Podcasting since 2005! Listen to Latest SolderSmoke
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?
Tuesday, March 8, 2022
Soldering to Aluminum with Mineral Oil
Hack-A-Day has a potentially useful workshop tip. Has anyone tried this?
https://hackaday.com/2022/03/06/how-to-solder-to-aluminum-easily/
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.
Monday, February 28, 2022
Free Download of AADE Filter Design Software
Very useful when homebrewing filters. I am using it now to build crystal filters.
http://www.ke5fx.com/aadeflt.htm
Thanks to KE5FX
LA6NCA Designs and Builds a Very Hybrid 80 Meter Transmitter (Si5351 and a 12A6 Tube) (Video)
Sunday, February 27, 2022
VK3HN's Amazing Summit Prowler 9 Homebrew Transceiver - A Masterpiece of Miniaturization (VIDEO)
Friday, February 25, 2022
Split Stator Temperature Compensation Also Used in Yaesu FT-101
Thursday, February 24, 2022
Old Military Radios at the Air and Space Museum Udvar-Hazy Center, and Autogyros
Wednesday, February 23, 2022
An Analog LC VFO for my 17/12 Meter SSB Transceiver (VIDEO #1)
Sunday, February 20, 2022
Saturday, February 19, 2022
Pete's Eclectic Approach to the Pea Shooter, San Jian counters on Analog VFOs, Non-Restaurant Menus
I liked Pete's comments on the various (analog, digital, mixed) approaches to homebrew:
http://n6qw.blogspot.com/2022/02/2022-return-to-peashooter-build.html
http://n6qw.blogspot.com/2022/02/2022-peashooter-20m-compact-ssb.html
I too have San Jian digital counters watching the stability of analog VFOs (DX-100, HQ-100, Mythbuster).
Variety is the spice of life!
I also liked Pete's comment about the fellow who does on-the-air menu counseling for FTDX-3000 owners. I sometimes run into guys on the air who want to do something similar with my simple homebrew rigs. They start by making comments about my audio -- they will usually say it is "too high" or something like that. Especially when I'm using the separate transmitter and receiver (which have to be "netted" imprecisely by ear), I have to explain that maybe resort to their RIT control would help. If they persist, I sometimes have to tell them that how my rig sounds depends A LOT on the placement of the carrier oscillator relative to the passband of the crystal filter (most recently, the filter from the 1963 Swan 240). Most of them have never had to do that kind of adjustment, so the "technical discussion" usually ends at that point, with my interlocutor saying 73, and presumably moving on to someone whose rig has menus to fiddle with. (Recently heard audio techno term: "massaging the codec.")
To each his own!
Friday, February 18, 2022
Thursday, February 17, 2022
How The Physics of Resonance Shapes Quantum Reality
Here is an interesting article that appeared in Wired. It will resonate with many SolderSmoke listeners!
Tuesday, February 15, 2022
Differential Temperature Compensation Capacitors in the Hallicrafters HT-37 Main VFO Tuning Circuit
Monday, February 14, 2022
Podcast (Audio) Version of Bill's Talk to the L'Anse Creuse Amateur Radio Club
Tony G4WIF suggested that I make this talk available as an audio recording. Good idea. Here it is:
http://soldersmoke.com/N2CQRHomebrewing.mp3
6EA8s in the Mate for the Mighty Midget, and WA9WFA Re-Builds a Heath HW-12
I reported to Scott and Grayson that I had finally gotten around to changing the three aging 6U8 tubes in my Mate for the Mighty Midget receiver. I replaced them with three more youthful 6EA8s. This switch really seemed to perk up the old receiver. I'm listening to 75 meters on it right now.
Speaking of 75 meters, Scott sent me this picture of his latest effort: re-building a Heathkit HW-12. FB. This is a way of experiencing (or re-experiencing) the construction of a Heathkit. I did something similar, but much less complicated) with a Heathkit VF-1. Scott did a wonderful job taking this old rig apart. That PC board looks great (see photo below).
Scott's e-mail:
Hi Bill and Grayson, I’m glad to hear of your good results with the 6EA8’s in your MMMrx! I had similar results when I finally got rid of the 6U8’s with their iffy performance and went with the 6EA8’s. I did put a set of 6GH8A’s and tried it out, it worked, but I don’t have any data on performance improvements. After completing the outboard power supply and audio amplifier, I’ve taken a break from my MMMRx and it’s sitting there on the bench. I’ll get back to it in a while.
In the meantime I’ve started a new project where I’m re-kitting a Heathkit HW-12 eighty meter transceiver. I have completed the disassembly process including the pcb. I bought a Hakko vacuum desoldering iron for taking all (ALL) parts off of the pcb, and it’s bare now. I’m planning to start rebuilding this coming week. 73 Scott WA9WFA
Friday, February 11, 2022
Bill Talking about Homebrew Radio with L’Anse Creuse Amateur Radio Club (Michigan) -- February 2, 2022 (Video)
Wednesday, February 9, 2022
Video of SolderSmoke Podcast #235
One contact on uBITX. More SW listening.
Repaired my Chrome Book in Santo Domingo!
Christmas Present for All: James Web Space Telescope launch
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
Sunday, February 6, 2022
FLASHBACK: The Herring Aid 5 Direct Conversion Receiver and Frank Jones (Video)
Saturday, February 5, 2022
Thomas K4SWL -- SOTA Activation on Bearwallow Mountain, North Carolina (video)
Friday, February 4, 2022
Barefoot Ham Radio -- PA2OHH's Wonderful Web Site
Barefoot technology or simple, non-professional radio technology and real Barefoot power or harmless QRP power, that is what you will find here. There are some complex designs but many designs are simple radio amateur circuits. They will never be used professionally!
These simple circuits and rigs can give you much fun: home brewing, portable activities during holidays, etc.
Batteries and inverted V dipole antenna's with a fishing rod as the center support are all you need to make many QSO's.
Much fun!
Barefoot technology and Barefoot power can give you much fun, but is not perfect... There are disadvantages like VXO control instead of a VFO, direct conversion receivers that receive both sidebands and simple frequency displays that are not so easy to read. But working with such simple equipment is often more exciting than working with a much better commercial transceiver.
Perhaps that you cannot believe that you can make many QSO's with QRP power of only 1 watt. Indeed, some practice is needed in the beginning so do not give up too soon. Every boring standard QSO becomes an exciting experience with QRP power!
--------------
Check out Onno's site: https://www.qsl.net/pa2ohh/
Mike WU2D -- VFO Video #3
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.
Wednesday, February 2, 2022
The NCDXF/IARU Beacons (very useful website)
Tuesday, February 1, 2022
Mike WU2D Shows Us How to Do Temperature Compensation in Homebrew LC Analog VFOs
Wednesday, January 26, 2022
Image of James Webb Space Telescope In Position at L2
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: