Thursday, August 7, 2014

Experimenting With 222 MHz And The UV3R

It has been over a year that I have had the Baofeng UV3R...and it has been a great little radio, despite some "technical issues".  The only thing to "fail" on the radio was the SMA antenna jack, but after work one night while transferred to Utica, I repaired it with a boat load of epoxy.

It had fallen onto concrete at a job site while using it on 462.5625, FRS Channel 1...to keep tabs on my apprentices from NYC.

Last year, I flashed the CPU with a small mod file that I found linked off of the UV3R.com website...and until recently, hadn't heard much on 220, other than some locals using 223.500 MHz simplex.

I re-read the directions recently, and learned that there are TWO ways to force the UV3R to reach 222 MHz...going UP in frequency from the VHF range, or going DOWN in frequency from the UHF range.  The "Read Me" file suggested that the radio performs better going DOWN from UHF, and I found this to absolutely true.  Where before I would hear NOTHING, now I have 12 repeater pairs programmed and scanning on the little radio.  It has been interesting hearing the 224.42 N3AU repeater in Niagara Falls, NY in ELMA lately.  220 is an excellent tropo band, as it shares MANY similar characteristics with both 144 AND 440 MHz.

There have been many discussions as of late on the Facebook "VHF/UHF AMATEUR RADIO" page concerning 222 MHz.  Many of the members, myself included, have taken the word to the streets about how good this band can be...despite a lack of widely available gear for the band.  Quite a few of the members are weak signal ops that use transverters...some have older FM gear, such as the IC-3AT or Kenwood TH-31AT (which I had in 2007)...and some have modern 222 gear, like the Wouxon KG-UV3D (144/220) or the Alinco DJ-G29 (222/900) or DR-235.

I have been spreading the word that the UV3R and UV5R can be flashed for 220 easily, and this has caused many to enter the band for FREE...LITERALLY.

In a few places on the Internet, it has been stated that since the UV3R wasn't intended to operate on 222, the power output is drastically low.  In some places, I have seen reported power levels as low as 5 mW, and some as high as 50 mW.  In one forum, a ham said that his could do 1 W, but I have yet to see anyone else claim that amount of power.

25-50 mW doesn't sound like much, but keep in mind that most of the HTs that Kenwood has produced for the last 20 years or so include a "Super Low" power level of 50 mW.  When in an area that has a GOOD repeater or activity, 50 mW is enough power, indeed.  (In the early-to-mid 90's, there was a local ham, Barney...don't remember his callsign...he'd sit in Niawanda Park in Tonawanda, and feed the squirrels.  He'd ALWAYS have his Kenwood...and every QSO made through the 146.73 Grand Island repeater was with 50 mW.  It was his claim to fame.  Of course, the GI machine was a mile away, and situated on top of an ENORMOUS tower shared with WUTV at the time.)

The next steps are to construct a gain antenna for 222.  There aren't many antennas available for 222, since there isn't the same demand for the gear.  But simple, GAIN antennas can be built readily.

First is the Moxon.  It's essentially a 2-element beam that is folded square for small size.  The image below shows dimensions for one built around 223.500.


Another simple antenna would be the "WA5VJB Cheap Yagi".  Simple in build, and adaptable for 3 or more elements, a Yagi would give you the ability to use 10 dB or more...and at 10 dB, your "effective radiated power" is 10x.  50 mW would "APPEAR" to be 500 mW.  And with directivity, 500 mW is plenty of power.

I plan on doing MUCH MUCH more experimenting and investigation into 222 operation with this radio as the summer goes on.

Whether it was from my Novice days when we were allowed to use 222.1-223.91, or from reading an OLD QST article titled, "Why 220"...I have always had an interest in this forgotten little band.  Perhaps if more people tried it, they would also find it as good as 2m.

Maybe.

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.