Ten-Tec Argonaut 505 / 509
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| Frequency | 80–10 m (amateur HF) |
| TX power | 2 W (~2 W output rated (505: 2 W on 80-15m, 1.8 W on 10m). Many 509s produce more - over 5 W on CW (80-15m), a bit under 5 W on SSB. 12-15 V DC, ~150 mA RX / ~800 mA TX.) |
| Modes | USB, LSB, CW |
| Weight | 3.2 kg (7.1 lb) |
| Connector | SO-239 |
| Year | 1972 |
| mic | varies |
| key | 1/4 inch phone |
| antenna | SO-239 |
Estimated (unverified): Weight ~3.2 kg (about 7 lb) is approximate. The 505 was introduced in 1972; the 509 followed in 1974.
One of the radios that helped popularize QRP - low-power amateur operation. The Argonaut 505 and 509 are full-featured HF transceivers (SSB and CW, 80-10 m) rather than stripped-down novelties, delivering Ten-Tec's hallmark quiet receiver and smooth full break-in CW keying in a compact, battery-friendly package at about 2 watts output. All solid-state and American-made in Sevierville, Tennessee.
At roughly 2 watts rated, QRP rewards good antennas and patience. The 505's receiver is basic; the 509 is the more refined of the two. Ten-Tec's modest production runs mean limited availability on the used market, and these are early-1970s designs without modern conveniences.
The Argonaut helped make QRP a recognized, respectable operating style rather than a curiosity, packing a genuine full-featured transceiver - quiet receiver, excellent QSK - into a low-power, portable rig. The 505 (1972) and 509 (1974) introduced many operators to the discipline of working the world on a couple of watts, and the Argonaut name carried on through later Ten-Tec QRP rigs. A clean 509 is a rewarding entry into classic QRP.
The Ten-Tec Argonaut is one of the radios that helped popularize QRP - low-power amateur operation, traditionally five watts or less, where the challenge and reward come from working the world on a tiny signal. The Argonaut established Ten-Tec as a company that took QRP seriously, offering a true full-featured HF transceiver rather than a stripped-down novelty. It covers the 80-10 m amateur bands in SSB and CW at about two watts output.
What made the Argonaut special was that it delivered Ten-Tec's hallmark qualities - a quiet, easy-to-listen receiver and smooth, silent full break-in CW keying - in a compact, low-power, battery-friendly package running from 12-15 volts DC. It became one of the rigs QRP culture was built around, and the Argonaut name carried forward through several generations of Ten-Tec's portable transceivers, from the 505 (1972) and 509 (1974) to the later Argonaut V and VI.
It is a discontinued classic. Compare it with the CW-only Century 21 and the open-source Rebel.