Topics

K4 Latency Time

Irwin Darack
 

I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB 
--
Irwin KD3TB

 

Still doing measurements, but it will be nominally similar to the K3, and better when optimized for minimum QSK delay. (In the K4, there’s no need to switch a synthesizer between transmit and receive modes.)

Wayne
N6KR

On Feb 4, 2020, at 6:07 AM, Irwin Darack <idarack@...> wrote:

I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB 
--
Irwin KD3TB

Rob Sherwood
 

That will be interesting with current rigs running from 10ms to 180ms.  Rob, NC0B


On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...> wrote:


I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB 
--
Irwin KD3TB

Ray Maxfield
 

I see most of the info is for CW on the new K4 !

I hope the DSP is a Lot Better for Phone operations than on My K3 !

Or Shall I start looking Now ?     Ray  WA6VAB ……………..

 

From: N6KR
Sent: Tuesday, February 4, 2020 6:23 AM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] K4 Latency Time

 

Still doing measurements, but it will be nominally similar to the K3, and better when optimized for minimum QSK delay. (In the K4, there’s no need to switch a synthesizer between transmit and receive modes.)


Wayne

N6KR

 


On Feb 4, 2020, at 6:07 AM, Irwin Darack <idarack@...> wrote:

I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

 

Irwin KD3TB 

--

Irwin KD3TB

 

Rob Sherwood
 

It takes about 5 minutes to make the measurement. Four minutes to hook up the equipment and 1 minute to measure it on a digital scope.  

I have data on 12 rigs at nc0b.com/latency

Download the PDF.  I need to add the TD-890S. 

Rob, NC0B


On Feb 4, 2020, at 9:58 AM, Rob Sherwood <Rob@...> wrote:

 That will be interesting with current rigs running from 10ms to 180ms.  Rob, NC0B


On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...> wrote:


I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB 
--
Irwin KD3TB

 

Rob,

What are you using as the stimulus for these tests? We'd like to reproduce this in our lab.

Wayne
N6KR

On Feb 4, 2020, at 12:07 PM, Rob Sherwood <rob@...> wrote:

It takes about 5 minutes to make the measurement. Four minutes to hook up the equipment and 1 minute to measure it on a digital scope.

I have data on 12 rigs at nc0b.com/latency

Download the PDF. I need to add the TD-890S.

Rob, NC0B


On Feb 4, 2020, at 9:58 AM, Rob Sherwood <Rob@...> wrote:

 That will be interesting with current rigs running from 10ms to 180ms. Rob, NC0B


On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...> wrote:


I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB
--
Irwin KD3TB

Rob Sherwood
 

Hi Wayne,

I use the same pulse generator that I use to test how a receiver's AGC handles impulse noise. The K3 is one of the few rigs where the AGC doesn't get captured by an impulse, like an electric fence. (This assumes the operator has this AGC feature turned on in the menu.)

The IC-756 Pro III was the last Icom rig to handle impulse noise properly, and no current Japanese rig from the big three OEMs works properly. No analog rig has this problem at all. I believe the Apache radios also handle impulse noise properly from an AGC standpoint. Now the latency info you wanted!

Unfortunate I don't currently have any K3 latency data. I need to correct this oversight.

I have both an HP pulse generator and a Tektronix, either set for a 10ns rise time. The duration of the impulse doesn't matter much, 500ns to 1ms is OK. The output is set for full output (10 to 16 volts) followed by a 20 dB pad. This provides the best signal to noise of the generator output stage vs. the pulse. This is more important when making the RX AGC test than making the latency test. It is convenient if you can set the rep rate to once every 5 or 10 seconds so the scope can be set to one-shot and ignore the following impulses.

The output of the 20 dB pad feeds a hybrid splitter, such as a Mini-Circuits ZSC-2-1. One output goes to the receiver antenna input and the other output goes to the external trigger of the digital storage scope. The audio output of the receiver goes to the vertical input of the scope.

You want to measure the time delta between the trigger point and the audio pulse, which will have ringing. I pick the first full amplitude point, as per the PDF on my website. If you look at the first picture in the PDF for the IC-7300 at 2400 Hz bandwidth, the cursor for the trigger point is shown on the left, and the audio pulse on the right is where the other digital cursor is set. The time delta in this case is 3.66ms. If on the other hand you look at the Flex 6600M set for the best filter shape factor (highest latency), the time delta is 170ms.

For a frame of reference, my pure analog IC-781 has a latency with a 2700 Hz bandwidth of 1.18ms and on CW with a 500 Hz bandwidth latency is 5.9ms. The IC-7610 with a 2400 Hz bandwidth has a latency of 7.96ms and on CW with a 500 Hz bandwidth the latency is 12.65ms.

What gets really interesting is using a radio over the internet with its added latency. Let's say two brand X radios had a latency of 100ms, and were working each other in a contest. The total latency could well be over 300ms. A contest over a year ago, where all the operators were remote, resulted in the US station consistently calling when the DX was transmitting.

Rob, NC0B

-----Original Message-----
From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of N6KR
Sent: Tuesday, February 04, 2020 1:15 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] K4 Latency Time

Rob,

What are you using as the stimulus for these tests? We'd like to reproduce this in our lab.

Wayne
N6KR



On Feb 4, 2020, at 12:07 PM, Rob Sherwood <rob@...> wrote:

It takes about 5 minutes to make the measurement. Four minutes to hook up the equipment and 1 minute to measure it on a digital scope.

I have data on 12 rigs at nc0b.com/latency

Download the PDF. I need to add the TD-890S.

Rob, NC0B


On Feb 4, 2020, at 9:58 AM, Rob Sherwood <Rob@...> wrote:

 That will be interesting with current rigs running from 10ms to 180ms. Rob, NC0B


On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...> wrote:


I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB
--
Irwin KD3TB

Rob Sherwood
 

Typo.  I meant I  need to add the TS-890S, and the K3 for that matter.   Rob, NC0B

 

From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of Rob Sherwood
Sent: Tuesday, February 04, 2020 1:08 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] K4 Latency Time

 

It takes about 5 minutes to make the measurement. Four minutes to hook up the equipment and 1 minute to measure it on a digital scope.  

 

I have data on 12 rigs at nc0b.com/latency

 

Download the PDF.  I need to add the TD-890S. 

 

Rob, NC0B



On Feb 4, 2020, at 9:58 AM, Rob Sherwood <Rob@...> wrote:

 That will be interesting with current rigs running from 10ms to 180ms.  Rob, NC0B

 



On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...> wrote:



I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

 

Irwin KD3TB 

--

Irwin KD3TB

David Box
 

The additional measurements I would be interested in are CS transmit, time from key closure to side tone and rf out.
de Dave K5MWR


On February 4, 2020 2:14:31 PM CST, N6KR <n6kr@...> wrote:
Rob, 

What are you using as the stimulus for these tests? We'd like to reproduce this in our lab.

Wayne
N6KR



On Feb 4, 2020, at 12:07 PM, Rob Sherwood <rob@...> wrote:

It takes about 5 minutes to make the measurement. Four minutes to hook up the equipment and 1 minute to measure it on a digital scope.

I have data on 12 rigs at nc0b.com/latency

Download the PDF. I need to add the TD-890S.

Rob, NC0B


On Feb 4, 2020, at 9:58 AM, Rob Sherwood <Rob@...> wrote:

 That will be interesting with current rigs running from 10ms to 180ms. Rob, NC0B


On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...> wrote:


I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB
--
Irwin KD3TB


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David Box
 

Fat fingered CS meant CW
de Dave K5MWR


On February 4, 2020 3:55:53 PM CST, David Box <dobox@...> wrote:
The additional measurements I would be interested in are CS transmit, time from key closure to side tone and rf out.
de Dave K5MWR


On February 4, 2020 2:14:31 PM CST, N6KR <n6kr@...> wrote:
Rob, 

What are you using as the stimulus for these tests? We'd like to reproduce this in our lab.

Wayne
N6KR



On Feb 4, 2020, at 12:07 PM, Rob Sherwood <rob@...> wrote:

It takes about 5 minutes to make the measurement. Four minutes to hook up the equipment and 1 minute to measure it on a digital scope.

I have data on 12 rigs at nc0b.com/latency

Download the PDF. I need to add the TD-890S.

Rob, NC0B


On Feb 4, 2020, at 9:58 AM, Rob Sherwood <Rob@...> wrote:

 That will be interesting with current rigs running from 10ms to 180ms. Rob, NC0B


On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...> wrote:


I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB
--
Irwin KD3TB


Groups.io Links: You receive all messages sent to this group.

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Rob Sherwood
 

That would normally be an adjustment to deal with an amp’s T/R switching time to prevent hot keying.  I set my TX delay to 15ms for my Acom and Alpha QSK amps.  The Alpha 89 has PIN diode T/R switching, and Alpha doesn’t recommend faster than 10ms.  I don’t know what Elecraft recommends for the KPA500 or KPA1500, as they are also solid-state T/R switching.  Other than the Alpha 87A, (and old 86), who has solid-state switching these days?   Rob, NC0B

 

From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of David Box
Sent: Tuesday, February 04, 2020 2:56 PM
To: Elecraft-K3@groups.io; N6KR
Subject: Re: [Elecraft-K3] K4 Latency Time

 

The additional measurements I would be interested in are CS transmit, time from key closure to side tone and rf out.
de Dave K5MWR

On February 4, 2020 2:14:31 PM CST, N6KR <n6kr@...> wrote:

Rob, 

What are you using as the stimulus for these tests? We'd like to reproduce this in our lab.

Wayne
N6KR


On Feb 4, 2020, at 12:07 PM, Rob Sherwood <rob@...> wrote:

It takes about 5 minutes to make the measurement. Four minutes to hook up the equipment and 1 minute to measure it on a digital scope.

I have data on 12 rigs at nc0b.com/latency

Download the PDF.  I need to add the TD-890S.

Rob, NC0B

On Feb 4, 2020, at 9:58 AM, Rob Sherwood <Rob@...> wrote:

 That will be interesting with current rigs running from 10ms to 180ms.  Rob, NC0B

On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...> wrote:


I realize that it’s a little early and Elecraft is most likely still fine tuning their firmware/software....has Elecraft published a expected RX/TX Latency Time for the K4?

Irwin KD3TB
--
Irwin KD3TB
 

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Sent from my Android device with K-9 Mail. Please excuse my brevity.

Paul Baldock
 

Rob -

Are your screen shots the delay in sending a DIT of the delay in receiving a DIT?

Have you done any test in the delay between speaking in to the MIC and hearing in the monitor?

Thanks

- Paul  KW7Y


At 02:58 PM 2/4/2020, you wrote:

On Feb 4, 2020, at 12:07
PM, Rob Sherwood <rob@...> wrote:

It takes about 5 minutes to make the measurement. Four minutes to hook up
the equipment and 1 minute to measure it on a digital scope.

I have data on 12 rigs at nc0b.com/latency

Download the PDF.  I need to add the TD-890S. 

Rob, NC0B


On Feb 4, 2020, at 9:58 AM, Rob Sherwood <Rob@...>
wrote:

 That will be interesting with current rigs running from 10ms to
180ms.  Rob, NC0B


On Feb 4, 2020, at 7:07 AM, Irwin Darack <idarack@...>
wrote:


I realize that it’s a little early and Elecraft is most likely still
fine tuning their firmware/software....has Elecraft published a expected
RX/TX Latency Time for the K4?

Irwin KD3TB 
-- 
Irwin KD3TB

 




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Roeland Jansen, PA3MET
 

>What gets really interesting is using a radio over the internet with its added latency. Let's say two brand X radios had a latency of 100ms, and were working each other in a contest. The total latency could well be over >300ms. A contest over a year ago, where all the operators were remote, resulted in the US station consistently calling when the DX was transmitting.

I've had issues with a flex/maestro combination with these latencies. That connection ws in the same city/country.