Friday, December 19, 2014

The 2014 QRP ARCI Holiday Spirits Homebrew Sprint, And The Pixie

Last weekend was the QRP ARCI Holiday Spirits Sprint.  The last time I operated this 4-Hour mini contest was in 2009, so having recently built the Chinese Pixie, I was excited to enter the contest.

Since it IS a minimalist transceiver that's as WIDE as a barn door on receive, I wasn't expecting much.  Broadcast interference is still a little bit of an issue during the day, but on Sundays the local station plays ethnic Polish music.  Think POLKA!  It was pretty cool hearing CW activity as well as Polka music.  I  was pretty shocked that I was able to still copy the CW as well as hear the music.  My skills, even after 26 years, are still improving!

Overall, I only made 2 QSOs...K2CYS and W3TS.  With only 500 mW and a single frequency to operate with, I wasn't going to dominate 7.030...so sharing was necessary.  However, I DID qualify for a x10 multiplier as well as a bonus 10,000 points for homebrew transceiver and portable operation WITH battery.

The Pixie certainly isn't a contest radio, but for smaller sprints and contests, it CAN work.

I just received my second Pixie in the mail from China yesterday and will be adding 2 crystals for the Straight Key Century Club's 7.114 and 7.120 MHz meeting places.

Tuesday, December 9, 2014

The Chinese Pixie 2...Installed To The Case


It took quite a bit of metalwork to make the Chinese Pixie 2 fit into the Newman's Own box...but that was my project last Thursday while in the office supervising a T1 cutover from Verizon.  Our heavy equipment room at our shop is on the other side of the warehouse, so I could play radio and still keep an eye on things...like making sure the new T was set for 4 digit, "Wink Start", B8ZS was enabled, and all the other good stuff that makes me insane.

I have been having fun playing with the little Pixie.  I never imagined that a radio this crude and simplistic could ACTUALLY be capable of real communications.  Through the years, I had read QRP articles that detailed how OTHERS had done it, but I passed it off as a novelty.

And this radio is indeed a novelty.

You actually have to WORK to make a QSO.  There are no filters to kick in...no true ability to QSY...and not enough power to call CQ and be heard regularly.

But there are the rare moments when I DO call CQ with it and am rewarded with a contact.

Since completion, I have made 3 QSOs with the tiny rig...which is interesting, since when I was using the Chinese "Super Rockmite", I only made 4...and that was over the course of 6 months.  (Marathon training, work demands, and life sometimes get in the way.....)

Most of the time, I simply listen to the signals that the radio receives.  I have listened to QSOs...I have heard some DX calling CQ (seriously...actual DX!)...and even listen to W1AW working stations.  The audio is so wide that I can hear JT65 on 7.076 from time to time.  This is not the norm, thankfully.

The BCI overload is a problem that is a force to be reckoned with.  Yesterday, as I was all set to make a few QSOs with my NVIS-style 40m antenna, WXRL...the local COUNTRY music station was just blowing over the top of the radio.

Now...I have to be honest...I HATE COUNTRY MUSIC.  It serves the lowest common denominator in society.  If it were classical or jazz, I probably would be more accepting of this interference, but when it's COUNTRY...that is when I turn off the radio and find something else to do...or use the SR8T.

Thankfully, after playing around more with grounding Pin 7 of the LM386 and some other shielding techniques, I was FINALLY able to use the Pixie last night.  After a few CQs, I worked N1PVP just outside of Boston.  Decent QSO, although he was using a "Bug"...not my first choice in CW keys.  When ill-adjusted, they are very difficult to copy...even with my 26+ years of CW experience.  (I HAVE a Vibroplex Original Presentation, but still prefer my Ten-Tec KR5 single-lever paddle)

I have estimated the power of the Pixie to be around the neighborhood of 500 mW.  I am able to light the 1/2 watt LED on my LDG tuner, so it is reasonable to assume that this is the power output.

And still...I am able to see THIS on the Reverse Beacon Network:


I ordered another one of these $7.59 wonders, as well as the K1EL keyer kit.  The K1EL keyer can not only be set in Beacon Mode, but it can also do QRSS.  With lower voltage into the Pixie to protect the transistors, it should be interesting to see who can receive the milliwatts this will be transmitting.


Thursday, December 4, 2014

The Chinese Pixie 2 QRP Transceiver-An Asian Twist On An Old Favorite

Many hams have read about, heard about, or even used/owned a micro transceiver that is the essence of simplicity itself.

The radio I'm referring to is the much loved AND reviled, and misunderstood "Pixie 2".

The origins of this radio are familiar to the ardent QRP enthusiast.  The original radio, called the "Foxx", was invented in 1982 by George Burt, GM3OXX.  It was a simple, 5 transistor rig, that produced a WHOPPING 2.5 watts of RF on 40 or 80 meters.

Soon after, Oleg Borodin, RV3GM slimmed it down by eliminating one of the amplifier transistors and a few other "non-essential" components.  This, of course, became the "Micro-80" transceiver.  This radio is the closest cousin to the Pixie, in that, the oscillator stage appears to be quite similar.

Finally, WA6BOY's version of the radio eliminated the transistor audio amplifier stage and used an LM386 I.C.  This is the version that we still "use" today...almost 20 years later.

The Pixie 2 can be breadboarded out of junk box parts, or acquired all at once from a few vendors that sell the Pixie 2 in kit form.

The first, and most widely known is the version available from Halted Specialties, or simply HSC.


I have built three of these kits, and NONE of them worked very well...or at all.  The last attempt was a 30m version.  The quality of the circuit boards is atrocious at best, and for the beginner, this kit is better left alone.  To call it garbage would be too much of a compliment.

Next is the QRPme kit that Rex Harper sells, the Lil Squall.

I have known a few people that have bought this version, and they really like it.  The quality of the kit is outstanding, and having a custom made enclosure included is top notch.  Rex stands behind his products as well.  This Pixie has the unique advantage over the other kits, in that changing bands is a simple as changing the daughter-board with the appropriate coil settings for the band.  Nice touch!

Next is the RadioKit Pixie, available on eBay from Yiannis Kontarinis in Athens, Greece.
I have no information on this radio, so I can't really say much about it, other than its cosmetics.  It's not as attractive as the Lil Squall, but it is still pretty sharp looking.

And FINALLY...the version available from DOZENS (and I truly mean DOZENS) of sellers in China...

These kits are called the "Shoes" in China, although I believe that has something to do with how the word "Pixie" is translated back into English.  It is the same two-transistor circuit, with LM386 for audio amplification.

However, there are a few nice changes with this particular version.  Firstly, this radio has a 47K variable resistor that allows for a few KHz of tuning around the crystal frequency.  While it was also something that is featured on the Chinese "Super-Rockmite"...and allowed the TRANSMITTER to also QSY a bit, this one is strictly for the RX only.  Next is the rather beefy BNC jack.  This is a DRAMATIC improvement to the typical RCA jack that is used for the RF connections on many Pixies.  And finally...my favorite thing about this radio is the PRICE!  I bought mine direct from a Chinese seller on eBay (although you can also purchase them directly through China's domestic shopping site, Taobao.com) for $7.59...and it was shipped FREE from China via China Post.  And there are many sellers that sell them for as low as $5.50 with free shipping. 

The true reason that I bought this Pixie was due to an unfortunate accident that I had with my Super Rockmite, which I have currently written about before.  I was connecting my Ten-Tec KR5 keyer to it, but after doing so, the RM went into a wild self-oscillation that quickly destroyed the 8W behemoth.  Being so close to Christmas, I wasn't able to afford to replace it.  That's when I saw the Pixie.

The radio was ordered on November 7th, and shipped out the next day.  The worst part of shipping from China is the wait times in Customs.  But ANY international commerce is rife with delays like these, and having purchased many things directly from the PRC, I was familiar with the wait time.  The radio arrived in Buffalo NY 11 days later, as expected.  

The kits all come in padded envelopes, and when opened....this is precisely what you get:

And that is LITERALLY all you get. 

NO instructions.  Nothing but your circuit board and a small baggie filled with parts.

In order to make this work, you have to do a little legwork.  That's why ALL of the schematics and parts lists are on the sellers' pages...and they ALL do it this way.  I like to think that it keeps the costs down by not having to photocopy instructions over and over and over again.

Back on the seller's page, you find THIS:

Thankfully, the English translation is on the parts list.  And with this information, AND the fact that the circuit board is marked with component locations (R1, D2, etc), it's not too difficult to get the components roughed into place and ready for soldering.

In addition to the parts as listed, I also ordered a 7.030 MHz crystal from Rich at ESS.  For $2.95, he sent the appropriate crystal for this rig.  For some odd reason, almost 100% of the CW rigs that you buy from China come equipped with crystals for 7.023 MHz.  As a General Class ham, I can't use 7.023, and I don't think I would want to...since QRPers hang out around 7.030-7.040 anyway.

The rig goes together fairly quickly, however, it must be noted, as it is on a recent YouTube video describing this rig, the kit comes with A LOT of extra parts...parts you DO NOT NEED.  I don't understand the reason for this...perhaps the person putting the kit together ran out of needed values, and added a bunch of stuff as a "good faith" gesture...but this just adds to the confusion.  As in the video, I too, had to add my own resistors...a 1K and the 33K to be precise.  They did not come with the kit.  THANK GOD Radio Shack still sells some components.  In the meantime, while not wanting to wait until I got to RS to buy some 33K resistors, I simply paralleled 3 of them at 100K ohms per...and it worked just fine. 

The solder pads underneath the board (and it's a through-plated board...nice touch) are tiny, so a small iron is a necessity.  I have an 18-watt iron that has a tiny pencil tip that saved the day.  You WILL need a larger iron for soldering the coaxial power jack, both of the 3.5 mm jacks (key and audio out) and the BNC male RF jack.

Total build time was just under and hour.  Your mileage may vary, depending on your comfort with a soldering iron and how much light you have in your work area.  I say this because some of the components are TINY...and the markings can be difficult to read.  At 42, I am beginning to wonder if I may be needing bifocals soon.

After nipping off the soldered leads under the board, I connected my antenna and earbuds (iPod style work QUITE well in this little radio) and then the power...and was delighted to hear 40m spring to life.

The audio is TYPICAL Pixie 2...it's as wide as a barn door...but the sensitivity is actually very good for what this little toy is.  If you've ever used an old Heathkit HW-7 (with the 40673 for the detector), it's comparable...except there are NO microphonics.  

When using this, or ANY Pixie that is using the LM386, a few things must be adhered to for the best possible performance.  For starters, using a power supply is not recommended, as you WILL HEAR HUM.  Write it in stone.  Battery power is where it's at with this rig.  And many like the idea of being able to use a 9V battery due to size, but the 9V doesn't supply enough current for the Pixie to both transmit enough power AS WELL AS not current starve the LM386.  Many hams complain of the buzz or motorboating sound when attempting to debug a misbehaving Pixie...and sometimes it's BECAUSE of not enough voltage/current.  Secondly, a good antenna is essential.  I was able to hear QSOs in progress and even be reported on the Reverse Beacon Network while connected to my Opek HVT-600 portable antenna, but with a proper antenna such as a dipole or an end-fed (such at the antenna I sue at home), the audio really wakes up.  

At my home QTH, I am 9.5 miles away from WGR550 AM's transmitting tower.  I was able to hear it when I had my HW-7, and occasionally I can hear it through the Pixie.  Some cures for it are to ground Pin 7 of the LM386 via a 10 uF capacitor.  I have done this and it works very well to mitigate the BCI interference.

On Monday night, December 1st, I made a few CQ's and was answered by N2BHA in Rome, NY.  We had a nice QSO, while I tried to contain my enthusiasm.  Sure, it's only 165 miles from point-to-point, but the fact still remains that it IS a radio capable of REAL communications.  I know that I will be installing this into a typical "Altoids" style box (although mine is a blue Newman's Own box...I like to be different) and also will be adding a a K1EL K-16BAT kit so I can use an Iambic A single-lever paddle.

In summation, this is a nice, BASIC, NO-FRILLS radio.

PROS:
-COST
-AVAILABILITY
-EASILY EXPANDED

CONS:
-BCI OVERLOAD IF IMPROPERLY GROUNDED, ETC
-LACK OF INSTRUCTIONS
-EXTRA AND MISSING COMPONENTS

73/72 de KB2HSH


Tuesday, June 10, 2014

The COMPLETED Chinese Super Rockmite/Octopus Clone


In the photo above, you see the finished result of all of the pieces and parts...fit together just right.

I originally went looking for Dupli-Color DE1618 to give it the "Heathkit" look, but settled on Ford Cayman green.  It resembles the Heathkit green, with a little extra gold sparkle to it.  The case accepted the primer and paint very well, and it has a smooth finish...much better than the raw aluminum case.

I even painted the MFJ CWF-2's box to match it.  They are roughly the same size...so they look pretty neat sitting next to each other.

Also, I re-crystalled the board, as stated before, for 7.030.  There is MUCH MUCH more activity on 7.030 than 7.023 MHz.  Just yesterday alone I made 5 QSOs at random times during the afternoon/evening.

So...all together, I spent $40 for the radio...$22 for the case, $11 for the crystals (from QRPme.com), and $7 for the paint.  Grand total: $80.

Next step is to build the "CT1IAO" portable single-lever paddle to use the internal keyer:

http://youtu.be/euuQJ-DXrgo

Next step...take 2:  Testing it portable with the Opek HVT-600 antenna.

Thursday, May 29, 2014

The Chinese "Super Rockmite" Clone

Recently, I was perusing my Twitter feed, which I have to admit I haven't been keeping up with.  Recently, my Twitter friend Matt, W2MDW posted a link to an eBay page showing the "Super Rockmite Clone" radios.

These radios are available in either kit form OR fully assembled...but that's not what makes them unique.  I have written before about the Chinese versions of Dave Benson's (now Rex Harper's) "Rockmite", known in the PRC as the "Octopus".  The Octopus is LOOSELY based upon the Rockmite...and the Super RM clone is even more of a departure.

I bought one of these radios for portable operation with an Opek HVT-600 antenna while at the YL's house.

The BEST part of this radio is the WHOPPING amount of power that it emits.  The CRK-10 was a stout little performer with its 3 Watts....but the Super RM Clone is an EIGHT WATT RADIO (@12V DC).  

YES....8 Watts.

There are some interesting upgrades with this particular radio, as well.  There is a DB9 port on it for what the website calls "PC Keying", but the software is difficult to find, as is the cable required to make it happen.  After quite a bit of navigating around ENDLESS Chinese websites, I was able to find the software, schematics, and instruction manuals for the rig.  


The Super RM is far from perfect, mind you.  The audio is anything but pleasant to listen to IF you are using regular (a.k.a. CHEAP earbuds....or "walkman" style headphones).  It is SO LOUD and SO HARSH as to not be comfortable for very long.  And, without a little tweaking of the sidetone pitch (via button 1 and 2 on the top of the circuit board), your keying sounds will drive you CRAZY.

The solution was fairly simple for me, since it had worked with the MINT CONDITION Heathkit HW-7 that my ex-wife bought for me last year:  1945 vintage Telephonics Corporation TH37 headphones and an OLD MFJ-CWF2 filter.


The old heapdhones in conjunction with the filter (when needed) really take the harshness out of the audio.  Your mileage may vary, but it is an ABSOLUTE improvement for me.

There ARE a few significant downsides to this radio in the "assembled" state:  ALL of these radios are coming from China with crystals for 7.023 MHz.  Extra Class license holders are the only ones allowed to use this frequency.  ALSO...the Super RM Clone uses THREE of the these crystals.  Two are for the filter, and the third is for the oscillator.  But, affordable crystals can be had by contacting Rex Harper via QRPme.com.  

I QSY'd mine to 7.030...the QRP "watering hole" for 40m CW.

And there is no case with the radio.  However, the matching aluminum box can be obtained by a quick trip to eBay.  

All in all, I paid $40 for the assembled kit, and another $15 for the matching aluminum box.  And when you purchase from the MANY eBay sellers, shipping from China is USUALLY free...another perk.  Arrival to the US is typically 7-15 days....mine came in 11.

More of these rigs can be seen on China's domestic shopping website, Taobao.


Make sure you are using a GOOD web browser, such as Google Chrome, so you can have the page translated into "Chinglish".

As I make changes and improvements to the radio, I will be posting them here.

video




Monday, November 26, 2012

The Chinese Rockmite: Meet the CRK-10

As with nearly everything in our modern lives, undoubtedly it's made in China.  As the US shifts from manufacturing to "service" and high-tech, many of the items we use on a daily basis are increasingly "Made in China".

Along with this concept, consider that the Chinese are masterful at duplication.  They can take an "already existing" product, and make a copy of it...typically cheaper and in greater numbers.  Quality is suspect at times, at others, sometimes the quality is BETTER.

This is the China Radio Kits "CRK-10".  It is a version of the Rockmite known in China as the "Octopus" (unknown as to WHY....but...OK).  It is available as a kit, or factory-assembled.  This rig was created by Bu Xianzhi, BD4RG.

The following is a chart that shows the comparison between the Small Wonder Labs "Rockmite" and the CRK-10:


ModelCRkits CRK-10SmallWonderLabs RockMite
Dimensions55x30x83mm56x24x90mm
Price(Board and case unassembled) $52,  $62 assembled$29 unassembled
CaseCase includedMity Box (sold separately) $25
Frequency7003, 7010,7020,7025, 70303560, 3579, 7015,7030,7040,10106,14060
Power3W (2SC1162)0.5W (2N2222 Metal Can)
MCU functionSPD / CQ MSG / Bug not be replaced (12F629 SOP)Yes SPD only retrofit PIC (12C508A DIP) Jackson Harbor Press
MCU message/ QRP can be addedNo
Automatic identificationYesNo
IF CrystalTwoOne
Adjust RF GAINNoYes
Switching sidebandRemodeling required: RIT cancellerswitch short press
Fabrication time1 hour (semi-finished board)3-4 hours
Manualhttp://crkits.com/crk10manual.pdfhttp://smallwonderlabs.com/docs/RM40_Inst.pdf
Outside wiring boardNoneYes 

The differences are subtle.  However, the biggest difference is in the power output capability.  The CRK-10 emits a WHOPPING 3 watts.  That's nearly "full-tilt" at QRP levels.  The additional power afforded by the 2SC1162 almost guarantees a QSO with a decent antenna.  Compared with the Rockmite under the same conditions (antenna, atmospherics, etc), this is at least a 2 S-unit difference!

Also, keep in mind that with the Rockmite, the basic kit is $29...the connector kit (optional, but still handy as hell to have) is $16.  Then, for the professional look and finish, the American Morse "Mity Box" is another $25.  Then...you still have to build it.  Total cost: $70.  The CRK-10...factory assembled and SHIPPED from Pudong New District, Shanghai, Peoples Republic of China...$70.  This is a NO BRAINER.

That's why I ordered one...fully assembled, for 7.030 MHz.

Adam Rong is very responsive to emails and requests via email for help in assembly, modification, and troubleshooting are answered promptly either directly, or via his Yahoo Group (http://groups.yahoo.com/group/CHINA_QRP/).  I have spoken with him on numerous occasions, and was quite impressed with his dedication to his products and his development of future kits.  Recently, Adam discontinued his KN-Q10B kit.  This was a 5-band (80/40/20/15/10), CW/SSB kit (also available assembled) that he closed out at $235.  THAT IS INSANELY AFFORDABLE.  I regretfully missed out on this chance to get one at this low price.  I have been dying to get back on HF since I had to sell my Yaesu FT-817ND.  But, after an email to Adam, he assured me that there are new multiband kits being developed.  By the time my tax return comes back, I will most definitely be adding one (factory assembled, of course) to my shack.

I have always been good at predicting the future.  It's an ability that I've had since I was a child.  I was spot-on when I had that "feeling" (it used to feel like a seizure when I was young) and told my mother to play the lottery in 1988.  She won $35,000 that night.  I predicted with alarming accuracy in 1985 that "someday, music won't be on 8-track or cassettes, or even record in the future."  I added, "in the future, buying an album will be like buying an item the size of a postage stamp.  Plug it in...there's the music".  At 13, I hypothesized that digital music was ahead for the world.  Again...I was correct.

I said last year in a conversation at a ham club satellite demo that I presented along with Keith WB2VUO, that once the Chinese enter the HF market (in addition to the LOW COST VHF/UHF transceivers), rigs that are capable of 10-50 watts and have decent HF coverage AND be priced in the sub-$200 range would be around the corner.  I was correct.  Between China Radio Kits and YouKits, these are only 2 companies in an ever-increasing Chinese production economy.

Currently, Small Wonder Labs is no longer in business.  However, Rex Harper from QRPme has undertaken the task of reproducing the Rockmite...with some subtle changes.  Namely...NO MORE SURFACE MOUNT!!!  Rex's version is all standard and typical components.  But, it's still the K1SWL design at heart.