FDIM 2026 Transmitter Challenge

 

Announcing:

The 2026 FDIM QRP Transmitter Efficiency Challenge

Among the many virtues which are embodied in the QRP radio hobby is that of economy. While the specific definition of QRP is operation at 5 watts or less, there is an unstated aesthetic which prefers the QRP radio do so with a certain minimalism in design, using as few components in its construction as possible, to be as economical as possible, and to operate with the highest efficiency possible.

While we have in past Design Challenges explored designs which have maximized power out from a few inexpensive amplifier devices, for 2026, we turn our attention to operating efficiency. We announce the 2026 FDIM QRP Transmitter Efficiency Challenge!


  1. The transmitter is to be operated from a fixed 12.0v power supply, and must demonstrate delivery of between 4.0 and 6.0 watts RF in the 40M band into a 50 ohm load.

  2. The transmitter is to employ a 40M crystal as the frequency source.

  3. A regulated 12.0 volt supply, 40M low-pass filter, dummy load, and power meter will be provided at the event.

  4. All circuit power is to be obtained from the 12.0v supply. No other power sources or energy storage may be used. Any cooling fans or other auxiliary circuits are to operate from this same 12v source, and their power consumption factored into overall efficiency.

  5. Output power from the 12.0v power supply will be calculated, and power into the dummy load measured. DC-to-RF efficiency will be calculated as the ratio of these two power numbers. The duration of the operational test will only be long enough to record power readings.

  6. There are no restrictions on the type of circuits, quantity or type of components, or class of amplifier that may be used, as long as the 40M crystal is the frequency source.

  7. Entries are to be checked in at the FDIM contest table by 8:30 PM on Friday May 15th during Club Night during the Four Days in May event.

  8. The circuit with the highest calculated DC-to-RF power efficiency will be declared the winner! Winners will be recognized at the FDIM Awards Dinner on May 16th.

  9. A schematic of the design is to be made available for review, and possible publication in QRP Quarterly magazine.

Good luck, happy designing, and see you in May!

73/72 Dave Cripe NM0S

 

QRP Hall of Fame - 2025

QRP-ARCI Announces Hall of Fame Induction - 2025

Dale Parfitt W4OP

QRPARCI is pleased to honor Dale Parfitt W4OP, with this induction into the QRP Hall of Fame.  Dale is a long time radio amateur, and the founder and president of PAR Electronics, a manufacturer and distributor of radio filters and antennas. Accepting this award on behalf of Dale was Jan N8CBX. 

Dale Parfitt W4OP - 2025 QRP Hall of Fame Inductee

Dave Cripe
NM0S
President QRP-ARCI

QRP Hall of Fame - 2025

QRP-ARCI Announces Hall of Fame Induction - 2025

Ron Potter AG1P (SK)

 

 

 

 

 

 

 

 

 

 

 

 

The votes have been tabulated, and QRPARCI is pleased to honor Ron Potter AG1P (SK) with this induction into the QRP Hall of Fame.  Ron was a long time QRP Amateur Radio Club International member and volunteer, as well as working with the 4 States QRP Group on many projects.  This award will reside with the Four States QRP Group as a memorial to Ron. 

Ron Potter AG1P - 2025 QRP Hall of Fame 

David Cripe
NM0S
President QRP-ARCI

QRP Amateur Radio Club International

QRP ARCI logo

QRP ARCI is a club for low power enthusiasts worldwide.

We produce a professional quality magazine (QRP Quarterly), organize an annual conference at Dayton ('Four Days In May' or FDIM), and sponsor various QRP contests and awards.

Our aim is to promote QRP and a variety of related activites. Many of our members enjoy home construction, kit building, antenna experimentation, backpacking and portable operation. Minimalist radios built in small tins are very popular but we also enjoy the very latest high performance radios such as the Elecraft KX3, the new SDR rigs, and great kits like the QCX from QRP Labs, kits from 4 States QRP Group, and the uBitx rigs. 

QRP-ARCI is an affiliated Club of the American Radio Relay League

Let us know if we can promote your club, group, kit or product.

New QRPARCI Mail List

qrparci.io

A new Mail List has been started for QRPARCI on the groups.io platform.  This mail list is open to members and non-members alike for the discussion of QRPARCI topics.  QRP-ARCI Staff handles the moderation of the list and you can gain access by sending an email to This email address is being protected from spambots. You need JavaScript enabled to view it. and requesting to be added  to the mail list.  Be sure to add your callsign in the request. You can get your mail in digest form as well if you prefer it that way.   73 de ARCI Staff Moderators

 

QRP Quarterly


 
QRP Quarterly - OCT 2025
 
Table of Contents - And More!  

Beyond the ’612—Jason Milldrum—NT7S

A Very Low Dropout Voltage Regulator—Don Cantrell—ND6T and Scott Schillereff—VE7SNJ

Exploring Common Mode Chokes—Brian R. Page—N4TRB

A Three-Element 20 Meter Vertical Beam—Carl Davis—W8WZ

Ham Sticks, Damn Sticks—Wayne Robertson—K4WK

Fair and Balanced: ATU Output Balance—Jerry Wolczanski—KI4IO

QRP on the Low Bands (Mainly 160M)—Gary Breed—K9AY

Ten Questions About Your QRP Operations—John Leonardelli—VE3IPS

A QRP Adventure in VE8—Jeff Hetherington—VE3CW

Review of the Xiegu G90—John Leonardelli—VE3IPS

SPOOLTENNA Review—John Leonardelli—VE3IPS

Field Day 2025—Jack Purdum—W8TEE

And much much more!

Sample of QRP QuarterlyTry it free !
Download the
January 2015
issue 

Subscribe/Renew from $25 per year