Tag Archives: David Cripe NM0S

New kit by NM0S: the 4S-Tuner/Antenna Coupler

November 10, 2015 k4swl 2 Comments

Dave Cripe (NM0S) has designed yet another QRP kit for the 4 State QRP Group: the 4S-Tuner/Antenna Coupler.

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 indicator 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. This makes tuning easier and leaves no doubt that it’s tuned for maximum power output. For a high SWR the red LED is at full brightness and the green LED is off. At 2:1 both are at equal brilliance. At 1:1 the green is full on and the red is off. The small size is perfect for portable operations. 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.

Specifications and Design Features

Wide tuning range: 80 meters thru 10 meters. Tested on EFHW and 100′ wire.

Maximum Power Throughput: tested at 10 Watts.

Low loss large toroid

Twelve taps for small inductance step selection.

Low insertion loss when matched.

Enclosure Size: 3″x3″x2″.

Pittsburg Construction.

Shipped price is $51.00 (US), $55.00 (Canada), $60.00 (Outside US/Canada).

Dave Cripe designs excellent kits for the ham radio community; they’re easy to build, fun and functional. If this kit is as popular as his past kits, the first run will most likely sell out in short order.

Click here to check out the 4S-Tuner/Antenna Coupler at the Four State QRP Group website.

Kits, People

NM0S’ Ozark Patrol regenerative receiver kit

September 24, 2014 k4swl 6 Comments

Just learned that David Cripe (NM0S) has a new kit for sale: the Ozark Patrol regenerative receiver kit.

The Ozark Patrol is a simple, straightforward kit, designed with beginners in mind. The kit is a through-hole design, which is to say, with no surface-mounted parts. All of the component values and reference numbers are silk-screened on the board to indicate each part’s location, making for truly quick and fool-proof assembly.

What’s more, Dave is a talented kit designer; he’s the brains behind the kit for our successful ETOW HumanaLight (originally conceived by engineer Greg Majewski). He’s not only clever like that, he’s also a great pal.

In the past, when Dave has announced new radio kits for sale, he’s sold out within a few days. That’s why I ordered mine the moment I saw the announcement.

And, hey…not only does just $40 plus shipping ($46 in the US) get you a superb regen receiver kit, but proceeds also support the Four State QRP Group. Win-win, in my book.

Here are a few specifications and design features listed on the Four State QRP Group’s website:

Frequency Range: 3.5-15 MHz in two bands
Sensitivity: Yes!
Power Supply: 6 x AA batteries
Audio Output: A 2.6” speaker is included, as well as a jack for 1/8” stereo headphones

Want one, too? Click here to order your own Ozark Patrol kit…and enjoy tinkering as well as listening!

Announcements, Hamvention, Kits, Product Announcements

David Cripe’s NM0S Cyclone 40 Meter Transceiver kit

May 10, 2013 k4swl 3 Comments

Readers, I just received this release:

A new kit from the Four State QRP Group and David Cripe (NM0S)

NM0S's Cylcone 40M QRP transceiver. Look for it at Four Days in May! — NM0S’s Cylcone 40M QRP transceiver. Look for it at Four Days in May!

Arising from Dave’s entry in QRP ARCI’s 72 Part Challenge Design Contest in 2010, the Cyclone 40 is an enhanced version of the original design. The transceiver designed for the design contest had 72 total parts, performed well, and won honorable mention. This improved version has less than 100 components and even better performance! The kit features all through hole parts and easy assembly. The receiver is a superhet design with very good sensitivity and selectivity, and tunes the entire 125 kHZ CW segment of the 40M Band – and does so at a comfortable tuning rate. A frequency readout is included so you know where you are at all times.

This is a complete kit, including the enclosure. A high quality board package includes the pc board, front and back panels, the sides, and top and bottom all of which make up the enclosure. The control and jack labels are silk screened in white letters and vividly contrast with the black solder mask, and the holes for the connectors and controls are pre-drilled. The ends are “dovetailed” together making a very rugged, easy to build, and attractive enclosure.

Features and Specifications

General

Enclosure: A very nice predrilled and silkscreened enclosure is included. It’s easy to assemble and looks great.
Ergonomics: Smooth solid tuning, a quiet receiver with QSK and well behaved AGC. Nicely laid out front and rear panels.
VFO: The VFO is a simple PTO design, is very stable, and also quite easy to build
Sidetone: Included!
AGC: Audio derived, fast and smooth.
Frequency Range: 7.000 – 7.125 typical.
Tuning Speed: 10kHz/knob turn typical.
Stability: 300 HZ the first 5 min after power up, less than 10 HZ/hour after that.
QSK: Fantastic QSK! Full Break in, excellent muting, really fast!
All Through Hole Parts There are NO SMT parts in this kit, and only three easy to wind toroids.
Dimensions: 4.4 x 3.6 x 1.9″
Power Connector: 2.5×5.5mm coaxial, center positive. Should be fused at 1A, fast blow at PS
Antenna connector: BNC

Receiver

Configuration: Superheterodyne, 11 MHZ IF, 4 Crystal IF Filter.
Sensitivity: MDS (Minimum Discernable Signal) -125, Typical, below the normal 40M band noise level.
Selectivity: Four crystal, 500 HZ IF filter
IMD3: 90 dB typical, better than most commercial gear!
IP3: +10 dBm typical – another very good number
Frequency Readout: 3 or 4 digit CW, 1 kHz or 100 Hz resolution (user selectable), developed by Adrian Hill, KCØYOI.
Band Edge Marker: A band edge marker is heard at 7.001 MHZ
Headphone Jack: 1/8″ stereo, standard earbud/Walkman® headphone compatible
DC Current consumption: 30 ma typical at 13.6 VDC.

Transmitter

Configuration: Stable, Wide Range VFO (PTO design), Efficient Class E Final.
Spectral Purity: All harmonics and spurs less than 50dB below the carrier.
Output Power: approximately 4W into 50 ohms
DC Current consumption: 500ma typical at 13.6 VDC Will operate down to 9v DC.
Key Jack: 1/8″ stereo, grounded shell, switching the tip keys TX. Contacts accessible for an internal add-on keyer

Kits should be available at QRP ARCI’s Four Days in May conference at Dayton, and will be for sale on the Four State QRP Group’s web site approximately May 20th. The final price hasn’t been determined yet but should be less than $100 plus shipping.