micro-BITX: a homebrew general coverage SSB/CW QRP transceiver

Image Source: uBITX)

Many thanks to Pete (WB9FLW) who shares the following:

Farhan VU2ESE Does It Again!

http://www.phonestack.com/farhan/ubitx/ubitx.html

A compact 10 watts, easy to build, general coverage SSB/CW transceiver for HF bands

Homebrewers have traditionally avoided making multiband transceivers as they can get extremely complex and difficult to make. There have been some remarkable successes in the past, the CDG2000 (designed by Colin Horrabin G3SBI, Dave Roberts G8KBB and George Fare G3OGQ)is one such design. The SDR route as followed by several designs offer some simplification at the cost of bringing digital signal processing and a PC into the signal path.

On the other hand, many of the homebrewers do need a general coverage transceiver on the bench as well as as a base transceiver for bands beyond the HF. I ended up buying an FT-817ND that has been a reliable old warhorse for years. Two years ago, I attempted a high performance, multi-band architecture with the Minima transceiver. The KISS mixer of the Minima, though a very respectable receiver front-end, had serious leakage of the local oscillator that led that design to be abandoned as a full transceiver. Over months, I have realized that the need for a general coverage HF transceiver was wide-spread among the homebrewers. Most of us end up buying one.

While achieving a competition grade performance from a multiband homebrew is a complex task as evidenced by the works like that of HBR2000 by VE7CA, it is not at all difficult to achieve a more modest design goal with far lesser complexity. The uBITX shoots to fulfill such a need. It is a compact, single board design that covers the entire HF range with a few minor trade-offs. This rig has been in regular use on forty and twenty meters for a few months at VU2ESE. It satisfies for regular work, a few trips to the field as well.

A key challenge for multiband transceivers has been to realize a local oscillator system with such wide range. Silicon Labs has now produced a series of well performing oscillators that solve this challenge trivially : You connect the oscillator chip over a pair of I2C lines and it is done. The Si5351a is one such a part that provides 3 programmable oscillator outputs in a small 10 pin TSSOP package. We will exploit this chip to build the multiband transceiver.

Having exclusively used homebrew transceivers all the time, I get very confused whenever I need to use a commercial radio. There are too many switches, modes and knobs to twirl around. The uBITX use an Arduino to simplify the front panel while retaining all the functionality in a simple menu system that works with the tuning knob and a single ‘function’ button. The rig supports two VFOs, RIT, calibration, CW semi break-in, meter indicator, etc. In future, more software can be added to implement keyer, SWR display, etc.

Click here to read the full description of this project and download diagrams/schematics!

This is brilliant!  Thank you for sharing, Pete!

Posted in Homebrew, News | Tagged , , , , , | 1 Comment

Ham takes SOTA activation to new level

(Source: Southgate ARC)

Amateur takes unusual route to SOTA

Colin Evans, M1BUU, from near Haworth, West Yorkshire attained SOTA Mountain Goat on Saturday 28th January on the summit of Whernside, G/NP-004.

Colin took rather an unusual approach to his activation of Yorkshire’s highest mountain, by constructing his equipment whilst on the summit.

Colin had taken a QRPme 20m RockMite kit, a home made key kit, a home made vertical antenna kit and a gas powered soldering iron along with him. Sheltering from the wind, rain and snow in a small tent, Colin successfully constructed the RockMite, key and antenna in just under 4 hours.

The first QSO for Colin with his 250mW RockMite was with N1EU near Albany, New York, over 3000 miles away, the three subsequent QSO’s were with European stations, satisfying the SOTA rule requirement of four QSO’s to claim the activation points.

SOTA Mountain Goat is awarded for gaining 1000 SOTA Activator points. For more information, visit www.sota.org.uk

Posted in News, SOTA | Tagged , , , , , , | 1 Comment

BITX40 Goes Digital

bitx40v3_main-1

Many thanks to Pete (WB9FLW) who notes that Ashhar Farhan (VU2ESE) has upgraded the BITX40 Transceiver with a Arduino Nano/Si5351 VFO:

http://www.hfsigs.com/

Thanks for the tip, Pete!

 

Posted in Kits, News | Tagged | Leave a comment

Kickstarter: HobbyPCB 5 Watt SDR starting at $239

Many thanks to Jim Veatch (WA2EUJ) who shares the following:

HobbyPCB is offering their RS-HFIQ 5W SDR on Kickstarter starting at $239. Check it out here:

Posted in Announcements, Product Announcements, Software Defined Radio | Tagged , , , | Leave a comment

BITX40: A Fully Assembled $45 SSB QRP transceiver

bitx40v3_main

Many thanks to Pete (WB9FLW) who writes:

Don’t know if you have seen this or not. VU2ESE of BITX20 Fame has just introduced the BITX40.

This is a fully assembled and tested SSB Transceiver for $45 including shipping from India!

http://www.hfsigs.com/

Wow! I may have to purchase one of these and try it out.

I’m currently teaching a HamRadio 101 course to a group of 13 year olds. One of them recently asked how much it would cost to get a basic HF radio kit with SSB mode.  HF rigs–even basic ones–tend to be quite expensive if they include SSB.

Here are details from the BitX40 order page:

BITX40
Work the world on 40 meters

When was the last time you used a radio you had built? The BITX40 board is single circuit board 40 meter SSB transceiver module. Inside an evening, you can be on-air with this SSB transceiver module, chatting with the local gang or chasing DX. Plug in the earphones, the included electret mic, tuning and volume controls and you are on air! Included are high quality connectors, all the needed sockets and jacks, tuning and volume controls, mounting hardware, etc.

Technicals

The BITX40 is a very clean, crisp and quite receiver. The front-end has a triple tuned circuit that cuts out-of-band signals from getting inside, a diode ring mixer front-end with a very low phase noise, all analog oscillator makes this a crisp receiver that doesn’t overload easily. The all analog signal path to your ear makes provides outstanding signal clarity that is to be heard to be believed.

7 watts of SSB provides you with enough juice to have thousands of contacts on 40 meters, daily rag chew and occasional DX chasing. Any common 2 ampere 12 linear volts supply will provide enough juice for this transceiver. Or you could simply run it from a battery!

Hackable

The BITX40 will inspire you to experiment. Modify it, mount it, tweak it, change it.

The PCB uses all analog large sized SMD components that are laid out on an easy to understand manner on a double sided board with broad tracks. This can be your main module around which you can start experimenting. There are jump-points from where you can add more modules like the DDS, more bands, better audio amplifier, etc. Imagination is your limit. You can separately increase the power amplifier’s supply voltage to 25 volts to be more than 20 watts of power : You will have to add a better heat sink. The mods are on the way!

The board can be installed inside any box that you like. Make your own station rigs, man-packs, trail radios or mount it in a cigar box and leave it on your bedside table. The tuning capacitor has been replaced by a varactor tuning so you can place the tuning knob anywhere as it only carries a DC voltage. Watch the instructions video.

Box Contents

We have tried to include connector/hardware you might possibly need to build a full radio. However, we also had to balance the shipping weight to keep the overall cost down. You will have to supply your own box, power supply and earphones/headphones/speaker.

  • 4-1/2 inches by 5 inches tested SSB transceiver module, covering any 150 KHz segment of the 7 MHz band
  • Small electret microphone
  • High quality BNC connector for the antenna
  • Two earphone style audio jacks for the mic and the earphones/speaker
  • A set of DC power socket and plug
  • Volume control with on/off switch
  • 100k linear pot for tuning
  • 4 Brass stand-offs with mounting nuts and bolts
  • Connectors with wires for all connections on the board

* Note : A speaker is not included in the kit as earphones/headphones/speakers are easily available locally. No cabinet is included to save on the postage cost. Almost any box maybe used.

Manufacture

The BITX boards are hand assembled by a collective of women. Each of the toroids is hand wound. This provides these women with livelihood. The assembled boards are then DC checked a final RF check is performed to check the receiver’s sensitivity as well as transmitter’s output before being shipped. Each board is individually numbered.

Click here to view the BITX40 ordering page. 

Posted in News, QRP | Tagged , | 3 Comments

The new CommRadio CTX-10 QRP general coverage transceiver

commradioctx-10

[Originally poublished on the SWLing Post.]

Many thanks to Fred Osterman and Dave Zantow for sharing information about the new CommRadio CTX-10 transciever.  Here is the description from Universal Radio’s catalog:

AeroStream Communications near Golden, Colorado entered the hobby radio market in 2013 with their revolutionary CommRadio CR-1 and follow up CR-1a SDR receivers. The success of these innovative radios left many asking for a transceiver of similar size and capability.

The answer is the just announced CTX-10.

The CommRadio CTX-10 blends high performance, internal SDR technology, high efficiency circuit design, compact size and simple operation. This multi-mission QRP radio is ideal for field use and emergency operations. Transmitter covers 160-10 meter amateur bands with output power adjustable from 1 to 10 watts. The new design uses ruggedized land mobile power amps in push-pull. Every aspect of the radio design is optimized for low power consumption.

The efficient and sharp OLED display is readable in low or high lighting conditions. The radio has three built-in #18650 3.7V 2600 mAh Li-ion batteries providing 28.8 watt-hours of operation. A built-in intelligent charger provides seamless power management.

The general coverage receiver section uses multiple preselectors for optimized reception from 200 kHz to 30 MHz. An integrated CW reader and antenna tuner enhances portability. The premium tuning knob optical encoder is rated at a million revolutions.

Entire enclosure is aluminum with metal knobs and front panel. External connections are through-hole mounted for durability. Includes USB cable, DC power cord and manual. DC power requirements: receive 1.5 W, transmit 20 W. This quality device is robustly built in Colorado, U.S.A.

I’m really looking forward to reviewing the CTX-10. If the CR-1 and CR-1a are indicators, this could be a very well-built unit with a top-notch receiver!

Follow the tag CTX-10 for updates.

Posted in Announcements, Product Announcements | Tagged , , , | Leave a comment

NPOTA: Photos from weekend “two-fer” activation of TR10 and PK01

[This post was originally published on my other radio blog, The SWLing Post]

npota-tr10-pk01-qrp-encampmentview

As seen from the Overmountain Victory Trail: The Revolutionary War encampment at the Museum of North Carolina Minerals.

As I mentioned in a previous post, what I love about the National Parks On The Air program is that it combines two of my favorite things: national parks and ham radio. My family visits national parks regularly, so it’s easy for me to pack a small radio, do a quick NPOTA activation all while incorporating non-radio activities that the family loves.

npota-tr10-pk01-qrp-2

On Saturday, I activated both the Blue Ridge Parkway (PK01) and Overmountain Victory National Historic Trail (TR10)–a “two-fer” activation.

Normally, I would set up my station somewhere close to the Museum of North Carolina Minerals which is situated at the junction of these two National Park entities. Saturday, however, was a special event at the museum: a Revolutionary War Encampment.

Blue Ridge Natural Heritage describes the annual event:

The Museum is located at Gillespie Gap, an important stop for Revolutionary War fighters on their way to the Battle of Kings Mountain. Each September the Museum hosts an encampment of re-enactors who assume the role of the Overmountain Men, primarily Scots-Irish settlers from Eastern Tennessee and Western North Carolina who came “over the mountains” and ultimately defeated the left wing of Cornwallis’ army at Kings Mountain, South Carolina. Many historians mark this victory as the turning point in the Southern Campaign of the Revolutionary War.

npota-tr10-pk01-qrp-encampment2 npota-tr10-pk01-qrp-encampment

My family loves living history events.

Radio time!

The Park Ranger kindly gave me permission to do the NPOTA activation, but not at the museum itself.  She was trying to keep the site set in the Revolutionary War period–a ham radio operator using a portable transceiver doesn’t exactly fit that description. Instead, around 15:30 UTC, I hiked up the Overmountain Victory Trail in search of an operation site near the Blue Ridge Parkway road.

npota-tr10-pk01-qrp-overmountain-trail-head

The trailhead was a little rough and overgrown. I didn’t have to trail-blaze, but I did have to wade through a lot of weeds with my gear and my canine companion, Hazel, on leash. It’s times like this I truly appreciate such a compact, lightweight, and packable station.

npota-tr10-pk01-qrp-trail-messy

Can you find the trail in this photo?

Once we entered the woods, though, the trail improved. I found a fantastic spot to operate between the museum and the parkway.

npota-tr10-pk01-qrp-7

Hazel the dog is a welcome companion does a wonderful job keeping my site free of black bears. She’s patient, too. I typically tie her leash to a small stake or tree next to me and she promptly takes a nap. Here she is admiring my new REI Camping Stool:

npota-tr10-pk01-qrp-rei-trail-stool

npota-tr10-pk01-qrp-antenna

You can see part of the EFT Trail-Friendly antenna hanging in this photo.

Setup was quick. I managed to raise the EFT Trail-Friendly antenna in record time. I connected the antenna to the Elecraft KX2 and was on the air, calling CQ on 20 meters in a matter of minutes. npota-tr10-pk01-qrp-elecraft-kx2-clipboardIn the space of 15-20 minutes, I only managed to work a few stations on the 20 meter band even though I had been spotted several times on the DX Cluster.npota-tr10-pk01-qrp-elecraft-kx2-logs

I moved to the 40 meter band and logged contacts quickly, however.

npota-tr10-pk01-qrp-hazel-and-station

My full station and my ferocious guard dog, Hazel.

Hazel, as I mentioned, is a great companion that’s sweet to everyone she meets. She’s happy to hang with me even if I’m just sitting there operating radio for an hour. She’s quiet and doesn’t bark unless she notices a true disturbance.

Still, Hazel does get bored. After I had logged about 20 stations, I heard her gnawing on something. I turned around and discovered that she found the reel of fishing line I use to hang my antennas.

npota-tr10-pk01-qrp-4

npota-tr10-pk01-qrp-fishing-line-hazel

Note to self: next time pack Hazel a bone.

She didn’t even look apologetic or guilty! Oh well…fishing line is pretty cheap to replace and I’m sure she assumed it was a chew toy I had placed there for her.

All in all, it was a very successful activation. In less than one hour, I put 22 stations in the log. The weather was perfect and the whole family had a blast.

npota-tr10-pk01-qrp-1

A photo I took prior to watching a reenactment of the Battle of King’s Mountain.

What a wonderful day to play radio, take in our national parks and re-live some of our history!

Posted in NPOTA, Portable, QRP | Tagged , , , , , , , , | Leave a comment

What can go wrong? A box, a cat, and a little CW.

Many thanks to my buddy, Philip (N4HF), for sharing this video that made me chuckle:

Posted in Funny | Tagged | Leave a comment

NPOTA: Activating the Carl Sandburg Home (NS07) today

Elecraft Kx2 ON Clipboard

This afternoon (September 8), I should have a chance to activate the Carl Sandburg Home again for the ARRL National Parks on the Air program. You might recall, I activated the site Sunday as well.

I’ll plan to use the Elecraft KX2 and EFT TRail-Friendly antenna combo once again.

I should be on the air starting sometime between 20:00-20:30 UTC (4:00 – 4:30 PM EDT). I’ll plan to operate SSB on two frequencies: 14286 and 7286 kHz. I’ll be on the air for one hour or so, if all goes well. Listen for my amateur radio call sign: K4SWL.

If you hear me on the air, please consider submitting a spot to the DX clusters!

Posted in News, Portable | Tagged , , | Leave a comment

NPOTA: Activating the Carl Sandburg home (NS07) today

It just doesn't seem possible that I have almost everything I need to make the NPOTA activation today in this pittle pack.

It just doesn’t seem possible that I have almost everything I need to make the NPOTA activation today in this pittle pack.

I am planning to activate the Carl Sandburg Home (NS07) for National Parks on the Air today. I should start sometime between UPDATE (17:00-18:00) UTC and operating for about one hour. I’ll be SSB/QRP on 14286 and possibly 7286 kHz (depending on the type of antenna I can deploy). I’m fitting this activation into a busy day, but will do my best to hit the air and work as many stations as possible.

I just finished packing everything for the activation.

This will be the first time taking my Elecraft KX2 to the field. It feels *very* strange not to pack even an external battery. Just the little radio, an antenna, a clipboard, an assortment of adapters and a short run of coax.

Not sure yet if I’ll hang the Par EFT trail-friendly antenna or use my telescoping fiberglass vertical (which performed admirably last week!). This is a sensitive archeological site, so I have to abide by the wishes of the park ranger on duty (though I’ve been given permission to install the vertical near their vegetable garden). I want to hang the EFT so I’ll have two bands (20 and 40) at my disposal.

If you have the time today, please try to work my station!

Posted in Portable | Tagged , , , | Leave a comment