Amazing $49 Rig from QRP Labs

Hans Summers' QRP Labs has an amazing new rig -- The QCX --  that is chock-full of features and FB technology. Hans has long been one of the most innovative guys in ham radio, and this latest rig is one of his most amazing creations.  Like Farhan's BITX40 Module, this new rig is priced in the 50 dollar range. Hams who are paying many thousands of dollars for their "radios" should be asking themselves a question:  Could I be having much more fun for far less money?  This rig is in big demand and there is already a waiting list, so place your order now if you want to work on this during the winter.  Here is the link: 
http://qrp-labs.com/qcx.html

  

QCX Features:

• Easy to build, single-board design, 10 x 8cm, all controls are board-mounted
• Professional quality double-sided, through-hole plated, silk-screen printed PCB
• Choice of single band, 80, 60, 40, 30, 20 or 17m
• Approximately 3-5W CW output (depending on supply voltage)
• 7-16V recommended supply voltage
• Class E power amplifier, transistors run cool… even with no heatsinks
• 7-element Low Pass Filter ensures regulatory compliance
• CW envelope shaping to remove key clicks
• High performance receiver with at least 50dB of unwanted sideband cancellation
• 200Hz CW filter with no ringing
• Si5351A Synthesized VFO with rotary encoder tuning
• 16 x 2 blue backlight LCD screen
• Iambic keyer or straight key option included in the firmware
• Simple Digital Signal Processing assisted CW decoder, displayed real-time on-screen
• On-screen S-meter
• Full or semi QSK operation using fast solid-state transmit/receive switching
• Frequency presets, VFO A/B Split operation, RIT, configurable CW Offset
• Configurable sidetone frequency and volume
• Connectors: Power, 3.5mm keyer jack, 3.5mm stereo earphone jack, BNC RF output
• Onboard microswitch can be used as a simple straight Morse key
• Built-in test signal generator and alignment tools to complete simple set-up adjustments
• Built-in test equipment: voltmeter, RF power meter, frequency counter, signal generator
• Beacon mode, supporting automatic CW or WSPR operation
• GPS interface for reference frequency calibration and time-keeping (for WSPR beacon)

An Si5351 Ham Sandwich from China (with video)

Ernesto Marquez alerted me to the offerings of CRKITS -- Chinese Radio Kits:

http://crkits.com/  Their Si5351-Arduino Pro Mini "sandwich" is quite interesting.  Here is a video on the device:

I must say, that nice little sandwich seems to be crying out for an organic slice of OLED.... How about it Adam?

While there is, of course, an enormous amount of electronics coming out of China,  I haven't seen much that comes from actual Chinese radio amateurs.  But CRKITS is the work of a real Chinese ham.   Adam Rong (Rong Xinhua) BD6CR seems like a very interesting fellow. From qsl.net:

About BD6CR/4

Adam Rong (Chinese name: Rong Xinhua), BD6CR/4 was first licensed in 1996 while in university in Hefei, Anhui province and now holds Class 2 Chinese amateur radio license (FCC Amateur General license equivalent). After graduation from university, he moved to Shanghai and call sign changed to BD6CR/4 in July 2003. Adam is now living in Pudong new district with his XYL and their son.
Adam holds a Master of Engineering degree in computer architecture and is an Engineering Program Manager in computer hardware industry. In spare time, Adam has written a lot about ham radio for magazines and papers, mainly about QRP, homebrew projects, APRS (Automatic Packet / Position Reporting System) and ham radio software applications. Adam has also translated two ARRL's books into Chinese for Post and Telecom Press in China, including part of the ARRL Handbook and ARRL's Low Power Communication: The Art and Science of QRP by Rich Arland, K7SZ.
You can contact Adam by email, or track Adam's real time position on Google map by clicking this link.

CONFIRMED: Andy G6LBQ Has The Knack (and OTD)

The early fascination with small light bulbs, switches, and batteries confirms the diagnosis. The Ladybird group seems to have led many a young British person down the path to OTD (see the web site for more info on this malady).

https://g6lbq.blogspot.com/

Andy writes:

Hi Bill

 

I have built a few BitX transceivers and developed a 9 band version which has been built by various hams around the world.

 

Always look forward to the SolderSmoke podcast which I enjoy immensely.

 

For your interest I have attached some pictures to show you some of the modules I have designed/developed and built for my Multi-Band projects. The SMD boards are for my latest project which I call the Irwell Transceiver, my intention is to make it all band HF and multimode.

 

Hopefully my pictures will meet with the SolderSmoke approval and the inauguration can take place for recognition that I officially have The Knack, failing this it will be a Basta moment at the G6LBQ workshop!

 

Keep up the great work you do with SolderSmoke which brings pleasure, fun and inspiration to hams all over the world.

 

Kind Regards

 

Andy de G6LBQ

 

More DSB, from Belgium and Spain

Frank ON6UU writes:

Hello Soldermelters,

 

Maybe some interesting news for you as there are some new kits at hand from EA3GCY (http://www.ea3gcy.com)

 

I’ve made the MFT-40 DSB without any problem,  all parts were provided with the kit,  only things to buy were a microphone connector,  a speaker and an antenna plug.   The box was taken from my attic and was a VGA-selector in his previous life.

Kit came together in a few evenings,  I followed the very well written manual,  all was well pointed out,  which resulted in a working kit.  After aligning the kit I could start making qso’s.   The microphone was made from a piece of tube,  a simple switch and a electret microphone,  it doesn’t look pretty but the microphone works.

 

Rx-Tx 7.066 – 7.133  (With DDS the complete 7MHz band)

Pwr :  some 3W peak.

Double Side Band

 

Made some You-tube films about it.  

https://www.youtube.com/watch?v=fPREwd1FowM

https://www.youtube.com/watch?v=3T2dxnTmF7I

https://www.youtube.com/watch?v=eHoPdhmbZz0

 

Easy to make,  no SMD,  easy alignment without necessity of expensive material.   Fine for someone who never made a transceiver,  hence the name...My First Transceiver,  MFT.   As soon as the weather permits I will take the TRX out in the field and activate a SOTA with it.

 

Now working on the MFT-20 DSB.   I’m hoping for an 80mtr version to come available too.  :-)

 

All info is on Javier’s site. (http://www.ea3gcy.com)

 

72, 73

Keep the solder melting !!

 

ON6UU

A Mighty Mite, a BITX40, an ILER, some Arduinos, and the Joy of Oscillation in the United Arab Emirates

Martin A65DC sent us this wonderful report on his efforts in the UAE.  His e-mail nicely conveys his enthusiasm.  I was especially pleased to see that wooden enclosures are catching on (another fellow on the BITX20 group is using a cigar humidor).  Thanks Martin!  Please keep us posted on your UAE homebrew adventures.

Hi Bill and Pete,

My name is Martin, and I am listening to every episode, sometimes more than once, thank you for an excellent show boys. I am a ham in the United Arab Emirates and operate radio as A65DC.

I just wanted to share my "JOY OF OSCILLATION” moment with you, I had the moment two days or so ago.. fantastic!

Well it is not super tidy, but as a proof of concept is totally acceptable. red and green goes to the variable cap (above).

Next to the Mighty Mite (above) is my bitX40, what a fantastic board!! I have big plans for this radio. But for now it will stay in its wooden box and keeps me company.

This (above) is another kit build, 20m SSB kit from EA3GCY Javier. ILER20, please have a look, this is where you should start if you are into kit building!! the instructions are fantastic.

I added some Arduino magic to it with a SI5351, and then I was sitting and looking at my big UNO board, hmmm USB port, why not further develop the code and use the port as CAT control.

I can now connect this rig to e.g. N1MM and control it, read and write frequency (in current version) I am simulating the protocol of a TS590, but that turned out to be a bad choice, I should have gone for a simpler radio, like a 140 or something, the 590 has loads of CAT commands that my code needs to answer… this radio is my QRO 20m as rig it sports the 20w amplifier kit from K5BCQ and will put out a whooping 22w!  Several contacts from A6 into Europe and some over to Indonesia.. fun stuff, two kits from different vendors together with some own building and coding.. I love it.

On the workbench now is an Arduino CW keyed based on K3NG, the Arduino code is very well written and it has loads of functionality, most of what I will never use.. but as a keyer it is superb.

This is my keyed circuit, super simple stuff, it is here connected to the Mighty Mite as a test, works 100%  I am now researching a good circuit for a CW transmitter/transceiver for 40m that will be in the 5 to 10w range to use my new keyer with.

Again, thanks for a fantastic show guys,

73

A65DC, Martin

Smoke-Free! On the Air with the W1REX Dayton Hamfest Buddy

After the Dayton Hamvention, our ace correspondent Bob Crane (W8SX) sent me the "Hamfest Buddy" kit that Rex Harper W1REX had put together and used in "The World's Biggest Build-a-Thon."

It is a single 2N2222 crystal-controlled oscillator for 20 meters.   All the parts are plug-in -- no solder smoke is released.   Mine went together in about 15 minutes and fired right up.  You can see it above.  It runs off the 9V battery. I had to hold it down with tape.   You can see the key button in the lower right.  That little inductor in the foreground is used to shift the frequency a bit.  I had to remove the 10K resistor in the emitter circuit because with my antenna the circuit was going into low-level oscillation even in key-up.  With the 10K resistor removed, this problem disappeared.

I hooked it up to my 20 meter dipole and called CQ.   With only about 60 milliwatts into a dipole under poor conditions, I really didn't think I'd get any answers.  But I figured the Reverse Beacon Network might pick me up.  It did:

Thanks Bob!  Thanks Rex!

Oz QRP2QRP From Mt. Bullfight, Pyramid Hill, and Melbourne's Chelsea Pier

Paul VK3HN has obviously made an admirable effort here, and a visit to his very nice blog shows that he has a lot of true homebrew gear available.  We hope that he will haul some of that HB stuff up the mountain, perhaps to find Peter Parker operating from the Melbourne pier with a Beach-40.  As I type this I am listening to VK3IO on 40 meters, coming in nicely on my Barebones Superhet (kit version).

Dear Bill and Pete,

I would like to claim an entry in the SolderSmoke Homebrew To Homebrew
(HB2HB) log. Here's the story. On Sunday 24th April 2016 I drove two
and a half hours north east of Melbourne into the edge of the Great
Australian Dividing Range, to climb two summits, for the fun of
operating my 40 meter SSB QRP (5 watt) rig in a beautiful, RF-quiet
setting, and to activate two Summits Of The Air (SOTA) peaks.

My first summit was Mount Bullfight
(http://www.sotawatch.org/summits.php?summit=VK3/VN-002), in the
Rubicon Ranges, at 1,490 meters ASL not high by American or European
standards but a good heart-racing climb through thick Australian bush.
After a successful activation with good signal reports into Tasmania
(VK7), around Victoria (VK3) and New South Wales (VK2), I descended,
and drove about 2 miles up the valley to an adjacent SOTA summit,
Pyramid Hill (1,314 meters) where the activation also went well. Just
as I was finishing up with the chasers, Peter Parker VK3YE called me,
operating portable from his beloved Chelsea Pier, and we had a very
pleasant beach-to-summit ragchew QSO. The RF path is about 62 miles.

Peter was running his MDT double sideband rig, with 2 watts. I was
using my MST400, with 5 watts SSB. Both rigs are kit radios from OzQrp
(http://www.ozqrp.com/). Both are assembled by hams -- I built my
MST400 18 months ago and Peter was using the MDT rig that OzQrp
founder Leon, VK2DOB designed, built and kitted, the one he sent to
Peter for a YouTube review. So it was built by a ham, just not by
Peter.

Now, I know that there may be some, possibly even you Bill, who may
question the legitimacy of my claim on a coveted HB2HB log entry in
this particular case. I can assure you that we did experience the Joy
of QRP/P operation, Peter basking in the late afternoon Australian sun
on a beach and I on the mountain top. And to further add authenticity
to my HB2HB claim we discussed QRP, aerial experiments, and 'whats on
your bench' topics for a full 20 minutes.

However, I would not want to risk disturbing the wrath of the Radio
Gods with a dubious claim.

I admit that neither radio was scratch-built, on copper board
ugly-style, or had the form of a wild birds-nest of separate modules
and interconnections, with parts loosely screwed onto an Italian
chopping board or a discarded lump of wood. Indeed, neither can it be
claimed that both operators built their rigs. So I will take a
rejection of my request with acceptance and dignity, acknowledging
that you are duty-bound to maintain the highest of standards, and that
entry into the SolderSmoke HB2HB log is not to be granted without
proper consideration.

I do understand that you may feel that accepting this QSO could set a
dangerous precedent and risk opening the flood gates to a tsunami of
dubious HB2HB QSO claims from hams using minimal assembly rigs, like
some of the Elecrafts. Who knows, some individuals might even be
tempted to claim HB2HB QSOs from VHF FM hand-helds after managing to
screw on the rubber-ducky antenna. Even unboxing a shiny new
Yae-com-Wood is, to some, a form of 'handiwork'.

Bill, the decision is yours. Peter VK3YE and I look forward to your
decision. Judge wisely.

73 from down under, Paul VK3HN, with agreement to this claim from Peter VK3YE.

Details of this day of activations are on my blog at:https://vk3hn.wordpress.com/

Peter's MDT review is at:  https://www.youtube.com/watch?v=2OtZeFkb1xw

Adafruit Profiled in "The New Yorker"

Congratulations to Limor Fried.  Her company got a very nice write up in "The New Yorker."

http://www.newyorker.com/tech/elements/limor-frieds-artful-electronics

"My Favorite Programming Language is Solder" -- Boldport Kits

Look closely at the inscription on that USB stick.   Obviously I sympathize.   The folks at Boldport have some very interesting ideas and projects.   And they operate from a very cool location, just south of the river Thames, not far from my old home in London. 

Here is their main site: http://www.boldport.com/blog/2016/2/21/boldport-club-project-1

Here is where you can subscribe to receive a monthly project (with parts!) from them:
https://boldport.cratejoy.com/

As for the solder quote from Bob Pease, this was discussed before on this blog, back in 2011.  We were talking about an intereview that had been done with Alan Wolke W2AEW:

I also liked Alan's response to the question about his favorite software tool: "Gee, solder is soft, can we consider that software? I use a lot of that!" This is very reminiscent of a quote from the legendary Bob Pease (colleague of Jim Williams): "My favorite programming language is solder." (That quote was sent to me by Steve WA0PWK. Thanks Steve.)

Awesome Kits from Austin Texas

http://www.qsl.net/k5bcq/Kits/Kits.html

If this is the kind of great stuff that results, then I agree with the bumper sticker:

KEEP AUSTIN WEIRD!

Scroll down to kit #25 for more details on the device pictured above.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

W1JSB's Very Cool Portable Rigs -- RadioSet-Go!

Brad Smith alerted me to this.  Very cool.   Hanz W1JSB is churning out some amazing trail-friendly rigs.   I really like the tinted-translucent front panel. 

Here is the site for Hanz's company:  http://radioset-go.com/

Here is his YouTube Channel:  https://www.youtube.com/user/w1jsb/videos


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

The 1Watter

There are currently only 2 in the universe.  And they have been talking to each other.  Soon there will be more.  Many more.

http://www.kitsandparts.com/1watter.php

http://www.1watters.com/

http://www.k7qo.net/onewatter.html

Chuck Adams explains (via the qrp-tech mailing list):
 

Aug 3 at 7:07 PM

 

Gang,

I and Diz have been playing on 20m with 1W.
OK, I've been playing. Diz has been working night
and day.

He has a kit coming out in two weeks or so. Don't rush
him. 

He has S/N 0001 and I have S/N 0002. These are the
only two 1Ws in the Universe. Yesterday (local time)
but 0000UTC today, I went to the lab to put a WWV
atomic clock above the desk for logging purposes.
I turned on the rig to listen while I put the screw into
the side of the shelf to hang the clock on. No warmup
drift. I'm tuned to 14.059MHz, the freq both Diz I start
out on and low and behold I hear him calling CQ. I pound
the paddle to call him and he went back to AF5XF in NTX.
Darn.

At 0031UTC I call him and I get a 229 and later a 339 and
he was a 539 here in AZ. So all the 1Ws in the Universe
have talked to each other. :-) The race is on, when and if
you get one to work us all. Or work us with the rig of your
choice and the power level of your choice....

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

National RF

 

Pete and I both spotted the ads in QST for this company and their little HF receiver.  In the finest tradition of Tuna Tins and Herring Aids, that receiver is in a SPAM can.   FB. 

 

http://nationalrf.com/75_NS-3.htm

 

I visited the company's web site this morning.  Lots of great stuff!   They are based in San Diego.  Who are the radio wizards behind this effort? 

  

http://nationalrf.com/products.htm

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Our New Sponsor: HOMEBREW 4 U! 家釀的你

                                             家酿的你

As I mentioned in the last podcast, we've been in some pretty serious negotiations with a new sponsor that I think is going to bring some MAJOR changes to the podcast.

"Homebrew 4 U"  家釀的你   is an innovative new company based in Fakeszuhow, China.  Up until now they  specialized in custom circuit board manufacturing, but they recently contacted us with an expansion idea that we found very interesting.  They have been listening to the podcast, reading the ham radio magazines, and monitoring the U.S. amateur frequencies (especially 75 and 40).  They noticed some things:

Most hams DO NOT build their own gear.... but many seem to feel vaguely guilty about this. They seem to react with unease when they encounter a ham using a homebrew rig.  They grow defensive and scornful.  The jealousy is quite palpable. Obviously there is an exploitable niche in those sentiments!

Many hams express a DESIRE to build gear but then follow-up and say they "have no time" (what with all the contesting, video games, NASCAR, and golf!) 

Other hams say that they really want to build their own gear, but don't know anything about electronics (even though they are Extra Class -- how did that happen?) and they don't really want to learn.

Some hams say they would really like to build their own gear but find parts of the process quite distasteful.  Like winding toroidal coils. Or reading schematics. And then there's all that soldering!  But they insist that in spite of all this distaste for actual building, they really DO want to join the ranks of the homebrewers.

So.... Homebrew 4 U is developing a FANTASTIC product line that meets the needs of these guilty, busy, knowledge-free, toroid hating,  solder-averse homebrew wannabes!

On April 1, 2016, Homebrew 4 U will roll out a line of GENUINE homebrew radios. To bolster their genuiness, they will henceforth be referred to not as radios but as "RIGS" (nice touch, don't you think?)  

Unless the buyers select the optional "really build" option (see below), each "rig" will be complete and ready to operate.  And here is the beautiful part:  it will be a genuine homebrew rig, BECAUSE the company is doing all their work in an actual HOME in Fakezuhow! Pretty great huh?  So you WILL be able to proudly announce on 40 meters that you are running a homebrew rig (Remember: rig, not radio!)

Each of the H4U rigs will share some common features, all designed to provide the proud buyer (I mean homebrewer) with opportunities to remind people that he is running a genuine homebrew rig:

-- They will drift a bit.  Not too much, but enough to provide you with the chance to mention that your "rig" is "homebrew." Prepare to be envied my friends! 
 
-- The frequency readout will be set up to put you automatically on "wrong" frequencies. 
Like 7.162.025 instead of the "correct" 7.162.000000000000000000000000000000000000.  Again, another opportunity to gloat. Pretty neat, huh?
 
-- The audio quality on SSB will be SUPERB.  EXCELLENT.  This will provide some wonderful opportunities to compare signals with the Enhanced SSB gang.  Yours will sound as good or better than theirs, and you can follow-up by telling them that you are using a Radio Shack electret mic element, a one transistor mic amp, and NO EQUALIZER.  They'll love it!

REALLY BUILD OPTION:   For those wanting to enhance the truthiness of their on-the-air homebrew experience, for just a few dollars extra, H4U will leave one part UNCONNECTED.  You will then be able to make that critical final connection (don't worry, it won't be a toroid, and the connection will be via alligator clips -- if you've gone this far we know you don't own a soldering iron!).  You will thus be able to tell your envious interlocutors about the happy day when you "finished" your radio.  I mean rig.  You know what I mean.

Pete is heading out to China this week to supervise the manufacturing (I mean the homebrewing).  Thanks Pete!  Skype in OM!

So remember, the roll-out is set for April 1, 2016.  Watch out Yaesu! 
  

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Almost Enough to Make You Abandon Manhattan: John's SW-40

Hi Bill,

 

You said you didn't mind if I sent you some of my finished projects so here is the latest.  I scratch built the SW 40 that I had previously built from a kit by K1SWL.  I always liked that radio, and thought by laying it out I would learn more about it.  In testing it out after I aligned everything I made a qso with Mike (K3WAS),and got a good report, and I didn't let out any of the magic smoke or sacrifice any chickens.  You gotta love this hobby. 

The rig tunes from 7.034 to 7.063, and I had about 2.3 watts out, but ran into some slight problems with instability at the end of the qso with Mike. The PA was getting a little hot, but with the excitement of having it work right out of the gate it really didn't matter at the time.  The board layout was done with express PCB, and using the toner method, placed it on the board.  Chuck (K7QO), has some great youtube videos showing the process. I have to admit I got more knowledge by laying out the board as opposed to manhatten construction, and came away with a better understanding of the radio itself. 

Now to build the case.  the board is 5.25 by 7.25 inches, and I may have to sneak one of my wife's alum cookie sheets to fabricate the case.  She doesn't bake till Christmas so it will be a calm summer.  I also made provisions on the board for a digital readout, but for now I just want to enjoy the rig as it is.

Thanks to both you and Pete for taking an interest, as well as the great job on soldersmoke.

73

N8RVE  John

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Analog FOREVER! Menus are For Restaurants! Hardware Defined Radio! Chris's PTO

Beautiful!  A Permeability Tuned Oscillator.   No need for a fancy variable capacitor -- that brass screw moving into and out of the coil varies the inductance and the frequency.  Collins style. 

Feb 20 at 6:58 PM

I also wanted to send you a shot of what today's project has been. It's WA6OTP's PTO.
I bought the plastic tube/screw/bracket from Jim and I provided the rest.
This is a 40 meter PTO that covers the entire 40 meter band.
A little Q dope secured the windings.
Chris
KD4PBJ

WA6OTP has a very nice PTO kit: 

http://www.wa6otp.com/pto.htm

And a lot more good radio info here: 

http://www.wa6otp.com/radio.html

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Finally! Dis-Intergrated Circuits! Discrete Component Op Amps!

That, my friends, is a discrete component version of the 741 op amp chip.  I like it!  No more mysterious miniature black boxes -- here's a "chip" that you can understand, troubleshoot, and modify.   Seven Forty Fun!

https://www.kickstarter.com/projects/1208645775/open-analog

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

An SSB kit from Spain

The ILER-20 and ILER-40 SSB transceiver kits of Javier Solans,
EA3GCY, look very interesting.

For more info: http://www.qsl.net/ea3gcy/


 Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Words of Wisdom from Farhan

I read the mail of the BITX20 group. Here is some good advice from Farhan:

I have often seen builders finishing an entire build, then powering it
up to face the frustration of a dead circuit. I suspect that the
trouble is with our kit building mind set. As a kit builder, we assume
that if it has worked well for a few hundred others, there is no
reason for it to not work for us. But the truth is more sobering ...
Of the hundred odd components, any of them could get swapped by
another, or a bad solder, wrong polarity, etc. can all conspire to
thwart your attempts. The bitx manuals are really some of the best
produced in the recent years and yet, even with leonard's videos,
troubleshooting kits is a challenge.
I am proposing a more elaborate, slower but surer approach to building the bitx.

It is as follows: build it one stage at a time, use one stage to test
the next. For instance, one could start with the bfo first. Just a
single transistor with the crystal. Then use an RF probe to check the
rf output. If there is no output, then sort that out before proceeding
to the next stage. With the addition of the buffer amp, the output
should go up. Then one could proceed to the audio amp. Injecting audio
from your mp3 player or computer could check that it works. Next,
replace the audio source with the mic amp, this tests the mic amp.
Now, if you add the two diode modulator, you should be able to receive
the dsb at 10 MHz on your HF transceiver.

This approach tests each stage individually and in isolation before
proceeding to the next. It also provides wholesome education to the
builder. In software industry, it is called a 'test driven
development' method of developing software.

In the end, this approach is no slower than the current approach,
except that surprises are not kept for the last.

I am sure that some of us can come out with a sequence of stages to
build where each stage is tested using the previous stage.

As much as bitx is about building it cheap, it is also about learning
your radio from inside. Bitx is also education on the cheap, don't
give up that opportunity.

- farhan VU2ESE

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

My .02 KW Linear Amplifier

Once again, die-hard QRP guys should probably look away at this point...

My Cycle 23/Cycle 24 refurbishing project continues. The JBOT amplifier in the 17 meter SSB rig is now working nicely, but unfortunately just as I got ready to make some contacts, the Coronal Mass Ejection hit us and conditions on 17 deteriorated badly. Looking for something to do, I noticed that in some pictures of my old Azores station, sitting alongside the SSB transmitter there was a small cabinet with a QRO/QRP switch on the front panel. Ah yes! My Ramsey Kit linear amplifier! This is a MOSFET-based device. Mine was designed for 20, but I changed the low pass filter and put it on 17. Later, in Italy, it went on 20 meters and for some reason I went back to the 20 meter low pass filter.

Yesterday I blew the dust off this thing, pulled out the 20 meter LP filter and replaced it with a filter that will let my 17 meter RF reach the antenna. Today I fired it up. Wow! 20 Watts! Look out 17 meters!

I really like the QRO/QRP switch -- it gives me the opportunity to lean back and say (just like the big guns) "Wait a second Old Man, let me turn on my LINEAR!" I even have a little fan in the box that you can hear when I go to the QRO position. Unfortunately it doesn't make the lights flicker. But we can dream...

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