Category Archives: QRP Radios

A review of Ten-Tec’s Argonaut VI QRP transceiver, Model 539

The Ten-Tec Model 539, A.K.A. Argonaut VI
The Ten-Tec Model 539, A.K.A. Argonaut VI

And now, what we’ve all been waiting for:  the Ten-Tec Argonaut VI has finally hit the market.   Manufacturer Ten-Tec has already begun shipping the new units–I hear they’ve already sold out the first production run.  For the past two months, I have had the pleasure of beta-testing this newest QRP transceiver, and I’m ready to share my findings.  [Do please note that, other than beta-testing, I have no relationship with Ten-Tec.]

I authored a post about the Model 539 when Ten-Tec first disclosed it at their 2011 Hamfest. The reactions and questions from readers came flooding in–so many, in fact, that I invited readers to send in those questions to share with the engineers at Ten-Tec.  I presented these to the company, and posted Ten-Tec’s helpful responses.

Prototype of the Ten-Tec Model 539 QRP transceiver
Prototype of the Ten-Tec Model 539 QRP transceiver from the 2011 Ten-Tec Hamfest. Note that the speaker no longer has an externally mounted grill.

In truth, I don’t think that Ten-Tec was quite prepared for all of the interest in their modest QRP transceiver. But it was no surprise to me: I’ve always been a fan of Ten-Tec, and although I’ve not been as excited by the QRP offerings since the early Argonauts, I knew I wasn’t alone in my appreciation of this US-based radio company’s quality products.

The following review is not a test-bench review–it is, rather, a consideration of the usability, ergonomics, design, basic performance and, well, fun factor of the new Argonaut VI.  It’s only fair to note that I don’t review transceivers often; rather, I focus primarily on receiver reviews at my alternate radio blog.  But I could not resist the opportunity to investigate the newest in this venerable line of transceivers.

Size-wise, the Argonaut VI is smaller than the Elecraft K2 in every dimension.
Size-wise, the Argonaut VI is smaller than the Elecraft K2 in every dimension.

You will note that I compare the Argonaut VI to the Elecraft K2 a number of times. Why? In my opinion, the K2 is the Argonaut VI’s closest competitor. It, too, is a front-panel QRP transceiver not for general coverage. While there are a number of differences, of course, I nonetheless feel the K2 is a closer match than the new Elecraft KX3, the Yaesu FT-817, or the Icom IC-703. Plus, I have a K2 that I already know and love here in my shack, so by default it has been my point of comparison throughout the beta-testing period.

Argonaut VI: first impressions

The Argonaut VI is an attractive, simple, sturdy little radio. It reminds me a great deal of the Ten-Tec Scout outfitted with its simple front panel. The front features two knobs: one controls the AF gain, while its outer ring controls RF gain; the other controls the bandwidth, while its outer ring controls the pass band. There is also an appropriately-sized display panel, quality tuning knob (see below), four multi-function buttons, and a three-position toggle switch.

The TMB switch is a simple and effective way of giving the Argo VI's four function buttons multiple assignments.
The TMB switch is a simple and effective way of giving the Argo VI’s four function buttons multiple assignments.

A toggle switch? I can’t think of a recent front-panel radio in production that has had a proper mechanical toggle switch. On the Argo VI, this makes for a simple method to give the four function buttons a total of three one-push functions, each, for a total of twelve functions. Ten-Tec refers to this switch as the “TMB” (i.e., “Top-Middle-Bottom”) switch.

Size-wise, the Argonaut VI is smaller in every dimension than the K2 (see photos). Its physical dimensions are 2.25″H x 6.5″W x 7.6″D, less the knobs and connectors. It weighs a mere 3.6 lbs, and feels very light in my hands. The Argo VI has a sturdy Ten-Tec bail that snaps into the perfect position for tabletop operations. The display is crisp and clear, and actually contains a lot of information:

The Argonaut VI display is compact, yet crisp, clear and displays all important information.
The Argonaut VI display is compact, yet crisp, clear and displays all important information.
  • Frequency
  • 2nd VFO frequency
  • Mode
  • AGC speed
  • S Meter/SWR
  • Output power
  • Pre-amp

The display can be switched (via an internal setting) to blue (default), green, or red. One nice touch: the dot in the Ten-Tec logo is actually a red LED that lights up on transmit and ALC peaks.

Tuning knob

This is the best tuning knob I've ever used on a QRP rig
This is the best tuning knob I’ve ever used on a QRP rig

Perhaps I place more emphasis on a tuning knob that other hams. I liken it to shutting the door on a quality car: you want the door to shut solidly and feel substantial. But it may be more like a car’s steering wheel–after all, the tuning knob is how one interacts with the radio. To me, the tuning knob is often a measure of a radio’s overall quality, in my humble opinion.  As for the Argonaut VI?  Here’s the answer:  I was so impressed with the tuning knob on the Argonaut VI that I actually confirmed with Ten-Tec that the beta-unit’s tuning knob would also be used on production models. In short, the Argo VI’s tuning knob is heavy, perfectly-sized, has a light tactile grip, and is silky-smooth to operate. There is no play whatsoever in the action. I like the adaptive tuning, too–when you tune slowly, you’re changing the frequency by hundredths of a kHz; spin the knob quickly and you’ve just shot across the band. After tuning the Argo VI for a bit, other small radios’ tuning knobs begin to feel cheap.

IMG_6508Ergonomics/Usability

When I first played with the Argo VI at the Ten-Tec hamfest, I was impressed with the simplicity of the front panel. This is an important factor because I simply won’t use a radio that isn’t pleasant to use/control, and I find that too many front buttons and general visual fussiness can be a distraction. To illustrate my point, when the Yaesu FT-817 hit the market over a decade ago, I was among the first to purchase one. I liked the idea of a small transceiver that I could tuck in my carry-on and take with me as I traveled. But I ended up selling the FT-817, however, because I hated the ergonomics and multi-function buttons. Button spacing was too tight for my larger hands, important multi-functions seemed to overlap, and menus were buried too deep for convenient operation. The FT-817 had a profound impact on all other buying decisions I’ve made since, and taught me that too much can simply be…too much.

The red dot in the Ten-Tec logo is actually a red LED that lights up on ALC peaks and CW transmit. (Click to enlarge)
The red dot in the Ten-Tec logo is actually a red LED that lights up on ALC peaks and CW transmit. (Click to enlarge)

Happily, on the Argo VI the most often used transceiver functions have dedicated buttons/knobs, and the display includes everything I need. Clean, clear, straightforward–this rig provides a pleasant operating experience.

For basic operations like rag-chewing, scanning the band, switching modes, switching bands, adjusting RF/AF/BW and PBT, you’ll be pleased, too.  None of these operations require calling multi-functions or toggling the TMB switch (assuming you’re already in the “M” position).

But after spending some time on the air, I realized that there is a bit of a learning curve you’ll have to overcome before front-panel operations become entirely fluid and intuitive. To change RIT, you need to toggle the TMB switch to “B”, then press the RIT (BAN) button to toggle RIT on and off. If you hear DX working split, you’ll need to move the TMB switch to the “T” position, then set the A/B and SPL buttons; if you need to change modes or turn on the pre-amp, then you’ll have to move TMB back to “M.”

In the first few hours of  testing the Argo VI, I found it easy to forget that I had the TMB switch set to a certain position when pressing a multi-function button, thus I was sometimes not receiving the response I expected. Several times I intended to change the band, but had the TMB set to “T” and resultingly opened the output power setting, or pressed the MOD button only to find that TMB was set to “T” as I toggled A/B VFOs.

Click to enlarge
Click to enlarge

While this was distracting at first, I soon became accustomed to changing the setting, then moving the TMB back to the “M” setting afterward. Now I find I very rarely make a mistake.

On the Argo VI, all of the buttons and knobs are adequately spaced. You could operate this rig outside with lightweight insulated gloves on, should the need arise.

All in all, the ergonomics are excellent on the Argonaut VI.

Performance

Before I begin talking about this little transceiver’s performance, I want to point out its two most obvious shortcomings:

  • The Argonaut VI lacks 12 and 60 meters (ouch!)
  • There is no internal ATU (auto antenna tuner), nor is there an option for one

If those two negatives are deal-breakers for you, I could certainly understand. You might want to consider a basic KX3 with ATU ($1070 unassembled, $1170 assembled) or a K2/10 with ATU ($1280 unassembled), instead.

IMG_6453
The Argo VI has a relatively small footprint on my radio shelf.

But if, like me, you use neither 12 nor 60 meters very often, you may not miss them.  Admittedly, the lack of 12 meters is unfortunate because it’s such an ideal band–when conditions are right–for easy QRP field operation. However, I am very pleased the Argo VI has 160 meters.

An internal ATU–or the option to have one installed later–is certainly a negative for those of us who like a simple Field Day radio set-up. From my point of view, other than my Elecraft KX1, I’ve never had a radio with an internal ATU; I have two portable tuners (the LDG Z11 Pro and Elecraft T1) that work wonders. The way my shack is designed, I have a remote auto-tuner outside at the feed point of my antennas and thus have no tuner in my shack–so if I had an internal ATU, I’d have to turn it off 95% of the time. If your shack is set up similarly, you might not mind not having an ATU.

If you’re concerned about the performance of the Argonaut VI, let me assure you now: you will not be disappointed. Indeed, the receiver in the Argonaut VI must be one of the best I’ve ever heard in any radioespecially in this price class ($1000).  It is truly remarkable.  I’m eager to learn how Rob Sherwood rates the Argonaut VI, but I suspect it will rank among the top few.

IMG_6479
Click to enlarge

What is most impressive in the Argo VI is its incredibly effective variable DSP filtering. I experimented with the variable bandwidth and pass band during crowded CW conditions, and found that each and every time I could zero in on one QSO and block everything else. It’s also highly effective when used with SSB. Based on the reviews I’ve read of the Eagle, this is obviously derived from its DSP architecture and has similar performance characteristics. [Future Argo VI owners, I eagerly welcome A/B comparisons of the Eagle and Argo VI–please comment!]

IMG_6494You’ll be happy with both the Argo’s sensitivity and its ability to reject adjacent signals. Compared with my Elecraft K2/10, the Argo VI’s sensitivity had an edge in every band I tested, and to my ear, the noise floor is lower on the Argo VI as well.  Most noticeably, however, is the Argonaut’s audio fidelity, which is far superior to that of the K2. Whether using headphones or using the built-in top mounted speaker, you will be pleased. The speaker delivers an impressive sound for its size. I tend to hook up external speakers to my smaller transceivers, but in this case I never felt I needed to. With headphones, the audio is even more impressive. I do wish the headphone jack was on the front panel instead of the back, though.

Though I haven’t spent enough time with the KX3 to compare audio fidelity, I imagine the KX3 and Argonaut VI would be a fair contest.

I can say that audio fidelity is the primary reason I continue to turn to Ten-Tec for transceivers and receivers. In my opinion, like Kenwood, Ten-Tec invests more resources into insuring superb audio fidelity–even at the cost (in this case) of uber-low current drain numbers (although the 550 mA drain on receive must be the lowest Ten-Tec has ever produced in a digital transceiver). The Argo VI’s audio is rich, inviting enjoyable listening for hours on end. It would certainly be a great pick for long-haul events like Field Day or 24/48-hour contests.

The back panel of the Ten-Tec Argonaut VI (Click to enlarge)
The back panel of the Ten-Tec Argonaut VI (Click to enlarge)

SSB/CW

But how does she sound on the other end? Immediately after unpacking the Argonaut VI, I caught band openings on 10, 15, 17 and 20 meters. Though I was only running 7 watts at the time (production units run a full 10W) I received great audio reports on SSB and was even  heard through a pile-up on 17M. Though I believe the default settings would have worked well, setting up the mic gain on this rig is also very easy and straightforward.

As for CW, reports have also been very positive. CW ops will be happy to note that the Argonaut VI has Ten-Tec’s silky-smooth QSK. Frankly, I expected nothing less.

Since I don’t operate digital modes often, I did not test the Argo VI in this capacity. I imagine reviews will emerge soon, but I expect them to be positive as several beta testers were impressed.

Summary

When I begin a radio review, I keep a checklist of pros and cons as I discover them to remind myself of my initial discoveries.  Here’s my list from the Argonaut VI:

Pros

  • Excellent top-of-the-line audio fidelity
  • Extremely effective DSP variable bandwidth
  • Silky smooth QSK
  • All mode with optional AM
  • Easily accessible primary controls
  • Uncompromised ham band performance (see con)
  • Quality tuning knob and adaptive tuning rate make for easy band scanning
  •  Simple front face and comfortably spaced buttons/knobs (see con)
  • Undoubtedly the best receiver of any QRP rig produced by Ten-Tec
  • Comprehensive and detailed owner’s manual
  • Made in USA
  • Ten-Tec’s US-based customer support, a major plus over many foreign manufacturers

Cons

  • No 12 nor 60 meters
  • No internal ATU, nor option for one
  • No internal battery nor option
  • Headphone jack on rear panel
  • Not general coverage (see pro)
  • Learning curve when using multi-functions (see pro)
  • Price of $995 is a little steep
  • RX current drain is high when compared with Elecraft K1/KX1/K2/K3 or KX3, or the Yaesu FT-817

To buy, or not to buy…

The Ten-Tec Model 539 Argonaut VI (Click to enlarge)
The Ten-Tec Model 539 Argonaut VI (Click to enlarge)

I really think the Argonaut VI is a streamlined Ten-Tec Eagle, and a very good rig. Its DSP architecture is based on the Eagle’s (in beta, we even used the Eagle software for the frequent firmware updates).

When I ask myself, “Who will buy the Argonaut VI?” I believe the answer is anyone who wants a QRP radio with the performance and interface we’ve come to expect from Ten-Tec.  If you can live without 12 and 60 meters, then you will be buying a rig that does not compromise on performance. The Argonaut VI is not a QRP radio designed for backpacking like the KX1 or KX3, but it would hang with the best in a QRP contest or on Field Day; operators would experience little to no listening fatigue with this smooth rig.

The Argo VI comes factory-assembled, warrantied, and ready to go, right out of the box.  There’s nothing to put together nor configure.

On a side note, I should mention that this is the first time I’ve beta-tested with Ten-Tec; this provided insight into the process of rolling out a new product and just how responsive and open the company is to both frank criticism and design requests. I believe all of the beta-testers would agree. Every concern I reported to Ten-Tec was eventually addressed by version 1.0 of the firmware.  That’s responsiveness I can really appreciate. Ten-Tec’s Software Engineer, John Henry, is nothing short of amazing. I’m not sure when he finds the time to sleep.

I’m happy to have had this little radio in my shack for the past two months. I’ll have to bid it farewell, though:  Ten-Tec has already sold out of their first production run, so my unit will be returned, upgraded with a new board, tested, inspected, and sold as a demo.  Alas, it’s hard to say good-bye.

I guess the proof is in the Christmas pudding:  I have to admit that I now prefer the Argonaut VI even over my trusty Elecraft K2. So, kind readers, if one of you is in the market for a K2/10 with SSB, and 160M, I may be in the market for an Argonaut VI.

It would bring tidings of great joy, indeed.  Happy holidays!

Ten-Tec holiday specials include QRP kits

Ten-Tec is discounting their 1380 and 1330 QRP kits for the holiday season. They’ve also extended their discount on the R4030 QRP tranceiver (details below).

(Source: Ten-Tec)

The 1380 and 1330 QRP transceiver kits, which are regularly priced at $124.00, are $99.00 through Christmas.  These are great QRP kits and many are used on the air daily and in QRP contests.   It is great fun to work 80 meter QRP in the winter months,  so order yours today.  http://www.tentec.com/products/80-Meter-QRP-Transceiver-Kit.html

The R4030 transceiver is still at $188.00 from their list of $249.00 and this price will continue through Christmas.  This is a great trail friendly QRP transceiver with lots of features like an LCD frequency readout display, cw memories and much more.  This is a great price for a full-featured QRP rig.  Read more about the R4030 at http://www.tentec.com/products/Sale-Price!-Two-Band-CW-QRP-Transceiver-%252d-40-%252d-30-Meters.html

Ten-Tec Hamfest, Argonaut VI update

Two Ten-Tec Model 539, Argonaut VI’s, will be on the air at the Ten-Tec Hamfest this weekend.

This weekend, I’m heading to the Ten-Tec Hamfest at the Ten-Tec factory in Sevierville, Tennessee.  This is, hands down, my favorite hamfest of the year. Not only is it completely free, but the ham radio flea market section has a higher percentage of real radio gear than any other hamfest with which I’m familiar. The event is being held today and tomorrow (the flea market is Saturday only). You can read details about the hamfest on Ten-Tec’s website.

Agonaut VI update…

I just got the following word directly from Ten-Tec Engineer, John Henry, regarding the Model 539 (Argonaut VI) transceiver; in a nutshell, they will not be taking orders at the hamfest as they had hoped, price is not fixed but ballparked, and rigs will be available at the hamfest for testing:

TenTec is not going to take early orders for the 539 at the TenTec Hamfest on 9-28/29-2012. Essentially the rig is performing to our specification level, but we have a few things to finish before we can ship them to customers, [such as] the user’s manual, FCC testing, etc.

We do have a pilot run of 25 units that will be visible to those taking the tour, and a couple will be set up for hams to use at the Hamfest this weekend. In about 1-2 weeks from now, some of the pilot run units will be distributed to hams for another round of beta testing.

Regarding the price of the 539, until we finish this last round of beta testing we aren’t sure if we have each and every cost factor taken into consideration. Never know what a broader field of testers will find that may increase costs. So, there is no final customer price yet. But as we have stated at all of the hamfests so far, we can still say it will be well below $1000, and we will still meet our goal of having the price of the 539 [plus] the price of the 418 to be less than the cost of the 599, at near the specification level.

The Ten-Tec Argonaut VI on the work bench at Ten-Tec

I plan to post photos from the Ten-Tec hamfest and report any other updates. Stay tuned!

Ten-Tec Argonaut VI: On schedule for ordering, shipping later this fall

I just received word from John Henry at Ten-Tec that their time frame for production runs of the Model 539 (Argonaut VI) is  on-track with estimates provided at the 2012 Dayton Hamvention.

John said:

We are running a small production run right now, working out the kinks of getting it into production. Most places call these “Pilot runs”. Pilot Runs basically get the factory up to speed with the units before we go to full scale production quantities.

He doesn’t see any reason, at this point, why they wouldn’t hit the late fall 2012 ship dates. He also said that they’re working hard to possibly take orders for the Argonaut VI at the 2012 Ten-Tec Hamfest being held at their factory in Sevierville, Tennessee, September 28-29th.

According to John, several Ten-Tec customers have said that they are going to buy a Model 539 and the Model 418 (companion 100 watt linear amplifier) when the 539 starts shipping.

I will attend the 2012 Ten-Tec Hamfest and plan to post updates on QRPer.com from there.

A Grocery Store Find — a Portable QRP Station Bag!

QRP Bag -- click to enlarge

I found an almost perfect bag for carrying a small QRP transceiver, simple antenna, and accessories yesterday in our local Aldi grocery store. The bag (photo) is manufactured by “Adventure Essentials”, is described as an insulated lunch bag, is available in several color-schemes, and cost all of $3.99 plus sales tax. I purchased the grey-and-black version, product number 41991. The bag looks to be very rugged, is covered by a two-year warranty, and the tag even includes a toll-free telephone number for customer service.

QRP Bag -- click to enlarge

As can be seen in the photos, the bag is almost ideally sized for carrying any of the current crop of trail-friendly-radios such as the Elecraft KX1 or KX3, the Ten-Tec 40×0 two-band or 4040 four-band rigs, the Youkits HB-1A three-band or HB-1B four-band rigs, or the MFJ 92xx single-band rigs.

If I didn’t already have a Pelican Case for my KX1 Mini Travel Kit, I could probably be very happy carrying the station in this insulated lunch bag!

Standard disclaimer: I have no relationship with Aldi other than being a satisfied customer.

Hamvention Photos: Hendricks QRP Kits

Doug Hendricks holding a Ft. Tuthill transceiver

Another very active table at the Dayton Hamvention and Four Days in May is that of Hendricks QRP Kits.

Doug Hendricks (pictured right) and his team produce some amazing, affordable QRP kits that fill many a niche in the shack. Below, I have photos of a small selection of their offerings at the Hamvention.  Note that all of these kits are available on the Hendricks QRP Kits website.

Many of Hendrick’s kits are suitable for beginners. If you’re in doubt about your kit building skills, simply contact the folks at Hendricks and they’ll help guide you to the right kit.

Video: Tuning the Ten-Tec Argonaut VI

As Ten-Tec was setting up at the Dayton Hamvention last Thursday, I was able to meet with their engineer (John Henry) briefly and had a little time to play with the new Model 539 Argonaut VI. As I tuned around the CW side of the 20 meter band, I recorded a short video. I’m sharing this with you here, but must ask your forgiveness for its quality and glitches; I want to make it clear that this material was recorded on my Android phone in some haste.

Moreover, this video does not do justice to the Argo VI’s audio, which is exceptional.  In fact, I can’t tell a difference between its audio and that of the Ten-Tec Eagle, both of which have very low noise floors and simply gorgeous audio fidelity.

Now, just a small taste of what this receiver can do…

Sneak peek: Ten-Tec Model 539 Argonaut VI and Model 418 Amplifier at FDiM and Hamvention

Yesterday, I had the opportunity to see the new Argonaut VI and Model 418 100 Watt amplifier up close and even operate them.

Though I’ll keep my comments short–I have a l o n g day at the Hamvention ahead of me–I thought I’d share a few first impressions.

The guys at Ten-Tec were kind enough to allow me to take a few shots of the Argonaut VI and the Model 418 Amp, both in Hara Arena and at Four Days In May yesterday.

Contest conditions

If you’re coming to the Hamvention, you will want to stop by the Ten-Tec booth. Through some sort of feat of engineering (or–as I first thought–dark magic!) they have a recorded chunk of 20M spectrum taken from a recent contest. They’re feeding most of their rigs with this spectrum IQ and you, in turn, hear exactly what each radio will sound like. Not only that, but you can operate the radio as if “live”–tuning, adjusting filters, bandwidth, notch etc. Indeed, you can use any receiver feature on the rig.

Additionally, they have one of the Argonaut VI’s hooked up to a Model 418 Amplifier. With these two linked, you can operate CW into a dummy load. Through this set-up I got a very good idea of how the Argonaut VI sounds and how well the amplifier works in conjunction.

First impressions are very positive.  A few notes about the Model 539 Argonaut VI:

  • Very low noise floor.
  • Excellent audio fidelity.
  • The knobs, buttons and all features are quite easy to operate.
  • The filters (especially as tested in CW) are simply amazing. I think they are comparable to the Ten-Tec Eagle.
  • I like the size–slightly larger than an FT-817, much smaller than the Argonaut V.
  • All of the important controls are right there on the front: AF/RF Gain, Bandwidth/PBT, Power, RIT, Memories, Split, etc.
  • Nice touch: On transmit, the red dot in the Ten Tec Logo lights up on both the Argonaut and ‘418. See photos below.

Not many criticisms yet, but mind you, these are first impressions.

The Model 418 100 Watt Amp

Though the Model 418 was hooked into a dummy load, I was able to get a feel for how well the amp responded while sending CW.  I’m happy to say that the QSK is silky smooth. Ten-Tec has never disappointed me on this point–their QSK is a benchmark.

Tomorrow, I will post the price of the Model 418 Amplifier–as I mentioned before, the Argonaut VI pricing is at least a few months off, most likely.

Many of you asked about the omission of 12 and 60 Meters. I asked Ten-Tec about this and, in short, it was a balance of performance vs. features. Through their research, they found that 12 and 60 would be the least missed, while 160M would be a great addition (initially, they did not plan to add 160M).

In an effort to save time, I’m simply posting a load of photos below in a thumbnail gallery. Simply click on the thumbnail to enlarge each photo. Feel free to comment and ask questions if you can’t make it to the Hamvention.  I will do my best to answer.

 

The Ten-Tec Argonaut VI: the Model 539 QRP transceiver follows the legend (while we follow the spec sheet!)

I well remember first speaking with a Ten-Tec rep at the Ten-Tec Hamfest last year when the company first displayed the concept Model 539 transceiver, which was beginning to generate enormous interest.  After viewing it, I casually asked the representative what the name of the new radio would be–? When he shrugged his response, I came to the point: “Will it be called an Argonaut?” “Time will tell,” he eluded.  But in retrospect, I realized his response was not so much evasive, as it was fair–an honest attempt to protect the original Argonaut line’s name.  Ten-Tec apparently wanted to finish the rig, to vet it thoroughly, and deliver performance that would live up to the legendary Argonaut status.

Now, it appears they’ve done it.  And the name?  Yes, folks–Ten-Tec has officially christened the new rig the Argonaut VI.

Introducing the Ten-Tec Argonaut VI

Ten-Tec, having been made aware of our avid interest in their new product, has been kind enough to provide QRPer with a preliminary spec sheet for the Model 539, and they’re permitting me to post it here, for the first time, today (see link below).  As you can see at the top of the page, it very clearly states that the ‘539 will be called the Argonaut VI.

Ten-Tec also allowed us access to the spec sheet for the new Model 418 Amplifier, which (to keep this post brief) will be featured in this separate post.

Click here to download the Ten-Tec Model 539 preliminary spec sheet

Ten-Tec tells us that the receiver on the Argonaut VI will perform much like the one in their Ten-Tec Eagle (Model 599). But you can hear it for yourself at the Hamvention: There, they’ll have a recorded contest playing over all of their rigs–including over the new Argonaut VI–so that hams can listen to and compare their receiver performance.

Specs

You can download the Argonaut flier that Ten-Tec will hand out at the Dayton Hamvention by clicking here. It covers these vital specs of the radio:

  • Modes: CW, LSB, USB, AM
  • Receiver Type: Double Conversion, ASR
  • RIT: +/- 8.2kHz
  • CW Keyer built in: Curtis Mode B, 5-50wpm
  • Typical receiver sensitivity: < 1 uv
  • DSP Selectivity: 100 built in DSP filters from 100Hz.
  • Dynamic Range: 91db
  • Display: Multicolor back lit LCD
  • Rf Output power: 1 to 10 watts
  • Transmitter Duty cycle: 100% for up to 10 minutes
  • Frequency Coverage: 160 through 10 meters with the exception of 60 and 12 meters.
  • Power Requirements: 9.5-14 Volts DC (550ma on receive, 3 amps at 10 watt TX)
  • VFO: Two independent “VFOs” for single or split operation
  • Speed Sensitive VFO tuning rate
  • Frequency Stability: +/- .5ppm
  • Memories: 100

Availability and Price–?

The Model 539 Argonaut will be available late fall of 2012. Though the software is in final stages and almost ready for Beta testing, Ten-Tec says they are still ironing out the parts list and firming up lead times and prices. They will not, alas, have a price for the Model 539 Argonaut VI at the Hamvention, but say that they will have firm pricing on the Model 418 Amp by then (more on that here, and to come).

Some questions answered…

The Model 539 will only draw 550 mah on receive unsquelched. That’s not as low as an Elecraft rig, but for a Ten-Tec rig (that consumes a little extra juice for audio fidelity) that’s a fairly miniscule number. Especially considering that its predecessor, the Argo V, consumed nearly double that figure on receive.  In fact, I’ll bet it’s the lowest receive current on any digital/DSP transceiver they’ve ever produced. Indeed, this Argo VI is almost as good as the venerable Yaesu FT-817 unsquelched. As a result, I imagine this new-generation Argonaut will be a great radio to take to the air on Field Day, or even to take backpacking/HF-packing.

If the price is competitive, and that’s still an if, this could be a real winner for Ten-Tec, offering high-performance on a QRP budget. If so, this may be an affordable way to get into a top-quality new radio whose performance is benchmark-able.  Couple it with the Model 418 Amplifier to provide 100 watts output as needed…Quite promising!

The Argonaut VI (and Model 418) will be on display at Dayton, and will be fully-functioning.  I’ll be one of the first visitors at their booth in Dayton Friday morning, and plan to post further details (and possibly a few photos) during the Hamvention.  So, check back and follow the tags: Ten-Tec and Dayton.

So, what could the Argonaut name mean for this rig, in terms of performance? Time will tell! 

••••••••••••

Just to be clear, all of this information came from straight from the horse’s mouth at Ten-Tec and is accurate-to-date.

We’re grateful to the folks at Ten-Tec for giving QRPer a preliminary look into these two products prior to the Hamvention, and allowing us to post their sheets so our readers can take a first peek. Thanks, fellas!

Vlado’s challenge: home-brewed QRP DXCC

Vlado (N3CZ)

My good friend, Vladimir (Vlado) Karamitrov (N3CZ/ZS6MG) is someone who likes to challenge himself. Perhaps this is why he’s such an accomplished DXer and contester.

Recently, at his QTH, he showed me one of his latest projects: a home brewed QRP transceiver. Vlado wasn’t content to simply build his own high-performance transceiver; no, he needed a built-in challenge.

Here is the story of his QRP radio, that he built mostly from junk parts, in his own words:


N3CZ's QRP rig front face

Challenge for all of us ….”Built your own radio”

By N3CZ / ZS6MG, Vladimir Karamitrov, 114 Russet Ln. Asheville, NC 28803 USA

Building your own radio is a challenge on its own. Using it to work DXCC is another challenge, probably less difficult. But combining the two brings a new spark and joy in our hobby. Isn’t ham radio about radios?

The purpose of this article is not to argue the need for building but to give ideas to those who have the time, like a new challenge and open up for ideas of building their own radios.

There are many different aspects to look into this. One is to build a radio from a kit. A search online will provide a list of manufacturers who offer these kits from basic thru intermediate to advanced designs.

The other approach is to build it your self. Yes, from scratch. Well, why not? Remember, time is what is needed most and of course some money and/or spare parts or junk parts. Time is not what I have available a lot, money is always on the agenda but having spare parts and stuff lying around your garage is another good resource.

N3CZ's workbench

So I decided to put something together. No time –means I can’t spend a lot on making this new rig look like a factory made, I have to use dead-bug design techniques and other easy methods to “glue” everything together. Available time is only after work and weekends and that is not much.

What kind a circuit and design to use? This was really the main question, because the answer will dictate what approach to take. First rule is check what parts and components you have available. There is something you have to remember here — when you go to a hamfest always bring some “junk” back home. You never know what you going to need. We all know this rule don’t we? Also don’t forget what your buddies have collected over the years, they will be able to help you with some of the missing parts if you need.

One of my passions is building my own equipment. Starting from antennas, to control boxes to switch them, pre-amps for the low bands and from time to time build a small QRP rig. Other interests are DX and Contesting, so while putting this radio together I cannot wait to hook it up to my antenna. This is where a little patience is required and I had almost none, hi. But I knew, bands are down for now, I have worked almost everything that was there to work, so will do this one little different and try to slow down a bit.

With my projects everything starts with the box. Few boxes I changed until the right one was in my hand. Next was to find a properly sized knob for the VFO. I then realized that it will take little more time to build all the components so I decided to use my $$ budget and get my self a nice DDS VFO. There are few different ones available online and for around $80. I got a nice programmable one with dual VFO’s and memories, with settable IF offset etc. This seemed to be the perfect fit for the project.

Transmitter

I thought I had all I need to start working on this project, but…..I wasn’t really sure about it yet. While looking for the “start” button and to actually take off with this project, I had yet to find that “trigger” that ignites the spark inside me, so I can say to myself, “yes I am ready, let’s just do this.”

You know the feeling – you feel a bit lazy at the beginning until that moment when that spark gets you. It’s like when you have to mow the lawn, and then you think, “no, it can wait another week, don’t feel like doing it now.” Well, I found my spark – it was not in the box, it was in the tuning knob that I got from a colleague also a ham and one who builds little QRP’s. I was actually explaining to him what I was planning to do, but not sure yet of the concept and how to handle certain parts of the circuit. While discussing all of this, he said he had some parts that he would bring for me and see if I could use some. He did not mention about any knobs, but when I saw them I knew I had what I was missing and now it iss the time to start working on this.

Transmitter PA

Now that I have the heart and the body, and the knob, I did some study of a number of different circuits published in ham radio literature including ARRL’s handbook and many online QRP resources. The goal was to build a simple radio easily reproducible, with reasonably good specifications so you can use it daily. Selection of IF frequency was the next and I decided on using 4MHz as I had access to a pile of some computer xtals of 4.032MHz.

Transmitter keying circuit and low pass filter

Junk stock provided the following:

  • Double balanced mixer SBL-1,
  • some 2N5109’s, J310 FET’s,
  • a few IF amps MC1350,
  • some toroids and
  • wire

I was ready to take on my own challenge – build it and work 100 countries with it!

Associated pictures with this article represent certain stages of the building process. As you can see I picked up an easy method for putting all together. I liked this approach for a simple reason that I can go step by step, keep adding components and test each stage as I move forward. There was no need for making PCB…who needs a PCB. In the old days, radios were built on a chassis and components hanging in the air and radio worked.

RX/TX antenna relay

On the other hand there was that perfection starring at me and making me feel a bit guilty, but I had no time to waste but hurry and build this radio in the short time I had available to me. Because you know what, the bands will just open up again, and then I had to do my other part – the DXing, hi so I may not be able to get this done.

I actually put the receiver in a working shape in one afternoon. I had the front end bandpass filter , double balanced mixed, post mixer amp, xtal filter, IF stage and audio section. All tested and worked first time. I spend the rest of the evening listening on 20m. Nothing much there but I found few stations up the band. There were few UA0’s as well. I managed to pick them up but signals were tiny. I decided to check my main radio and compare. I see now…signals were stronger, much stronger, S9 + on my TS850. So I checked few things and found few problems with my initial design: I had to amplify the input signal and my LO signal was too low to produce satisfactory mixing with SBL1. I used a J310 FET transistor for my front end pre-amp, and used single NPN transistor to boost the output of the DDS oscillator to appropriate level.

The receiver

I was ready to fire this thing and …wow, what a difference. I could still hear the UA0’s calling CQ and working others, and the signals were just incredible. Next obstacle was the Xtal filter. I had choose computer xtals that were somewhat matched in frequency, but the filter was way too narrow. I started experimenting with the capacitors around it and found a good medium that showed some good response on the signal quality and bandwidth.

Received signals now sounded “almost” like my ‘850. But I wasn’t happy yet. I was missing some “dynamics” in the signal. It was just a plain CW signal and nothing more to it. Next few days I experimented with an AGC circuit and variable bandwidth for the Xtal filter. After number of changes, I came up with a solid audio AGC circuit and S-Meter. That made a whole lot of difference. Everything was still sitting on the bench, loosely connected together and I was listening up and down the band. There were more stations now…hmm the bands must be opening up or something?

Receiver (left) & Transmitter (right)

For the xtals filter I ended up replacing the fixed caps with varicap diodes which I pulled out from an old TV tuner found at one of the local hamfests. You know that feeling when you can actually adjust xtal filter bandwidth. That is what was missing. I spend hours listening and trying to get into motion for my next step. I was simply amazed what I could pick up with the receiver and how I was able to select different signals, some of them very weak.

I went back and forth between my main radio and this little receiver that was sitting in front of me, still in pieces. “Not much difference is it?”–I was thinking to myself. I actually ended up spending hours in this year’s CQ WPX CW contest and only listening on my new receiver. I was able to pick every signal I wanted, even thru some heavy pile ups. It passed the test! Now I wanted to call these all these stations, so it was time for me to start thinking about the transmitter part.

Receiver front end and mixer

This was nother challenge. I tried one circuit and it worked. Straight forward a TX mixer, bandpass filter, couple stages amplification, low pass filter to the antenna. But I could not get the output power I wanted. I was getting something like 1 W barely making it to 2W. I figured out the reason. It was the transistors I used. Each stage must have enough gain to drive the next one. My final transistor was capable of producing an easy 10 watts out, but I was lacking drive power. I checked the complete circuit and components I had available on hand then decided to make few changes. Remember: the goal was to use what was available and not to go and spend any extra money. I ended up adding extra amplification after the TX mixer. Yep! That was it. That is what I was missing. I was now getting an easy 8W out. I couldn’t wait to hook up the antenna. I had no antenna switching circuit yet, so I hooked up my 3 element SteppIR on the little transmitter and used my vertical antenna on the main radio. Nothing easier than this. I was able to hear my transmitted signal and, at the same time, I could listen on frequency. First call and into UR land…559, “not bad,” I though. I then moved up the band and found a French station ending up a QSO, so I called him and worked him too. I got 579 for my signal. This was getting exciting. I ended up working 10 different countries that evening, mostly Europeans.

I spent the next week or so working on the box and figuring out how to implement the mechanical part of this project and get everything together. I tried using the little radio on 2 different bands (20 and 17M) with excellent results. These have been my main bands this year after they stabilized somewhat and we have them open after work until late. This is the perfect time for experimenting.

Receiver bandpass filter

Final touches can be seen on the rest of the pictures displayed here. I actually used this rig in the IARU CW contest for a while as well as in few QSO party’s on 20m, all with great success. The crown of everything was still to come.

It was getting close to the end of ST0R operation and I had them worked with my main station and KW into antenna on every possible band and mode I could hear them, but that one evening I was listening to their easy going pile-up on 20m working NA stations. The pile-up wasn’t that big and I was thinking,
“should I try this little rig and see if maybe somehow they will hear me?” I wasn’t sure this was going to work, but I hooked up my memory keyer and started pushing the button to send my callsign out. I did this for almost 2 hours. Yes, there was nothing else to do, while I was reading a magazine, I just used the preprogrammed call sign and kept sending it over and over.

Top view of N3CZ's QRP transceiver

Then I heard Lynn W4NL working ST0R with his QRP rig…NO WAY! What is he doing differently then me? And I am going crazy and about to give up, but….I was careful enough to check what frequency was W4NL transmitting so I tune up a little higher then he was. At the same time I received email from Lynn saying he worked ST0R QRP! Yes, I know I heard you Lynn…so I pressed few more time on the keyer. Guess what? It took couple more calls and there he was….smiling at me ST0R called me N3CZ 599 BK. There must have been another CZ I thought, so I send my call, then 599 and then my call again. Sure enough he came back with N3CZ TU. That was it! I did it! I just worked ST0R–a new country in a pile-up with my little homemade radio. I had them worked already on 20 CW , so what if it was a dupe? I knew I did it with my little radio and that was good enough for me. This is where I actually stopped and realized that I have accomplished my challenge. At least I have made it to a milestone, a major milestone. At that time I had well over 60 DXCC countries worked with the little radio, and it was barely 2 and a half months since I started working on this project.

I found this encouraging and I would challenge those readers who are thinking about a similar endeavor to not think twice–just do it!  Order yourself a kit at least and put it together. The reward cannot be described here or told by anyone. You have to feel it on your own. Put a challenge for yourself. Make a goal to work 10 states maybe or 10 DXCC countries, or 100. It doesn’t really matter. What matters most is that you give this hobby of ours another chance. A chance that makes it different from any other hobby on this beautiful planet we live on. What better can it be than communicating with others over a the vast emptiness of the space around us and bounce few signals now and then of the ionosphere?

“DX RULES” as my good friend Bill N2WB from Florida say.

N3CZ's QRP rig front face

I say “HAM RADIO RULES!” nourish it with everyday ideas, build your own stuff, don’t just buy that new radio and antenna, ready assembled and waiting for you to simply push few buttons and “work that rare DX”. There are many aspects of this hobby and like with anything in life we have to find it on our own. Sometimes we get help from another ham, sometimes a complete stranger to us, but with the same ideas.

Thanks to Dave K4SV, Phil W9IXX, Lynn W4NL and Carl N4AA who insisted on getting this article done [originally for The DX Magazine]. And all the stations who logged N3CZ/QRP. That was me who called you with this little homebuilt-junk parts radio. Drop me a note if you find this interesting and inspiring, because that was my intention anyway. By the way, I am already gathering parts for my next project. This time it really started with a nice box, but we’ll see. I don’t see that spark yet. I will let you know how it goes.

Until then,
73 & CU on the bands.
TU de N3CZ / ZS6MG / Z35C
Vlado

And thank you, Vlado, for sharing this article for QRPer.com readers! To contact Vlado, grab his email from QRZ.com.

If you have a home-brew QRP project that you would like to share with QRPer.com readers, simply contact us or comment!