N7UN Talks About Summits on the Air (FDIM Interview by Bob Crane)

Bob Crane, our intrepid correspondent at the Dayton Hamvention talked to Guy N7UN (pictured above) about taking ham radio up to the mountaintops.  It was nice to hear Guy mention Wayne Burdick and Wes Hayward and WG0AT.    Thanks Bob!  Thanks Guy!

Listen here:

http://soldersmoke.com/N7UN.mp3

More on N7UN here:

http://www.n7un.com/

Reggae Knack?

Could it be that Bob Marley's son Ky-Mani has The Knack? Probably not (no mention of it in Wikipedia) but he certainly has some nice old receivers on his 2007 album cover.

The Joy of Analog Oscillation -- A Character-Building Experience

Gentlemen,

I'm a younger ham, just 26, and I've just experienced what I think you call Joy Of Oscillation as I completed my first L-C VFO. What fun!

I'm working on Peter Parker VK3YE's Beach 40 Double-Sideband transceiver, and while my natural proclivity is toward the SI5351 and it's brethren, I figured it would be character-building to actually put together an analog VFO for once.

After much tweaking of the feedback capacitor in the oscillator, and massaging the tank inductors, and conking out an additional buffer stage to drive the diode-ring mixer at the appropriate level, and gluing Manhattan pads on top of Island pads.... I say, without reservation, that this was great radio fun! And isn't that what it's all about?

(Now it only it didn't drift so much... so I guess it's not quite complete yet)

Just wanted to share, love the podcast and the blog, I learn something new each episode.

All the Best,

Jeff, KK9JEF

---------------------------

Great stuff Jeff.  Character building indeed!    As for the drift, try this:

-- Replace the toroid in the oscillator circuit with a coil wound on a non-metallic core.  I use a cardboard tube from a coat hanger.

-- Make sure the capacitors in the oscillator and even in the buffer are NP0 caps (they don't change in value as they heat).

-- Try to run the oscillator stage at reduced voltage.  Six volts is better than nine.

--  After you solder, always let the device cool down for several hours (or even overnight) before you evaluate it.  Heat from the soldering iron will be dissipating and changing the freq for a LONG time.

Above all, IGNORE the inevitable recommendation from Pete Juliano that you forget about all this nonsense and just go with an Si5351.

Please keep us posted on your progress. 

73  Bill   N2CQR

An Irish Knack Story

I think Tryg should get that Ladybird receiver working again. 

-------------

Hi Bill,

Thanks for the great podcasts and also to Pete for his unique contributions. I have been interested in radio since I was a kid but only really got back into the hobby in 2009. Back when I started playing with electronics in the 1970's I hankered after a soldering iron of my own. I bought the one in the picture in 1977. A "modest" 60 watt job, it was the cheapest one in the shop but I used it to harvest parts from all manner of abandoned old iron. I was really surprised to find it clearing up recently. The snips in the picture was a tool that my late Uncle had surplus and passed on to me, it too played a role in my scavenging for parts. In Ireland in the 1970's it was hard to get parts. I remember my Grandmother taking me from Galway to Dublin - 3 hours each way!!!) to buy parts for my first project, Rev. G.C. Dobbs venerable transistor radio from the "Making a Transistor Radio" book by Ladybird. I still have the book and the dusty remnants of the radio, long since plundered for parts. When I returned to the world of radio it wasn't long before I discovered QRP and the GQRP club. It was a real surprise to find the good Reverend was at the helm there. I just thought that the picture and story might raise a smile amongst followers of the blog. Thanks to yourself and Pete for the podcast. Keep up the great work! QRP Forever!

73,

Tryg de EI7CLB

---------------------

KB8M's Mighty Mite -- Beware the Treacherous P2N2222!

Doug KB8M did a beautiful job with his Michigan Mighty Mite.  But, as often happens, it still didn't work. He turned to us for advice.  I gave him a long list of things to check, but Pete brought the power of superior tribal knowledge to the problem and spotted the defect immediately: The transistor was in backwards.  It is a P2N2222.  That means the pin out it C-B-E  not the usual E-B-C.  I had fallen into this trap with one of my BITX rigs and had to pull out and reverse many of those transistors.  Fortunately for Doug he had used a socket for the transistor.  TRGHS!!!!!!!!!!!!!  JOO!!!!!!!!!!!

Some Really BIG Coils

I met W1VLF on 40 meters last week.  "VLF" was a hint.  And indeed, Paul has been experimenting in the 10 kHz range.  His antenna loading coil is seen above.
More info here: http://rescueelectronics.com/9-Kilohertz.html
Very cool that Mike was working with Jay Rusgrove, W1VD, on this project.  Jay designed the 6 watt VXO rig that was my first homebrew transmitter.

And additional VLF info here:
http://n3cxv.com/WH2XND_station_1.pdf

The National HRO Manual. 1939. 10 cents.

Lots of good info from 1939 in this manual:

http://www.cryptomuseum.com/df/hro/files/hro_manual.pdf

SolderSmoke Podcast #189: Juliano Blue, FET Amp, Si5351 QSK, Bill LC VFO, QSOs

SolderSmoke Podcast #189 is available:

http://soldersmoke.com/soldersmoke189.mp3

Billy in Europe.  Bill in Virtual Reality. 

Great News:  Little Gonzalo is "all clear."  Thanks for the help.

BENCH REPORTS:
Pete paints the rigs blue. 
Pete's FET amplifier project with FET switching and key pad
Using an Si5351 for CW offset and QSK.

Bill working on VFO for a rig built around HRO dial and gear box.
HRO gears seem a bit loose.  What should I do?
The search for an Imperial Whitworth.
For variable caps, brass is better, but two bearings beats brass.

QSO REPORTS
Pete having fun with homebrew rigs.
Bill works K3MRK, WA3O, W4OP, W1VLF and N6ORS

MAILBAG:
Dallas CBLA
Conventional Current Flow Controversy
"I regret ever listening to your podcast!"
LCR recommendations

Gonzalo just turned TWO and is doing very well

Dallas Mighty Mites from a MakerSpace

Bill,

I sent you an email a few weeks ago to let you know that I joined the
Colorburst Crystal Army and that I was preparing to teach a couple of
classes at the Dallas Makerspace on constructing the MMM.  We had our
first class last night,

https://talk.dallasmakerspace.org/t/build-a-radio-transmitter-class/11010/8

It was a great success, every student had a working transmitter at the
end of the class!  So there are six new enrollees in the CCA!  For all
but two of the students this was the first piece of radio electronics
they had ever built, including one who had been a HAM for 15 years.

Just wanted to thank you for preaching the MMM, it was just the simple
circuit needed to get folks started!  We have another class on the 20th,
and requests have been made to schedule additional classes!

73
Walter Anderson
AF5WH

Walking the Plank with N8NM's 60 Meter Rig

Steve N8NM writes:

The free-range rig is coming along!  I'm receiving with decent sensitivity (my generator's only calibrated to -100 dB/m, and I hear a CW note there just fine) and I'm getting about -2 dB/m out of the mixer.  Yippee!

I ended up using an IF of 20 MHz, mainly because I had a bunch of crystals left over from my Minima.  The architecture (left to right) is: Diode ring mixer using 1N4148s, 20dB W7ZOI bilateral TIA, 6 pole crystal filter (BW ~= 2.3 KHz), Another 20dB bilateral TIA, 1N4148 product detector (cribbed from the Minima), 2N3904 audio driver, LM380 PA.  Microphone amp is two FET stages (J310).  Oscillators are courtesy of an Si5351, controlled by an Arduino Uno.  T/R switching is done using a couple of counterfeit 2SC1969 RF transistors that, ironically, don't amplify at RF, but work fine as power supply "pass" transistors.

Yet to do is the PA, which I've noodled in LTSPICE (shooting for 20W PEP using a bunch of BD139s, just because...) and cleaning up my Arduino sketch.  Right now, I just modified the start-up values of the sketch from my all-band rig for testing.  Since that code is pretty full featured (dual VFOs, RIT, filter switching, LCD Display, etc.) using multi-function pushbuttons to select all sorts of crap, I'm betting that 80% won't be used in this rig.  Adding simplicity is always good.

So, nearing the end, I'm already thinking about my next rig (that and building a 60m antenna...)  I think this one will be similar to my "all band" rig, but limited to the WARC bands (I have a WARC tribander that's screaming for a rig of it's own.)  That's kind of boring, so, to challenge myself, I'm going to try using a touch screen in lieu of the usual pushbuttons.  What would really be cool, though, is an interactive slide-rule dial - don't think anyone's done that before!  One of the things that has always drawn me to the SX-101 is that large slide-rule dial.  To me, that allows each station to occupy a physical place on the dial, so after scanning the band, you know were everyone is.  It's really a joy to operate those rigs!

73!  Hope to work you HB2HB on 60M soon!

-Steve

W9ZN's CW Warm-up: "Ben's Best Bent Feet"

I happened to come across this fellow's signal on 40 a week or so ago.  His warm up routine really had me scratching my head.   I've been on the air for a long time, much of it on CW, and I never heard anything like this.   Listen to the video (!) and you will see what I mean. Harmless fun I guess, and there does seem to be a connection to radio history. 

Pilgrim's Progress: A Peregrino Rig Concealed in a Book

On the G-QRP list guys have been talking about the Peregrino.  This is a nice little homebrew rig out of Spain.  Peregrino = Pilgrim and usually refers to people who are hiking along the Trail of Santiago that runs through the North of Spain to Santiago de Compostela.

I'm normally averse to chips, but this little rig uses two very understandable NE602s and an equally understandable LM386.  It has a homebrew crystal filter.  I like it.

GM4WZG came up with a really wonderful enclosure for his rig.  This reminded me of the time I put a QRSS transmitter inside a copy of "The DaVinci Code."

The Spanish guys have a nice site that describes the rig.  Google Translate should help, but even without it you can get most of the info you need from the schematic, chart, and foto gallery.  Check it out: http://ea3ghs.qrp.cat/peregrino.html

Enhorabuena!

Juliano Blues

Pete swears the rigs work better with this color. 

We are adding Sherwin Williams "Juliano Blue" paint to our investment mutual fund: Drake 2Bs, copies of SSDRA, QF-1 Q Multipliers and now, Juliano Blue! We'll all be RICH!  

http://n6qw.blogspot.com/2016/07/yikes-another-blue-radio.html

"The Radio Times"

Wonderful stuff:

https://en.wikipedia.org/wiki/Radio_Times

Which way does current REALLY flow?

I've talked on the podcast about launching a worldwide campaign to require the reversal of ALL those little arrows on the symbols for transistors and diodes.   You see, they are saying that electricity flows from the positive to the negative.  Engineers apparently got that idea from Ben Franklin, and they are sticking with it.  It is time for a change!   Reverse the arrows!  Down with CCF!  Viva Electron Flow!  Let's tell the truth!

This morning Bob Crane W8SX sent me this very interesting article on this topic from Nuts and Volts:

http://www.nutsvolts.com/magazine/article/which-way-does-current-really-flow?utm_source=Newsletter+%2332&utm_campaign=Newsletter+%2332&utm_medium=email

The article describes very well the origins of this controversy. (There were one or two scary moments in which I thought the author was getting ready to tell us that positive ions can move through wires and transistors (NO!) but he pulled back from the brink and clarified that he was talking about ion flow in electro-chemical batteries.  Whew, that was scary!)

But here's a question for the philosophers and historians of electronics:  When physicists decided to label the electron as "negative" this was an arbitrary choice, right?   They could have just as easily decided to call it "positive" with the protons being called "negative" right?  In this case all the arrows in our diagrams would not be in need of reversal, right? 

Shotwell had the Knack (Car Knack), and so does Jay Leno

I've joked about homebrew cars -- we have a bumper sticker on Café Press that says "My Other Car Was Homebrewed From Junkbox Parts."  Well, in this video Jay Leno shows us a true homebrew car, this one built by a 17 year-old in 1931.  In the video you will hear some interesting comments from Jay on the kind of technical and mechanical skills that were expected of young men in the 1920s and 30s.  At the end of the video, watch Jay suffer the consequences of replacing a 20 amp fuse with an 8 amp fuse.  Who among us have not done something similar?   

Cool, Blue, and Homebrew! Pete Juliano's Tiny SSB Rig

Blue is the new Black!  I think some smart paint manufacturer should put a trademark on "Juliano Blue."

Check out Pete's latest efforts:
http://n6qw.blogspot.com/2016/07/small-radio-big-signal.html

Building LC Oscillators

Yesterday I came across this very nice video -- I thought you guys would like it.  2E0VIR obviously has The Knack!

I'm building a very simple LC VFO today. This is for the HRO Dial Receiver that I've been slowly working on. Mine is a Hartley, from Chapter 3 Figure 7 of SSDRA.   Stay tuned!

CBLA Dallas Division: Multiple Mighty Mites in the Lonestar State

Bill:

Just thought you would like to know that I am a new member of the color
burst army.  I am also a member of the Dallas Makerspace and our Amateur
Radio Special Interest Group is planning on offering classes (open to
HAMS and non-HAMS) where we build these Mighty Mites for the colorburst
frequency.

The class version will have a resistive dummy load instead of antenna,
to allow the project to be built by non-HAMS.  The idea is to get our
HAMS who just use commercial radios interested in building radios.  It
is also to get our general members (who like making things) into HAM radio.

Walter

In Search of the Elusive Imperial Whitworth

This beautiful old variable capacitor came out of a 1930's British regen receiver that I picked up years ago at the Kempton Park rally near London.  When I rebuilt that receiver, I found that the cap was thoroughly stuck.  No amount of solvents could loosen it.  I put it in the junk box and used a more modern cap in its place.

When planning for my current BIG VFO project (see yesterday's post) I re-read Frank Harris's chapter on VFOs.  Frank recommended a non-linear cap -- actually a cap that maintains a constant percentage change in capacitance as it goes through its tuning range.  My old British cap seemed to fill the bill.  Also, it appears to be brass or bronze which is said to have better temperature stability.  So I pulled the Brit cap out of the junk box.  It was still stuck, but as I tugged on it a bit, it suddenly loosened up.  Wow!  TRGHS.

When I tried to mount the capacitor in the QF-1 box, I discovered another problem:  the nut for the main mounting screw was missing.   And guess what:  None of the nuts in my "big box of screws and nuts" (I know you guys all have one of these boxes) was the right size.  Or, as Pete put it, all were of two sizes: a bit too big, or a bit too small.

Dex ZL2DEX informed me that the needed nut was likely an "Imperial Whitworth" (Don't you love British names?).  I started to think about how to get such an elusive part.... I thought about walking into Home Depot and asking them where they keep their Imperial Whitworths.  This wouldn't have been productive.

Then I started to wonder where the original nut went.  It would have stood out in my junk box because it is brass-colored.  I looked again in the junkbox.  No luck.  Then I realized that I might have used it to mount that replacement cap in my rebuild of the old British regen.  I pulled that old beast (wooden chassis!) off the shelf.  There it was, the needed brass nut.  Cap and nut were reunited, problem solved.   

It is kind of fun to include an old part like this in the new project.

Thanks Dex.  And thanks again to Frank Harris for the great book.