Showing posts with label SPRAT. Show all posts

SolderSmoke #171 DC RX in QQ, Power Supplies, Small Screens, 12 Buck Counters, HW8 Error?, KX3 RX



SolderSmoke Podcast #171 is available: 

http://soldersmoke.com/soldersmoke171.mp3

Bench Report: 
Pete's Small Screens (in Color!) 
Si5351s
Bill's Graph Paper Frequency Readout
Bill's Broadened Barebones Barbados RX.  DIGITIZED! 
Another AD9850 DDS using M0XPD Kanga UK Shield
New 13 dollar Color Display (Prettier than Graph paper!) 

Pete and Ben's Article in QRP Quarterly Available free here: 
http://www.qrparci.org/qqsample/qqsample.pdf

The DEEP SPIRITUAL REWARDS of DC Receivers 
The Importance of Good Power Supplies
SPRAT Article on HW8 Design Error
Latest Edition of Hot Iron
Elecraft KX3 -- Has one of the best receivers in the world  

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

A Thatched Roof, Some Palm Trees, A Dipole, and a Homebrew Rig

 

Look at the drawing above.  That is the banner logo of Rod Newkirk's column in QST magazine.  For many years Rod regaled us with exciting reports on the activities of intrepid foreign radio amateurs, transmitting from exotic locations using ingeniously devised homebrew radio equipment.  Look at the picture on the left side.  See the palm trees?  See the thatched roof shack with the dipole antenna?  Well, that's pretty close to what it was like for me out on the Samana Peninsula in the Dominican Republic last month. 


I set up the station under the thatched roof in this picture:


The red pins mark the spot:



Here I am, tuning the rig while looking across Bahia Rincon: 


The rig was my Azores-built, oft-modified, NE602-based, ceramic resonator DSB transceiver with a recently added India-designed BITX IRF510 RF amplifier chain.  A little article I wrote about the ceramic resonator VXO was featured in SPRAT 127.  My antenna was a half wave dipole strung up in the thatched roof. Power came from 10 AA Batteries.  So this was the Double A, Double Sideband, Dipole DX-pedition.   

I had given some thought to building an SSB rig for this trip, but because of the efforts of Peter Parker, VK3YE, I felt compelled to take a DOUBLE Sideband rig with me to the beach. 

Here is an old (2006) video on the rig.  The power amplifier has been significantly modified: 




Here is some more information on the rig, including a schematic for the receiver and the SPRAT article on the Variable Ceramic Oscillator:

http://www.gadgeteer.us/PORTABLE.html
 
Here is the log book for my contacts.   

17 DECEMBER 2014
W1JPR PAUL MT. DESERT ISLAND MAINE
8P6AE (BARBADOS) COULD BARELY HEAR ME, BUT GOOD QSO

18 DECEMBER 2014
N4USA DAVE IN FLOYD, VA. FAIRS NET. (KK4WW.COM)
KE4UGF DON ALSO FAIRS, NICE GUYS. FUN CONTACTS!
KA4ROG ROGER NORTH OF ORLANDO

19 DECEMBER 2014
WB2HPV GUIDO TALKING TO ITALIANS EVERY MORNING FROM WAYNE NJ.  HE HAD TROUBLE HEARING ME.   
CONDITIONS SEEMED POOR, BUT I WAS HEARING AUSTRALIAN STATIONS
W8GEO GEORGE IN THE INTERCON NET.  HEARD ME.  ALSO ON INTERCON: KA4AOQ AND 6Y5MP (JAMAICA) ALSO HEARD ME.
N4PD PAUL
W3JXY/4 NAT IN KEY WEST
N1FM TOM, NORTH OF MIAMI SOLID QSO.
KM4MA PAUL IN ORLANDO WITH MARITIME MOBILE NET.

20 DECEMBER 2014
NA2LF LLOYD IN NY
WB8YWR JIM IN DALLAS 
KM4MA.
W1AW/3 IN MARYLAND (TOOK ME A WHILE TO GET HIM)

21 DECEMBER 2014   NICE 4 WAY SPANISH LANGUAGE QSO:
KI4PZE MIGUEL
CO8OT JUAN IN SANTIAGO DE CUBA
WA4RME RAFA IN CHARLESTON S.C.
C08KB MARCO IN CUBA


Here is a short video showing the station and the location.  Note the little birds (Golondrinas or Swallows) flying by.  They nest in the thatched roof.   They often got confused and flew inside the house.  Billy and Maria rescued many of them.  Whales breed in this bay in January and February.  There are also  manatees.  It is really a beautiful place. 



There were obviously other attractions (!) so I didn't spend a lot of time on the radio -- just a half hour or so every now and then.  But it was really very satisfying to carry this little homebrew device with me, set it up in this amazing place, and use it to send my voice across mountains and hundreds of miles of ocean.   I built this rig in the Azores and have used it in the UK, France, Italy and the Dominican Republic.  It contains circuits devised by members of the British QRP club and by my friend Farhan in India.  The ceramic resonator circuit is something I cooked up on my own.  The microphone is from my old Sony Walkman and the pen that serves as its support is from that wonderful magazine "Electric Radio."  In short, there is a lot of soul in this little machine.  And it was a lot of fun to take it to the beach.  

Thanks to Elisa for finding us this wonderful place.  And to Rod Newkirk and QST for the DX inspiration. 


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

Graham G4UEK has THE KNACK



Thanks to Stephen for alerting me to the homebrew page of Graham G4UEK:

http://www.sandrock.org.uk/radiostuff/Rigs.htm

I really liked the description of his progress as a homebrewer, and the way he was helped by G-QRP, SPRAT and Ian G3ROO.  FB.

Graham has a nice personal ham radio story:

http://www.sandrock.org.uk/radiostuff/Radio.htm

Thanks Stephen!  Thanks Graham!   

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

Pete Juliano's Bilateral Rigs (with videos)


 
Hi Bill,
 
I was finally getting around to reading one of the recent SPRAT’s and saw a photo of your magnificent BITX17. Congratulations! A tip of the hat to Farhan for that very excellent design and it truly is a design that has traveled the world and made a radio available to many who otherwise would not be on the air.
 
It is a very robust design as I scratch built one in 2005 (or maybe 2006) and just for fun socketed every transistor so I could try various devices. I even had a bag of 2N706’s dating back to the late 1960’s. They all worked except for the carrier oscillator where I just couldn’t get enough swing in the oscillator to correctly place the CIO on the filter slope. That I attribute to the junction capacitance of the 2N706. By far the lowly 2N3904 that I bought for 4 cents each worked the best. Back when I built this I was W6JFR. Adding the EI9GQ frequency stabilizer really added a nice touch to the radio.
 
I should also tell you that when I built the radio my intent was to uses a piece of single sided copper vector board for the main chassis. It was the weekend and I didn’t realize the piece I had was not  big enough for the project. So I took a piece of standard perf board and overlaid that on top of a piece of single sided copper PC board –AND hand drilled all of the holes – I went blind, cross-eyed and had a terrible hangover after consuming 6 beers in a short time span! See the photos below.
 
BTW I also built a 17M SSB transceiver using the bilateral amp stage from G4GXO as appeared in the SPRAT 128. That used a 4.9152 MHz IF and a 23 MHz Super VXO. In the case of the VXO I used 11.52 MHz crystals in the VXO and used a diode doubler to put the LO at 23 MHz. With the doubler –you get the bonus of 2X the frequency shift of the Super VXO. I also had made a custom set of crystals and used a small relay to switch those into the circuit and that essentially gave me almost the full SSB Band coverage. You can see that here
 
 
Also I have been using a simple bilateral stage consisting of a 2N3906 and 2N3904 and the results have been amazing. The latest work is a follow on to my shirt pocket transceiver and uses SMD components. See attached.
 
Here are some  videos of the latest –which is now a two bander 40 and 20M. (Originally it was 75 and 40M)
 
Have fun – this is such a wonderful hobby!
 
73’s
Pete N6QW
 






 
 
 
 
 
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

Standard Computer Crystals for 17 Meter SSB VXO and IF Filter


Pete Juliano, N6QW, is an electronic  genius.  The ideas in his SPRAT article will be of great use to all those who share in Doug DeMaw's devotion to VXOs and reluctance to spend money.  I'm really tempted to go back and re-do my BITX using Pete's 11.52 MHz computer crystal super-VXO and 4.9152 IF (I could then take my expensive 23.1 MHz crystals and put them back in my Doug DeMaw Barebones Superhet).  I also like Pete's DPDT reed relay crystal switcher too.  Three cheers for Pete Juliano, Doug DeMaw, and SPRAT!  And thanks to WB9FLW for reminding us of Pete's articles.

Hi Bill,
 
Your BITX17 really has me fired up! I came across an interested Super VXO by Pete N6QW for use on 17 Meters.

He uses standard computer xtals (4.9152 MHz for the IF) and (3 - 11.520 MHz freq doubled in the VXO)

This gets you on 18.120 to 18.150 using these two standard xtals.

See Link Below:
 
http://www.jessystems.com/SPRAT%20Article.pdf

http://www.jessystems.com/Images/23%20MHz%20VXO.jpg



Thanks for all your efforts they are much appreciated!!

Best Wishes,
Pete WB9FLW
 


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

Occam's Microcontroller


Paul, M0XPD, has what I'm sure is a wonderful article on a simple microcontroller-based rig in the current issue of our beloved SPRAT.   I look forward to seeing it.  And I really like the logo with William of Occam (of razor fame). I have encouraged Paul to take a break from the microcontrollers and build something discrete and analog... like a BITX!  

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20