Pete Tries Baluns on the DBM

A couple of weeks ago I ran a post about an old 73 Magazine article that extolled the virtues of putting baluns at the RF input and IF output of diode ring mixers.   Dedicated experimenter that he is, Pete Juliano gave it a try: 

Hi Bill,

I did the modification and used 20 bifilar turns of #26 on a FT-50-43 core for each transformer.

The most important observation is that I did not see any degradation of performance and in fact I think has helped an overloading situation I was seeing on some extremely strong signals.

The photo is of a DBM that is behind a bilateral stage that on Rx is the RF amplifier and on Tx is the Tx pre-driver. I do have another single transistor RF amp ahead of this. In normal operation the next stage would be the Band Pass Filter.

The back end is an IF amplifier, AGC, Product Detector, balanced modulator and mic amp stage all on a board that came out of a Hallicrafters FPM-300 SSB/CW transceiver. There is a you tube video of this prototype project.

73’s

Pete N6QW 

Thanks Pete! 

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Double A DSB DXpedition

Having a lot of fun with my old Azores 20 meter DSB rig here in the Dominican Republic. So far 11 solid contacts. People are amazed when I tell them the power source is 10 AA batteries! I feel I am redeeming myself as a QRPer after transgressing with the 120 watt amp project. We leave Samana and go to Santo Domingo on Sunday. 73 Bill

Sent from my iPhone

In Samana

Current portable ops in Samana!
YouTube video!

http://www.youtube.com/watch?v=eBCg3-feSrc&sns=em


Also. Today is Pete Juliano's birthday!  Send him greetings!

N5AB's Mighty Midget 40

Bill & Pete,

Your recent podcast on the Michigan Mighty Mite got me excited about hooking up

the one I built a few months ago.

The wattmeter claims it’s putting out 700 mW into a dummy load.

The old crystal I’m using is 7.108 mHz

The shack receiver verifies I’m on 7.108

The receiver also says I’m very strong on 14.216

I added a low-pass filter kit (now apparently discontinued) from kitsandparts.com

Even with the filter, I’m still hearing a strong signal on 14.216.

I’m not sure what’s going on here. Perhaps the transmitter coil is radiating the harmonic I’m

hearing on the shack reciever.

You guys are putting out some great podcasts! keep up the good work.

Bill N5AB

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Liberating a 3.579 Rock in a Home Depot Parking Lot

I think Ben should give that crystal another chance.  It may still be working on 3579.  But in any case, for the quick thinking and dedication to the cause displayed in that Home Depot parking lot, I hereby award Ben KK6FUT the Brass Figlagee medal.   (Who can tell us the origin of that prestigious award?) 

Hi guys, thought I’d share my story about two free toilets, Home Depot, the record breaking rainfall, and my failed attempt to join the Colorburst Liberation Army.

 

The short version, is our local water company gave away free low flow toilets today, and in my process of (absolutely failing) to install them at home (give me solder over plumbing any time!!) ran to Home Depot for some parts.

 

In the parking lot, someone had smashed a television set, and I suddenly recalled your story about how old televisions use 3.579Mhz crystals!!

 

I jumped out of my car, and immediately spotted and “liberated” the crystal above! I pulled it from the TV while in the middle of the parking lot...

 

However, it appears the rain the TV had been subject to in the last few days (or maybe the smashing) changed the crystal in question somewhere in the range of 10.2Mhz to 10.4Mhz... So no go! But an amusing adventure anyway, and I do have a random 10.4Mhz crystal to show for it.

 

Ben

KK6FUT

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A New Jersey Battalion for the CBLA? The NJQRP SNAP on 3.579

Back in 2000, the NJQRP club came up with a nice little transmitter called the SNAP. It was designed by Chuck Adams K7QO.   Dave K5YFO alerted us to it and suggested it as an alternative to the Mighty Midget.  One advantage over the MMM is that the SNAP needs no variable capacitor.  But it does need a couple of coils wound on toroids.   The SNAP design includes a low pass filter, something that has to be added on to the MMM.  Check it out.   Even if you've already built the MMM, you could easily take the crystal and use it in a SNAP build.  

More info on the SNAP here: 

http://www.njqrp.org/atlanticon/atlanticon%202000/snap.html 

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Another Great Blog from Canada

Earlier we wrote about QRP POP's reemergence in blog form. 

Here's another great blog from Canada, this one from Steve VE7SL: 

http://ve7sl.blogspot.com/ 


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Midwest Mighty Mite from KK0S

Wow, beautiful job Bruce.  I was hoping that a check of the Reverse Beacon Network would reveal that someone had heard you, but no joy.  Keep at it.  You may become the first CLA member in this round to make a contact.  

Bill - 

Hello from the Midwest chapter of the CLA.  Here's pix of my just completed Michigan Mighty Mite.  Nothing was purchased specifically for this project.  It was put together using only parts already on hand.  The only previously unused parts were the front panel sockets and one resistor.  The rig uses a 2N2219A transistor salvaged from a junked industrial control board and a color burst crystal that actually first oscillated in a tube-type color TV some 40 years ago.  Loading into my ground-mounted vertical, this MMM seems to be most stable at a draw of 87ma at 12.6 volts.  The arithmetic seems to work out at somewhere around 650mw into the ether.  I called for about half an hour around 2300Z, but got no takers... it was still pretty early for 80m and I had an extremely high local noise level.  The rig seems to run about 1khz high. I'll give it another go this weekend. 

72 - Bruce - KK0S.

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Jean Shepherd's Shack Gets Hit by Lightning

Yikes!  This is really good!  Thanks to Harv for sending us this link:  Poor Shep!

https://www.youtube.com/watch?v=akyTVNorXQ8&feature=player_detailpage

Greetings Bill,

Have been loving each Soldersmoke Podcast and Blog Segment recently.
You and Pete have made the program a superb treat while I've been busy with the Radio Room construction.


Building the Radio Room is like constructing an ARK in your Basement. Everything is being done in pairs
and the water keeps rising. (No kidding)...
I encountered two water breaks in the Radio Room while construction was under way but, that is a whole different story.
Fortunately none of my prized boat anchors were damaged.

The project; (The Radio Room), includes operating positions for 14 complete stations.
That wouldn't be too bad except I'm constructing walls, benches and over-head lighting from complete scratch.
While this is going on, I wanted to finish my 3.579 MHz CBLA transmitter and return to the Minima build that I started in April 2014.
However, in September, I retired and moved to another state.  The reality of the latter took awhile to sink in. Most Ham Projects took a back seat to higher priorities. I will soon have the Radio Room I always dreamed of. The Drake 2B fills the space with the sound of 20 Mtr CW and the anticipation of having the HT-37 brewing away is just around the bend.

I'm taking a short sabbatical from the Ham Shack construction to get caught up on some other household projects.
In this notion of taking a needed break, I rediscovered Jean Shepherd's programs on Youtube.
I started to dissect Sheps monologue when I found that familiar path in my own life as a 15 yr. old Ham in the mid-1960s.
I'm sure you too can relate to Jeans' life as a kid.
I really liked his broadcast https://www.youtube.com/watch?v=akyTVNorXQ8&feature=player_detailpage
"Lightning Hits the Ham Radio." Near the end of the program, he mentions that his life was over because his
Dad hammered him over the damage to the house by the lightning strike. I'd love to hear the rest of that story!!!

Please keep up the great efforts with Soldersmoke and bringing us all that good Tribal Knowledge. I think we should all go build something.
Looking forward to what's next. Thanks to You and Pete.

73's
De -=WA3EIB=- Harv
Eastern Idaho 


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Mahalo! WH7TT's Hawaiian Mighty Mite

This is our western-most MMM.  Edward took one of the 3.579 rocks and, using a Radio Shack breadboard (much used by Michael Rainey AA1TJ) built his version of the Mighty Mite.  When I saw the long clip leads to the coil I was apprehensive, but obviously it works.  Great job Edward and thanks for sharing with us your island rig.  Mahalo! (I like saying that!)

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W1KF's Connecticut Mighty Mite

Steve W1KF's Connecticut Mighty Mite is the neatest build so far:   it has a front panel and knobs and plugs and everything!  Pete Juliano commented: "Very cool –and elegant. I loved the transistor in a front panel mounted socket with heat sink. Wished I had thought  of that –great idea."  Steve is on the air at grey line times, looking for contacts at 3.579 Mhz.

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New Homebrew Book: The Joy of Homebrew Oscillations

Sent to us by Ben Tovar.  Soon to be available in EE-book (get it!)   Thanks Ben! 

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SolderSmoke Podcast 169: The Colorburst Liberation Army, Arduino DDS and the Tradition of Ham Experimentation

SolderSmoke Podcast #169 is now available: 

http://soldersmoke.com/soldersmoke169.mp3

-- 25 crystals "deployed"  to new Colorburst Liberation Army recruits
-- OBJECTIVE:  For now, just oscillation 
-- Using the Reverse Beacon Network (when time comes to transmit)
-- W2DAB's Mighty Mite: trials, tribulations, triumphs (and karma)
-- Explaining the Mighty Mite (all 7 parts)
-- Minima IF evolution -- up to 25 Mhz? 
-- Chuck Adams and "Experimental METH"!!!!!!!!!!
-- Different kinds of Arduinos
-- Si5350s and amateur experimentation
-- First menus, now KEYPADS! 
-- The launch of Orion
-- N2CQR/HI  Beach Portable DSB on 20
-- Video review:  "The Wanderers"

EL CLA UNIDO JAMAS SERA VENCIDO!   

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Launch of the new Orion rocket

The Saturn V was, of course, far more impressive and beautiful.  But the Orion is pretty cool. When  I was looking at the drawings depicting the various stages of the spacecraft,  that Apollo-shaped capsule brought back some deep memories.  I was 10 years old when Apollo 11 launched.  

A page from the scrapbook I made during the flight of Apollo 11. 

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CBLA Field Manual

I'm starting to worry about a visit from Homeland Security.   I found this on the blog of W6IEE. He blames K6FWT. 

The CBLA has a Yahoo Group: https://groups.yahoo.com/neo/groups/CBLA/info


Up the revolution!  Fight the Powers that Be!

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Another NY Mighty Mite Oscillates -- on 40! N2HTT (Video)

Inspired by all the talk of Mighty Mites, N2HTT put together a nice 40 meter version: 

Details on his blog:  http://n2htt.net/

Click on the video above to see and hear it in action. 

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Manhattan Mighty Mite: "Rockin' the Big Apple on 3.579"

Dave W2DAB got his Manhattan Mighty Mite oscillating nicely!  Hooray!  

Check out Dave's report on his Mighty Mite adventure: 

http://w2dab.bamford.net/

So far we have sent out 20 colorburst crystals.  Already we have two circuits oscillating (not counting Pete's and mine). 

CLA is on the march! 

E-mail from Dave: 

Dear Bill & Pete:

Thanks for all your help, I can joyfully announce the birth of my first Michigan Mighty Mite, Oscillating at the frequency of 3.579!  Yes, Pete’s sage advice to flip the coil over was a great help and also my good friend from Vermont (A Michiganian by birth ).  OK, so Bill… you remember your most embarrassing moments in home-brew? Well, here’s mostly what happened: I was reading the article I found online and somehow got 40 meters stuck in my head even though your colorburst was for 80 - So I build a 40 meter coil.  When I realized my mistake I thought - well why not build two of these so I pulled out the Colorburst and put in a Norcal 7.040 and then built a new board with a new 80 coil oriented properly and the pic below is the one you see.  Now I have two Mighty Mite’s that work, how great is that.

My next goal is to continue forward using Pete’s Build Something Video’s, so more fun to come.

I will post a video on my blog of the 80 Meter Colorburst Michigan Mighty Mite uttering it’s joyful tones, but for now I’ve put a lovely photo at the bottom.

Success is sweet when you hear the sounds of the beep!

Cheers and 73 Gentlemen

Dave

W2DAB

("Manhattan is more fun in Manhattan”)

 

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VK5FJ's Open SDR Rig (Arduino and SI5351)

Morning OM's,

I've amassed the parts for my 12v Regen Rx inspired by a projects from VK3YE and an audio amp, using a pair of 12AU7's. I'll publish more about that soon on my blog.

In the mean time, I'd like to thank you guys for inspiration on the si5351 VFO in use with various projects.  After we found the first articles by NT7S, we discussed that there are a lot of possibilities.

I've just finished my build of an Arduino controlled SDR transceiver prototype using the Si5351A.

See attached images. Lots of collaboration with Mark VK5QI and David VK5DGR. More at; http://openradio.net.au/index.php/OpenRadio_SDR

This week I'm tinkering with the LPF for 20meters. Puts out a whopping 20mW.

Everything is on schedule for the presentation using this SDR at Linux.Conf.Au next year. Got some coding to do to add I&Q for the SDR side over the summer break.

72, Kim VK5FJ

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Building a Better Diode Ring Balanced Modulator (with Knack Karma)

So yesterday Pete and I were talking about Dave W2DAB's Michigan Mighty Mite malady. Dave is tantalizingly close to the joy of oscillation.  Wizard that he is, I think Pete diagnosed the problem with his eyes closed from 3000 miles away.  I sent Dr. Juliano's prescription to Dave this morning and expect the concrete canyons of Upper Manhattan to be ringing with pure 800 Hz tones as soon as Dave fires up his soldering iron. 

Anyway, I then told Pete that I'd been looking through my bookshelf for something suitable for my 11 year-old nephew Sebastian.  I found something for him, but I also came across a book that was too advanced for the young fellow:   "The Master Handbook of Ham Radio Circuits." TAB Books, 1977.  By "The Editors of 73 Magazine."   Between turkey sandwiches I started looking through this book.  I immmediately found an article of interest:  "A Better Balanced Modulator."   The author (unnamed) looks closely at the performance of our beloved and much-used diode ring mixer with dual trifilar transformers.  He concludes that the unbalanced input and output coils (in the traditional configuration) detracts from the balance needed for optimum carrier suppression.  He suggest the use of baluns at input and output (see above) and claims significant improvement in carrier suppression.   Very interesting. (If anyone wants to dig into this, e-mail me.)  There is also a very simple solid-state VFO circuit that promises phenomenal stability.   

Anyway,  I found myself trying to remember where this great book came from.  Then I remembered someone sending it to me.  A quick check of my e-mail revealed the source:  Dave W2DAB sent it to me three years ago.  Thanks again Dave!  


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35% Off on Bill's Books

35 % off on "SolderSmoke" (the book!),  "Contra Cross", and my new book: "Us and Them" 

All available in print and e-book form here: http://www.lulu.com/spotlight/soldersmoke

Sale through Dec 3.


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