Category Archives: QRP

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.

An External Battery for the KX1

NOTE: I am embarrassed to admit that I made a significant error in my original measurement methodology and the numbers originally listed below were inaccurate. I’ve redone all the measurements and the text and tables below reflect the corrected measurements. *

Your host, K4SWL, asked me to share my experiences in trying to find a small, lightweight, battery pack for use with my field-portable QRP station. While I’m looking for a battery pack specifically for my Elecraft KX1, what I’m learning should be useful for users of any low-current QRP transceiver.

original 10-cell battery-holder -- click to enlargeCurrently, I’m experimenting with a pair of ten-cell AA battery-holders, one of unknown provenance (photo) and a new, more rugged one from Batteries America (p/n 10AAT, photo). When filled with ten AA NiMH cells, the resulting battery-packs provide about 14v at full-charge. At the 2012 Flight of the Bumblebees, my KX1 generated an indicated 2.6w on 20m and 4w on 40m while being powered by one of these packs; the nearly four hours of low-stress operating during this event did not discharge this pack of 2,000mAh cells very deeply. The use of two AA dummy-cells will also allow the use of eight lithium primary or alkaline cells in an emergency.

new 10-cell battery-holder -- click to enlargeI became concerned about using this style of spring-contact battery-holder when I found an article (link) by Phil Salas, AD5X, in which he reported that this sort of battery-holder is likely to display significant voltage drop under load.

I tested my original battery-holder with ten 2,000mAh NiMH cells and my KX1 transmitting into a dummy load. In addition to measuring whole-pack voltage-drop, I measured the voltage-drop of each of the individual 2,000mAh cells as I transmitted into the dummy load on 20m.

Original Battery-Holder / 2,000mAh cells
Band ΔVpack ΣΔVindiv.
20m 0.76v 0.52v
30m 0.79v
40m 0.75v
80m 0.70v

The sum of these individual drops was 0.52v, so I’m losing 0.24v in the spring-contacts and/or battery-holder’s “transistor battery” output connector.

After replacing the original nylon connector with a pair of Anderson Powerpoles, I tested the same 2,000mAh NiMH cells in the new, more rugged battery-holder, this time only on 20m:

New Battery-Holder / 2,000mAh cells
Band ΔVpack ΣΔVindiv.
20m 0.73v 0.53v

I’m losing about 0.20v in the battery-holder’s spring-terminals, slightly less than with the older battery-holder.

The 0.20v ~ 0.24v drop from the spring-terminals doesn’t seem excessive to me and the difference in these measurements between the two battery-holders is probably not significant. I am more concerned by the 0.53v ~ 0.54v voltage-drop I measured in the individual cells. It is likely that these older 2,000mAh cells, which have been cycled many times, are exhibiting greater voltage-drop than new cells would. To test this theory, I purchased new 2,100mAh cells to measure.

I measured the new cells as above, again on 20m into a dummy load, and found that with each of the battery-holders, the sum of the individual cell voltage-drops was 0.22v, so my speculation appears to have been correct–the new cells do have lower voltage drop under load than the old cells do.

Orignal Battery-Holder, 2,100mAh cells
Band ΔVpack ΣΔVindiv.
20m 0.48v 0.22v
New Battery-Holder, 2,100mAh cells
Band ΔVpack ΣΔVindiv.
20m 0.47v 0.22v

The new 2,100mAh NiMH cells are marketed by Polaroid and cost $6 per four-pack at Big Lots; the least expensive AA NiMH cells available at Batteries America, 2,500mAh Sanyo cells, cost $3 each at the time of this experiment. I don’t know if the Polaroid cells will last for as many cycles as the probably-higher-quality Sanyo cells would but trying the significantly less expensive Polaroid cells seemed like a a good gamble.

As indicated above, the new battery-holder (Battery American p/n 10AAT) is more rugged than my original battery-holder; it holds the AA cells more securely and and doesn’t use a “transistor battery” connector to connect to the load. I replaced the original nylon connector with a pair of Anderson Powerpoles. This battery-holder will be my preferred battery-holder for field operations with the KX1.

In his article (link), Phil Salas, AD5X, recommends foregoing battery-holders in favor of soldered/welded battery packs but I will continue to experiment with battery-holders. I prefer to charge my NiMH cells individually, using an intelligent MAHA charger, rather than charging an entire pack. In addition, my KX1 draws significantly less current on transmit than Phil’s IC-703 does so the the IxR losses I’ll experience will be less significant than that which Phil experienced.

Visit my website to learn more about my QRP operations or to learn more about my KX1 Mini Travel Kit.

* What had I done wrong? I discovered when testing my new battery-holder that the previous measurements of the old and new NiMH cells in the original battery-holder had been made with the KX1 transmitting into a 50Ω dummy load with the KX1 autotuner configured in tune mode instead of in bypass mode; because the KXAT1 autotuner doesn’t sense a mismatch and automatically tune, this meant that transmitter current–and the measured IxR voltage losses–might be also be significantly different than with the KX1 transmitting into a matched load. Comparisons of my original numbers to measurements made later of the new battery-holder wouldn’t be meaningful, so I had to do all the measurements again.

Ten-Tec Model 418 100 Watt Amplifier now shipping

The Ten-Tec Model 418 100 Watt Linear Amplifier (Click to enlarge)

(Source: Ten-Tec)

TEN-TEC Inc. Announces the Model 418

160-6 Meter Solid State Linear Amplifier in stock and ready for shipment

Generating 100 Watts of output from as little as 5 Watts of input, the Model 418 Amplifier raises the bar for reliable and efficient recreational, emergency, and even contest communications.

TEN-TEC Engineers have utilized state of the art, silicon MOSFET technology to create a continuous 100% dutycycle operations in both CW and SSB Modes. The Model 418 is also compliant with AM, FM, AFSK, and PSK modes of operation.

Measuring only 3.625” x 6.5” x 7.6” inches and weighing just 5.4 lbs, the Model 418 will operate from any 13.8VDC (+/-15%), 20 Amp power source.

Designed to interface with the new TEN-TEC Model 539 QRP Transceiver, the Model 418 amplifier can be easily connected to most low power transmitter designs (20 Watts or less input). The amplifier’s comprehensive User’s Manual and TEN-TEC’s industry standard Technical Support department make set up quick and easy.

The Model 418 can switch bands automatically or manually. It also has a two position manual antenna switch. Bypass operation allows low power operation until higher power is needed.

The Model 418’s large LCD front panel readout gives the operator essential information about Output Power, SWR, Operating Voltage, and even Operating Temperature.

The TEN-TEC Model 418 Amplifier is competitively priced at $785.00

Don’t for get to send us your latest Shack Photographs and submit links to your club or community event for the community page. This is a great way to get some exposure for your organization or a community event station.
The TEN-TEC SSB Net meeting frequency has changed to 7.260 LSB Sundays at 4PM Eastern Daylight Saving Time.

73
Jim Wharton, NO4A
Vice President

Elecraft KX3 Tops Sherwood Engineering’s Receiver Test Data

Wow–the Elecraft KX3 has some serious ears! Most impressive, Elecraft!

2012 Fort Tuthill QRP Conference July 26-28

(Source: John Stevens, K5JS, via QRP-L)

It’s time once again to join the Arizona ScQRPions at the annual Fort Tuthill QRP Conference in mountains of Flagstaff, Arizona!! Spend the weekend camping with us at a cool 7500′ playing radio and listening to our outstanding speakers present topics on using Microchip micro-controllers, troubleshooting, Software Defined Radios, and
batteries.

Thursday afternoon, July 26, is for the early bird campers to arrive and get set up. Stake out your territory at our reserved campground site. Water is available, but no electricity. There are fire rings / grills for your outdoor cooking and no known fire restrictions inside
the campground at this time. Daytime temperatures should range from mid-70s to low 80s during the day and 50’s at night. Brief (usually) mountain thunderstorms with gusty winds are possible at all times especially during the afternoons.

Campground activities Friday, July 27, could include such things as easy expeditions to local SOTA peaks, operating, trading, renewing old friendships and making new ones, experimenting with antennas, and many other activities. There are plenty of tall Ponderosa pines for those wire antennas. Friday evening is our traditional group supper at one of the local restaurants.

Saturday, July 28, is our day for the technical forums at a nearby facility. We’ll adjourn about 3pm and head back to the campgrounds for our Saturday afternoon picnic. We have a covered ramada that will accomodate 70 easily. Water and electricity is available. You might want to bring a chair and/or table just in case as we don’t have quite the number of picnic tables as we’ve had in the past.

No tickets to buy. Prizes. No tickets to buy. All are welcome.

Bring your own entree for the picnic and we’ll do the rest! Look for many more details on our website at http://www.azscqrpions.com which is being updated. Watch for updates at the website or from @azqrp at Twitter. Send me your cell phone number if you want text updates.

Select Ft Tuthill 2012 in the menu.

Pass the word and we hope to see you there!!

73 john k5js

A QRP Family Holiday on Prince Edward Island, Canada

K4SWL portable VY2!

This year, during our family’s summer holiday, I’m enjoying the hospitality of Prince Edward Island, Canada (hence, the lack of recent posts on QRPer).  This is our family’s second visit to the maritime island, and each time we’ve been  fortunate to stay at the same off-the-grid cabin on the eastern coast, less than twenty meters from the water.

Of course, staying in an off-grid cabin comes with its radio challenges—namely, supplying power—but also comes with one supreme advantage:  no noise from the typical electrical devices that plague most of our homes. What’s more, this cabin sits on 60 acres, so not even a neighbor’s home appliances disturb my RX ears.

On our previous visit, I brought my (then) Yaesu FT-817, a 9aH gel cell, Micro M+ charge controller, 10W Solarex PV panel, some 300 ohm window line, loads of 22 AWG wire and an LDG ATU.  Unfortunately, I found I had very little time for radio, and propagation was dismal. Indeed, it was during that trip that I discovered my FT-817’s finals had blown, so part of the time I was transmitting less than QRPpppp levels.

This year, since I knew the site well, I came better prepared.

My full 2012 setup consists of the following:

  • An Elecraft K2/10
  • An Elecraft KX1 (4 band w/built-in ATU)
  • Elecraft T1 ATU
  • LDG 4:1 Balun
  • One 35 aH gel cell
  • Two 9.5 aH gel cells
  • Two PowerFilm Solar foldable 5 W PV panels
  • My radio toolbox with various connectors, crimpers, cutters, wires, caps, multi-tester, etc.
  • Enough wire and 300 ohm antenna line to make a couple of wire antennas

So…how’s it all working out? Brilliantly!

In the past few years I’ve done a lot of QRP CW—mainly rag-chews with some buddies on the lower bands. I’ve done less QRP SSB phone. When I first arrived at the cabin and began the process of unpacking, I couldn’t find the jumper cable to attach to my Vibroplex single-lever paddle (the paddle being a Dayton 2012 find, by the way). So, I plugged in a microphone and tuned to the phone portion of the 17 meter band.

Talk about radio fun!

I’ve once again re-discovered the joy of operating QRP SSB. It’s challenging to make those DX contacts and to transmit a long call sign (“VY2 portable K4SWL”) across the ether,  but occasionally the propagation gods smile upon you, and you’re able to participate in a good rag-chew or quick DX with a 57 to 59 signal report.

Being 20 meters from the salt water is a bonus I don’t usually enjoy in my US hermitage. Due to its excellent propagation characteristics, despite my lower power set-up, I have easily worked stations from Russia to North Africa, from  the Caribbean to Japan.   I am thoroughly reveling in it, and the process has re-connected me with my ham radio roots.

As Gunter, VA3GA, told me in a recent Canadian rag-chew, “ham radio holidays give you a chance to explore areas of the hobby you don’t normally think to enjoy.”

So true, Gunter. That’s what I love about ham radio in general– the hobby is so broad, you constantly discover and re-discover favorite elements about it.

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.

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!

The Ten-Tec Model 418 100 Watt Amplifier update and spec sheet

The Ten-Tec Model 418 100 Watt Linear Amplifier (Click to enlarge)

Along with the newly released specs of the Ten-Tec Model 539 Argonaut VI transceiver, Ten-Tec has kindly provided QRPer with a spec sheet of their new Model 418 100 watt solid-state linear amplifier.

This versatile amp shows promise, and may turn out to be a really big seller for Ten-Tec. Perhaps their biggest.  Here’s why:

  • The Model 418 amplifier will work with almost any QRP rig on the market (new or used)
  • Just 5 watts in, delivers 100 watts out
  • It covers the full HF spectrum plus 6 meters
  • It has 2 HF antenna inputs with a manual switch, and a separate 6 meter antenna port that is automatically engaged when you switch to 6 meter operation
  • It offers an easy bypass mode
  • It offers auto or manual band selection
  • Power, SWR and voltage are all displayed on the back-lit LCD panel
  • It offers 13.8V DC input with standard Anderson Powerpole connection
Click here to download the Ten-Tec Model 418 spec sheet

Ten-Tec will announce the price of the Model 418 at the Dayton Hamvention this Thursday. We look forward to that, and once announced, will be sure to post it here, same day.

The upshot: If priced competitively, the Model 418 is basically a little box that can turn your Argonaut V, Argonaut VI, Yaesu FT-817, Icom IC-703, Ten-Tec Cub, Elecraft K1, K2/10, K3/10,  KX3, Index Labs QRP+, or most any other QRP radio on the market into a 100 watt rig. It appears to be truly plug-and-play, too, with auto band switching.

In my case, for example, this would be a very useful product. Though I primarily operate QRP, I do on occasion like a shot of extra power, such as when conditions are bad or I’m trying to bust through a particularly heavy pile-up. I rarely–if ever–run more than QRP when operating portable, though. The Model 418 could plug into my K2/10 while in the shack, and I could pump up the wattage as needed. It would also work with any future QRP rigs I may buy. When operating Field Day with my club, I could take the K2 and ‘418, which would give me a 100W transceiver without adding the 100W module to the K2, thus keeping the K2 lighter for my portable operations outside of Field Day.

Yep, as you’ve guessed, I want one already…!

••••••••••••••••••••

Again–just to be clear–this is not idle speculation; the facts I’ve posted above, including the spec sheet, came directly from Ten-Tec today. We appreciate that Ten-Tec has provided us with the spec sheets for the Model 539 and the Model 418 prior to the Dayton Hamvention, exclusively for QRPer readers. Thanks, fellas!

The ultimate Field Day tent?

The 2 kW "Power Shade" is the right size to cover a full-size military tent.

Power Film Inc. is a developer and manufacturer of thin, flexible solar modules.  The company designs, manufactures and retails their products in Ames, Iowa–a quality made-in-USA product.

Last year, at the Dayton Hamvention, PFI’s booth was very popular. Why? Their sale of small, rollable and foldable solar panels, absolutely perfect for field use, drew crowds of hams, DXers, campers, and/or frequent travelers.  Needless to say, sales were brisk.

While browsing their website recently (just for fun), I came across their PowerShade™ Solar Field Shelters. They’re available in 1 kilowatt and 2 kilowatt versions at 15.4 V or 30.8 V.  Wow…

This paneled tent is primarily focused at the military market.  Perhaps exclusively.  And I readily admit, it would be overkill for QRPers, even for a multi-op QRP Field Day.  After all, aren’t we about “less is more”–?

But is it wrong for me to fantasize about this wonderful 2 kW creation? A tent-topper that sucks in Sol’s readily-available energy and, with the assistance of a battery bank, produces enough juice to fuel several QRP rigs?

I dunno.  I’m too busy fantasizing to care…!