Low Field Day Score Leads to Club Disbanding

Sad.  But failure has consequences my friends.

http://hamhijinks.com/finger-pointing-name-calling-as-club-fails-miserably-at-field-day/

Thanks to Jeff Murray K1NSS for alerting us to this sad situation.  

Useful Boards From Whole Foods

Maybe it has something to do with the fact that this chain of stores is sometimes referred to as "America's Temple of Pseudo-Science" but I just don't seem to find a lot of radio-useful stuff in Whole Foods.   However, at the check-out stand this week something caught my eye:  Grilling Planks!  Who knew?   Apparently you soak these boards ("Sustainably Produced in the Pacific Northwest - USA") in water, then you grill your food on them.  They are available in various wood types -- above you can see Cedar and Hickory.  I put the Altoids can in there for a size reference. These grilling planks seem well suited to serve as breadboard-style chassis, front panels  or even cabinets for homebrew rigs.  

Free Book!

I decided to make my book "Us and Them -- An American Family Spends Ten Years with FOREIGNERS" available to a wider audience. The suits at Amazon Kindle allow me to make it available in e-book Kindle form FOR FREE for a five day period starting today. So this would be a good time to put a copy in your Kindle. I think it would be a good book for the beach.

Please spread the word -- let friends know of the free book offer.

Here's the link: https://www.amazon.com/Us-Them-American-Family…/…/B00L8DR4RK

SolderSmoke HQ Station WINS Field Day! Again!

First, I need to make clear that that is NOT me in the picture above.  This year I chose to compete as an "E" station:  "At home, with the air conditioner on, but using a battery instead of the normal AC poser supply."  This is, of course, only one step from the bottom on the laziness scale -- I did hook up the 12 volt gel-cell.

But I made up for it with an unusually large dose Knack-ness.   I used my BITX Digi-Zia scratch-built homebrew SSB transceiver.  So, with my whopping 11 contacts I feel confident that I won the "1E Homebrew SSB Transceiver, Northern Virginia" category.    

NASA'S New Mars Recruiting Posters

More like this one here:
http://marsmobile.jpl.nasa.gov/multimedia/resources/mars-posters-explorers-wanted/


Bill,

Doesn't this fabulous artwork remind you of the 1950-60's era and the intense interest we all had in space and spacemen?
http://marsmobile.jpl.nasa.gov/multimedia/resources/mars-posters-explorers-wanted/

I recall there was so much inspiring artwork showing men in spacesuits, even though at the time it was before we had put men in obit around the earth never mind set foot on our moon. Packets of breakfast cereal came with plastic model spacemen and rockets.

It struck me that amateur radio will play a huge part for those who venture to Mars and Phobos, as they will need the type of people who have the practical abilities to improvise and repair equipment while severely restricted in the availability of spare parts.

NASA should do a poster showing an intrepid Mars Soldersmoker with his workbench with some piece of electronic equipment in pieces.
73
David GM4JJJ
-------------------

Jeff K1NSS? 
http://www.dashtoons.com/

Arecibo in Danger

http://www.extremetech.com/extreme/230637-flat-science-budgets-could-kill-the-arecibo-observatory-the-worlds-largest-telescope

Some Sympathy from the New York Times Crossword Puzzle

Hi Bill,
Pete "The Crossword Guy" K4PHS here again.
In the New York Times Crossword for Tuesday June 21, 2016 the clue for 52 across is:
"Enough, Enrico!"
And the answer is:
"Basta!"
72, Pete, K4PHS

And from October 5, 2015

Hi Bill,

The clue for #7 across in todays New York Times Monday Mini Crossword puzzle is:

“special talent”

And, of course, the answer is KNACK!

72, de K4PHS Pete
"Keep Calm and Melt Solder"

An Excellent Morning at the Manassas, Virginia Hamfest

I was quite pleased with the valuable items obtained at the Manassas Virginia Hamfest this morning.  Armand WA1UQO and I once again combined forces, offering each other advice and counsel (NO!   Forget it!) as we went through the flea market. 

Above you can see what I got:
TOP ROW: 1)  A bunch of boxes.  Nice aluminum boxes and two really good chassis.  I may now have to build something with thermatrons.   Armand gave me a really nice Ten-Tec box.  Thanks Armand!
MIDDLE ROW 2)  Ten much needed coax patch cords.  I promise to check the connections before using them.  Really.  I mean it this time. 
3)  A nice circular coax switch.
4) Two large hemostats.  I told the woman I needed them for some surgery that I'd be performing later in the day.  She was not amused.
5) A homebrew SWR Monimatch box.  Amazing.  Dennis Klipa and I have been talking about these, so I bought this homebrew version.
6) Nice Jackson Brothers reduction drive with tuning indicator. 
7) Really nice variable cap.
8)  Three crystals: two for 3.579 MHz CBLA work, the other for 40 meter phone.
9) Forehead "coalminer" lamp
10)  Some PC boards.
BOTTOM ROW 11) LARGE box of 455 kc IF transformers

As we were making the rounds we ran into Charles AI4OT.  On the tailgate of his truck Charles had a BITX20 in operation!  You can see it in the picture.  Great to see you Charles and FB on the BITX.

Jan PA3GSV's Amazing Mate for the Mighty Midget

We have featured the amazing homebrew work of PA3GSV before:

http://soldersmoke.blogspot.com/2016/04/my-mate-for-mighty-midget-thermatron.html

Jan is at it again, this time building a Dutch version of Lew McCoy's Mate for the Mighty Midget.  Look at front panel! But wait, there is more!

Here is a side view of the chassis.  Wow.  What, you may ask, is that round thing?

Holy cow!  Homebrew Vernier reduction drive made from the cap of a sewer pipe.  And a homebrew dial cord arrangement.  Jan is clearly breaking new ground in ham radio homebrew re-purposing.

Jan writes:

Bill:

Here a little update on the MMrx.

Got almost all the parts, except for the Miller 4411 300 uH coils, for which I am attempting to make my own.

While I was looking for some pictures of this coil, if it was shielded or not (found a vintage online Miller catalogue J ),

I stumbled across this article, the W2MQ “Hamster”

There is no mention of the MMrx, but the text is very in line with the latter. Nice read.

 http://www.njarc.org/broadcaster/BC2010-04.pdf

 Also while looking for parts, I saw this supplier of FT-241 xtals who sell for reasonable prices ($10) .

Maybe you already know this company:

 https://www.fairradio.com/catalog.php?mode=view&categoryid=198

 Vernier drive 1:19

The drum is made from a sewerage end cap got from the hardware store.

Still under construction J

Added a front control to switch the BFO on/off, together with another crystal or some arrangement to make AM (broadcast) reception possible.

I want to try a regen detector instead of the 2 germanium diodes, followed by a pentode for some more audio output.

Regen and AF gain control are also at the front.

In your video it looked like there was a screwdriver sticking out of the BFO oscillator coil, a trigger to put this control on the front as well J

As there is no AGC, the (S) meter will measure the plate current of the RF amplifier tube.

So, a lot of experimenting to do, and still busy with some of the mechanics.

 73  Jan

Inside a Millen 61455 IF Transformer

I found this in my junk box.   I've put it in my old Mate for the Mighty Midget receiver, in the place of the Toyo  CM455 crystal-mechanical filter (which I found to have excessive insertion loss).  I think its very cool how they squeezed two variable caps into that little can.  Designed in 1956.  Works great.  Note the promised passband: 4.7 kc at 6 db down.  Not bad for an LC device.
Here is the spec sheet:

 

Bob Crane Interviews Eric Schwartz of Elecraft About the New KX2 (with Si5351!)

Our ace correspondent Bob Crane W8SX caught up with Eric Schwartz WA6HHQ of Elecraft at the FDIM event n Dayton last month.    Here is Bob's interview with Eric:  

http://soldersmoke.com/WA6HHQFDIM.mp3

Pete and I were very pleased to see that Elecraft made use of our beloved Si5351 chip in their amazing new KX2 rig.   Check it out:

You can click on the diagram or see it directly on page 62 of the manual at this site:

http://www.elecraft.com/manual/KX2%20owner's%20man%20A4.pdf

Here's the KX2:

Three cheers for Elecraft!  Three cheers for Bob Crane! 

Excitatation! The Inspiring Knack Story of N3IC

Steve Silverman sent me this link.  This web site has been getting a lot of attention from the solder melting community.  And justifiably so.    Behold (above) the first transmitter built by Robert Glaser,  now N3IC, circa May 1969. The chassis and front panel were made from flimsy printing press sheet metal.  Note the key (as in lock and key) switch that the OM put on the front panel -- he took his responsibilities under FCC regs quite seriously.   My favorite part of this rig's story is that when he got it done, he didn't have the two 6146s for the final.  So he just took a capacitor and used it to connect the driver tube to the output network. Brilliant!  With that arrangement he made his first contact.  No wonder he labeled it "Excitatation!"  It was clearly more exciting than your standard excitation.  

Those TV power transformers look very familiar.  I was using similar devices to build a power supply for an HW-32A a few years after Dr. Glaser built this rig.  It's a wonder we survived.

FB.   Check out his site.  It is a wonderful catalog of all the stuff this very prolific builder has made over the years:

Ham project here:

http://www.icengineering.com/n3ic/projects/ham/

A broader range of projects here:

http://www.icengineering.com/n3ic/projects/

   

ANOTHER SSB Transceiver made in India

Check out the GEK:   http://homebrewcorner.blogspot.in/p/r.html

Spectacular Solar Weather

This amazing picture was taken last night at the Bharati Indian Base Station in the Larsemann Hills of Antarctica. The researchers there report that the aurora was so bright that it cast shadows.

Yesterday I was having a nice 40 meter SSB contact with N3TDE.  Rich is 179 miles away, in Pennsylvania.  At 1650 UTC, his signal very suddenly dropped into the noise. 

The purple lines along the bottom of the chart below probably explains both the aurora and the abrupt end of my 40 meter contact.

Re-purposed Computer Power Supply Box Provides a Home for a BITX Transceiver

Jaydip VU3JOJ came up with a really inventive way to box up his new BITX transceiver.  Nicely done. I especially like the way he put the speaker  in the space intended for the fan. Very nice.

This appears to be one of the new BITX 40 meter "modules" described in yesterday's blog post.  FB!  How fortunate the new board fits in the power supply boxes.  That's very lucky.

You know, I had an old computer power supply in my hand  just yesterday.  I almost threw it out.  Obviously that would have been a mistake.

Today was a BITX day.  Using my BITX DIGI-TIA on 40 I had a long QSO with Rich N3TDE.  Rich has a BIT20 built from a Hendricks kit acquired at Dayton.  He takes it with him on the Appalachian Trail.  

A Really Nice Project: Farhan's BITX40 Module

Wow, that board is a thing of beauty.   And the story behind it is even more beautiful. Our friend Farhan took his famous BITX circuit, shifted it to 40 meters, and put the whole thing on one small board. It is now a module, but a module that makes up an entire SSB transceiver.  The idea is that this module can provide a base for expansion and experimentation.   You can add a digital display.  Or a (gasp!) digital VFO.  Or an RF amplifier.  Or more bands.  Or all of the above.  It is a very cool idea.

Here is the most beautiful part:  In an effort to help people who need help, Farhan has arranged for a collective of women to assemble the boards in their homes. They needed work, and Farhan gave it to them on good terms.  Bravo Farhan!

In keeping with the earliest purpose of the BITX rigs (simple transceiver for Indian radio amateurs) this board is currently only available in India.  

Check out the site:

http://www.hfsigs.com/buy.html

The circuit description is especially good:

http://www.hfsigs.com/circuit.html

Ryuu's Receiver (Superhet using Si5351 and Color Display with IF at 10.7 MHz from JA2NKD)

The influence of Pete Juliano is spreading far and wide.  Those little color screens attached to Si5351s seem especially popular in Japan.  Above is the receiver of Ryuu JA2NKD.  Below is the schematic.  Click on it for a better look, or use this link:
http://ja2nkd.c.blog.so-net.ne.jp/_images/blog/_206/JA2NKD/7MHzcolorLCDSchematics.jpg?c=a1

Ryuu's blogs are here : http://ja2nkd.blog.so-net.ne.jp/
and here: http://ja2nkd.blogspot.jp/
They are in Japanese.  Google Chrome does a poor job at translating them, but you can get the gist.  In any case the pictures are great and the schematics are understandable by all of us.  Thanks Ryuu!

Manhattan-style Vacuum Tubes: "An Evolution of Thermatron Homebrew Techniques" by Grayson Evans

Grayson Evans was at Dayton.  Scheduling problems prevented him from being interviewed by ace correspondent Bob Crane, but Grayson was kind enough to e-mail us the essence of his presentation.  And it is really wonderful.  He brings the advantages of the Manhattan construction technique (fast prototyping, all components on the same side of the board, easy modification) to the world of tubes (aka valves or, as Grayson prefers, thermatrons).  We also see in Grayson's work an admirable willingness to bridge the digital-analog design, to bring into his rigs the best of the old and the new.  Thanks Grayson!

Grayson writes:

An Evolution of Thermatron Homebrew Techniques

For a long time I have been trying to develop some techniques to prototype Thermatron projects as easily as the typical “Manhattan style” solid-state construction.  Thermatron projects you see now-a-days still use the traditional technique of mangling aluminum-drilling and mounting everything to a “bud” style chassis. This just takes too much time and my projects always look disappointing.

Fortunately, around two years ago, Rex Harper, W1REX, came to the rescue after hearing an earlier talk of mine and developed a set of thermatron socket pads. The MeTubes panel from QRPme consists of 10 prototype pads for thermatron sockets. The panel has v-scores for breaking the panel into single tube pads. The panel has pads for mini 7 & 9s, octal, compactrons and acorns. Awesome.

The best sockets to use with the pads are PCB style.  These provide a large pin area to bend out and solder to the pad (see photos). 

I pre-mount a dozen or so of the 7-pin and 9-pin sockets on MeTube pads so I have them ready to go when prototyping. The “crude” example below shows and 7 and 9-pin socket on one of my prototypes.  I think this was a microphone amp for my AM transmitter.  Pardon the mess.

The nice thing about the pads is that they provide plenty of room to tac solder lots of parts to a single pin–easy to add or remove parts.  This is a lot easier than using the traditional tube socket pin. 

Prototyping thermatrons in this way is FAST.  No more punching out holes to hold thermatron sockets in aluminum chassis!

But it is still nice to be able to have the thermatron on the “top” of the board and the components on the “bottom” of the board.  To do this and still use the MeTube pads, the thermatron has to be mounted on the other side.  I did this by mounting the socket through the MeTube pad.  This requires making a hole in the center of the pad to pass the socket through and then soldering the pins in the usual way.  This is way easier with PC mount thermatron sockets and make a very nice installation. 

This technique has some great advantages over using the traditional socket with pins.  The pad has a lot more room to mount components to each pin.  Normal thermatron socket pins are difficult to attach more than two wires and it’s a bit more difficult to get a good solder connection.  The pads are easy to solder to and allow components to be easily attached in any direction since the “socket” is now flat.

It is also easy to attach the socket/pad to a copper clad board.  The same hole must be made in the copper clad board to pass the top of the socket through, then the pad is superglued to the board in the regular way.  



This is another example of “right side up” thermatron mounting on a prototype test board for crystal filters.  I mounted a small “plug board” (not sure what you call these things) in the center to allow me to easily swap filter components.  Notice the acorn thermatron soldered direct to the pad.  The board works great, the filter design sucked.  I gave up.  Maybe too much distributed C.

I used this technique, combined with Roger Fell’s idea of using inverted aluminum chassis, to build my latest project, a QRP AM/CW transmitter.  I’ve been wanting to try out a few new ideas and this seemed like a good project to try them on.  I also wanted to build the transmitter in modular “blocks”, interconnected in a similar way to Rogers. It worked pretty good although I am still trying to get the thing to work right.  Even new construction techniques can’t cure my screwups.  BTW, the ANALOG VFO is ROCK SOLID.  +/- 10 Hz over 30 min.   Even I was impressed.  The Hartley oscillator is the best circuit for thermatron circuits by far.

I’ll send an update when I get it fully working on AM and CW.

73,

Grayson

TA2ZGE

JH8SST Build's Pete's Simpleceiver (video)

Jun JH8SST made this nice video about his version of Pete Juliano's Simpleceiver.   I like the approach of putting the stages on separate boards, but perhaps Jun could have made things easier by using Manhattan-style construction on those boards.  And of course I like the breadboard-style aluminum sheet.  FB Jun.  

Jun writes:

I've built a simpleceiver, which is a modified version.   My first main board didn't work because of several problems, and that's why I decided to divide the board into several separated PCB's with some circuit modifications.

 

RF and Mixer stages are original, but I employed an 8pole 9MHz ladder Xtal filter.   The J310 X 2 is used in IF amplifiers, but load resonant circuit is modified to use a type 10K coil form and a ceramic capacitor.

J310 product detector is original and built on a tiny PCB, as shown in attached photo and YouTube Video.

 

This modified Simpleceiver has high sensitivity and more than enough gain. I needed to reduce RF/IF gain to eliminate product detector distortion caused by stronger signals.

 

This simpleceiver works really nicely.

 

I'm going to re-modify it to make it as original as possible.

 

The block diagram is:  J310X2 RF－DBM－9MHz 8 pole X'tal Filter－J310X2 IF－J310X2 IF－J310 product detector－AF　μA741－AF LM380 with NFB.

 

I'm going to re-modify it as:  J310X2 RF－DBM－J310X2 IF－12MHz 4 pole X'tal Filter－J310X2 IF－J310 product detector－AF　μA741－AF LM380 with NFB.

 

I'm also going to add an AGC system using a modified W1FB AGC circuit.

 

NP0 Is the Way to Go!

Much to the consternation of Pete "Digi" Juliano, I have been working on analog LC VFOs for simple superhet receivers.   As described in earlier posts, I recently converted an old Barebones CW superhet to 40 meter SSB.   At first, the VFO (2 -2.3 MHz) was not stable enough -- it would slowly drift in frequency. ("We have a solution for that," chuckled Pete.)   My first effort at stabilization involved replacing the toroidal coil.  The material in the core is sensitive to temperature changes and this can lead to instability.  I found my traditional cardboard tube from a coat hanger, and made a coil of the needed inductance (you can see it in the pictures).  This yielded some improvement in stability, but it was still drifting.  

Next I tried taking out all the silver mica and disc ceramic caps in the LC circuit of the oscillator and replacing them with NP0 ceramic caps.  The feedback caps are in the box below the tuning cap, but you can see some of the little NP0s on the outside of the box, connected to a rotary switch.  This serves as the equivalent of variable "Bandset" variable cap, with the tuning cap serving as the "Bandspread."  I have seven switch positions, each covering about 40 KHz (with some overlap).  This gives me all of the phone band and the bottom 30 kHz of the CW band.  

Switching to NP0 caps really did the trick.  The receiver is now very stable. When I told Farhan about my VFO woes, he mentioned that he'd had very good stability results with surface mount caps.  I wonder if this success has more to do with those caps being NP0 than with their surface mount configuration.  

Here is a good description of NP0:

NP0 Ceramic Capacitors are single-layer ceramic capacitors made from a mixture of titanates.

A NP0 ceramic capcitor is an ultrastable or temperature compensating capacitor. It is one of the most highly stable capacitors. It has very predictable temperature coefficients (TCs) and, in general, does not age with time. 
NP0 stands for negative-positive 0 ppm/°C, meaning that for negative or positive shifts in temperature, the capacitance changes 0 part per million, meaning that it has a flat response across a wide range of temperatures; the capacitance of the NP0 capacitor stays constant (at the same value) despite variations in temperature.  

From: http://www.learningaboutelectronics.com/Articles/What-is-a-NPO-ceramic-capacitor

But I think it is a stretch to claim that these marvelous caps do not "age with time!"  That would be a really astounding property of the titanium dielectric.  That would be a Negative-Positive Zero FLUX capacitor, right?