Raspberry Pi Pico Brings the Heathkit Pocket Packet Back to Life

An inexpensive Raspberry Pi Pico is giving a classic piece of packet-radio equipment a second life.

A new project called Pocket Pico recreates the Heathkit HK-21 Pocket Packet TNC—but there's an interesting twist. Instead of simply copying what the old TNC did, the Pico emulates the original Z80 processor and runs the old HK-21 firmware.

That makes this more than another modern APRS gadget.

Classic Packet Radio on Modern Hardware

The original Heathkit Pocket Packet was a small terminal node controller, or TNC. It allowed a computer and radio to communicate using packet radio.

Pocket Pico moves that job onto the inexpensive Raspberry Pi Pico.

The Pico also handles 1200-baud Bell 202 modulation and demodulation, eliminating the need for the original modem hardware.

According to Hackaday, the project supports:

• AX.25 packet

• APRS

• A personal packet BBS

• Older packet-radio software

That's an interesting combination of old and new.

Why This Project Is Interesting

Modern APRS applications can hide much of what's happening between the computer and radio. That's convenient, but it doesn't necessarily teach you much about packet radio.

Pocket Pico takes a different approach.

You get an opportunity to experiment with the technology behind traditional packet while using hardware that is inexpensive and readily available.

There's also something pretty neat about a tiny modern microcontroller pretending to be a Z80 processor so it can run amateur-radio software designed decades ago.

Old Ham Radio Technology Doesn't Have to Stay Old

Projects like Pocket Pico demonstrate one of the things I enjoy about amateur radio. Older technology doesn't necessarily become useless when the original hardware disappears.

Sometimes it just needs a new platform.

A Raspberry Pi Pico recreating a Heathkit packet TNC is a great example—and perhaps an inexpensive way for another generation of hams to discover packet radio.

Read more about the Pocket Pico project:

https://hackaday.com/2026/09/25/pi-pico-recreates-the-heathkit-pocket-packet/

More amateur radio, QRP and practical operating information:

https://ke2yk.com/

72 es 73 de KE2YK

Five Watts and RTTY This Weekend [QRPARCI]

The CQ World Wide RTTY DX Contest is this weekend, September 26–27, and QRP operators have their own 5-watt categories. Whether you're a regular RTTY contester or just interested in seeing what five watts can do with plenty of stations on the air, this is a good weekend to give it a try. You don't have to operate all 48 hours to participate. But there's one change you don't want to miss: Your log is due by 2359 UTC Tuesday, September 29—just 48 hours after the contest ends. That's a much shorter deadline than many contesters may remember from years past. Don't finish Sunday and plan to take care of the log next weekend. The full story has the QRP categories, operating information, records and links to the official rules.

GET READY FOR THE CQ RTTY CONTEST

Beyond 599: Give Useful CW Signal Reports

When making a Morse code contact, give a report that matches what you hear. The three RST numbers describe readability (1–5), signal strength (1–9), and tone quality (1–9).

For example, 539 means perfectly readable, weak, and a clean tone. A signal can be easy to copy without being strong!

During everyday contacts, an honest report helps QRP operators check antenna changes and spot signal problems. Listen carefully instead of sending an automatic 599.

See the RSGB guide to RST signal reports.

For more practical ham-radio guides and reviews, visit KE2YK.com.

Watch the Band Edge—Your SSB Signal Needs Room

Your radio’s display tells only part of the story. On upper sideband (USB), your voice signal spreads above the displayed frequency. On lower sideband (LSB), it spreads below it.

ARRL Volunteer Monitors sent notices to hams using SSB on 7.299 MHz for operating too close to the band edge. That’s a useful reminder for all of us, including those running just five watts.

Before calling CQ, leave enough room for your whole signal to stay within the band limits allowed by your license. A dial reading inside the band is not enough.

Read ARRL’s Volunteer Monitor report (PDF).

For more practical ham-radio guides and reviews, visit KE2YK.com.

Tiny 5-Watt QRP Tuner Adds a Chance to Try 160 Meters

Japan’s QSY team has made its small antenna tuner even smaller and added support for trying the 160-meter band. It handles up to five watts and uses one tuning knob—a handy idea for hams who like to pack light.

There’s a catch: tuning depends on your wire length and setup, especially on 80 and 160 meters. The report lists 160–10 meter coverage, but also quotes the builder giving a 15-meter upper limit. Check those limits before planning your antenna.

Read the full story at hamlife.jp (Japanese).

For more practical ham-radio guides and reviews, visit KE2YK.com.

Watch the Band Edge—Your SSB Signal Needs Room

Your radio’s display does not show all the space your voice signal uses. Upper sideband (USB) spreads above the displayed frequency. Lower sideband (LSB) spreads below it.

ARRL Volunteer Monitors sent notices to hams using SSB on 7.299 MHz for operating too close to the band edge. It’s a useful reminder: leave enough room for your whole signal to stay inside the band limits allowed by your license—even when running just five watts.

Read ARRL’s Volunteer Monitor report (PDF).

For more practical ham-radio guides and reviews, visit KE2YK.com.