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 

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

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/ 


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

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.

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

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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