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Saturday, January 9, 2016

A Good Radio Morning at N2CQR


The Radio Gods were smiling upon me this morning.  I started out on 17 meters and had three nice contacts with European stations:  OH5CZ, a young fellow near Helsinki;  HB8DQL; then RM2D in Moscow. FB.

Then Pete showed up on the Skype. As he has said on his blog, he is still struggling with a family medical emergency, but I am happy to report that he is coping well, making good use of his can-do project manager background and his good sense of humor.  It was great to see him.

Inspired by my talk with Pete, with 40 meter AM playing in the background, I turned to my R2 FRANKENSTEIN phasing receiver.  Last night I completed the 90 degree phase shift network.  This is built around two quad op-amp chips and is designed to take the audio output from the two DC receivers and create a 90 degree phase difference between them.  I tested this stage by sending the same audio into each set of op amps.  I then put one scope probe in the output of one chain of op amps, and the other probe on the output on the other chain.  Wow.  Bingo.  90 degrees of phase shift across the 300 -- 3000 Hz audio spectrum. 

Emboldened by this positive result, I put the completed stages together this morning.  They passed the smoke test.  Then I tuned to 40 meters.   Wow again!  As promised, opposite sideband rejection without resort to crystal filters.  But as luck would have it, I ended up with a configuration that suppressed the Lower Sideband.  For 40 meters, obviously I needed to suppress the other side of zero beat.  But all I had to do to remedy this was to reach into the DDS box and switch the I and Q jumpers on the M0XPD/Kanga UK Arduino AD9850 shield.  This switch put me on LSB.  Very cool.

Here is a view from above:

The AD9850/Arduino DDS box is in the bottom center.  Above that, near the center of the picture,  is the board (from N6QW) with the two SBL-1 mixers and the initial AF amp stages.  The small green board above that is the IC phase shift network.  At the top of the picture you see the 3000 Hz low pass filter. Below that, the board with the little blue pot has an IC AF amplifier and a 300 HZ high pass filter.


I still have to build the audio amplifiers prescribed by the designer, Rick Campbell KK7B.   But obviously I am already having a lot of fun with phasing.  Here is the QST article on Rick Campbell's R2 receiver:
https://www.arrl.org/files/file/Technology/tis/info/pdf/9301032.pdf

Friday, January 8, 2016

N8NM: Thermatron Meets Silicon (Part II or III)

Steve N8NM has been pushing the limits of radio hybridization.  In this receiver he has 12AX7 thermatrons running alongside an Arduino and a Si5351.  Somehow I find this both very appealing and deeply disturbing.  Many of you will know what I mean. But FB Steve -- keep them coming.  Put these unique rigs on the air and strike a blow against the Yaesu-Icom-Kenwood monotony!   

Bill:

Here's a pic of a Thermatron-Meets-Silicon receiver that I've been working on.  Tubes are 12AT7 mixer, 2x6BA6 IF amps, 2x12AX7 (product detector, AGC amp and 1st AF) and 6AQ5 audio out.  An Arduino controlled Si5351 provides the LO and BFO as well as handling all of the switching, and the mixer and product detector use variations on Dr. Pullen's dual-triode circuit.  I've had this one on the air, but the hardware and software still need some, um, refinement.  And painting the panel has to wait until spring as my XYL doesn't share my affinity for paint fumes.

73 - Steve


Wednesday, January 6, 2016

N6ORS's Min-X Crosses the Pond on First Contact


Very cool!  Reports on new phone rigs keep coming in.  It is great to see them in their "still out on the bench" condition.  And reports of the first contacts are always exciting.  I like the MIN-X name.  This is indeed another testament to the contributions made to the radio art by our friend Farhan.   

Hello Bill,

Well I  just finished tweaking my new rig, I named it Min-X because I outright stole bits and piecesof the BITX and the Minima, thanks Ashhar. I made my first contact today and what a contact!

The contact was made with the rig as shown. The amp is a home brew FET push-pull.
I had a chat with Beth MW0VOW in South Wales! From Wisconsin to Wales on 15w PEP.
Oh, most of the rig was 'noodled' and constructed while enjoying you and Pete on the
SolderSmoke podcast.

Best 73,
Keith N6ORS





Monday, January 4, 2016

ZL2CTM's New Zealand Double Sideband Success


New Zealand and Australia seem to produce an amazingly high percentage of the world's double sideband transceivers.  Charlie ZL2CTM adds to the count.  He took inspiration and circuitry from DSB  hams in both countries and produced this beautiful DSB transceiver.  It is obviously -- as Charlie notes -- chock full of soul.  I definitely identify with his comment about "taming some kind of  electro-mechanical machine" and also, of course, with his remark about the feelings that come with putting a homebrew rig on the air.  So follow the advice of Charlie!  Build a DSB rig and put it on the air!  Make this your ham radio resolution for 2016!  Give it a go!    

Hi Bill:

I have been following you and Pete Juliano for many years now, and thought I would send you a photo of my 40m homebrew rig that I finished yesterday. Hopefully, it will help encourage others to melt some solder and make their own rigs. The rig is based on ideas and designs from Eric Sears ZL2BMI, Peter Parker Vk3YE and of course Pete N6QW. The aim is to make the final version relatively compact so I can take it tramping/hiking here in New Zealand.

The VFO is an AD9850 being controlled by an Arduino Pro Mini. The output is amplified to provide sufficient drive for the balanced modulator. I was using a nice 1” OLED screen to show the frequency, but that generated a huge amount of noise, so I changed to a LCD. Changing frequency is simply a matter of moving the curser left and right then using the up and down buttons to change the number. Very quick and easy. I was contemplating a rotary encoder, but I find those always seem to skip and jump every now and then. Must be the way I use them...   

The balanced modulator is a 4148 diode ring. I do have some SBL-1s lying around, but I thought I’d go with the discrete diode ring for something different. I’m using a standard electret mic and a simple single stage amp. The switch above that switches between phone and CW.
The PA is two stages; the first a 2N3053 and the second a BD139. At this stage it puts out just over 1W into a 50ohm load. I might look to add another stage and get that up to 3-5W.

The audio amp is a simple LM386. I am not running it hard out as per the datasheet as it generates quite a bit of high frequency hiss in that configuration.

Unlike Pete, I don’t have access to a milling machine to make squares to mount the components on. Instead, I use vero/strip board upside down and solder directly to the strips. This works really well for me on HF. I cut tracks with the twist of a small drill bit.

Last night I made two contacts with the rig. The farthest was 527km according to some well known mapping software. Both reports said the audio was ‘very nice’, which was great to hear. The receiver worked surprisingly well too, and I managed to hear stations in Europe.

As for user controls, you will notice that the pots, switches and plugs are all over the place. I did that to keep leads short. I like it as i feel like I am taming some kind of electro-mechanical machine to generate and receive RF.

Anyway, this little rig has a ton of soul in it and is really fun to use. There is something different about making a contact with a rig you built. I really encourage everyone to give it a go!

The next iteration will be a SDR using a Teensy. Rheslip over at Open Emitter has done some great work with that.

73s
 Charlie
ZL2CTM  






Sunday, January 3, 2016

TIA-Tube Hybrids from Steve N8NM (Part 1)


Last week Steve sent us a picture of his Straight Key Night rig which consisted of a homebrew thermatron transmitter and a TIA BITX as the receiver.  I asked Steve for more info on the TIA BITX. 

Bill:

Shot these right after making the first QSO using the TIA rig as the receiver.  The Arduino and '5351 are still on a breadboard, otherwise, all of the PCB modules except the filters and PA are installed on the chassis. 

The QSO was uneventful, which is a good thing!
73!
Steve



Friday, January 1, 2016

A SolderSmoke Holiday Charity Appeal -- Help Elisa help little Gonzalo!

We are going "off topic" for a moment, for a good cause.  Listeners to the podcast will have heard about my wife Elisa's strong connections to her home country, the Dominican Republic.  The new year finds Elisa trying to help a Dominican cousin who has a very sick little boy.  Details below.  All contributions large or small from the SolderSmoke community would be gratefully received.  Just click on the link to make a contribution.  And please consider forwarding this appeal to friends or relatives who might also be willing to help.


My name is Elisa Meara, and I am raising money for my dear cousin Eliana and  her 18 month old baby boy Gonzalo.

The week before Christmas Eliana and her husband Pedro were happily preparing to celebrate the festivities with their only child Gonzalo. This was Gonzalo's second Christmas and the first one he would be aware of.   Gonzalo wasn't feeling well and his pediatrician recommended that he be admitted to the hospital for a few days.  "Just another childhood virus" I am sure Eliana and Pedro thought.

But the morning of the day before Christmas they learned Gonzalo was very ill.  The diagnosis was leukemia.   While the world around them celebrated, they were living every parent's worst nightmare.  Baby Gonzalo needed emergency medical attention to save his life.

On Christmas Eve, trying to give their son the best chance possible, they left their home and families behind in The Dominican Republic to take him to Jackson Memorial Hospital in Miami for treatment. The morning of Christmas Day he received his first round of chemotherapy. The treatments will continue for the next six to eight months.

Needless to say,  this young and hard-working couple is devastated.  They are trying to do everything they can to help their baby boy.

While they have health insurance, the costs and expenses -especially those associated with living in a foreign city- are growing very quickly. We are hoping to help ease this tremendous heart-ache and suffering with prayers and financial support.

No contribution is too small and every little bit will help.  You can contribute here:



 And please consider forwarding this appeal to friends or relatives who might also be willing to help.

Happy New Year! Straight Key Night on 160 Meters


A while back, when I first mentioned getting on 160 meters by year's end, Pete suggested I shoot for Straight Key Night.  As many of you know, suggestions from Pete somehow seem to have a way of becoming ham radio MORAL IMPERATIVES.  He seems to be a prophet of sorts, a prophet of THE RADIO GODS.  So following the guidance of the oracle of Newbury Park, I found myself in front of my DX-100/HQ-100 on New Year's Eve, on 160 meter CW for the first time in my 42 years as a radio amateur.

It was great.  A couple hours prior to the official 0000Z start of Straight Key Night I had my first 160CW QSO.   It was with John WA2MUA up in Summit, NY.  John's QRZ page includes this: Years ago--as a teenager-- in an attempt to get enough wire for 160 I wrapped a quarter wave of wire around a pvc pipe, strapped it to a wooden gutter----burned a large notch in the gutter and could have burned my parents' house down!”   That, my friends, is 160 meter KNACK!  

Then, just minutes after SKN kick-off, I worked John W3LR in Eastern Pennsylvania.  It was also John's first SKN contact.

Next up was Eric NO3M.  Wow, this one was amazing.  Eric was running the homebrew rig pictured above.  On his blog Eric describes the rig:   "The transmitter is running a 89 Clapp oscillator, 802 buffer, 811 final...  Output power is approximately 75W. "
Eric's antenna is even more amazing:  it is a 160 meter four square featuring FOUR aluminum tubing vertical elements with capacity hats and --GET THIS -- a radial field consisting of 22,000 feet of bare copper wire. TWENTY TWO THOUSAND FEET OF BARE COPPER WIRE.  Wow, you just don't run into stations like that on 20 meter sideband.   Eric's blog: http://no3m.net/  But Eric -- a Vibroplex Champion?  On SKN? 

I then worked KC2LSD and K1EEE.  FB!

My last contact of the evening (and the year) was K1WHS, Dave in Maine.  On his QRZ.com page, Dave reports:
On 160 meters, I have a small setup right at my house. I use a K3 with a homebrew 3-1000 amplifier that runs at 1300 watts. The antenna is an 80 ft Rohn 25 in my backyard with some top loading and shunt feeding.  I laid out a bunch of radials in an effort to get the efficiency up. At last count I had about 107 1/4 wave radials strung out. 160 is the only band where my feedline is not big fat hardline. I use a run of RG-213.  For receive, I have several beverages running in the woods. I use this setup often in the winter as many times, the hilltop shack is not accessible due to heavy snow.   I have nothing up for any of the bands between 160 and 10 meters”.
 Thanks to all of my SKN contacts!  And Happy New Year to all  SolderSmoke readers and listeners! 
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column