Here we take a look at the RS-HFIQ 5 Watt HF SDR Transceiver by HobbyPCB.
The RS-HFIQ is an open-source HF transceiver project designed to translate I and Q baseband signals to RF in the 80/60/40/30/20/17/15/12/10M Amateur Radio bands. The I and Q signals must be provided/processed by external signal processing which could be a PC running Software Defined Radio software or a stand-alone digital signal processor
The receiver in the RS-HFIQ consists of 5 band-pass filters to reject out-of-band signals, an LNA with frequency dependent gain and a conventional quadrature down-converter.
The transmitter in the RS-HFIQ uses a Quatrature up-converter followed by the same band-pass filters used by the receivers, a 5W power chain and a low-pass filter bank.
The Local Oscillator is based on a Silicon Labs SI5351 chip that can product up to 3 RF outputs, the LO signal for the up/down-converter, a built-in test signal for calibrating I and Q offsets and an external signal.
The control of the SI5351 and all switching functions is provided by an Arduino Nano running open-source software and programmed with the Arduino IDE.
Special care has been taken to insure noise and ground-loop set-up. The RS-HFIQ has three separate DC isolated ground planes; RF/Chassis ground, Baseband/Audio ground and Digital ground. This allows the same PC to be connected to the audio in/out and the USB port on the Arduino Nano without creating noise/grounding issues.
5W not enough power? Add a HARDROCK-50 to your station to boost up to 50W. The RS-HFIQ and HARDROCK-50 seamlessly integrate together for a powerful base station!

Specifications
- Frequency Range – 3-30MHz (performance guaranteed on 80/60/40/30/20/17/15/12/10M ham bands)
- Sensitivity – MDS < -128 dBm on 80M dropping to < -135 on 10M (depending on processing bandwidth and sound card performance)
- Noise Figure –
- TX Power 5W typical, 4W minimum
- LO Feed-thru < -50 dBc @ 5W output
- Spurious and Harmonics < -50 dBc typical
- DC Power 13.8VDC, 2 amp max plus USB power for the Arduino Nano
- Size – 100MM x 160MM
Requirements
The RS-HFIQ is NOT a stand-alone transceiver, it is a part of a Software Defined Radio system. The SDR system consists of:
- Radio front-end – The RS-HFIQ
- Data conversion – Analog to Digital and Digital to Analog typically provided by a high-quality sound card
- Computer hardware – A digital signal processor or high speed general purpose processor.
- SDR Software – to process TX and RX signals
While many different configurations are possible and even encouraged, we have developed a ‘standard’ configuration that will help users new to SDR’s go up and running quickly. To get on the air with the RS-HFIQ in the standard configuration you will need:
- RS-HFIQ
- StarTech – 96 KSPS sound card
- Windows PC – running Windows 7, 8 or 10 with speakers and two available USB ports
- 13.8V 3A power supply
- Microphone
- Various USB and audio cables
- HDSDR and Omni-Rig software
- A valid Amateur Radio license is required for transmitting
- Antenna system
Visit the RS-HFIQ Transceiver Wiki for more information.
Review
Receiving a Gmail email over HF radio with Winlink system
Short video showing how I receive an email sent from gmail over my Ham radio. Read more
Baofeng UV-5R Extreme Test! – Fire , Water , Freezer
Baofeng UV-5R Hello all! K5CLC here to share a really crazy and extreme field test I did on my year old Baofeng UV5R, to test its merit under the most... Read more
Scouting’s Jamboree on the Air Set for October 16, 17, and 18
Jamboree on the Air (JOTA) and Jamboree on the Internet (JOTI) will be held this year on October 16, 17, and 18. Register online as an... Read more
DV4home – Basic setup and menu navigation
This is the part 1 video of the DV4home, showing the basic setup and menu navigation. Read more
Equipment
Anker’s massive 120,600mAh portable battery weighs 9 pounds
Most portable batteries pack a few thousand mAh of power into a pocket-sized package. Not this one. It’s an overgrown brute that boasts a ridiculous 1... Read more
PTRX-7300 Panorama Adaptor for the IC-7300
A panorama adapter for the IC-7300? What’s the point, you might ask, the IC-7300 has such a nice spectrum and waterfall display? Right, but unfo... Read more
ACOM 1010 160-10m amplifier
FEATURES Easy operation. The plate-load True Resistance Indicator (TRI) is an ACOM innovation that provides quick and precise tuning, typically... Read more
LDG RT-100 Remote Tuner
RT-100 LDG has announced the RT-100. The RT-100 is a 100 watt coax in / coax out remote tuner designed to be placed near the feedpoint of the antenna.... Read more
Small QRP-GO-BOX powered by Raspberry Pi4, KX2 and TH-D74
Small multifunctional, digital, very compact amateur radio station for the radio operation at home, on the way or in the emergency radio. For the digi... Read more
Antenna
HF/VHF LINEAR LOADED VERTICAL ANTENNA
The adjustiwave antenna system is an efficient adjustable quarter wave vertical antenna that can be used anywhere between 3.5Mhz and 148Mhz (80m to 2m... Read more
Butternut HF9V 9 Band Vertical Antenna
Brand:Butternut Manufacturer’s Part Number:HF9V Part Type:HF Vertical Antennas and Packages Product Line:Butternut HF9V 9-Band Vertical An... Read more
The Take-off Angle Theory
“Kyle, W0AAV, is wondering if there is an optimal angle to put his vertical antenna or is the Take off angle not really important or is is more... Read more
Grounding a Counterpoise on End-Fed Half Wave Antenna
Laurence, WA2TLY, is asking some questions about a few aspects of the EFHW 80-10 antenna, Why they are there and what they are for? Read more
7Mhz 4elements Fullsize Yagi [ Video ]
7Mhz 4elements Fullsize Yagi – 50 meters H Read more
App - Mobile
FlexRadio Systems Announces Partnership With DL8MRE – APP for Iphone
FlexRadio Systems and Marcus Roskosch, DL8MRE announced today a partnership to develop, market and sell a client interface application for both iPad®... Read more
iWSPR TX – WSPR for iOS version 2.8 now available
WSPR WSPR implements a protocol designed for probing potential propagation paths with low-power transmissions. Normal transmissions carry a station’s... Read more
RS-MS1A – Remote Control Android App
Ray Novak and George Thomas show you how to control the ID-51A with the RS-MS1A Android app. Read more
Pocket Radio Android App ( TX and RX )
This is an Android application used to remotely control several HAM radio – any CAT enabled transceiver over Bluetooth, USB/Serial or with secu... Read more
MagicSDR – A NEW ANDROID AND IOS RTL_TCP CLIENT
MagicSDR makes it possible to interactively explore RF spectrum using panadapter and waterfall visualization, demodulate and play AM, SSB, CW, NFM, WF... Read more