Date   

Re: K4 Latency Time

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
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Irwin KD3TB


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Re: K4 Latency Time

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
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Irwin KD3TB


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

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Re: K4 Latency Time

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


Re: K4 Latency Time

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


Re: 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


Re: K4 Latency Time

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


Re: K4 Latency Time

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

 


Re: K4 Latency Time

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


Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

Bob McGraw - K4TAX
 

That display should be indicating OUTPUT power.  

I suggest you use an external meter of known accuracy and a 50 ohm dummy load of known accuracy.  Measure both the input to the amp from the transceiver and the output of the amp as indicated on the external meter.      From your earlier numbers, they appear to be of some noted inaccuracy.

Also note that just because a dummy load says 50 ohms on the label is no assurance it is actually 50 ohms.   I have 2 of which neither are actually 50 ohms.   One is 13% high measuring 56.5 ohms.  Since most ham power meters are measuring voltage referenced 50 ohms, any error in the 50 ohm load will likewise show as an error in power measurement.

Based on ~15 dB amp gain and 1500 watts output into 50 ohms Resistive, the drive power should be 47.5 watts for a gain of 14.99 dB.

73

Bob, K4TAX

On 2/4/2020 10:34 AM, Jim Denneny wrote:
Adrian, I mean 1500W as indicated on the led power bar whatever that means - input / output.

73, Jim K7EG


Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

Jim Denneny
 

Adrian, I mean 1500W as indicated on the led power bar whatever that means - input / output.

73, Jim K7EG


Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

Ray
 

FCC max gain for amps is 15 dB.
Ray
W8LYJ


Re: 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


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


Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

John Canfield <bucket@...>
 

I think that was a typo - I'm sure he meant 1500 watts out.


Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

Adrian Fewster <vk4tux@...>
 

Jim, Can you clarify what you mean by 1500 watts input ?

I thought that 1500 watts was the output figure on the amp with that drive,

and that the input value would be much higher allowing for efficiency?


Or do you mean to the the antenna input ?


Adrian ,   vk4tux



On 4/2/20 5:42 am, Jim Denneny wrote:
About 25 - 30 watts for 1500 watts input.
Jim K7EG
_._,_._,_



Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

Jim Denneny
 

About 25 - 30 watts for 1500 watts input.
Jim K7EG


Re: New release of Win4K3Suite

Steve Black
 

Just curious, Why before the end of February? Will my laptop turn into a pumpkin? ;-)) Steve kb1chu


On 2/1/2020 11:07 AM, Tom Blahovici wrote:

Hello,

There is a new version of Win4K3Suite available, version 2.018. This release improves the entity lookup from ClubLog as well as other minor items.  You must download this before the end of February.

 Win4K3Suite is a full featured control program for the K3/S, KX3 and KX2.  It has a built in Panadapter that works with LPPAN and a sound card, as well as the SDRPlay RSP's. It supports the KAT500, KPA500/1500 and the KXPA100 on most of the above radios. 

 

A unique feature is that is has 6 built in Virtual Radios, each of which works just like an Elecraft radio.  This allows sharing of a single COM port with up to 6 applications.  It also has a built in HRDLogbook server and the EiBi Shortwave database.

You see more information here: https://www.youtube.com/results?search_query=win4k3suite

and download a fully functional 30 day trial at va2fsq.com

73 Tom

va2fsq.com


Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

Clay Autery
 

Sounds friggin' awesome! 

______________________
Clay Autery, KY5G
(318) 518-1389
On 02/02/20 08:53, John Canfield wrote:

Hey guys,

Thursday the Brown Santa (UPS) delivered my birthday present for the next ten years - a KPA1500 amp. I'm slowly learning how to use it and I'm not sure if things are acting right. Going directly into a dummy from the amp, it only takes about 28 watts drive from the K3s for a full 1500 watts output. I can reduce the drive to five watts or lower and drop the amp's output to ~150-200 watts.

Does this sound correct? Thanks for any advice.

John, WB5THT


Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

Christopher Scibelli
 

Good.  35 watts of drive from my K3 drives my Alpha 8410 to legal limit power.

Chris  NU1O


-----Original Message-----
From: Rob Sherwood <rob@...>
To: Elecraft-K3@groups.io <Elecraft-K3@groups.io>
Sent: Sun, Feb 2, 2020 11:00 am
Subject: Re: [Elecraft-K3] K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #KPA1500

Yes the K3 is cleanest around 35 watts.  No I never tested it at 30 watts vs. 35 watts, etc.  I doubt you could tell the difference. Rob, NC0B

 

From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of Adrian Fewster
Sent: Sunday, February 02, 2020 8:03 AM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #KPA1500

 

I would expect it designed that way for best IMD results and cleanest signal quality.

The K3 specs would be best at that low wattage. I use to run mine at 15v under load  for best results.

Adrian ,   vk4tux

On 3/2/20 12:53 am, John Canfield wrote:

Hey guys,

Thursday the Brown Santa (UPS) delivered my birthday present for the next ten years - a KPA1500 amp. I'm slowly learning how to use it and I'm not sure if things are acting right. Going directly into a dummy from the amp, it only takes about 28 watts drive from the K3s for a full 1500 watts output. I can reduce the drive to five watts or lower and drop the amp's output to ~150-200 watts.

Does this sound correct? Thanks for any advice.

John, WB5THT


Re: K3s driving a KPA1500 - how much drive power is nominal for 1500 watts? #kpa1500

John Canfield <bucket@...>
 

Thanks again guys and thanks Bob for the numbers. I wasn't making notes when tracking drive vs. output power - just a fairly gross report of what I was seeing. The entire reason for my question is my Acom 1000 amp (4CX800) would need about 55 watts drive to produce ~950 watts, I was very surprised the KPA1500 needed so little drive power.

That Acom 1000 was a very good amp and practically idiot proof which I needed with wire antennas, now I have a DB18E and a 75M inverted V dipole so we're always under 2:1. (The Acom was sold 45 minutes after I listed it on QRZ!)

73 de John WB5THT

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