Lineage of Ten Tec HF Amateur Equipment

Ten Tec Amateur HF Transceivers

The following is an attempt at describing the lineage and characteristics of HF amateur radio transceivers as manufactured by Ten Tec.

This summary is based on discussions held on the Ten Tec e-mail reflector list (January 2001), material on the "unofficial" Ten Tec web site, and various other sources.

This summary is in three parts:

(a) order of development/production
(b) lineage of transceivers
(c) design innovations/considerations (basic engineering specifications).

Last edited 27 January 2001, by Kevin Anderson, K9IUA


Order of Development and Production

Dates indicate year of production start, if known (dates in parenthesis are QST or CQ reviews).  Most of the start-production dates have question marks as we won't know for sure.

Powermite series
 -- modules TX-1, MX-1, VO-1, AA-1 -- 1969
 -- models  PM-1, PM-2 / PM-2A / PM-2B, PM-3 / PM-3A  -- 1969/1973

Tube Transmitter (TX-100, Solid-state receiver RX-10, and VFO-200 - 1971/1972

Argonaut 505 -- 1971

Argonaut 509 -- 1973

Triton I / II  -- 1973 and 1974 ?

Triton IV 540 -- 1976

Century 21 Analog -- 1976? (12/77)

Triton IV Digital/Model 544 -- 1977 (others told me 1978) (7/79)

Century 21 Digital -- 1978?  (In a 1979 AES catalog)

Argonaut 515 -- c1978/1979

Omni A -- 1979
Omni D -- 1979

Delta 580 -- 1979?

Omni A/D Series B -- late 1979?

Omni C -- 1980 (production late 1980 & 1981)

Argosy 525 -- 1980? (10/80)

Corsair -- 1983 (Ten*Tec never made a Corsair "One."  It's just CORSAIR, okay?)

Argosy II 525D -- 1982 (10/82)

Century 22 -- 1984 (5/85)

An advertisement in QST for AES, which was selling Ten Tec back in 1984, lists the Century 22, Argosy II, and Corsair, with the original Argosy 525 on closeout at $399.95!

Corsair II -- 1987? (8/87) (production 1987 to 1990)
Paragon I 585 -- 1988? (5/88)

Omni V -- 1990?  (11/90)

Argonaut II -- "Available Oct 1990"? (1/92)

Delta II  -- "Available Nov 1990"? (1/92)  My Ten Tec brochure, which must have been printed sometime in late 1990, indicates the above two availability dates for the Argonaut II / Delta II, but it may have been just wishful thinking and it was early 1991.

Omni VI -- 1992 (1/93)

Paragon II 586 -- sometime before July 1993

Scout 555 -- early 1993 (12/93) I have a brochure I received in late 1993 from Ten Tec that pictures the Paragon I, Delta II, and Argonaut II, but with separate inserts for the Scout 555 and Omni VI 563.  The included July 1993 price list gives the Paragon II, Omni VI, Scout 555, and the Argonaut II/Delta II

Argo Scout 556 -- late 1993 or early 1994?

Omni VI+ -- 1997? (11/97)

T-Kit Single-Band Transceivers (1320, 1330, 1340, etc.) -- 1998

Pegasus -- 1999 -- May @ Dayton  (2/2000)

Jupiter -- November 2000

Lineage of Transceivers

The following "lineage" view (I would suggest it is more of an "intended audience" or market view) is from Paul Valko, W8KC (w8kc at

QRP Rigs

Power Mite 1, 2, 3 ==> Argonaut 505/509/515 ==> Argonaut II  ==> Argo
                                                                                                    ==> Delta II (100W)


Century 21 ==> Century 22 ==> Argosy ==> Argosy II ==> Scout


Triton I ==> Triton II ==> Triton IV ==> Omni A/B/C ==> Corsair =>...
                                                      ==> Delta ==> Delta II

(continued from Corsair above) ... Corsair II => Omni V => Omni VI => Omni VI+

Tube Transmitter

TX-100  (matching receiver RX-10, and VFO 200)

General Coverage / PLL Attempt


Radio/PC hybrid

Pegasus ==> Jupiter

Kevin's comments on the above lineage

From a purely "market" orientation, Paul's category of "mid-power" including the Century and Argosy series (ending in the Scout) makes sense.

But from a technology/design standpoint there is really two series:

Mid-power -- Novice / CW-only (direct conversion):
 (Powermites) ==> Century 21/Century 21 Digital ==> Century 22

Mid-power CW/SSB (economical performance superhet):
 (Argonauts/Triton I) ==> Argosy ==> Argosy II ==> Scout

The transceivers indicated in parenthesis are, I suggest, the antecedents for the Century and Argosy series.  Further, my sense, being the owner of a Century 22, Argosy II, and Scout 555, is that the Argosy, while sharing many of the same modules as the C22, is definitely a different beast in overall design.  The outward appearance between a C22 and Argosy II is striking, clearly acknowledging their period of time (1980-1985), but the use of superhet (same 9 MHz as other rigs) and inclusion of SSB in the Argosy suggests parallel, not sequential, production.

Also, it should be noted that in the above listing, the 555 Scout and 556 Argo Scout have a very different IF frequency as compared to its predecessors, but do represent the commonality of mid-power "economy" (or entry level) for a transceiver market.

Design Innovations and Considerations

The following, provided by Dave Kelley, NB4J (, was originally created by him from notes collected from K0CQ and N4PY about a year ago.  Dave was interested in engineering issues such as what types of front-end mixer and amplifier circuits were used.  (Also included is yet again another list
of the dates for QST/CQ reviews.)

Here is Dave's summary as sent to me:

Here's the information I've been able to gather.  (Much of it came from K0CQ and N4PY):

[Dates (mo/yr) are for QST Product Reviews]

Triton I: 50W, single conversion: IF at 9 MHz
Triton II: 100W, single conversion: IF at 9 MHz 
Triton IV (540/544-7/79): dual-gate MOSFET RF stage and MC1496 mixer;
  single conversion: IF at 9 MHz

Omni A - analog display, 9MHz IF.  No WARC bands
Omni D - (1/80): digital display, 9Mhz IF.  No WARC bands
Omni Series B: Same as above but squelch control replaced no WARC bands?
Omni C: 17-m not practical, single conversion: IF at 9 MHz; dual-gate MOSFET RF amp, tunable preselector.

Corsair: 3 IF filters, same AGC system as Omni-C, dual conversion (IFs at 9 and 6.3 MHz and then back to 9 MHz for PBT), stock 4-pole 9 MHz IF filter, PBT, diode ring mixer followed by transformer feedback amplifier stage, band pass filters instead of tunable preselector

Corsair II (8/87): same basic receiver, 3 IF filters, dual conversion, stock 9 MHz IF filter upgraded to 8 poles, PBT, audio filter, NB?, transformer feedback amplifier stages before and after first mixer (diode ring), adds 3 selectable audio filters and a notch filter within the AGC loop to Corsair I.

Omni V (11/90): uses synthesizer rather than PTO; IFs at 9 and 6.3 MHz (and then back to 9 MHz for PBT, like Corsairs) Omni VI (1/93): added RIT, sidetone that follows CW offset, internal keyer, low pass DSP filter to reduce IF hiss instead of "tone control", increased microprocessor clock speed, crystal oven for xtal osc, minor changes in firmware controlled items Omni VI+ (11/97).

Paragon I (5/88)
Paragon II: up conversion to 45-75 MHz, then IFs at 9 and 6.3 MHz and back to 9 MHz again for PBT

Pegasus (2/00): up conversion to 45 MHz, then IFs at 455 kHz and 12 kHz (the last for DSP) Jupiter: up conversion to 45 MHz, then IFs at 455 kHz and 12 kHz (the last for DSP)

Powermite Series  PM1, PM2, PM3

Century 21 (12/77)
Century 22 (5/85)

Argonaut 505/509/515: single conversion: IF at 9 MHz
Argonaut II (1/92)

Delta 580:  dual conversion: first IF is 11-11.5 MHz, second is 6.3 MHz (to solve Omni C 17 M problem); digital readout does not sum all oscillators directly but is scaled - not always accurate 

Delta II (1/92)

Argosy I (10/80 or 82)
Argosy II: stock 4-pole 9? MHz IF filter; covers 80, 40, 30, 20, 15 & 10 meters; 2.4 kHz 8-pole SSB and 500 Hz 8-pole CW filter positions and dual-position AF filter?

Scout (12/93)

RX-320: up conversion to 45 MHz, then IFs at 455 kHz and 12 kHz (the last for DSP)


In addition, Carl, N4PY, recently posted a similar shortened discussion
to the e-mail list:

The Delta 1 is a double conversion receiver.  The first IF is 11 to 11.5 MHz and the second IF is 6.3 MHz.  It stands by itself in this scheme.   The Tritons, Argonaut I, OMNI A+D, C, Corsair I and II, are essentially single conversion receivers using a 9 MHz IF.  The Corsair's had an extra conversion from 9 MHz to 6.3 MHz and back to 9 MHz for passband tuning.  The OMNI V and VI also use the same scheme as the Corsair's.

I do not know the scheme in the Delta II and Argonaut II.

The Paragon I and II , up converted to 72 MHz and then to 9 MHz, also with the passband tuning scheme going form 9 to 6.3 to 9.

The Pegasus,  Jupiter, and RX-320 up convert to 45 MHz, then 455 kHz,
then 12 kHz for DSP.

Carl Moreschi  N4PY
Franklinton, North Carolina

And I (K9IUA) can add the following:

Powermite:   Direct conversion
Century 21:  Direct conversion
Century 22:  Direct conversion (VFO 6.0 to 6.5 MHz, with xtals mixed for each band)

Scout/Argo Scout:
Single conversion, VFO from 2.2 to 2.7 MHz, IF at 6.144 MHz, two sequenced filters, a 4-pole fixed bandwidth portion and a 5-pole variable bandwidth portion "Jones" filter.

Hopefully we can correct the dates (I dream that we eventually can have both start *and* end dates for production), improve on the lineage and design changes, and otherwise learn more about the equipment we love to operate (at least I do).


Kevin Anderson, K9IUA
Bismarck/Lincoln, North Dakota


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