The Four State QRP Group is pleased to
offer these quality kits to the QRP community. Click the links below for each kit's homepage, which includes design features, specifications, and ordering information.
All proceeds go to fund our annual Conference, OzarkCon. Please SCROLL DOWN for all the kits, and thank you for supporting the Four State QRP Group.
This excellent random wire antenna tuner is the classic T-Match design which is known for wide matching range and smooth operation. Dave has added a nice wrinkle - the SWR indicater employs TWO leds, not the normally seen single red LED. A green one indicates output power with a red one indicating reflected power. The beauty of this arrangement is that the operator sees the output power peaking as the SWR goes down, just like a power meter with dual meters - very intuitive. Add this dandy little tuner to your portable ops go bag, or use it at home. It's equally at home on a picnic table, in a tent or camper, as well as on the operating desk in your shack.
NMØS 4S-Low Pass Filter
Featuring the famous NMØS Spiral coils, it is a None Simpler design.. This Low Pass Filter (LPF) is a must have for experimeters and those wishing to make sure their rig is legal. It's available in either an 80M or 40M version. The kit includes all the components to finish the build, including a beautiful jet black pcb enclosure - another NM0S hallmark. At 3"x 2"x 3" it will fit easily in your portable operating bag, and on your desk or workbench. It is a quick build, and has been chosen as the build session kit at OzarkCon 2015.
The kit features the easy building Pittsburg style pc board, which also is a feature of the Ozark Patrol regenerative receiver kit.
AAØZZ EZKeyer III
Building on the popular EZKeyer and EZKeyer II, this third generation very capable Morse Code keyer has some additional features - a beautiful new easy building enclosure, a smaller footprint, new more powerful PIC microcontroller, Speed Pot, larger message memories, new printed circuit board layout, and large push button switches. All connectors, switches, the speed pot, and components are board mounted, making the keyer completely self contained on the board. It has many of the features of a high end keyer while remaining inexpensive and very user friendly.
NMØS Ozark Patrol
The Ozark Patrol is a two-band shortwave regenerative receiver, using only three NPN transistors in its circuit. It features a pre-drilled and silkscreened circuit board front panel, with a total of 38 through-hole components mounted on pads etched on the back of the panel. This style of PC board is known as a Pittsburg style board.
Click here for a picture of that style of board, and also refer to the photo page for pictures of the actual board. Component values and reference numbers are silk screened by each part location making this kit an excellent first kit for any builder. The Ozark Patrol makes great shortwave receiver to introduce youngsters to the magic of Short Wave Listening.
This well designed transmitter is a companion to K8IQY's highly regarded SS-40 receiver. It produces up to 9 watts (can be set to 5W)and uses a hefty, cool running MOSFET as a final. All parts are through hole lead parts.
K8IQY Designer Dream Boards
These PC boards are targeted at the DIY designer/builder who would like to construct their own RF or control designs using time tested bits of circuitry, already in a PC board environment. The boards facilitate the construction of a myriad of of RF systems or sub-systems including receiver, converters, transmitters, and etc. utilizing builder supplied parts. Each circuit “element” has its input(s), output(s), and control(s) via 2-pin headers, or alternately, pad-to-pad wiring.
Four State is very pleased to continue the availability of Dave Benson K1SWL's famous Freq-Mite frequency counter.
Upon retirement, Dave graciously offered the kit to us to continue production.
Along with his SW+ transceiver series, the Freq-Mite is one of his signature designs.
The Freq-Mite provides audio frequency annunciation, and is intended to be installed as a frequency counter inside a
rig. Thus providing an inexpensive alternative to an LCD display.
NMØS Hi-Per-Mite CW Filter
The HI-PER-MITE is a HIgh-PERformance SMALL audio filter. It is designed to be
very versatile, have low parts count, be inexpensive,
yet provide outstanding performance. This is a flexible design
that can be used as a stand-alone unit driving headphones, earbuds,
or speakers, or it can be easily integrated into an existing
receiver needing additional CW filtering, see manual for details.
K8IQY SAVXO Stand Alone VXO.
SAVXO stands for Stand Alone Variable Crystal Oscillator. This is a Super VXO
design which has it's origins in the Super VXO of the SS-40 receiver.
It is crystal controlled yet combines frequency agility with smooth
stable tuning. It is ideal for driving your NS-40 or other crystal controlled transmitter or recever. It can be used on any of the HF bands, and is also a great
starting point for a transmitter strip of your own design.
K8IQY SS-40 Stable and Sensitive 40M Receiver
The SS-40 high performance receiver is the latest design effort from Jim Kortge, K8IQY. SS stands for "Stable and Sensitive". It exhibits the signature IQY extremely quiet amplifier chain. Disconnect the antenna and the receiver's noise floor is almost undetectable. A matched crystal IF filter provides a steep sided 500 cycle bandpass and outstanding opposite sideband rejection. Covering the 40M QRP "watering holes", a Super VXO provides 25-30 kHZ of smooth stable tuning, with NO PERCEPTIBLE DRIFT, even from a cold start!
The kits below are retired, however the documentation will remain available.
NMØS Cyclone 40M Transceiver
(Sold out and retired)
This innovative and simple transceiver is an improved version of Dave's QRP ARCI's 72 Part Challenge Design Contest entry in 2010.
It has less than 100 components and even better performance than the original design! The kit features
all through hole parts and easy assembly. The receiver is a superhet design with very good sensitivity and selectivity, the VFO
tunes the entire 125 kHZ CW segment of the 40M Band at a comfortable tuning rate.
K8IQY Magic Box TR Switching System
(Sold out and retired)
The Magic Box is a solid state, all electronic, transmit/receive switching system that allows a separate receiver and transmitter to transceive with full (or semi) QSK.
An Atmel Microcontroller handles the timing for 5 functions- xmttr keying, xmittr antenna switch, rcvr antenna switch, rcvr audio switch, and side tone oscillator.
NMØS QRPometer Power/SWR Meter
(Sold out and retired)
This useful accessory is a highly accurate and easy to use power and swr
indicating meter. All components are through-hole for easy assembly, and there
NO toroids. It features a digital readout and a silk screened pcb
AAØZZ EZKeyer II
(Sold out and retired)
Building on the very popular EZKeyer, this new and very capable Morse Code keyer has some additional features - a beautiful blue easy building enclosure, new PIC microcontroller, larger message memories, additional commands, new printed circuit board layout, and large panel mount push button switches. Additionally, all connectors and switches are board mounted, making the keyer completely self contained on the board. No external parts or wires are required (excepting battery leads).
NS-40 Class E Transmitter (Sold out and retired)
The NS-40 Transmitter is an upgraded version of the overall winner in the FDIM 2008 Homebrew Contest. It is a truly unique QRP transmitter design. NS stands for None Simpler, so this is the None Simpler 40 Meter Transmitter. Why is it called the None Simpler? Because there are only 14 electronic components, and NO TOROIDS or COILS of any kind to wind - NONE! All inductors are incorporated directly on the PC board as etched spirals.
NMØS 4S-Link Digital Interface (Sold out and retired)
The 4S-Link, pronounced "Force Link", is an easy to build, low parts count
interface that connects your computer to the digital radio world.
Attaching the 4S-Link to your computer is as easy as plugging into your
sound card, a serial port or adapter is not required.
AAØZZ EZKeyer (Sold out and retired)
This full featured PIC-based iambic Morse code keyer features 3 memories and
very easy use. It has been superceded by the EZKeyerII, see above.
NMØS Ham Can Minimalist Regen Transceiver (Sold out and retired)
The HAM CAN is a two transistor minimalist crystal-controlled CW transceiver.
Clear Top Tins
Here are the perfect tins to show off and protect your home built projects. (Sold out and retired)
NB6M HF Test Set
The HF Test Set is a multi-function test instrument ideally suited for the QRP workbench. (Sold out and retired)
NT7S VRX-1 Receiver
A direct conversion receiver for 40 meters, but can be easily modifed for any band from 160 to 10 meters. (Sold out and retired)
KD1JV Tenna Dipper
The "Tenna Dipper" is a low
power antenna analyzer and ATU tuning aid. (Sold out and retired)
KD1JV Power and SWR Meter
The KD1JV Power and SWR meter is a compact RF power and SWR measuring device for use in the shack or in the field. (Sold out and retired)
K8IQY Enhanced Manhattan Islander Audio Amp
The Enhanced Manhattan Islander
Audio Amplifier is perfect for boosting the sound level from your
headphone-only QRP rig. (Sold out and retired)
Four State Dummy Load SMD Starter Kit
The SMD Dummy Load is an easy way to learn SMD soldering techniques
and finish with a handy addition to your test bench (Sold out and retired)