Icom IC-705 QRP radio




Frequency coverage (Unit: MHz)
  Receiver 0.030–199.999*
  Transmitter 1.800–1.999
Mode USB, LSB, CW, RTTY, AM, DV, FM, WFM (Rx only)
No. of memory channels Memory channels: 500 channels (100 groups)

Scan edges: 25 channels

Call channels: 4 channels (2 channels × 2 bands)

Antenna connector BNC connector (50Ω)(One connector for all bands)
Power supply requirement 13.8 V DC ±15% (with external power supply)

7.4 V DC (with BP-272)

Operating temp. range –10°C to +60°C; +14°F to +140°F
Frequency stability Less than ± 0.5 ppm

(–10°C to +60°C; 14°F to 140°F)

Frequency resolution 1 Hz
Current drain
Tx (Max. power)
RX (Max. audio)
RX (Standby)
13.8 V DC
Less than 3 A (10 W)
0.5 A (typ.)
0.3 A (typ.)
7.4 V DC
Less than 2.5 A (5 W)
0.8 mA (typ.)
0.5 mA (typ.)
Dimensions 200×83.5×82 mm; 7.9×3.3×3.2 in (W×H×D, projections not included)
Weight 1.1 kg; 2.4 lb (approx.; including BP-272)

* Some frequency bands are not guaranteed.

Output Power
13.8 V DC
0.1 to 10 W
0.025 to 2.5 W
7.4 V DC
0.1 to 5 W
0.25 to 1.25 W
Modulation system SSB : Digital PSN modulation

AM : Digital low power modulation

FM : Digital phase modulation

DV : GMSK digital phase modulation

Spurious emissions Less than −50 dB (HF)

Less than −60 dB (50 MHz)

Less than −60 dB (144/430 MHz)

Carrier suppression More than 50 dB
Unwanted sideband More than 50 dB
Receiver system
0.030 to 24.999 MHz
25.000 MHz and above
RF Direct Sampling
Down Conversion IF Sampling
Intermediate frequencies 25.000 MHz and above:38.85 MHz±0.5 MHz
(HF: Preamp-1 ON,
50 MHz: Preamp-2 ON,
144/430/440 MHz: Preamp ON)
0.500 to 1.799 MHz 1.800 to 29.999 MHz 50 MHz to 54 MHz 144/430/440 MHz
  SSB/CW(10 dB S/N) 0.20 µV 0.15 µV 0.11 µV
  AM(10 dB S/N) 13.0 µV 2.0 µV 1.0 µV 1.0 µV
  FM (12 dB SINAD) 0.5 µV
(28.000 to
29.700 MHz)
0.25 µV 0.18 µV
  DV (1% BER) (PN9) 1.0 µV
(28.000 to
29.700 MHz)
0.63 µV 0.35 µV
Selectivity (Filter: SHARP)
SSB(BW=2.4 kHz)
CW(BW=500 Hz)
RTTY(BW=500 Hz)
AM(BW=6 kHz)
FM(BW=15 kHz)
DV(12.5 kHz spacing)
More than 2.4 kHz/-6 dB / Less than 3.4 kHz/-40 dB
More than 500 Hz/-6 dB / Less than 700 Hz/-40 dB
More than 500 Hz/-6 dB / Less than 800 Hz/-40 dB
More than 6.0 kHz/-6 dB / Less than 10 kHz/-40 dB
More than 12.0 kHz/-6 dB / Less than 22 kHz/-40 dB
Less than -50 dB
Spurious and image rejection ratio
50 MHz
144 MHz
430 MHz
More than 70 dB* (except for ADC aliasing)
More than 70 dB*
More than 65 dB
More than 54 dB
*At intermediate frequency in -25–30 MHz or 50–54 MHz: More than 50 dB
Audio output power
Internal SP
External SP
More than 530 mW (12Ω load at 10% distortion)
More than 200 mW (8Ω load at 10% distortion)

Supplied Accessories

  • HM-243 Speaker-microphone
  • BP-272 Battery pack
  • OPC-2421 DC power cable



Lab599 TX-500 QRP radio


Download The Product Manual Here:

The Discovery TX-500 Has Received FCC Certification!

The Discovery TX-500 is an ultra compact all-mode transceiver ideal for travelling and portable use.

It’s compact size and light weight means that you can take this radio with you to remarkable places while creating unforgettable experiences.

The strong case offers protection against moisture and dust, ensuring the use of TX-500 in extreme conditions. While a sharp monochrome display will allow you to clearly see the information in either bright sunshine or low light, thanks to a multi-mode backlight.

The transceiver parameters and functions will also make it possible to successfully use the unit at a Home Station or in a Mobile/Portable Environment.

Record-low current consumption in reception mode (up to 110 mA) will extend the battery life, providing the user with longer operating time between charges.

Because the TX-500 is a software-defined radio (SDR), you can expand its capabilities using computer applications. New features will be added with free firmware updates.

The TX-500 Discovery has an integrated high-performance spectrum analyzer, allowing you to see signals before you hear them.


  • 160-6-meter ham bands
  • General ‘receive’ coverage 0.5 – 56.0 MHz
  • All modes: SSB, CW, DIG, AM, FM
  • High-performance 32-bit floating-point DSP
  • Current drain as low as 100 mA in ‘receive’ mode (backlight on, preamp off, no signal)
  • External power supply DC 9-15V, 1 to 2.5A typical in transmit
  • High-contrast LCD with 256*128 px
  • High-performance real-time pan-adapter (48 kHz wide)
  • On-line firmware updates
  • Tilted feet (rear), fold up for transportation
  • Ultra-Compact Size: (H*W*D): 90 mm (3.5″) * 207 mm (8.1″) * 21 mm (0.8″)
  • Weight: 0.55 Kg (19.4 oz)


  • Sensitivity (MDS) -136 dBm (typ. with preamp on)
  • Quadrature down-sampling mixer compatible with PC-based SDR (Software Defined Radio) Applications
  • Receiver I / Q outputs for PC soundcard
  • Switchable low-noise preamp and attenuator
  • 3-band receive audio equalizer
  • 4 adjustable digital filters
  • Automatic notch filtering
  • Adjustable noise reduction and noise blanking
  • Audio Output ext. speaker, 3W typ.


  • Adjustable output, 1 to 10W PEP
  • Rugged, SWR and temperature-protected final amplifier stage
  • Carrier Suppression > 50 dB typ.
  • Harmonic / Spurious Outputs > 50 dB below carrier
  • CW Sidetone/Transmit offset 400-1200 Hz, adjustable
  • Speaker-microphone with PTT
  • 3-band microphone audio equalizer
  • 2 adjustable digital filters
  • DSP RF speech processing for excellent ‘punch’

* Specifications apply only within ham bands except as noted. All measurements taken with 13.8 VDC supply.


  • Internal CW keyer with 10-300 CPM range
  • 100 general-purpose memories store VFOs, modes, etc.
  • Computer control via USB
  • Full remote-control command set (with kenwood emulates)
  • One-click online firmware upgrades (with free PC software)


  1. Speaker-microphone
  2. CAT cable for on-line software update
  3. Power cabel for external power source DC 9-15V (battery not included)
  4. Headset and mic adapter with PTT (3.5 mm jack)
  5. CW adapter (3.5 mm jack)


Manufacturer’s Website