Date   

Re: Review - Digitech AR-1733 DSP MW/FM/LW/SW/Air World Band Radio Receiver

Michael Schuster
 

While It's great that this radio has continued to work out well for you, I am somewhat puzzled by the love.

When the CCrane Skywave was announced it was noticed that the Redsun-produced AR-1733 bore a remarkable physical resemblance to the upcoming product from Ccrane. Eventually it became apparent that this was the starting point from which the Skywave was redesigned as a new model.

Intrigued by this, I ordered one from Jaycar's US web site and played with it for while; was totally unimpressed. The main issue was the lack of any effective AGC on the AM-modulated bands. It was impossible to get any useable volume out of the thing even on moderately strong signals.

Rather than return it, I sent mine to Gary DeBock (who was gracious enough to offer to repay me for it!) who did a complete teardown. He he subsequently compared with a teardown of the Skywave once it hit the market. As noted in his initial review of the Skywave it has completely different redesigned internals which, among other things, corrected the AGC issue. Perhaps later production runs of the AR-1733 addressed this.

I see the Skywave listed on Amazon AUS but there is no price as they don't have any stock. 


Oklahoma TP DX 10-16-20

Richard Allen
 

I listened from 1203 until 1246 and only some of the “top guns” were heard.

702 unID het heard against KHSE at 1231.

747 JOIB poor at 1207; fair at 1220 up to good by 1224.

828 JOBB poor in WCCO het at 1209.

972 HLCA poor-to-fair with strong het at 1203-1206; fair with KJLT het at 1216; poor at 1245 (LSR 1240) until fading under KCFO at 1246.

1566 HLAZ poor-to-fair at 1235 with slight XERF splatter.

Usual JOUB 774 wasn’t heard this morning.

Skywave SSB with 8-inch FSL. 

Richard Allen,
near Perry OK USA.


October 15, 2020-- High School Football & COVID-19

Les Rayburn
 

COVID-19 continues to impact high school football. The Courtesy Program Committee (CPC) of the NRC and IRCA continue to track these impacts on a state-by-state basis and provide a weekly spreadsheet to help aid DX’ers. 

One benefit of the delayed seasons is that high school football will continue much later into the fall/winter than normal-hopefully resulting in quieter conditions. 

Hoping conditions improve before tonight’s games and this weekend’s DX Test. 

Special thanks to Joe Miller, KJ8O & Paul Walker for all their hard work on the CPC. 





73,

Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114
EM63nf

NRC & IRCA Courtesy Program Committee Chairman
Member WTFDA, MWC

Perseus SDR, Elad FDM-S2 SDR, AirSpy + Discovery, SDRPlay RSP-2 Pro, Sony XDR-F1HD [XDR Guy Modified], Dennon TU-1500RD, Sangean HDT-1X, Ray Dees RDS Decoders, Korner 9.2 Antenna, FM-6 Antenna, Kitz Technologies KT-501 Pre-amps, Quantum Phaser, Wellbrook ALA1530 Loop, Wellbrook Flag, Clifton Labs Active Whip. 

“Nothing but blues and Elvis, and somebody else’s favorite song…” 


Re: World DX Day

keith beesley
 

That's a great idea, Paul! 


Keith Beesley
Seattle WA USA


On Thursday, October 15, 2020, 08:26:27 PM PDT, Paul Blundell <tanger32au@...> wrote:


To keep all the discussion in one place, I have created a group for this:
https://groups.io/g/WorldDXDay


Re: World DX Day

Paul Blundell
 

To keep all the discussion in one place, I have created a group for this:
https://groups.io/g/WorldDXDay


Re: Review - Digitech AR-1733 DSP MW/FM/LW/SW/Air World Band Radio Receiver

Paul Blundell
 

Review - Digitech AR-1733 DSP MW/FM/LW/SW/Air World Band Radio Receiver

 
Written: October 2012
Last Updated: October 2020

Yesterday I walked in to my local Jaycar outlet and spotted this radio which had only just been placed on the shelf. Being quite involved in the Ultralight dxing hobby I am a big fan of these types of cheaper pocket size radios, for the cost which is between $30 and $60 they respect good value.


The specs of this radio are:
FM: 87.5MHz - 108 MHz
AM (MW): 522 - 1620 kHz (9K) / 520 - 1710 kHz (10K)
SW: 2300 - 26100 kHz
LW: 153 - 279 kHz
AIR: 118 - 137 MHz

500 programmable memory bank
Sleep timer
Manual, auto and preset station search
Battery indicator
Lock button
Requires 2 x A batteries
Dimensions: 120W x 75H x 20D mm 


After getting home and opening the box I was quite impressed by the size, it is a dead ringer for the AR1745 and looks to even use the same style case only with a couple of different buttons on the front and side. 

Starting with the front panel the normal 0-9 number keys are nicely spaced and serve a dual purpose, they both allow you to enter frequencies and also recall memories from the PAGE memory system. The 0 key also allows switching between 9 and 10kHz steps on the medium wave band when the key is held for 3 seconds or more. The first thing I noticed is that the keys are much easier to press, a common issue with the AR1745 is that the keys take a lot of pressure to register the key press, this is not a problem with the AR-1733. 


Moving on to the other 9 keys on the front panel, these all have multiple functions which the owners guide explains well. The top red button is the power button; a tap turns the radio on. A short press while the AR-1733 is on cycles through the sleep timer of various times, a longer press turns the AR-1733 off. Below this is the key lock button, a short press enables the keypad lock and a longer press disables this. Next are the two arrow keys, these keys move up and down the bands in the default "fast" steps. 

Starting at the top bedside these is the AM BW / 12/24H / FM ST key. On the AM bands this key selects either the wide or narrow DSP setting. On the FM band it enables / disables the FM Stereo option. Pressing and holding this key while the power is off changes between 12 and 24 hour time display. Below this is the PAGE / ALARM key. Pressing this key when the AR-1733 is on scrolls between the pages of the memory system, when off it allows the alarm clock to be set. The final key on this row is the CHARGE METER / AIR SQUELCH key, this key is used to control the onboard charging system which I have not used. If the AR-1733 is on the air band this key controls the squelch setting between off, 1 - 9. I run mine on 1 and this seems to work well. 

The last two multi function keys are the FREQ / T.SET and BAND / ATS keys which are either side of the 0 key. Pressing the FREQ key allows you to use the keypad to set the receive frequency, pressing and holding this allows you to set the time on the AR-1733. Pressing the band key cycles between the receive bands, LW, MW, SW, AIR & FM. Holding this key enables the "Auto Tuning System" (which is not covered at all in the manual) this system searches the current band and saves any active frequencies to the pages memory system for that band. I ran this on the SW band and it found quite a few active stations which you can scroll through with the keypad. 

Moving on to the right side panel you have the volume control and the tuning wheel, at first I could not work out how to use this until I tried pressing it in, this switches between slow, fast and stop. The left side panel has a 3.5mm ear phone socket and a USB charging socket which takes a normal mini A type connector to charge the batteries.

The screen is automatically back lighted every time you press a key or turn the tuning knob for about 5 seconds. The screen also has a 3 segment battery meter and a 9 segment signal meter.

Now on to how it works. My test bed for last night was sitting in my lounge chair with our LCD TV on, my wife on her laptop and my laptop charging but not switched on. I repeated the same tests later in the night with all these switched off and the results were the same. Firstly I started on the air band and after programming in the various ATC and company frequencies I have a listen to these, while the AR-1733 does not have any sort of scan system you can use the keypad to change frequencies by pressing the key for each memory. I have 118.7MHz in mem 1, 123.45MHz in mem 2 and so on up to130.35MHz in mem 0. By pressing 1 I can tune to 118.7MHz or pressing 3 brings up 123.8MHz. The audio for this is quite good and I can just hear the ATIS on 134.75MHz. Even running my laptop right beside the radio I have not found any problems with the frequencies in this band I normally listen to. The squelch has a short tail noise and this is not at all annoying.
Next was the FM broadcast band, all our normal stations were received and sounded as good as I have ever heard them.
I have little experience with the long wave band so I have not looked at this yet. 

Using the ATS on the shortwave band about 11pm last night found about 74 stations between 2300 kHz and 14500 kHz. These sounded good with the wide DSP setting but much better with the narrow DSP setting. I have little experience with the shortwave bands. The various time stations on 5000kHz and 10000kHz were both nice and clear with much tighter audio with the narrow DSP setting.

Moving on to the Medium wave band which is where I spend most of my time in a 1 hour period I logged 77 stations including two new ones which I had never logged before. The DSP really "cleaned up" the signals and comparing it beside the AR1745 it was much easier to hear multiple stations on the AR-1733. Scrolling between frequencies with the tuning knob was a pleasure and except for the slight break in audio as the DSP kicks in on each frequency it was a smooth process. I have a 5KW station on 1008kHz on the other side of town from me and normally this takes out most stations about 30kHz either side, with the AR-1733 using the narrow DSP setting I was able to copy stations on 981kHz and 1026kHz easily. Trying the same on the AR1745 didn't hear anything except the station on 1008kHz. 

For a radio costing less than $60 it is hard to fault it, everything works as you would expect and using it can only be described as a pleasure. They have really gotten this one right.

Update - March 2014
After my original AR-1733 died recently (due to external forces, nothing to do with the radio itself) I was tempted to look at a different radio to replace this. After checking online and some stores locally nothing came close to this for the features I wanted and price, based on this I purchased another AR-1733.


After 18 months of use my original AR-1733 was working as well as the day I got it. After doing some side by testing between my new AR-1733 and my 7.5” Loopstick Tecsun PL-380 the results are consistent with what I experienced with my previous AR-1733.  The audio quality of the AR-1733 has a slight edge, where as the PL-380 has a clear advantage with signal levels and the ability to pull in weak signals, a station that is an easy copy on the PL-380 can be a mixed bag on the AR-1733, sometimes the AR-1733 won’t hear anything, other times very little separates them. 

The advantages of the AR-1733 is VHF air band coverage and the ability to lock the tuning steps to 9kHz on the medium wave broadcast band, this at times can be a huge advantage over the PL-380. The battery life of the AR-1733 is also amazing; I could not recall the last time I had to change the batteries in my original AR-1733. 

Overall both radios are now the main stay in my portable ultralight dxing kit, the Tecsun PL-380 is used for serious dxing and the AR-1733 is used mostly to spot check frequencies such as when tracking down stations carrying the same programming (mostly ABC stations) and also for listening to the VHF air band. 
 
Update - October 2020
Now a full eight years after I purchased my first AR-1733, I recently picked up a new one. While speaking to the salesman at my local Jaycar, he informed me that this was new stock and had been improved from the earlier model. 
 
After getting it home and testing it over the past week, I have noticed a few things:
- The box art was much brighter, this suggests new stock which had not been sitting around for too long.
- The tuning knob has much less "play" and has a solid feel about it.
- The audio from headphones has a nicer tone, this is very clear to hear on FM.
- On the airband, it seems to be pulling in signals much better, our local ATIS signal does not drop out as much as on my previous model.
 
 






World DX Day

Paul Blundell
 

Hi all,
 
I am thinking / planning on launching a "World DX Day" in 2021. The idea behind this would be to have a single day where all DXer's are encouraged to get out and about and undertake some DXing. 
I am thinking a website for this and having an area where logs / photos can be uploaded, ideally I would like to make this an annual event.
 
- Has anybody tried this in the past?
- Is it a good idea?
- Would people participate?
 
Thanks
Paul
https://ultralightradiodxing.blogspot.com/


WNJC 1360 DX Test Saturday, October 16-- EURO SPECIAL & 5 kW DAY POWER

Les Rayburn
 


The Courtesy Program Committee (CPC) of the International Radio Club of America (IRCA) and the National Radio Club (NRC) are pleased to pass along details of another DX Test from WNJC 1360 in Washington Township, NJ. 

Details of this special two-part test were passed along by their Chief Engineer Duke Hamann: 


FT8 TEST TO FAVOR EUROPEAN DX’ERS 

"So this week I am switching things up a bit. I am going to try to give the inland folks over the pond a better chance to and copy our FT-8 test. I will be starting 2 hours early with the FT-8 DX test at 02:00 UTC 10/17 (10:00pm 10/16 EDT). We will be operating our regular 2 tower, 800 watt nighttime pattern to the SSE.” 

This test will be in the amateur radio weak-signal mode FT8, which can be received well below audible levels. The signal is transmitted in AM (double-sideband) and good results have been achieved by setting your receiver to LSB or USB mode. Google “Getting Started on FT8” to get started. Recommend that you test on 20 Meters tomorrow or Friday to make sure you’re ready to go. 

This is the best chance for DX’ers across the pond to receive this station. 

WNJC AM Coverage Map


DAY POWER (5 kW) TEST WITH MUSIC, SWEEP TONES, AND A LIVE DJ 


"At 04:00 UTC the FT-8 test will conclude and we will conduct the DX audio test continuing on our nighttime pattern. At 0500 UTC I will be switching to our daytime pattern at 5kw using 4 towers directional to SSE with the DX audio test concluding at 0600 UTC. From 0600 - 1000 UTC I will be leaving the transmitter in daytime mode but be playing our normal playlist of 80s - 2010 pop, rock, dance, country and whatever else I grew up listening to and feel like playing. Listen for the sweepers between songs of movie & tv show clips along with our voice-over guy.” 

This sounds like a fun test and some great music too. Conditions have been good the past few days, so let’s hope this one is widely heard. 

Duke wrapped it up with the following message regarding verifications: 

Reception reports are greatly appreciated and can be emailed to kc2dux@... or snail mailed with at least a 4x6 SASE to PO Box 84 Dennisville, NJ 08214. I ordered 250 QSL cards and gave away 122 so far! I don't want to keep that many LOL! Look forward to having another fun weekend with the DXs out there!"


73,

Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114
EM63nf

NRC & IRCA Courtesy Program Committee Chairman
Member WTFDA, MWC

Perseus SDR, Elad FDM-S2 SDR, AirSpy + Discovery, SDRPlay RSP-2 Pro, Sony XDR-F1HD [XDR Guy Modified], Dennon TU-1500RD, Sangean HDT-1X, Ray Dees RDS Decoders, Korner 9.2 Antenna, FM-6 Antenna, Kitz Technologies KT-501 Pre-amps, Quantum Phaser, Wellbrook ALA1530 Loop, Wellbrook Flag, Clifton Labs Active Whip. 

“Nothing but blues and Elvis, and somebody else’s favorite song…” 


File Notifications #file-notice

main@UltralightDX.groups.io Notification <noreply@...>
 

The following files have been uploaded to the Files area of the main@UltralightDX.groups.io group.

By: Paul Blundell


The following files have been uploaded to the Files area of the main@UltralightDX.groups.io group.

By: Paul Blundell


The following files have been uploaded to the Files area of the main@UltralightDX.groups.io group.

By: Paul Blundell


WPTF 680 kHz OFF-AIR TONIGHT -- Midnight Eastern

Les Rayburn
 

The Courtesy Program Committee (CPC) received word that WPTF 680 “NewsRadio 680” in Raleigh, North Carolina will be off-air tonight starting at Midnight Eastern time for a “couple of hours” according to a message sent from WPTF Engineer Allan Sherill. 

Mr. Sherill explained to CPC Member Paul Walker that the station would be off-air while performing some maintenance and “taking measurements.” 

WPTF is a 50,000 watt station with a nighttime pattern designed to protect KNBR in San Francisco. The nighttime pattern also helps to avoid interfering with WRKO in Boston and CFTR in Toronto. 

Alan Sherill was kind enough to provide advance notification of the off-air period by sending a message via CPC-Member Paul Walker’s Facebook group, alerting us to this opportunity. The off-air period provides a chance for DX’ers to pick up weaker signals normally masked by WPTF’s powerhouse signal. DX’ers on the West Coast should also be listening when the station returns to the air—as their testing might provide a chance to log WPTF as well. 

We’re very grateful to WPTF and Allan Sherill for the notification. 

WPTF AM Coverage Map





73,

Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114
EM63nf

NRC & IRCA Courtesy Program Committee Chairman
Member WTFDA, MWC

Perseus SDR, Elad FDM-S2 SDR, AirSpy + Discovery, SDRPlay RSP-2 Pro, Sony XDR-F1HD [XDR Guy Modified], Dennon TU-1500RD, Sangean HDT-1X, Ray Dees RDS Decoders, Korner 9.2 Antenna, FM-6 Antenna, Kitz Technologies KT-501 Pre-amps, Quantum Phaser, Wellbrook ALA1530 Loop, Wellbrook Flag, Clifton Labs Active Whip. 

“Nothing but blues and Elvis, and somebody else’s favorite song…” 


Re: The RADIOWOW R-108 is in the Amazon Prime-Day deals for $41.57

mediumwavedx
 

I saw this yesterday and ordered one. Great price. This to replace my ailing PL-380 whose buttons don’t make contact anymore.

Bill


Oklahoma TP DX 10-14-20

Richard Allen
 

I listened at 1142 to 1252 and it was one of the better mornings here for TP DX (LSR at 1238).
567 JOIK poor at 1155.
594 JOAK poor at 1237.
657 unID barely audible trace at 1227.
693 JOAB fair at 1222 in KGGF 690 slop.
702 JOKD poor-to-fair at 1220-1224. It always surprises me when I hear this 10 kW station.
711 unID het in KGNC 710 sideband.
747 JOIB fair at 1142 in WSB 750 splash; fair on barefoot receiver (good with FSL) at 1201.
774 JOUB fair at 1146 with severe QRM from semi-local KSPI 780.
828 JOBB poor with strong het at 1206; fair at 1224; faded out at 1242.
837 unID barely audible at 1209.
972 HLCA fair with strong het on barefoot receiver at 1200.
1287 JOHR barely audible JJ at 1235.
1566 HLAZ fair with JJ talk at 1234; poor-to-barely audible at 1241-1252.
Skywave SSB with 8-inch FSL.

Richard Allen,
near Perry OK USA.


Cheap(?) Sony ICF-SW20 on eBay

Matt Gumm
 

Hoping it’s okay to post this here. Thought it might be of interest.

Seller says there is an issue with the antenna if you tighten it too much (see the pics), but even so, this looks cheap, & I thought someone might be interested. (I’m not technical enough to fix iut if it’s got a serious issue.)

https://www.ebay.com/p/18038323907

Matt Gumm


The RADIOWOW R-108 is in the Amazon Prime-Day deals for $41.57

Neil Goldstein
 


Long Term DX Project - 13/10/2020

Paul Blundell
 

Date: 13/10/2020

Time: 17:10

Location: Talbot Road Lookout, Launceston Tasmania

Notes: A late afternoon session with a mixed bag of signals. Both the 50KW power house stations of 3RN and 3LO hit “good” signal levels but most others were much lower of totally missing. It was really nice to be able to get out for a portable session.

 

FREQ

CALLSIGN

LOGGED

DATE

RADIO

AERIAL

531

3GG

POOR

13/10/2020

AR-1733

Internal

549

2CR

POOR

13/10/2020

AR-1733

Internal

594

3WV

AVERAGE

13/10/2020

AR-1733

Internal

621

3RN

GOOD

13/10/2020

AR-1733

Internal

774

3LO

GOOD

13/10/2020

AR-1733

Internal

1053

2CA

UNLOGGED

13/10/2020

AR-1733

Internal

1179

3RPH

POOR

13/10/2020

AR-1733

Internal

1341

HPON GEELONG

WEAK

13/10/2020

AR-1733

Internal

1422

HPON MELBOURNE

UNLOGGED

13/10/2020

AR-1733

Internal

1503

3KND

UNLOGGED

13/10/2020

AR-1733

Internal

 

Photos: https://ultralightradiodxing.blogspot.com/2020/10/long-term-dx-project-13102020.html


DX750 - Setting Up a 750km Target List

Paul Blundell
 

I started ultralight DXing in 2011. My goal was to hear as many stations as I could. Now almost 8 years later, I am more focused and these days I like to have more purpose about my radio hobby. I have run a couple of “long term” projects where I focus on various stations, this has been a mix of logging stations both in total number and also trying for “DX”, that is stations a long way away.

 

DX750 Project.
I have recently started a new project, I call this “DX750”, this is a challenge to attempt to log all AM BCB stations within 750km of my home.

I have exported all stations within 750km from the ACMA database and after cleaning up this data, I have produced the below data:

 

FREQ

CALLSIGN

Area Served

Purpose

Power

DIST

531

3GG

Warragul

Commercial

5k

500

540

7SD

Scottsdale

Commercial

5k

250

585

7RN

Hobart

National

10k

250

594

3WV

Horsham

National

50k

750

621

3RN

Melbourne

National

50k

500

630

7RN

Queenstown

National

400

250

666

2CN

Canberra

National

5k

750

675

2CO

Corowa

National

10k

750

693

3AW

Melbourne

Commercial

5k

500

720

3MT

Omeo

National

2k

500

747

7PB

Hobart

National

3500

250

756

3RN

Wangaratta

National

10k

750

765

2EC

Bega

Commercial

5k

750

774

3LO

Melbourne

National

50k

500

810

2BA

Bega

National

10k

750

828

3GI

Sale

National

10k

500

846

2RN

Canberra

National

10k

750

855

3CR

Melbourne

Community

3500

500

864

7RPH

Hobart

Community

2k

250

882

3RPH

Warrnambool

Community

2k

750

918

2XXL

Cooma

Commercial

2k

750

927

3UZ

Melbourne

Commercial

5k

500

936

7ZR

Hobart

National

10k

250

945

HPON

Bendigo

HPON

2k

750

963

2RG

Griffith

Commercial

5k

750

981

3HA

Hamilton

Commercial

2k

750

990

3RN

Albury/Wodonga

National

500

750

1008

HPON

Launceston

HPON

5k

250

1026

3PB

Melbourne

National

10k

500

1053

2CA

Canberra

Commercial

5k

750

1071

3EL

Maryborough (Vic)

Commercial

5k

750

1080

HPON

Hobart

HPON

5k

250

1089

3WM

Horsham

Commercial

5k

750

1116

3AK

Melbourne

Commercial

5k

500

1125

1RPH

Canberra

Community

2k

750

1134

3CS

Colac

Commercial

5k

500

1152

2WG

Wagga Wagga

Commercial

2k

750

1161

7FG

Fingal

National

1k

250

1179

3RPH

Melbourne

Community

5k

500

1206

2CC

Canberra

Commercial

5k

750

1224

3EA

Melbourne

National

5k

500

1242

3GV

Sale

Commercial

5k

500

1260

3SR

Shepparton

Commercial

2k

750

1278

3EE

Melbourne

Commercial

5k

500

1314

HPON

Wollongong

HPON

5k

750

1323

HPON

Canberra

HPON

400

750

1332

3SH

Swan Hill

Commercial

2k

750

1341

HPON GEELONG

Geelong

HPON

5k

500

1377

3MP

Melbourne

Commercial

5k

500

1413

HPON

Shepparton

HPON

500

750

1422

HPON

Wagin

HPON

2k

500

1440

1EA

Canberra

National

2k

750

1476

5MG

Mount Gambier

National

1k

750

1494

2AY

Albury

Commercial

2k

750

1503

3KND

Melbourne

Community

5k

500

1521

2QN

Deniliquin

Commercial

2k

750

1566

3NE

Wangaratta

Commercial

5k

750

1584

7SH

St Helens

National

100

250

1593

HPON

Melbourne

HPON

5k

500

1602

3WL

Warrnambool

National

250

750

 

Over the next few months in to our summer, I will be focusing on this and posting my results and updates as I go along.

Paul
https://ultralightradiodxing.blogspot.com/2020/10/dx750-setting-up-750km-target-list.html


Yahoo Groups Formal Shutdown Notice

Paul Blundell
 

The below was sent to me earlier today, while have fully migrated this group here to groups.io, please keep in mind if you are still a member of any Yahoo Groups, they are being shut down in two months time.

Paul

Dear Yahoo Group Moderators and Members,

We launched Yahoo Groups 20 years ago to connect people around their shared interests. We helped our users navigate new towns, keep in touch with college friends, learn new skills, and most importantly, build connections they may have lost or never had in the first place. While we could not have been more proud of what we accomplished together, we are reaching out today with heavy hearts to let you know that we have decided to shut down Yahoo Groups on December 15, 2020.

Yahoo Groups has seen a steady decline in usage over the last several years. Over that same period we’ve witnessed unprecedented levels of engagement across our properties as customers seek out premium, trustworthy content. To that end, we must sometimes make difficult decisions regarding products that no longer fit our long-term strategy as we hone our focus on other areas of the business.

Beginning December 15, 2020 the Yahoo Groups website will shut down and members will no longer be able to send or receive emails from Yahoo Groups. We’ve compiled a comprehensive FAQ here that includes alternative providers and information on how this will impact your group content.

Thank you for helping us build one of the earliest digital communities — we’re proud and honored to have forged countless connections over the last 20 years and played a small part in helping build your communities.

Sincerely,
The Yahoo Groups team    


Re: Soft mute disable

Paul Blundell
 

Thank you for that excellent post with such good and interesting information, it explains a lot of what people have been experiencing.

Paul

On Mon, Oct 12, 2020 at 8:20 PM mediumwavedx <desertbilly@...> wrote:
Hi Guys,

Interesting this subject comes up on soft mute. I've been working on a blog post about soft mute and just what it is and its technical parameters.

Here's the data on soft mute:

What is soft mute?
 
Soft-mute is a further lowering of the audio level of the received signal when it drops below a prescribed signal-to-noise ratio. It was implemented in consumer grade DSP radios to provide a more "comfortable listening experience" for the casual listener and not the DXer. The idea is to relieve the listener from all that nasty low level "static" and "interference", or as Silicon Labs states: "....to attenuate the audio outputs and minimize audible noise in compromised signal conditions."
 
Soft mute attenuation is available in the Si473x digitally-tuned series of chips as well as the Si483x analog-tuned series of chips. The soft mute feature is triggered by the SNR (signal-to-noise) metric. The SNR value is directly readable by the chip's software when you tune to a station. The SNR threshold for activating soft mute is programmable, as are soft mute attenuation levels, attack/release rates and attenuation slope.
 
The Tecsun PL-380, PL-310, PL-330, and other radios all may set different soft mute values than the chip's default values shown below. Settings for soft mute are initialized during the power up sequence.
 
The 4 soft mute parameters: Rate, Slope, Max Attenuation, Threshold.
 
Rate (default): 278 dB/second (range 1-255, actual figure 278 = setting * 4.35)
Determines how quickly soft mute is applied/released when soft mute is allowed (enabled). 
 
Slope (default): 2 dB (range 1-5 dB per dB of SNR)
The attenuation slope for soft mute application - in dB of attenuation per dB SNR below the soft mute SNR threshold. Translated: how much audio attenuation to applied as the SNR and signal quality decreases. A setting of 2 will lower the audio by 2 dB for each 1 dB reduction of SNR below the starting threshold at which soft mute kicks in. An example: soft mute starts to kick in when the SNR decreases to 10 dB. At 10 dB, there is 0 dB of soft mute. When the SNR decreases to 9 dB, soft mute reduces the audio level by 2 dB. When the SNR decreases to 8 dB, soft mute reduces the audio level by another 2 dB (4 dB total). By the time the SNR hits 2 dB, the soft mute has reduced the audio level to a max of 16 dB. It will go no lower as the max soft mute has been applied. Note that every 6 dB of audio reduction is a halving of the audio voltage level. 12 dB of reduction is then 1/4 of the original audio voltage level. 16 dB (max soft mute) is a reduction of 84.2% (0.158).
 
Max Attenuation (default): 16 dB (range 0-63 dB, max attenuation of soft mute)
If set to 0, soft mute is disabled entirely.
 
Threshold (default): 10 dB (range 0-63 dB, SNR at which soft mute starts to engage). Silabs states, "for a tuned frequency".
 
Note that the Threshold setting is applicable only "for a tuned frequency". I take this to mean that soft mute is dis-engaged totally when not tuned to an exact 9 or 10 KHz channel, which is apparently why the 1 KHz off-tuning hack works.
 
What you're hearing when a signal's SNR lowers below the threshold and the soft mute kicks in is the Slope factor in action. The Slope factor is lowering the audio volume accordingly.
 
Two other interesting parameters effecting tuning and seeking.
 
AM Seek/Tune SNR Threshold.
SNR Threshold which determines if a valid channel has been found during Seek/Tune.
Specified in units of dB in 1 dB steps (0–63). Default threshold is 5 dB.
 
This tells us that when you do a scan, only stations with >5 dB SNR are elegible to be stored.
 
AM Seek/Tune Received Signal Strength Threshold (RSSI).
RSSI Threshold which determines if a valid channel has been found during
Seek/Tune. Specified in units of dBµV in 1 dBµV steps (0–63). Default threshold is
25 dBµV.
 
This tells us that when you do a scan, only stations with >25 dBµV RSSI are eligible to be stored.

Bill
RADIO-TIMETRAVELLER
https://radio-timetraveller.blogspot.com



--
Paul


Oklahoma TP DX 10-12-20

Richard Allen
 

TP DX today wasn’t up to that of yesterday (LSR at 1234 GMT).

567 JOIK barely audible talking at 1231,

594 JOAK poor // 567 at 1231.

693 JOAB poor in KGGF 690 splash.

702 unID barely audible trace at 1235.

747 JOIB fair with moderate CKJH 750 QRM,

774 JOUB fair with KSPI 780 splash at 1219; fair at 1227 on barefoot receiver.

972 HLCA poor at 1221.

1287 JOHR barely audible JJ talk at 1224.

1566 HLAZ poor at 1237.

Skywave SSB with 8-inch FSL.


Richard Allen,
near Perry OK USA.


Re: Soft mute disable

mediumwavedx
 

Hi Guys,

Interesting this subject comes up on soft mute. I've been working on a blog post about soft mute and just what it is and its technical parameters.

Here's the data on soft mute:

What is soft mute?
 
Soft-mute is a further lowering of the audio level of the received signal when it drops below a prescribed signal-to-noise ratio. It was implemented in consumer grade DSP radios to provide a more "comfortable listening experience" for the casual listener and not the DXer. The idea is to relieve the listener from all that nasty low level "static" and "interference", or as Silicon Labs states: "....to attenuate the audio outputs and minimize audible noise in compromised signal conditions."
 
Soft mute attenuation is available in the Si473x digitally-tuned series of chips as well as the Si483x analog-tuned series of chips. The soft mute feature is triggered by the SNR (signal-to-noise) metric. The SNR value is directly readable by the chip's software when you tune to a station. The SNR threshold for activating soft mute is programmable, as are soft mute attenuation levels, attack/release rates and attenuation slope.
 
The Tecsun PL-380, PL-310, PL-330, and other radios all may set different soft mute values than the chip's default values shown below. Settings for soft mute are initialized during the power up sequence.
 
The 4 soft mute parameters: Rate, Slope, Max Attenuation, Threshold.
 
Rate (default): 278 dB/second (range 1-255, actual figure 278 = setting * 4.35)
Determines how quickly soft mute is applied/released when soft mute is allowed (enabled). 
 
Slope (default): 2 dB (range 1-5 dB per dB of SNR)
The attenuation slope for soft mute application - in dB of attenuation per dB SNR below the soft mute SNR threshold. Translated: how much audio attenuation to applied as the SNR and signal quality decreases. A setting of 2 will lower the audio by 2 dB for each 1 dB reduction of SNR below the starting threshold at which soft mute kicks in. An example: soft mute starts to kick in when the SNR decreases to 10 dB. At 10 dB, there is 0 dB of soft mute. When the SNR decreases to 9 dB, soft mute reduces the audio level by 2 dB. When the SNR decreases to 8 dB, soft mute reduces the audio level by another 2 dB (4 dB total). By the time the SNR hits 2 dB, the soft mute has reduced the audio level to a max of 16 dB. It will go no lower as the max soft mute has been applied. Note that every 6 dB of audio reduction is a halving of the audio voltage level. 12 dB of reduction is then 1/4 of the original audio voltage level. 16 dB (max soft mute) is a reduction of 84.2% (0.158).
 
Max Attenuation (default): 16 dB (range 0-63 dB, max attenuation of soft mute)
If set to 0, soft mute is disabled entirely.
 
Threshold (default): 10 dB (range 0-63 dB, SNR at which soft mute starts to engage). Silabs states, "for a tuned frequency".
 
Note that the Threshold setting is applicable only "for a tuned frequency". I take this to mean that soft mute is dis-engaged totally when not tuned to an exact 9 or 10 KHz channel, which is apparently why the 1 KHz off-tuning hack works.
 
What you're hearing when a signal's SNR lowers below the threshold and the soft mute kicks in is the Slope factor in action. The Slope factor is lowering the audio volume accordingly.
 
Two other interesting parameters effecting tuning and seeking.
 
AM Seek/Tune SNR Threshold.
SNR Threshold which determines if a valid channel has been found during Seek/Tune.
Specified in units of dB in 1 dB steps (0–63). Default threshold is 5 dB.
 
This tells us that when you do a scan, only stations with >5 dB SNR are elegible to be stored.
 
AM Seek/Tune Received Signal Strength Threshold (RSSI).
RSSI Threshold which determines if a valid channel has been found during
Seek/Tune. Specified in units of dBµV in 1 dBµV steps (0–63). Default threshold is
25 dBµV.
 
This tells us that when you do a scan, only stations with >25 dBµV RSSI are eligible to be stored.

Bill
RADIO-TIMETRAVELLER
https://radio-timetraveller.blogspot.com

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