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RS918 HF SDR Transceiver

RS918     HF SDR Transceiver


Product details


Spectrum Dynamic Waterfall Display
Multiple Working Modes:Receive Mode,Transmit Mode,TUNE Mode,VFO Mode,SPLIT Mode
DSP(Digital Signal Processing) Noise Reduction
Automatic Notch Filter
Humanized Interface Color Display
Receive Fine Tuning Function,Changeable MIC Gain Value VCC Power Supply Voltage Indication Table
Transmit Signal Strength Display Table
Multifunctional Instrument: SWR Standing Wave Ratio Meter, AVD Audio Frequency Meter,
ALC Signal Modulation Meter


Frequency Range: 1MHz-30MHz
Output Power: Maximum 15W
Receiving Sensitivity: <-95dBm
Operating Mode: SSB(J3E),CW,AM,FM,FREE-DV
Operating Voltage Range: DC 9-15V
Maximum Current: 3.5A



Attention: Please well connect correct power and antenna before power on for use. Power supply and improper may damage the
transceiver antenna connection.
-HF Transceiver QRP, put the battery 12v and ant can qso.
-DC IN:9-13V Max:3A
-Output power :<= 10W
-Baud rate: 160,80,60,40,30,20,17,15,12 and 10 meter amateur bands.
-Receive: 3.5-30 MHz nominal including general cover, 0.8-32 MHz reduced specifications.
-Mode: CW,LSB,USB,AM,FM(N,W),SAM, freeDV
-Bandwidth: 300Hz-10Khz Adj
-SWR:Display 1-5
-Better di-108 dBm (0.89uV) in a 2.3 kHz bandwidth
-Better di-120 dBm (0.22uV) in a 300Hz bandwidth
-Enclosure design: Removable
-Stm32f407VGT6 1M memory
Because this is a software defined radio and due to ongoing changes/improvements of the software and hardware, the specifications
of continue to improve.
-Receiver sensitivity for 10dB S/N, filtering CCITT, got 28.3 MHz:
-Frequency enabled translation:
Best di-111 dBm (0.6uV) in a 2.3 kHz bandwidth
Best di-126 dBm (0.11uV) in a 300Hz bandwidth
Disabled frequency translation:
Best di-108 dBm (0.89uV) in a 2.3 kHz bandwidth
Best di-120 dBm (0.22uV) in a 300Hz bandwidth
The above specifications are for one receiver to the published sensitivity changes are performed.
Frequency coverage:
-Baud rate: 160,80,60,40,30,20,17,15,12 and 10 meter amateur bands.
-Receive: 3.5-30 MHz nominal including general cover, 0.8-32 MHz reduced specifications.
Note: the capacity of Si570 to tune your radio to below 2.5 MHz is not guaranteed in its specifications, but most units have
enough range to tune just below 1.8 Mhz. Maybe there are some ‘piccoli spaces where it does not work-if it works, works
well.Indicator is the color
The digit frequency:
-White: fully working
-Yellow: mostly work, maybe there are some small spaces
-Red: does not work
Spectral Display mode:
-Application spectrum: this is a spectrum analyzer with vertical divisions representing userdefinable variations of amplitude of
5,7.5,10, 15,20,1 S-Unit (6dB),2 S-Drive (12dB) or 3 S-drive). The baseline (“reference level”) of the analyzer is automatically
adjusted so that the passband signals within the displayed best fit the dynamic range selected by the userselected dB/division. A
lattice along the bottom of the display shows the frequency of the signal that is displayed on a width approximate +/- 24
kHz.((48kHz total)
-Waterfall display: as with the spectrum scope, the frequency is displayed along the “x”-axis, but the signal strength is implied
by the color displayed. The newest signals are displayed along the bottom of the screen, but as new readings arrive, the
representations of old signals are moved up giving an ephemeral time record of recent activity on the nearby frequencies. There
are several options for the “color palettes” ranging from simple grayscale a “cold-hot” for “Rainbow” to represent weak to strong
There is also a “magnification” mode: For both the Spectrum Scope and waterfall display mode that provides 2x magnification,
reducing the visible spectral width for only +/- 12 kHz (24 kHz total.) Both the Spectrum Scope and waterfall display are very
highly configurable. You can turn off one or both spectral display mode, if desired.
Large-capacity management signal: continuous “Warning” occurs above about-28 dBm and real A/D cutout and distortion occurs at and
above about-18 dBm for signals +/-the oscillator frequency local and increased for signals outside this range.
Transmitter output power :<= 10 watt, typical, linear. Modification can be done to increase this: follow the discussions in the
Yahoo group.
Frequency stability: +/- 30Hz to 14 MHz throughout the range of 10 to 35 C, environment with the transceiver in the case or better
with the TCXO active. (Which can be much better than this.
Available TX/RX mode:
-CW,USB,LSB,AM(Full-carrier, double-sideband),SAM (double-sideband reception) and FM.AM transmitter and FM transmission/receiving
capacity are available only if the “frequency translation” is active (highly recommended!)
-FM options: Carrier (ultrasonic) squelch,subaudible tone encoding and decoding, tone burst (“whistle up”) generation,
“tight”(+/-2.5 kHz) and “wide” (+/-5 kHz) deviation and selection of 7.2,10,12 or 15 kHz pre-detection receive bandwidths.
FM sensitivity for 12 dB SINAD,CCITT filtering:
7.2 kHz BW filter: -103.7 dBm (1.46uV) with 1 kHz tone to +/-1.5 kHz
10 kHz BW filter: -102.1 dBm (1.75uV) with 1 kHz tone to +/-1.5 kHz
10 kHz BW filter: -104.0 dBm (1.41uV) with 1 kHz tone to +/- 3kHz
12 kHz BW filter: -102.7 dBm (1.63uV) with 1 kHz tone to +/- 3kHz
15 kHz BW filter: -99dBm dBm (2.50uV) with 1 kHz tone to +/- 3 kHz
CW mode receiving/sending and frequency display details: nine mode CW display/displacement are available to emulate the various
brands of radio and user the taste of, ranging from no displacement, display-only displacement, display and displacement and
manual or automatic LSB/USB displacement.
Mode CW “CW-L” or “CW-U”, depending on if LSB displays or USB port is used for receiving.
CW speed range: 5-48 WPM.
Available audio filter bandwidths in this firmware version: 300Hz, 500Hz,1.8 kHz,2.3 kHz,3.6 kHz, with a “wide” filter 5,6,7.5
or10 kHz to be selectable in every way except FM, where the filtering is done before demodulation as noted above. All filters are
softwaredefined and additional bandwidths could be made available. Filters can be used as BPF or as LPF selectable in the main
DSP filtering capacity: noise reduction and automatic Notch filter with adjustable parameters. Notch filtering is disabled in CW
mode for (for obvious reasons) or when using a “wide” receive bandwidth.(devel-branch: because no instability leads to activation
of mcHF is off by default. If you want to use (and the risk of instability in various scenarios) you can activate NR in setup menu
“latest item”. Setting not be stored and must be activated after each ignition. When no problems are fixed and NR will be improved
this function will be outdated.)
S-Meter calibration: “industry Standard”(IARU Region 1, technical recommendation R.1) smeter where S-9 = -73dBm calibration(50.2uV
@ 50 ohm) with each “S” units representing 6 dB. Unit above S-9 are in dB unit, as shown.
External audio input/output connections:
-“Line In” and “Line out” audio ports, and a “PTT (Push to Talk) are supplied with 3.5mm connectors to allow connection to an
external device. With these connectors is possible to interface with an external device (a computer or tablet/smart phone) and to
use “sound card” mode with mcHF such as SSTV,PSK31,WSPR and other analog/digital mode.
-(Devel-branch only): there is cat function and audio in & out even as IQ inside and outside via USB available. Input is the main
menu setting #60 or by long press M3.
-Line out signal levels: Rated 1 volt peak-peak, maximum when AGC is running.
-Line in signal levels: rated 0.1-1.0 volt peak-peak, adjustable with the “line of input gain” settings.
-Transmission type ALC: look-ahead gain compressor with both pre-set and available “customized” settings.
Operating voltage range:
-16.0 volt Max (when parallel C27 and tantalum capacitors for C106 both rf board are 25V)
-Min at 11.0 volts for full power transmission
-A 9.5 volt for reduced power transmission
-Starting at 6.5 volts, receive-only: only very low power transmission can be possible-distortion peak audio (SSB,AM) you can
check out.
Current consumption:
-Not modified, approx.410mA on 40 meters and below to 13.0 volts, approx.440 but in 10 meters, minimum volume, maximum brightness
of the display.
-Selection of minimum display brightness can reduce this by 40-60mA.
2.Transmit(A 13.0 volt power supply): Full power around 3A;-10W around 2.5

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