AmateurRadio.com

The following blogspot was originally published in July, 2016. Hopefully some will find this of interest as the topic is still very relevant.

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A recent posting on Yahoo's Perseus SDR Group inquired about the use of external or PC-based DSP manipulation of signals partially masked by noise to improve readability. The most interesting part of this short discussion was the result of one response indicating:


"BTW one of the best and most simple noise reductions is to lower the volume."

to which the original inquirer responded:

"BTW, lower the volume to reduce noise ... ?? That was a joke, right ??"

Other comments soon followed, including my own, initially:

"Actually, for whatever reason, this works...at least when copying very very weak CW signals. I think it is more of an ear-brain thing where the noise
gets more focus than the signal when listening at moderate levels but
cranking everything down to a very low level has always improved copy for
me....not sure why this works as well as it does."

From Roelof Bakker, PAØRDT:

"The ear brain system works much better at low volume as it is easily
overloaded by strong signals. Similar like too much direct light in 
your eyes will degrade contrast. I guess this is getting worse with
age, but I am not sure about that.

I have been watching many videos on YouTube which demonstrate ham
radio gear and most if not all use far to high volume settings,
which degrades readability. I believe it is a normal habit to raise
the volume for weak signals, but this is often contra productive.

When listening for weak signals at low volume settings, a quiet room
is mandatory. I have taken considerable effort in building a quiet
PC, that is aurally quiet.

What does wonders for copying weak signals with the PERSEUS is to
switch off the AGC."


"No it's not a joke and it's not the RF Gain. It's one of the capabilities of the human ear.

Of course qrm can be limited and reduced but noise is difficult. What you often see is that with all those noise reduction things is that the volume drops. Make an audio recording of a part with and without a (white) noise limiter switched on. Open it into an audio editor and you will see that the amplitude of the part where the noise reduction is on is lower. Now amplify that part to the same level as where the limiter is not active and play it back. You will be astonished how little the difference is.

It's probably also a thing that can differ from person to person but I've never seen tools that can make an unreadable signal readable. Most of the time they sound just different, not better."

Likely there is a ton of data showing how our ear / brain link deals with noise or tones buried in noise. With audio levels set to anything above bare minimum, I think it's very easy for your brain to react mainly to the noise and not to the tone. Reducing this level possibly puts the two back on even levels ... even though there really has been no change in signal-to-noise ratio.

When trying to copy very weak, difficult signals, I've always found that turning audio levels down to bare minimums helps me personally. As Roelof mentioned, the entire environment must be dead quiet as well so that there are no outside distractions. Even the sounds of the headphone cord, brushing against clothing or the table top, can make the difference between copy and no copy. Decades of copying very weak ndb CW idents buried in the noise as well as spending several years on 2m CW moonbounce, has taught me that my ear-brain connection works best when audio inputs are very, very low.

courtesy: http://justagwailo.com/

As an interesting aside, my years of copying weak CW tones, has shown itself in other ways as well. Before retirement as a high school tech ed teacher, staff were required to have their hearing checked annually, as part of the medical plan's requirement. Each year the mobile audio lab would roll-up for the tests. I would always make sure to sit perfectly still, with no headphone cord wires brushing against my clothing. The tones varied in frequency and intensity and were often extremely weak, not unlike the weak echoes I was used to copying from the lunar surface. The reaction from the examiner was always the same, every year ... complete astonishment when checking the results and usually a comment that I had the hearing of a teenager! Thankfully my hearing, which I've always been careful to protect, remains exceptionally good, for which I am truly grateful ... so often this is a genetic thing and there is little one can do about controlling hearing-loss as one ages.

I shudder anytime I see a young person with headphones or earbuds firmly in place and with the music volume cranked up to unbelievably high levels. Sadly, many of them will likely pay the price for this later in life as such hammering-away at the delicate auditory mechanism has a cumulative rather than a short-term effect.

So ... the next time you find yourself trying to copy that ultra-weak signal just riding along in the noise, try turning the audio way, way down. Take a deep breath and listen to the tone, not the noise. If you ask me, the best signal filter is still the one between our ears.
Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

Sat Sep 28 and Sat Oct 5
(8 AM to 5 PM)

Black Forest Fire Station
11445 Teachout Road
Colorado Springs, CO 80908

The General License provides access to regional and worldwide communications on the HF bands, greatly expanding your ham radio fun!

• Upgrade from Technician to General Class radio privileges
• Pass your FCC General Class amateur license exam Oct 12*
• See live equipment demonstrations and activities
• Learn to operate on the HF bands, 10 Meters to 160 Meters
• Gain a deeper understanding of radio electronics and theory
• Take the next step with antennas, amplifiers, digital modes

Registration fee: $30 ($20 for under 18 years of age)

Prerequisite: Students must already have their Technician License

The required study guide is:

HamRadioSchool.com General License Course
Third Edition, effective 2019 – 2023, $24.95

* Free FCC exam session on Oct 12 at Black Forest Fire Station 9:30 am.

To register for the class, contact Bob KØNR,  [email protected]

Sponsored by the Tri-Lakes Monument Radio Association

The post General License Class – Black Forest, CO appeared first on The KØNR Radio Site.

Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

Stories you’ll find in our August, 2019 edition:

The Yagi-Uda Mystery: The Remarkable Backstory of this Ubiquitous Antenna
By Richard Fisher KI6SN

Shintaro Uda and Hidetsugu Yagi were mirror images of the antenna they created in 1926—known around the world today simply as the Yagi—an array invented by Uda in collaboration with Yagi. Ninety-three years later, this design is still widely in use for both amateur and commercial installations on the HF, VHF/UHF bands and beyond. It is the antenna so often seen atop amateur radio towers, at military installations and many municipal and commercial buildings. Yet Shintaro Uda seems to have faded from the picture of the origins of this antenna. Richard tells us about two stories of intrigue and historical significance behind the Yagi.

TSM Reviews: Yaesu FT3DR and Radioditty GD-73A
By Cory GB Sickles WA3UVV

The Yaesu FT3DR and the Radioddity GD-73A are two very different digital voice (DV) portables, with widely divergent feature sets. Each needs to be considered for its merits and the applications you have in mind. The Yaesu FT3DR is the latest of a series of DV hand-held portables with the features you’d expect from a full-featured HT. The Radioddity GD-73A is a UHF-only, DMR/analog portable with minimal features: There is no provision for an external antenna and the internal one protrudes under plastic, much in the same way as a 0.5-watt blister-pack FRS (Family Radio Service) transceiver is packaged. Cory goes deep into the details and tells us there’s more to each than may be at first apparent.

The USS Thresher on Eternal Patrol
By Scott A. Caldwell

The USS Thresher(SSN 593) was an icon of the United States Navy and was often used in recruitment posters. She was regarded as the most technologically advanced submarine in active service, designed to hunt and engage Soviet submarines that patrolled the deep North Atlantic Ocean. Her loss on April 10, 1963 shocked the entire nation and the subsequent inquiry raised more questions than answers, in light of the confusing radio transmission with the submarine escort vessel USS Skylark (ASR 20). Underwater communications were subjected to temperature and density fluctuations that often deflected and distorted the amplitude of the sound waves. Scott looks at the difficulties of undersea communications while telling the story of this disaster.

The Care and Feeding of Electronic Equipment: Part 2
By Robert Gulley K4KPM

Electronic equipment for our radio hobby requires periodic checks for proper operation, as well as occasionally performing preventive maintenance or repair as needed. This includes radios, power supplies/connections, computer hardware, antenna systems, and a host of other potential troublemakers. In this second article Robert discuss troubleshooting tips, electrical and antenna system maintenance, computer hardware/software updates, and other preventative measures to help keep things running as smoothly as possible.

Scanning America
By Dan Veeneman
Scanning Michigan

Federal Wavelengths
By Chris Parris
Las Vegas Mysteries and Frequencies

Milcom
By Larry Van Horn N5FPW
A New Way to Monitor the Military on January 1, 2020

Utility Planet
By Hugh Stegman
Cycle 25: Coming to an Ionosphere Near You

Shortwave Utility Logs
By Mike Chace-Ortiz and Hugh Stegman

VHF and Above
By Joe Lynch N6CL
The ‘Ah-Ha’ Behind Some Types of Aurorae

Digitally Speaking
By Cory GB Sickles WA3UVV
Another Look at D-Star

Radio 101
By Ken Reitz KS4ZR
The Trouble with Alexa

Radio Propagation
By Tomas Hood NW7US
Sunspot Cycle 24 Solar Minimum is Coming!

The World of Shortwave Listening
By Rob Wagner VK3BVW
Whatever Happened to the 11-Meter Band?

The Shortwave Listener
By Fred Waterer
German via Shortwave Plus BBC Highlights

Amateur Radio Astronomy
By Stan Nelson KB5VL
The Next Generation Very Large Array: ngVLAA

Adventures in Radio Restoration
By Rich Post KB8TAD
The Rolls-Royce of Radios: National HRO Part 2

Antenna Connections
By Dan Farber AC0LW
The End-Fed Antenna

The Spectrum Monitor is available in PDF format which can be read on any desktop, laptop, iPad®, Kindle® Fire, or other device capable of opening a PDF file. Annual subscription is $24. Individual monthly issues are available for $3 each.

Ken Reitz, KS4ZR, is publisher and managing editor of The Spectrum Monitor. Contact him at [email protected].

Hello and welcome to Episode 295 of Linux in the Ham Shack. In this episode, the hosts address two e-mails received which both talk about native contest logging under Linux. A brief compare and contrast of YFKtest and TLF leads into a deep dive into the setup, operation and special features of TLF and why it may be a better choice as a lightweight contest logging option for Linux users. Thank you for listening and have a great week.

73 de The LHS Crew

Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

Here is this week’s space weather and geophysical report, issued 2019 Aug 05 0339 UTC.

Highlights of Solar and Geomagnetic Activity 29 July – 04 August 2019

Solar activity was very low under a spotless solar disk. Other activity included a filament eruption observed in SDO/AIA 304 imagery beginning at 04/1640 UTC in the NW quadrant. Analysis is on-going for any potential coronal mass ejections (CMEs) as coronagraph imagery becomes available.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was normal levels during the period.

Geomagnetic field activity ranged from quiet to unsettled levels. Solar wind parameters indicated the arrival of a co-rotating interaction region (CIR) preceding a negative polarity coronal hole high speed stream (CH HSS) beginning midday on 30 Jul. Total field increased to 11 nT by 30/2024 UTC while solar wind speed increased to a maximum of 596 km/s at 01/0503 UTC. The geomagnetic field responded with quiet to unsettled periods on 30 Jul-01 Aug.

Forecast of Solar and Geomagnetic Activity 05 August – 31 August 2019

Solar activity is expected to continue at very low levels for the forecast period (05-31 Aug).

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach moderate levels on 05 Aug and 18 Aug. High levels are expected on 06-17 Aug due to CH HSS influence.

Geomagnetic field activity is expected to be reach unsettled to active levels on 05-08, 10-11, 17-18, 26-28, and 31 Aug with G1 (Minor) geomagnetic storm levels likely on 05-06 Aug due to recurrent CH HSS effects.

Don’t forget to visit our live space weather and radio propagation web site, at: http://SunSpotWatch.com/

Live Aurora mapping is at http://aurora.sunspotwatch.com/

If you are on Twitter, please follow these two users: 1. https://Twitter.com/NW7US 2. https://Twitter.com/hfradiospacewx

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Be sure to subscribe to our space weather and propagation email group, on Groups.io

https://groups.io/g/propagation-and-space-weather

Spread the word!

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Links of interest:

+ Amazon space weather books: http://g.nw7us.us/fbssw-aSWSC
+ https://Twitter.com/NW7US
+ https://Twitter.com/hfradiospacewx

Space Weather and Ham Radio YouTube Channel News:

I am working on launching a YouTube channel overhaul, that includes series of videos about space weather, radio signal propagation, and more.

Additionally, I am working on improving the educational efforts via the email, Facebook, YouTube, Tumblr, and other activities.

You can help!

Please consider becoming a Patron of these space weather and radio communications services, beginning with the YouTube channel:

https://www.patreon.com/NW7US

The YouTube channel:
https://YouTube.com/NW7US

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Visit, subscribe: NW7US Radio Communications and Propagation YouTube Channel

In this episode, Martin M1MRB is joined by Chris Howard M0TCH, Dan Romanchik KB6NU and Frank Howell K4FMH to discuss the latest Amateur / Ham Radio news. Colin M6BOY rounds up the news in brief and this episode’s feature is AMSAT US with Keith KB1SF.

ICQ AMATEUR/HAM RADIO PODCAST DONORS

We would like to thank Marcellino Gemelli (KM6EAY) and an Anonymous Donor and our monthly and annual subscription donors for keeping the podcast advert free. To donate, please visit - http://www.icqpodcast.com/donate

- No Consensus Reached for FCC on 'Symbol Rate' Issues - Brazilian Students Building QO-100 Ground Station - Distracted Driving Measure Among Many New State Laws - New Raspberry Pi 4 Problem Reported with Certain USB-C Cables - Millions of AMPRNet Internet Addresses Sold to Fund Grants and Scholarships - Missing Amateur Radio Operator - ILLW 2019 Final Countdown - Siglent Joins as Homebrew Heroes Award Corporate Sponsor

Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].

Today started early, about 5:30am or so, getting email, RSS feeds, and social media perused, worked or avoided so I could communicate on behalf of the Mississippi Section ARES Simulated Emergency Exercise (S.E.T.) from 9am-9pm. I won’t work the entire 12 hours but I did assist our RACES Director, Mike N5DU operate the MS Emergency Management Agency’s EOC Radio Room. A few other hams, like Todd K5TDD, Bob KG5ZDZ, and Jim K0UPW (newly relocated from State of Washington) also came by to assist.

Mike N5DU has a RACES Team that he is growing, putting together continual training for those who can be deployed to other emergency zones around the country and those who will remain local (like me) to operate either at the MEMA Command Center or sheltered in-place at their QTH. It’s always a growth process as volunteer hams come and go, tire of EmComm, or leave our midst due to health reasons. But it takes organized, thoughtful, and diligent leaders like N5DU to keep the ball rolling.

MEMA has grown in it’s technical capability since the 2005 Hurricane Katrina. Our team working the SET today got a tour of the Command Center when integral state agencies, non-government organizations, and selected others have designated “seats” in front of PCs on the floor of the Command Center. The facility meets federal security standards specified by FEMA, Homeland Security, and other relevant regulations.

Our THIS IS A DRILL scenario today was at sudden, significant seismic activity at the New Madrid Fault in Northeast Arkansas. It is pronounced New Maaa-drid, unlike the city in Spain, commonly pronounced Ma-DRID. I texted our Section’s Emergency Coordinator, Robert KC5IMN, the correct pronunciation to relieve him of future abuse at the hands of Emergency Coordinator’s near Memphis!

We had a good response and participation during the first four hours with one-hour shifts for net control operators around the state. Steve K5OMK in Starkville did a great job as did the ARES Team in Starkville. They had a lost person beacon chase (successful) in addition to the earthquake activity. I guess that was simulated preparation for the start of Southeastern Conference Football weekends in StarkVegas. Operators in Houston, Vicksburg, and elsewhere worked until we closed the MEMA EOC operation about 12:30pm. They are still at work as I write this blog post. As Assistant Delta Division Director, I’m proud of the work that Malcolm W5XX, Bob KC5IMN, and Mike N5DU have engaged in this annual activity.

The MS Section finished # 1 in ARES Section rankings for the SET in 2018. Whether that ranking continues this year matters not, if we all get more effective, efficient, and engaged in bringing our amateur radio communications game to a higher level. You keep score to motivate teams to get better, not to just win rankings, when lives are on the line. Thank God, it’s just a drill today.

Here’s a gallery of pictures from the MEMA Command Center, Levels of Activation, how this agency is organized into regions, and the radio network operating in the State, called MSWin. A staffer at MEMA today kindly gave us a brief tour.

Frank Howell, K4FMH, is a regular contributor to AmateurRadio.com and writes from Mississippi, USA. Contact him at [email protected].