY STEP: .1, .5, 1.0, or 2.5 kHz.
FREQ Step: ‘F’ is displayed (Press MEM to enter).
9.7
ADJUST ‘FAST’ INCREMENTAL VALUE (CMD + FAST)
While pressing CMD and FAST simultaneously, but momentarily,
turn main tuning knob to adjust the incremental value by .1, .5, 1.0,
or 10 kHz. To store this value into memory, press MEM.
9.8C A L I B R ATE FREQUENCY DISPLAY (CMD +
"XCVE")
To calibrate the frequency display, press CMD and "XCVE" simul-
t a n e o u s l y, but momentarily. All three mode LED’s
("XCVE",RIT,SPLIT) will be on. Adjust by turning the main tuning knob. To store this calibration, press MEM.
Note: If the frequency display has been re-calibrated, the default
channel memory frequencies will be offset by the same corrected
value. If an adjustment has been made, it may be necessary to reenter the frequency into the 20 memories.
10.0 POWER - ON OPTIONS
1 0 . 1“CMD” BUTTO N
Note: Holding the “CMD” button upon power up will cause the
LCD to display “C”. This has no user function and is for factory
use only. The sequence will abort to normal radio operation about a
second after the “CMD” button is released.
1 0 . 2R E S TORE FA C TO RY MEMORY DEFA U LTS (MEM)
To restore factory memory defaults, hold MEM upon powering up
of unit.
1 0 . 3BACKLIGHT DEFA U LT ON / OFF and LED Te s t
Power up the radio while depressing the ‘LIGHT’ button. Hold it
until either ‘dl ON’ or ‘dl OFF’ is displayed. Select whether you
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want the backlight on or off when the radio is turned on. This is done
by using the ‘REV’ button to toggle between ‘dl ON’ and ‘dl OFF’.
Store the choice by depressing the ‘MEM’ button. Once the ‘MEM’
button is released, a sequential test is performed on each LED and
the backlight. The radio then reverts to normal operation.
1 0 . 4LOCKOUT ("PBT" + RIT)
To toggle the lockout function on or off, hold "PBT" and RIT
simultaneously upon power up. This command locks out all functions except LIGHT, "BW", MEM (select or scan), NB, and DC
VOLT METER. ‘REV’ toggles the choice between ‘on’ and ‘off.’
To store this choice into the memory, press MEM.
10.5CODE REVISION DISPLAY (REV)
Pressing REV upon power up displays firmware revision.
10.6MEMORY CHANNEL RECOVERY PROCEDURE
The following procedure will cure the loss of the 20 memory channels, when the display reads 66 MHz at power up .
(A) Power up the radio
(B) Engage "channel scan" mode, by doing the following:
(1) depress and hold "CMD" button
(2) depress "MEM" button
(3) release "MEM" button
(4) release "CMD" button
NOTE: It may take up to 5 minutes to re-establish the memories,
although it is usually accomplished in just a few seconds.
(C) Exit "channel scan" by depressing any key.
Warning:This problem can occur
A. If power is removed intermittently.
B. If battery or low DC voltage exist and transmit is operated
Please avoid the above conditions.
NOTE: For proper and faster recovery please insure the input voltage is higher than 12 volts DC.
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11.0 BARGRAPH DISPLAY
11.1POWER / S-METER
In receive the bargraph shows relative signal strength in S units. In
transmit the output power is also displayed. Hold the “REV” but-
ton while transmitting and the reflected power will be displayed.
The display returns to forward power indication when the “REV”
button is released. Remember, that when operating SSB voice
transmission the displayed peak reading on the bargraph will be
substantially lower than the actual peak output power being trans-
mitted and does not indicate a transmitter fault.
S-METER LEVEL DEFINITIONS
LEDApproximate Level
S1Always on
S2.8µv
S53µv
S712µv
S950µv
+10150µv
+30500µv
+401.5mv
+5015mv
NOTE 1: The above S-Meter levels are approximate, and accurate
calibration is not supported.
NOTE 2: The power levels in transmit are approximate, and accurate
calibration is not supported. The bargraph will also work in the Iambic
key mode.
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