Note: I no longer own an Argonaut 509, having sold it in September, 2009. This page will remain for archival purposes.
From the Argonaut 509 manual:
|Sensitivity:||less than 0.5 uv for 10 db signal-plus-noise ratio|
|Selectivity:||2.4 kHz at 6 db down; 1.7:1 shape factor at 6/50 db|
|Input:||low impedence unbalanced coaxial input|
|Output Impedence:||8 ohm speaker or headphone (high or low impedence headphones can be used)|
|Power Ouput:||1 watt at 8 ohms with less than 2% distortion|
|Spurious Response||more than 50 db down|
|Automatic Gain Control||(max) for 100 db change in input signal level, output changes less than 6 db|
|Offset Tuning||with pull-out defeat switch|
|DC Power Input:||5 watss PEP; 5 watts CW|
|RF Power Output:||2 watts (50 ohm non-rative load), minimum|
|Output Impedence:||50 to 75 ohms|
|Transmit-Receive Operation:||SSB: PTT|
CW: complete break-in
|CW Sidetone:||internally switched; operates only in CW mode|
|Microphone Input:||high impedence; crystal, ceramic or dynamic|
|Carrier Suppression:||40 db from single tone output|
|Sideband Suppression:||30 db down from a single tone output at 1000 Hz reference|
|Frequency Coverage:||3.5 to 4.0 MHz|
7.0 to 7.5 MHz
14.0 to 14.5 MHz
21.0 to 21.5 MHz
28.0 to 30.0 MHz
|Frequency Stability:||less than 100 Hz change from 10.5 to 14 VDC|
|Modes of Operation:||normal sideband, reverse sideband, CW|
|Dial Calibration:||+/- 5kHz on 80 through 15 meters; +/- 10kHz on 10 meters|
|Tuning Rate:||approximately 25 kHz per knob revolution 80 meters through 15 meters; 100 kHz on 10 meters|
|Front Panel Controls:||resonate, offset (pull-off), band selector, tuning knob, rf gain, af gain/power on-off, mode switch, meter switch, drive|
|Rear Apron Connectors:||antenna, dial light switch, microphone jack, headphone/speaker jack, receiver antenna, auxillary 12v output jack, key jack, power in jack, receive/transmit antenna switch, accessories socket|
|Semiconductor Devices:||32 transistors, 3 MOSFETS, 3 I.C. and 18 Diodes|
|Power Requirements:||13-14 VDC regulated to 10% with 1 ampere load|
|Cabinet Dimensions:||HWD 4-1/2" x 13" x 7-1/2"|
side panels: cycolac
|Net Weight:||6 pounds|
|Shipping Weight:||8 pounds|
The Argonaut 509 was the second in the fabled Ten-Tec Argonaut series of low-power transceivers. The transceiver provides for SSB and CW operation on the 80, 40, 20, 15, and 10 meter bands with power output of about two watts. It might be argued that this rig and its immediate predecessor, the Argonaut 505, convinced the ham radio world that not only was QRP operation possible, it was fun. The Argonaut 509 originally sold for $329 and was introduced about 1973.
The Argonaut 509 was a well-designed but bare-bones CW/SSB rig. Enhancements were offered by Ten-Tec in the form of external units. These included the Model 206 100kHz Pulsed Crystal Calibrator, the Model 208 CW Filter, the Model 210 Power Supply, the Model 215P Ceramic Microphone, and the Model KR5-A Keyer. For times when a bit more power was needed, the Model 405 Linear Amplifier provided 50 watts with three watts input. As an indication of the care that the designers put into the design of this rig, the Model 208 CW filter, an external, four stage, 400Hz and 150Hz audio filter, was kept inside the AGC loop and the CW sidetone doesn't pass through the filter.
The Owner's Manual is surprisingly comprehensive to one who is familiar with manuals that accompany modern rigs. The manual contains thorough circuit descriptions, disassembly instructions, and complete alignment instructions for all circuit sub-assemblies.
I acquired my Argonaut 509 in December of 2005 from the estate of NorCal co-founder Jim Cates, WA6GER (SK). Unfortunately, this classic 80m-10m CW/SSB QRP rig required service as soon as I received it. I replaced the dial-cord and, with the help of W8MHV, repaired a problem in the receiver audio chain and realigned the receiver to solve low sensitivity on several bands.
I don't have the Model 208 CW Filter, and use an MJF CWF-2 active audio filter instead. This filter works outside the AGC loop so it isn't nearly as effective as the Model 208 would be.
Since dial-calibration varies with each band, I have built a VE3DNL Marker Generator as an external crystal calibrator.
Although I operate primarily CW, and lacking a genuine Ten-Tec microphone, I re-wired an old Sharp 23-channel CB hand-mic for use on SSB.
Update: I no longer have my Argonaut 509. I sold it at the 2009 Ten-Tec Hamfest in Sevierville, Tennessee in September of 2009.
Argonaut Advertisements & Brochures: