WA7MLH's RD16HHF Amplifier

OK, so now that I have the MOXON in the air, my thoughts are turning to amplifiers and a possible winter project. Hey, even QRP guru Doug DeMaw conceded that every once in a while a fellow needs a few more db. And the sunspot count will be dropping.  

On the BITX group there has been an interesting discussion of using RD16HHF MOSFETs in place of our familiar IRF-510s.  I thought these devices were new, but some Googling this morning led me back to the wonderful website of QRP giant (hey, he is IN SSDRA!) Jeff Damm,  WA7MLH.   Jeff has been using these devices for quite some time.  As with all of Jeff's projects, I find his EXTREME UGLY building methods to be inspirational and reassuring.  Even if you have been there before, you should visit his site:

http://www.neoanderthal.com/wa7mlh1.html

Even his QRZ.com page makes you want to build something:

http://www.qrz.com/db/wa7mlh

Thanks Jeff! 

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Part III with Pete Juliano this Saturday

 

It looks like Pete Juliano, N6QW, and I will be able to do Part III of our discussion of homebrew SSB gear this Saturday.  We might start out with ladder filters.  Other possible topics include construction practices (shielding, decoupling, the handling of heat, etc), junk-box practices, essential test gear and, time permitting,  tube (or, as Grayson would say, "thermatron") gear. Speaking of which,  here are some pictures that Pete sent me of a 20 meter CW rig he is working on. 

"Here is a 20 Meter station that I recently got working and hope to have it on the air soon. The Rx is something I cobbled together and it does have a Crystal filter. The Tx is an amalgamation of several Handbook radios – one feature it uses a bandpass tuning network from the oscillator to the final. The screen voltage has a separate regulator. Each unit  size is 4 inches high, 4 inches wide and 8 inches long. There is still some work needed for the control and TR."  

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Moxon Aloft!

We put it up on the roof this afternoon.  I think it looks great!   The neighbors have not yet risen up in opposition to the new skyhook.   My family thinks it cool that I can spin it around.   I have it pointed at Europe and I notice a big difference.  I've worked F5LIW, OT4A, YL2BJ,  F5BBD.  Lots of fun. 

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

Gravity Light -- A Potential Power Source for QRP Ops in the Field

Nice idea.

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 First Listener: Brad Smith, WA5PSA

I got a nice message yesterday from Brad Smith, WA5PSA.  Brad told me that he had listened to both of the Pete Juliano podcasts...TWICE.  As a result, he is planning to build a phone rig.

In the message Brad reminded me that he was the source of the very first feedback that Mike, KL7R, and I received about the SolderSmoke podcast.   I remember it very well.  We had uploaded SolderSmoke#1, and were wondering if ANYONE had listened.  Then came this message from Brad (was it an e-mail?) saying that he'd listened to the show AS HE JOGGED THROUGH TULSA, OKLAHOMA.  Wow!  Tulsa!  Our voices from London and Juneau had been heard in ear-buds by a jogger in Tulsa, OK.   It was a bit like when you were a kid and you ran into the kitchen to tell your mom that you had just talked to a guy in TULSA.  Somehow, that day, Tulsa seemed as exotic as Tokyo.

Thanks Brad!  Good luck with the phone rig.  Hope to work you on 17.

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

VK2SJA's Minima in a Realistic DX-100 Case

Steve, VK2SJA, is doing to a Realistic DX-100 what I have been thinking about doing to a Heathkit HW-101.   With this kind of encouragement, who could blame me for making a Minima-101?  I've been planning on keeping the 6146s and all the final (and perhaps driver) circuitry.    

Here is Steve's very nice description of his project thus far:

http://www.hfsignals.org/index.php/UnRealistic_Minima

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

Scrap wood, some wire, four fishing poles and an old tripod: Moxon Update

 

It is not up on the roof yet, but we are getting close.   Above you can see he center "hub" -- just some scrap plywood and 8 u bolts.



 

Here is how I handled the corners.  The coil thing is from the end of a bungee cord. It makes for easy disassembly. 

 

 

 

Here is how the mast connects to the hub.  I had some 1x1 scrap wood. The 1x1 will be U-bolted into the rotator.  



 

 

 

Made of wire and fishing poles, Moxons are not very photogenic.  But I think mine looks great.  The 17 meter version is quite small. 

 



 

A bit of a balun.  Just to keep RF currents off the outside of the braid.

 



 

That tripod was last aloft in the Dominican Republic (1992-1996!).  Two spray cans of flat black paint have been applied.  Stealth!  

 

Four 16 foot "crappie" telescoping fiberglass poles purchased from Amazon.   



 

The only thing holding me up at this point is a safety concern.  The roof has a somewhat steep pitch, and I am not at agile as I used to be.   So before I install this magnificent sky hook I'm getting one of those roof safety harness systems that roof workers are supposed to use (but rarely do).  This sill also benefit the poor fellow who comes to clean our gutters.  



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

Crazy Joe May Have THE KNACK

http://www.crazyjoe.org/studio.html

Check out Joe's VERY long-running audio studio project.  It appears to be mostly appliance/commercial gear, but look closer and you will discover that most of it is homebrew.


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

Thomas's Magnificent Minima

Wow, Thomas's page makes me really want to build a Minima.  Note the Manhattan style with Rex Harper's Me-Pads.  Excellent.   Thomas provides a really great stage-by-stage description of the project with the kind of candid descriptions of mistakes that SolderSmoke listeners are so fond of!  

http://www.sarfata.org/ham/minima/

Thomas himself has an interesting "international brotherhood"  personal history:

http://www.sarfata.org/about.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

ISEE-3 Recovery Hiccup

Now that's a McDonald's that you would want to work in!  That's the headquarters for the ISEE-3 recovery effort. (Is it also the place where they recovered the long-lost moon photos from the 1960s?) 

This week the ISEE-3 effort hit a bump in the road.  Getting old gear to work properly is never easy.   Be patient fellows! 

http://www.nytimes.com/2014/07/09/us/in-effort-to-shift-abandoned-nasa-craft-a-hiccup-or-burp.html?action=click&contentCollection=Science&region=Footer&module=MoreInSection&pgtype=article

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

Jason's WBR Regenerative Receiver

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