Podcasting since 2005! Listen to Latest SolderSmoke
Friday, March 15, 2024
Finishing up (?) Version 2 of my 15-10 Transceiver (Video) -- An Annoying Residual Carrier Problem
Tuesday, January 30, 2024
Yet ANOTHER Homebrew 15-10 SSB Transceiver (Video #1)
Wednesday, January 3, 2024
Monday, September 4, 2023
SolderSmoke Podcast #248 -- Back from the Summer -- Spurs and Filters, S-meters, 6BA6 mania, Shirtpocket rigs, MAILBAG
SolderSmoke Podcast #248 is available for download:
Audio: http://soldersmoke.com/soldersmoke248.mp3
Travelogue: Trip to the Dominican Republic 3-9 August. Thinking about the M0NTV video on mixers...
Solder Smoke Shack South is almost done. I am thinking about workbenches, operating tables and antennas. How high should an electronics workbench be? Table height? Or workbench (woodwork) height?
My son and I went to see "Oppenheimer" Trinity test scene very cool. They wanted to see if the gadget would work!
Is the SolderSmoke blog completely archived on the WayBack Machine? Please check and let me know. Thanks.
Bill's Bench:
-- I've been working a lot of DX with the homebrew rigs: Indonesia, Australia, Japan, Hawaii. Lots of fun. 15 meters has been especially good. But the rigs still need work:
-- M0NTV's video got me to put TinySA to work. I found that output from dual banders could be improved. Spurs and harmonics. Yuck. I need more TinySA -- ordered the TinySA Ultra.
-- Allison KB1GMX helped a lot. EB63A amp was unstable, especially on 10 meters. Higher frequencies are harder! Tightened up shielding, negative feedback, and bypassing. This all helped, but I found that I needed to take the higher frequency LP filters out of the amplifier box. W3NQN filters are better, with steeper skirts and better 2nd harmonic rejections. NanoVNA proving very useful. https://www.gqrp.com/Datasheet_W3NQN.pdf
-- Also worked on the Bandpass filters for these rigs. Farhan's comments on skirts of different filter configurations. Some are "LSB" filters (with steeper skirt at the highest freq) and some are "USB" filters (with the steeper skirt at the lower frequency) See diagrams on the blog page. So I built USB new filters for 12 meters and for 10 meters.
-- Phase Noise rears its ugly head again. See blog posts.
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SHAMELESS COMMERCE DIVISION:
Mostly DIY RF getting ready to release PsssT kits. Target date: December 18, 2023 (E Howard Armstrong's birthday). https://mostlydiyrf.com/
Amazon Search box seems to have died. I can't get it back. Can anyone tell me what happened? (There seems to be "explanations" from Amazon about this, but they are written in a strange language that I cannot follow.) Something similar happened with the Google Ads on this blog page. Apparently you can't have ads both on YouTube and blogger.
But hey, there is Patreon for those who want to support the podcast and blog.
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Pete's Bench
An S-meter for Bill?
6BA6 Mania!
QRP SSB with 6BA6
Shirtpocket rig re-build
Mailbag:
Walter KA4KXX has a great article about homebrewing in the September 2023 QCWA Journal.
Steve KC1QAY -- Has joined the CBLA. I sent him a 3579 crystal. He built a MMM and experienced JOO. And Allison KB1GMX is in his local radio club. TRGHS.
Ajay VU2TGG in Pune, India -- launching a high school receiver effort.
Denny VU2DGR The Wizard of Kerala: https://soldersmoke.blogspot.
Joe VK4BYER working with kids a remote Australian community. FB.
Todd K7ZF -- Wants to get into homebrewing. Advised him to start small.
Dean KK4DAS: Fixing Hallicrafters Worldwide RX. Ciudad Trujillo! Got question from Mark in the VWS Makers Group: HOW DOES Michigan Mighty Mite REALLY Work. See blog.
Trevor Woods -- Info on Super Islander Mark IV made in Cuba from old CFL bulbs. FB.
Bob KD4EBM sent me some great stuff: Sony SW receiver, QCX Mini. Made a CW contact with the QCX. Felt virtuous -- it is going to the DR. Thanks Bob.
Peter KD2OMV: One of the guys I worked with the ET-2 transceiver. Great to hear from him.
Armand WA1UQO Richmond area radio museum? https://www.youtube.com/watch?
Mike WN2A -- Sent me a great care package with lots of toroids. A lifetime supply! Thanks Mike!
Nate KA1MUQ got his Doug DeMaw receiver going after 38 years! FB. Been there, done that!
Tony: G4WIF Liked Valveman video about Gerald Wells. He visited him! https://soldersmoke.blogspot.
Dean KL7MA Bill talked to him on 15 SSB. He had worked Wes W7ZOI! FB!
Thursday, January 12, 2023
On Ten Meters with a uBITX from the Eastern Tip of Hispaniola
Wednesday, December 14, 2022
Faust Gonsett and the SB-33 in 1963
- It is a hybrid rig using Germanium transistors –the transistor was only 15 years old
- The Mechanical band switching showed the strong use of mechanical assemblies
- The small size was simply amazing
- The Bi-lateral circuitry predates any Bitx circuits.
- The urban legend was that a team of illuminati were involved in its design (Don Stoner is one name that pops up)
- The Japanese were a quick study and the FTdx100 in 1967 is a result, only better.
- Many are still around in shacks. I have three
Gonset was well known for innovative designs – the Gooney Box is another example. Look at all of his compact mobile equipment.
The next point – the final owner of SBE was Raytheon thusly the next generation of SDR Radio Equipment for the US Air Force can trace its pedigree to the SBE-33.
This was the appliance box of 1963. I saw my 1st SBE-33 (August 1963) when likely you were in the 2nd Grade and I was headed off to Midway island.
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Thursday, September 1, 2022
New Video: Farhan's Presentation on the "Daylight Again" Analog Transceiver
Tuesday, August 23, 2022
SolderSmoke Podcast #156 -- November 4, 2013 -- Interview with Peter Parker VK3YE of Melbourne, Australia
Special hour-long interview with Peter Parker, VK3YE
-- Early experiences with radio
-- CW
-- DSB Gear
-- Simple gear, and gear that is TOO simple
-- VXOs, Super VXOs and Ceramic Resonators
-- Building receivers
-- Chips vs. Discrete
-- Making the leap to SSB
-- The Knob-less wonder and the BITX
-- No need for a sophisticated workshop
-- Advice for new phone QRPers
Peter's Blog: https://vk3ye.com/
Peter's YouTube Channel: https://www.youtube.com/user/vk3ye/featured
Wednesday, May 25, 2022
HF Bandsweep with the Hammarlund HQ-100 (video)
Wednesday, April 6, 2022
The First Commercial SSB Trans-Atlantic Radiotelephone System
Wednesday, March 23, 2022
First Ever Contact on 12 Meters: Homebrew, QRP, SSB, DX (Video)
There is a LOT of soul in this new rig. Here is a partial list of contributors:
-- Overall BITX design: Farhan VU2ESE
-- Termination Insensitive Amplifiers (TIA): Wes Hayward W7ZOI and Bob Kopski K3NHI.
-- TIA boards from Todd K7TFC
-- ASK-1 Mixer from Armand WA1UQO
-- VFO design parameters from Joe Carr K4IPV (SK)
-- VFO stability ideas from Frank Harris K0IYE and Mike Murphy WU2D.
-- HT-37 Tuning Capacitor bought from e-bay at suggestion of Pete Juliano N6QW.
-- Pine board base of the rig: Frank Jones (SK) W6AJF's preferred building technique.
-- DTC Band-Pass filter circuits from Han Summers G0UPL.
-- Low pass filter values from G-QRP web site.
-- Idea of using RD06HHT instead of IRF-510 in the final: Pete Juliano
-- Heat sink from Chris KD4PBJ
-- Trifilar Toroids used in many places from Farhan VU2ESE.
Thanks to all. 73 Bill
Sunday, March 13, 2022
Video #3 17/12 Transceiver -- Receiver is Working on 12 and 17 meters (Listen! Video!)
Wednesday, March 9, 2022
Video #2 17/12 SSB Transceiver -- Receive RF Amplifier Needed?
Thursday, March 3, 2022
Tuesday, March 1, 2022
Dennis WC8C's FB Homebrew 6 Meter Rig -- Any Ideas or Suggestions?
This is my 6 Meter homebrew transceiver, currently work in
progress. It is a single conversion
super –heterodyne design. I constructed
each stage independently with SMA connectors.
This is so I can re-make sections as needed, and will allow me in the
future to swap sections to experiment with alternate designs. The VFO and BFO are controlled using a SI5351
with an Arduino micro controller. I
currently have separate SI5351 modules for VFO and BFO because I suspected
issues with cross-talk. These issues may
not actually be real, so once I am happy with the performance, I will test
again with just one module to see if it is OK.
The Power Amp is still on the to-do list, so output is well under 0 DBm
The Blue boards were designed by me and ordered
on-line. The other boards I etched
myself. Construction is mostly surface
mount because I find it easier than drilling all the holes. SMD components are mostly 805 and 1206 size.
Transistors are SOT23.
The Band Pass filter is a 5 coil design made with air-core
inductors.
3 bi-directional termination insensitive (TIA) amps are used
(blue boards). Total RX gain is about
44db. Total TX gain is about 16db. Each board has its own independent RX/TX
switching circuitry (mosfet based) and is fed with +12.5, GND, and RX/TX logic
signal from the Arduino (3V logic and up will work)
The Mixer and modulator are both Diode Ring mixers.
The 12 MHz SSB filter is a crystal ladder filter similar to
the one used in the uBitx.
The Mic and audio pre-amp (also a blue board) is made on a
modified TIA amp board. I had 10 of
these boards made, and the needed circuitry was largely the same, so I modified
the board with a rotary tool and jumpers.
The Audio amp is a PAM8403 module and drives a headset. I did make some modifications to the module so
it runs in-spec and to eliminate the power on audio pop.
The challenges I have been having are mostly related to
spurs, splatter, carrier suppression and TX audio quality. I have been gradually tweaking these things
to improve operation before I start on a power amp. My IF is 12 MHZ, and I was using the LSB side
of the crystal filter because it is sharper (VFO 62 – 66 MHz) but have recently
changed over to the USB side of the filter (VFO 38 – 42 MHz). This eliminated the spurs I was seeing near the
pass band. I still need to make some
adjustments to the crystal filter as it is too broad.
I still have some splatter and audio quality seems low, but
I am starting to doubt my test setup. I
see the splatter on the RTL SDR, but I don’t see it on the Tiny SA. The spatter happens at ~160 KHz
intervals. I am hoping to find someone
local with a better spectrum analyzer to help me verify if it is the rig or my
SDR dongle/test setup.
The modules to the side of the picture are my
rejects/experiments. The one covered in
copper shows how I eventually will shield all the modules. I 3D printed a cover for the board, when
wrapped it with copper tape, soldered to the bottom ground plane. The one shown is a diode ring modulator. For some unknown reason the carrier
suppression is rather poor. I had
previously made a junk-box modulator that had much better carrier
suppression. I don’t know why it is
better than the one I more carefully made for the radio, but until I figure it
out, I am using the junk box version.
The junk box modulator uses unmatched schottkey diodes, whereas the
“final” one uses a 4 diode SMD package because I wanted them matched – I
thought this would be better, but maybe not.
Sunday, February 27, 2022
VK3HN's Amazing Summit Prowler 9 Homebrew Transceiver - A Masterpiece of Miniaturization (VIDEO)
Monday, February 7, 2022
SolderSmoke Podcast #235 NE-602, Azores Rig, Spur Problems, SSB Rigs, Peashooter, HB Filters, MAILBAG
SolderSmoke Podcast #235 is available for download:
One contact on uBITX. More SW listening.
Repaired my Chrome Book in Santo Domingo!
Christmas Present for All: James Web Space Telescope launch
Thursday, February 3, 2022
Exorcism Lite -- Spur Suppressed on 17 meter Transmitter -- Split TX/RX Station On The Air
2) Try putting a series LC shunt circuit tuned to 41 MHz at the output of the carrier oscillator (between the oscillator and the buffer).
3) Reduce the voltage to the oscillator/buffer. I have this on a pot, so I can adjust it down to the point where the remnant of the harmonic is no longer audible, while keeping the main carrier osc signal sufficiently strong.
It seemed to work. I could now hear the desired frequency for spotting, without the confusing tone from the spur.
Why had I been able to do this back in 2002 in the Azores using a simple trimmer cap to ground? My guess is that I was using my Drake 2-B as the receiver. The trimmer cap to ground may have reduced harmonic output. And I was probably cranking back the RF gain on the 2-B to the point where I could hear the desired signal but not the remnants of the spur. I have no RF gain control on the Barebones Barbados receiver that I am using in this project.
So, what's the lesson from all this? Well, if you are faced with a serious technical problem, and you find yourself considering complicated and difficult solutions, go to the Dominican Republic for about a month (especially if it is January or February), and then take another look at the problem when you return. If you are unable to travel this far or for this long, taking a walk or taking a weekend break from a troublesome problem will likely have a similar mind-clearing effect.
The video above shows part of a February 1, 2022 QSO with Gar WA5FWC using the split TX/RX 17 meter rig. Gar is an amazing long-time SSB homebrewer who got his start with phasing rigs back in the day.
Friday, January 21, 2022
"From Crystal Sets to Sideband" -- A Great Book about Homebrew Radio by Frank Harris K0IYE (FREE!)
I first came across the above picture of K0IYE's inspirational, completely homebrew station many years ago in the pages of "World Radio" magazine. I have already linked to Frank's book many times over the years, but it is so good that I regularly feel compelled to write about it again. Frank updates the book. Just check out the introduction to his website. Frank even has a Spanish language version of his book. All for free. Thank you Frank.
The introduction to Frank's web site:
Monday, January 10, 2022
Exorcism Not Quite Complete -- Thinking of Other Options
As often happens, I may have jumped the gun in declaring the exorcism of my 17 meter transmitter to be a success. As readers of this blog will recall, my problem was that when trying to "net" my separate 17 MHz receiver and transmitter, at around 18.116 MHz I could hear more than one tone as I tried to get to zero beat. The 8th harmonic of my 5.176 MHz carrier oscillator was mixing with the 23 MHz VXO signal and producing a spur. I could probably knock the level of this spur down below FCC limits, but -- and here is the problem -- I probably could never knock it down to the point that it would not be audible in the sensitive receiver that sits right next to the transmitter. So this is really a netting problem, not really a spur problem.
I don't want to try another filter frequency -- I have VXO crystals that really work only with a filter at 5.176 MHz.
So here is my current idea: Build a receiver board and turn this thing into a transceiver. Switch with relays the input and output of the 5.176 MHz filter, and use relays to switch to the receiver board the VXO and carrier oscillator signals.
Making this thing a transceiver would eliminate the need for netting. This should solve my problem.
What do you folks think?
73 Bill