Date   

Re: World Map 1.2.7

Mike Bott
 

It appears that the long path is anchored on the opposite side of the earth from the Home Location

On 5/14/22 02:48, Simon Brown wrote:

Something for the weekend: World Map 1.2.7 with a few funky new features.

 

https://www.g4eli.com/world-map

 

 

Simon Brown

https://www.g4eli.com

https://www.sdr-radio.com

 


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Spectral Subtraction

martinbradford2001
 
Edited

What is the hardware requirement, Simon? Is this processing the two channels of a device like the RSPDuo?

Regarding the artefacts, yes they can be annoying, but this level of noise reduction would only usually be used on signals at the limit of readability. Failing to get a new DXCC in the logbook is even more annoying than a bit of burbling and a confirmed log entry!

--
Martin
G8FXC


World Map 1.2.7

Simon Brown
 

Something for the weekend: World Map 1.2.7 with a few funky new features.

 

https://www.g4eli.com/world-map

 

 

Simon Brown

https://www.g4eli.com

https://www.sdr-radio.com

 


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Spectral Subtraction

Max
 

On Fri, May 13, 2022 at 10:25 AM, Conrad, PA5Y wrote:

Watch the video below at 08:24, this is about the best in amateur radio I’ve heard, the artefacts are there but acceptable for our purposes.

 

https://www.youtube.com/watch?v=KR5t4Hei9FA

Conrad, that is one of the best ever NRs I've ever heard. No detectable "burbling" on the voice, just noise reduction. Very nice. Hope Simon can emulate this and will be fantastic.

73

Max


Re: Spectral Subtraction

Simon Brown
 

Indeed, that paper you referenced is my next reading material.

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 13 May 2022 10:42
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Spectral Subtraction

 

I am quite sure that you will do a good job!

 

Conrad

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 13 May 2022 11:30
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Spectral Subtraction

 

Conrad,

 

This is being worked on, I’m now at a stage where I can move forward with Luciano Dato’s work.

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 13 May 2022 10:25
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Spectral Subtraction

 

Simon thank you for your work.

 

I find the burbling sounds associated with Spectral subtraction most off putting. I believe it is called ‘musical noise’ and is more obtrusive with speech than music.

 

This is interesting.

https://www.vocal.com/noise-reduction/musical-noise/

 

It offers suggestions as to how it may be reduced which do work. Probably Simon has already incorporated these techniques.

 

I have been working commercially on this very subject exclusively with AM radio for the last 4 months with great success, unfortunately I cannot share what we have done.

 

SDR# suffers from the same affliction, at least based on the recordings that I could find online. If anyone has any good examples of spectral subtraction with SDR# please post them.

 

Watch the video below at 08:24, this is about the best in amateur radio I’ve heard, the artefacts are there but acceptable for our purposes.

 

https://www.youtube.com/watch?v=KR5t4Hei9FA

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 13 May 2022 09:29
To: SDR-Radio@groups.io
Subject: [SDR-Radio] Spectral Subtraction

 

Understanding spectral subtraction and its use in noise reduction for SDR Console. Not yet as good as SDR# but a step in the right direction!

 

https://www.g4eli.com/blog/spectral-subtraction

 

 

Simon Brown

https://www.g4eli.com

https://www.sdr-radio.com

 


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Spectral Subtraction

Siegfried Jackstien
 

i am sure you can make it perfect ...

if that slight hiss that is left is also filtered away then there is no need to use squelch anymore ;-)

good job

dg9bfc sigi

ps tnx fer restoring the max values up

Am 13.05.2022 um 11:30 schrieb Simon Brown:

Conrad,

 

This is being worked on, I’m now at a stage where I can move forward with Luciano Dato’s work.

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 13 May 2022 10:25
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Spectral Subtraction

 

Simon thank you for your work.

 

I find the burbling sounds associated with Spectral subtraction most off putting. I believe it is called ‘musical noise’ and is more obtrusive with speech than music.

 

This is interesting.

https://www.vocal.com/noise-reduction/musical-noise/

 

It offers suggestions as to how it may be reduced which do work. Probably Simon has already incorporated these techniques.

 

I have been working commercially on this very subject exclusively with AM radio for the last 4 months with great success, unfortunately I cannot share what we have done.

 

SDR# suffers from the same affliction, at least based on the recordings that I could find online. If anyone has any good examples of spectral subtraction with SDR# please post them.

 

Watch the video below at 08:24, this is about the best in amateur radio I’ve heard, the artefacts are there but acceptable for our purposes.

 

https://www.youtube.com/watch?v=KR5t4Hei9FA

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 13 May 2022 09:29
To: SDR-Radio@groups.io
Subject: [SDR-Radio] Spectral Subtraction

 

Understanding spectral subtraction and its use in noise reduction for SDR Console. Not yet as good as SDR# but a step in the right direction!

 

https://www.g4eli.com/blog/spectral-subtraction

 

 

Simon Brown

https://www.g4eli.com

https://www.sdr-radio.com

 


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Spectral Subtraction

Conrad, PA5Y
 

I am quite sure that you will do a good job!

 

Conrad

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 13 May 2022 11:30
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Spectral Subtraction

 

Conrad,

 

This is being worked on, I’m now at a stage where I can move forward with Luciano Dato’s work.

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 13 May 2022 10:25
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Spectral Subtraction

 

Simon thank you for your work.

 

I find the burbling sounds associated with Spectral subtraction most off putting. I believe it is called ‘musical noise’ and is more obtrusive with speech than music.

 

This is interesting.

https://www.vocal.com/noise-reduction/musical-noise/

 

It offers suggestions as to how it may be reduced which do work. Probably Simon has already incorporated these techniques.

 

I have been working commercially on this very subject exclusively with AM radio for the last 4 months with great success, unfortunately I cannot share what we have done.

 

SDR# suffers from the same affliction, at least based on the recordings that I could find online. If anyone has any good examples of spectral subtraction with SDR# please post them.

 

Watch the video below at 08:24, this is about the best in amateur radio I’ve heard, the artefacts are there but acceptable for our purposes.

 

https://www.youtube.com/watch?v=KR5t4Hei9FA

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 13 May 2022 09:29
To: SDR-Radio@groups.io
Subject: [SDR-Radio] Spectral Subtraction

 

Understanding spectral subtraction and its use in noise reduction for SDR Console. Not yet as good as SDR# but a step in the right direction!

 

https://www.g4eli.com/blog/spectral-subtraction

 

 

Simon Brown

https://www.g4eli.com

https://www.sdr-radio.com

 


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Spectral Subtraction

Simon Brown
 

Conrad,

 

This is being worked on, I’m now at a stage where I can move forward with Luciano Dato’s work.

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 13 May 2022 10:25
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Spectral Subtraction

 

Simon thank you for your work.

 

I find the burbling sounds associated with Spectral subtraction most off putting. I believe it is called ‘musical noise’ and is more obtrusive with speech than music.

 

This is interesting.

https://www.vocal.com/noise-reduction/musical-noise/

 

It offers suggestions as to how it may be reduced which do work. Probably Simon has already incorporated these techniques.

 

I have been working commercially on this very subject exclusively with AM radio for the last 4 months with great success, unfortunately I cannot share what we have done.

 

SDR# suffers from the same affliction, at least based on the recordings that I could find online. If anyone has any good examples of spectral subtraction with SDR# please post them.

 

Watch the video below at 08:24, this is about the best in amateur radio I’ve heard, the artefacts are there but acceptable for our purposes.

 

https://www.youtube.com/watch?v=KR5t4Hei9FA

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 13 May 2022 09:29
To: SDR-Radio@groups.io
Subject: [SDR-Radio] Spectral Subtraction

 

Understanding spectral subtraction and its use in noise reduction for SDR Console. Not yet as good as SDR# but a step in the right direction!

 

https://www.g4eli.com/blog/spectral-subtraction

 

 

Simon Brown

https://www.g4eli.com

https://www.sdr-radio.com

 


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Spectral Subtraction

Conrad, PA5Y
 

Simon thank you for your work.

 

I find the burbling sounds associated with Spectral subtraction most off putting. I believe it is called ‘musical noise’ and is more obtrusive with speech than music.

 

This is interesting.

https://www.vocal.com/noise-reduction/musical-noise/

 

It offers suggestions as to how it may be reduced which do work. Probably Simon has already incorporated these techniques.

 

I have been working commercially on this very subject exclusively with AM radio for the last 4 months with great success, unfortunately I cannot share what we have done.

 

SDR# suffers from the same affliction, at least based on the recordings that I could find online. If anyone has any good examples of spectral subtraction with SDR# please post them.

 

Watch the video below at 08:24, this is about the best in amateur radio I’ve heard, the artefacts are there but acceptable for our purposes.

 

https://www.youtube.com/watch?v=KR5t4Hei9FA

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 13 May 2022 09:29
To: SDR-Radio@groups.io
Subject: [SDR-Radio] Spectral Subtraction

 

Understanding spectral subtraction and its use in noise reduction for SDR Console. Not yet as good as SDR# but a step in the right direction!

 

https://www.g4eli.com/blog/spectral-subtraction

 

 

Simon Brown

https://www.g4eli.com

https://www.sdr-radio.com

 


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Spectral Subtraction

Simon Brown
 

Understanding spectral subtraction and its use in noise reduction for SDR Console. Not yet as good as SDR# but a step in the right direction!

 

https://www.g4eli.com/blog/spectral-subtraction

 

 

Simon Brown

https://www.g4eli.com

https://www.sdr-radio.com

 


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Future version 1.27 of the "World Map" #future

jdow
 

If you are a developer type there are performance counter functions that can give you the actual clock frequency. The dithering approach still applies.

{^_^}

On 20220512 08:15:41, David J Taylor via groups.io wrote:
On 12/05/2022 12:27, jdow wrote:
Technical extreme quibble:

In order to get approximately 1 kHz clocks a timer, not atypically running off
a US TV receiver color subcarrier crystal, is divided by 3580. This obviously
gives a frequency about 545 ppm off to which the clock's accuracy of maybe as
bad as 100 ppm is added. The best you can do is dither this divider so that on
the average you get 1 kHz with as many 0s after the decimal point as you wish.
If the oscillator is perfectly on 5e6/88*63 Hz you can work out the dither
pattern to give arbitrary accuracy from 3.57954545454545... MHz. In a simple
case with an imprecise computer oscillator, if the clock alternates between
3580 and 3579 for the setting you move the accuracy down to about 46 ppm from
the basic process and whatever the clock might be. If you compare with an
external precision timer you can work out a dither pattern for the divisor that
leads to greater long term accuracy. Unfortunately this sort of bassakwards
approach is required because the timer clock has no software adjustment
potential so you cannot slide the oscillator right in with a D/A converter
feeding a VCXO input.


{^_-}  Did anybody manage to stay awake through that nonsense?

Completely agreed, but I do wonder when the NTSC colour subcarrier frequency
was last used as a master clock in PCs!  I have heard of folk replacing the
master oscillator with a TCXO, but that's a little extreme.

David GM8ARV
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv





Re: Future version 1.27 of the "World Map" #future

jdow
 

On 20220512 07:47:26, Brian Morrison wrote:
On Wed, 11 May 2022 22:15:50 -0700 "Radioman ZeroZero" <radioman@...> wrote:
A pc clock cannot maintain time accurately.  It is all very well setting a very accurate time but after half an hour it will have drifted.
If you're running something like Fedora Linux then you can use chronyd to supervise the system clocks, it's far better than ntpd on its own. There are also packages like oscillatord which can discipline PC clocks from a 1pps GPSDO signal.
I'm not sure what amateur radio part of the hobby requires a super accurate time.
Accuracy is addictive, once you have it you can find things to do with it ;-)

In this case synchronizing a fast frequency hopping ECCM radio to a network.

{^_-}


Re: Future version 1.27 of the "World Map" #future

David J Taylor
 

On 12/05/2022 12:27, jdow wrote:
Technical extreme quibble:

In order to get approximately 1 kHz clocks a timer, not atypically running off
a US TV receiver color subcarrier crystal, is divided by 3580. This obviously
gives a frequency about 545 ppm off to which the clock's accuracy of maybe as
bad as 100 ppm is added. The best you can do is dither this divider so that on
the average you get 1 kHz with as many 0s after the decimal point as you wish.
If the oscillator is perfectly on 5e6/88*63 Hz you can work out the dither
pattern to give arbitrary accuracy from 3.57954545454545... MHz. In a simple
case with an imprecise computer oscillator, if the clock alternates between
3580 and 3579 for the setting you move the accuracy down to about 46 ppm from
the basic process and whatever the clock might be. If you compare with an
external precision timer you can work out a dither pattern for the divisor that
leads to greater long term accuracy. Unfortunately this sort of bassakwards
approach is required because the timer clock has no software adjustment
potential so you cannot slide the oscillator right in with a D/A converter
feeding a VCXO input.


{^_-}  Did anybody manage to stay awake through that nonsense?
Completely agreed, but I do wonder when the NTSC colour subcarrier frequency
was last used as a master clock in PCs! I have heard of folk replacing the
master oscillator with a TCXO, but that's a little extreme.

David GM8ARV
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: Future version 1.27 of the "World Map" #future

Brian Morrison
 

On Wed, 11 May 2022 22:15:50 -0700
"Radioman ZeroZero" <radioman@...> wrote:

A pc clock cannot maintain time accurately.  It is all very well
setting a very accurate time but after half an hour it will have
drifted.
If you're running something like Fedora Linux then you can use chronyd
to supervise the system clocks, it's far better than ntpd on its own.

There are also packages like oscillatord which can discipline PC clocks
from a 1pps GPSDO signal.

I'm not sure what amateur radio part of the hobby requires a
super accurate time.
Accuracy is addictive, once you have it you can find things to do with it ;-)

--

Brian G8SEZ


Re: Future version 1.27 of the "World Map" #future

Brent Seres/ VE3CUS
 

I use NTP on my PC to sync with CHU or WWV and it works well

 Brent 
VE3CUS





-------- Original message --------
From: jdow <jdow@...>
Date: 2022-05-12 07:27 (GMT-05:00)
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Future version 1.27 of the "World Map" #future

On 20220512 02:14:17, David J Taylor via groups.io wrote:
On 12/05/2022 06:15, Radioman ZeroZero wrote:
A pc clock cannot maintain time accurately.  It is all very well setting a very
accurate time but after half an hour it will have drifted.  I'm not sure what
amateur radio part of the hobby requires a super accurate time.
--
Thanks Steve M0ZEH

Steve,

Reference NTP software (but not all so-called "atomic clock" programs) does not
only set the time initially, but it also measures the drift rate and adjusts
the clock rate so that accurate time is maintained even with a drifting
undisciplined clock.

There's more here:  https://www.satsignal.eu/ntp/setup.html#why

73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv

Technical extreme quibble:

In order to get approximately 1 kHz clocks a timer, not atypically running off a US TV receiver color subcarrier crystal, is divided by 3580. This obviously gives a frequency about 545 ppm off to which the clock's accuracy of maybe as bad as 100 ppm is added. The best you can do is dither this divider so that on the average you get 1 kHz with as many 0s after the decimal point as you wish. If the oscillator is perfectly on 5e6/88*63 Hz you can work out the dither pattern to give arbitrary accuracy from 3.57954545454545... MHz. In a simple case with an imprecise computer oscillator, if the clock alternates between 3580 and 3579 for the setting you move the accuracy down to about 46 ppm from the basic process and whatever the clock might be. If you compare with an external precision timer you can work out a dither pattern for the divisor that leads to greater long term accuracy. Unfortunately this sort of bassakwards approach is required because the timer clock has no software adjustment potential so you cannot slide the oscillator right in with a D/A converter feeding a VCXO input.


{^_-}  Did anybody manage to stay awake through that nonsense?


Re: Future version 1.27 of the "World Map" #future

jdow
 

On 20220512 02:14:17, David J Taylor via groups.io wrote:
On 12/05/2022 06:15, Radioman ZeroZero wrote:
A pc clock cannot maintain time accurately.  It is all very well setting a very
accurate time but after half an hour it will have drifted.  I'm not sure what
amateur radio part of the hobby requires a super accurate time.
--
Thanks Steve M0ZEH

Steve,

Reference NTP software (but not all so-called "atomic clock" programs) does not
only set the time initially, but it also measures the drift rate and adjusts
the clock rate so that accurate time is maintained even with a drifting
undisciplined clock.

There's more here:  https://www.satsignal.eu/ntp/setup.html#why

73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv

Technical extreme quibble:

In order to get approximately 1 kHz clocks a timer, not atypically running off a US TV receiver color subcarrier crystal, is divided by 3580. This obviously gives a frequency about 545 ppm off to which the clock's accuracy of maybe as bad as 100 ppm is added. The best you can do is dither this divider so that on the average you get 1 kHz with as many 0s after the decimal point as you wish. If the oscillator is perfectly on 5e6/88*63 Hz you can work out the dither pattern to give arbitrary accuracy from 3.57954545454545... MHz. In a simple case with an imprecise computer oscillator, if the clock alternates between 3580 and 3579 for the setting you move the accuracy down to about 46 ppm from the basic process and whatever the clock might be. If you compare with an external precision timer you can work out a dither pattern for the divisor that leads to greater long term accuracy. Unfortunately this sort of bassakwards approach is required because the timer clock has no software adjustment potential so you cannot slide the oscillator right in with a D/A converter feeding a VCXO input.


{^_-}  Did anybody manage to stay awake through that nonsense?


Re: Future version 1.27 of the "World Map" #future

David J Taylor
 

On 12/05/2022 06:15, Radioman ZeroZero wrote:
A pc clock cannot maintain time accurately.  It is all very well setting a very
accurate time but after half an hour it will have drifted.  I'm not sure what
amateur radio part of the hobby requires a super accurate time.
--
Thanks Steve M0ZEH
Steve,

Reference NTP software (but not all so-called "atomic clock" programs) does not
only set the time initially, but it also measures the drift rate and adjusts
the clock rate so that accurate time is maintained even with a drifting
undisciplined clock.

There's more here: https://www.satsignal.eu/ntp/setup.html#why

73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: Future version 1.27 of the "World Map" #future

jdow
 

On 20220511 23:56:07, Alan G4ZFQ wrote:
On 12/05/2022 05:15, Radioman ZeroZero wrote:
not sure what amateur radio part of the hobby requires a super accurate time.

Steve,

Super accurate, not many. http://www.dxatlas.com/faros/ is one that measures propagation delay, it actually contains it's own NTP clock.
The Kiwi radio network uses GPS PPS to use TOA station location.

Meinberg as mentioned is one that sets PC time and maintains it  to within miliseconds.

73 Alan G4ZFQ

I've run across a reference of an ntp server that maintains time by fiddling with the counter settings. If you have a 3.57954545454 MHz timer oscillator (5e6/88*63) then it fiddles the time keeping divider up and down from 3579 to account for the fractional part and apply further correction so that long term timing is in the microsecond range if you can supply it with an accurate time tick. The pro radio astronomers use an even fancier setup to make precision time using motherboards that reference time to 100 MHz or higher oscillators in the PCs. (I wonder how many replace the timer oscillator with a TCVCXO and lock the loop. I bet the VLB array uses this sort of technique.)

PCs have a lot more potential than most people realize, especially for a hardware hacker.

{^_^}


Re: Future version 1.27 of the "World Map" #future

jdow
 

As long as the temperature is fairly stable a PC can do remarkably with a normal NTP installation. The Linux PC used as a router here maintains our ntp install and maintains time within +/- 30 ms across multiple time sources. At the moment it has chosen a GPS locked source and is within +/- 6 ms jitter on teh link and an offset of about 0.34 ms. It is +/- 8 ms across the 5 sites it monitors. Modulo your definition of accurately that's surprisingly good considering it does not vary all that much. It applies corrections to the PC's timers so that they tick off accurate 1ms ticks with jitter in the sub-microsecond range that is intentionally used to keep the clock accurate.

On my Windows PC I am running an old ntp tool that does not touch the timers and instead jam sets 1ms plus, zero, or minus corrections as needed once a minute. (This PC's clock is pretty pathetic, too.) I should probably get a proper ntp for the machine. I believe NIST has one.


{^_^}

On 20220511 22:15:50, Radioman ZeroZero wrote:
A pc clock cannot maintain time accurately.  It is all very well setting a very accurate time but after half an hour it will have drifted.  I'm not sure what amateur radio part of the hobby requires a super accurate time.
--
Thanks Steve M0ZEH


Re: Future version 1.27 of the "World Map" #future

Alan G4ZFQ
 

On 12/05/2022 05:15, Radioman ZeroZero wrote:
not sure what amateur radio part of the hobby requires a super accurate time.
Steve,

Super accurate, not many. http://www.dxatlas.com/faros/ is one that measures propagation delay, it actually contains it's own NTP clock.
The Kiwi radio network uses GPS PPS to use TOA station location.

Meinberg as mentioned is one that sets PC time and maintains it to within miliseconds.

73 Alan G4ZFQ

1761 - 1780 of 67997