Podcasting since 2005! Listen to Latest SolderSmoke
Wednesday, November 14, 2018
W7ZOI: Direct Conversion Receivers -- Some Amateur Radio History
http://w7zoi.net/dcrx68.pdf
Farhan and Pete WB9FLW alerted me to this wonderful article by Wes Hayward, W7ZOI. I guess my interest in DC receivers must have been noticed by the Google algorithm because I am bombarded by ads extolling the virtues of "Zero IF." Hey Google -- I'm already a believer! I was converted by W7ZOI's 1968 article in QST. And my belief in the technique has been greatly reinforced by his November 2018 50th anniversary article.
There is so much good stuff in Wes's look-back piece. The travails of trying to write for QST are presented very well. And we learn that none-other-than Doug DeMaw himself is responsible for the use of the word "presence" in describing amateur radio audio.
This article has inspired me to take a new look at the DC receiver I built last winter. Mine needs some work. I think it is kind of deaf. It could probably benefit from a diode ring detector. But it already has presence.
http://w7zoi.net/dcrx68.pdf
Thanks Wes. And thanks to Farhan and Pete for the heads up.
Labels:
ARRL,
DeMaw--Doug,
direct conversion,
Farhan,
Hayward--Wes,
Phasing Rigs
Tuesday, November 13, 2018
1972 Solar Flare Caused Naval Mines to Explode
There are reports out this morning that a big solar flare in 1972 caused naval mines placed by the U.S. off the coast of Vietnam to explode.
https://www.livescience.com/64062-mines-solar-storm-1972-vietnam.html
https://www.colorado.edu/today/2018/11/12/1972-solar-storm-triggered-vietnam-war-mystery
Background info:
https://oraprdnt.uqtr.uquebec.ca/pls/public/docs/GSC418/F1929448428_Solar_Superstorm__Astronomy_Sept_2008.pdf
I remember this solar event. It caused aurora near New York City:
https://soldersmoke.blogspot.com/2009/09/carrington-flares-aurora-where-were-you.html
https://www.livescience.com/64062-mines-solar-storm-1972-vietnam.html
https://www.colorado.edu/today/2018/11/12/1972-solar-storm-triggered-vietnam-war-mystery
Background info:
https://oraprdnt.uqtr.uquebec.ca/pls/public/docs/GSC418/F1929448428_Solar_Superstorm__Astronomy_Sept_2008.pdf
I remember this solar event. It caused aurora near New York City:
https://soldersmoke.blogspot.com/2009/09/carrington-flares-aurora-where-were-you.html
Labels:
Aurora,
solar cycle,
Sun
Monday, November 12, 2018
Getting Ready for Farhan's Satellite (videos)
I've been getting ready for the November 24 launch of the CubeSat that Farhan and his friends in India built. I started out with my trusty Drake 2-B and a Hamtronics 2-to-10 downconverter, but I quickly switched to an RTL-SDR dongle and HD-SDR software. My 3 element quad antenna is visible in the first video. So far, I am using the Armstrong method to turn the antenna.
In that first video I keep saying that I am waiting for AO-71. In fact is was AO-73, the "FunCube" from the UK. I think it is similar in power and antenna configuration to Farhan's satellite, so I think we are almost ready for launch.
(Any ideas on what that mysterious pulsating sig in the satellite passband signal is in the first video?)
Labels:
Farhan,
India,
satellites,
SDR,
UK
Monday, November 5, 2018
Pete N6QW Rejuvenates the Atlas Twins with an Arduino and an Si5351
Pete Juliano N6QW has turned his attention to the Atlas Twins, a nice single conversion multiband rig. Pete has used an Arduino/Si5351 to replace the analog oscillators in the old Atlas. This improves stability and allows for USB/LSB operation.
Pete very graciously kept the old analog circuitry in the rig, allowing the Atlas to be returned to its pristine analog state at some time in the future. Pete also made some very kind comments about the surprising stability of the original analog oscillator circuitry.
Check out Pete' site for more details:
http://n6qw.blogspot.com/2018/11/2018-year-of-ssb-transceivers.html
Labels:
Arduino,
Juliano -- Pete,
Old radio,
Si5351
Saturday, November 3, 2018
Oliver Heaviside
https://hackaday.com/2018/10/30/oliver-heaviside-rags-to-recognition-to-madness/#more-330784
Like many of the giants we looked at, Oliver definitely had his problems, and didn't end well. But he deserves a lot of respect and credit for his many innovations and discoveries. I didn't know that he is the one responsible for those 88 mH coils in my junk box.
Labels:
radio history
Saturday, October 27, 2018
SolderSmoke Podcast #207 -- 15 mtrs, 60 mtrs, Giants of Radio, Cubesats, Pete's rigs, SDR MAILBAG
SolderSmoke Podcast #207 is available:
http://soldersmoke.com/soldersmoke207.mp3
-- Giants of Radio
-- Pete on 15 Meters
-- Bill on 60 Meters with the uBITX
-- Pete's Sudden and Heath Filter Transceivers
-- Cubesats to orbit! To the moon! And to Mars!
-- Bill rebuilds his 2 meter "Ray-Gun" Quad (for Farhan's Cubesat)
-- Homebrewing Variable caps and stockpiling NP0
-- My "by ear" Minimal Discernible Signal Technique
-- Thoughts on Direct Sampling SDR and the Radio Art
MAILBAG
-- A request for feedback from GQRP
-- G4WIF reports G3ROO on UK TV with spysets
-- VU3XVR builds FB rig from EMRFD
-- M0KOV Charter member of the 3 Scratch-built BITX club
--KD4PBJ's PTO Turtle DC Receiver
-- AB1OP builds Pete's LBS receiver and gives us a new acronym: SITB
-- KD4EBM -- Thanks for the scanner Bob!
-- A possible sponsor from California...
-- Pete's dream neighborhood...
Labels:
15 Meters,
60 meters,
antennas,
heathkits,
radio history,
satellites,
SDR,
SolderSmoke Podcast,
test gear,
VHF
Friday, October 26, 2018
Homebrewing Your Own Variable Capacitors
It is people like Jeremy Cook who will save us from total domination by DDS and PLL "oscillators" and their whimpy little "rotary encoders."
Labels:
DDS
Subscribe to:
Posts (Atom)