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Author Topic: New rig that's great on CW especially QSK  (Read 1191 times)

K9AO

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New rig that's great on CW especially QSK
« on: September 29, 2022, 07:08:42 PM »

I'm looking for some good advice here, finally saved my pennies and dimes and it's time to pop for a new rig. This time I promised myself it would be the top CW performer I could get, with good QSK and excellent filtering and DSP for noise reduction.  Being able to tie it in with CAT to an amplifier would be a huge plus. I'd have a 1500 watt transceiver that way. I think that's possible.

I have not actually been able to touch any of the new rigs out there. I could make a several day pilgrimage to do that, or ask for a local to help. But I'm trying to gather advice on a possible rig first.

I've looked at the Flex 6600 series (not much development going on to improve the CW performance but the Power Genius amp integrates flawlessly and so do other accessories), the Elecraft K4 (that looks to be good and is so I hear on CW, though I see a lot of development still going on to get CW right, and the KPA1500 would get me the full-power transceiver I want), but what am I missing? I think there are other Japanese transceivers out there that are excellent, but I'm told there is relay switching involved and I have gone that route before. Still, how is the QSK on anything you'd recommend.

Any thoughts or  advice you might have for me is greatly appreciated.

Rick Kunath, K9AO

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N5PG

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Re: New rig that's great on CW especially QSK
« Reply #1 on: September 29, 2022, 08:24:37 PM »

I like the top Yaesu offerings. FTDX-101D/MP or FTDX10(single rcvr). Maybe a used FTDX-5000.
How much do you want to spend ?
73, good hunting :)
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ZL1BBW

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Re: New rig that's great on CW especially QSK
« Reply #2 on: September 30, 2022, 01:11:00 AM »

The RX on a 7610 is as good as anything I have ever used in 50 years plus of operating Commercial & Amateur.

Having enjoyed true QSK I find that the offerings that call themselves QSK all fall far short of my expectations, so still use normal semi break in.

But the Rx is really good, especially the narrow filter then throw in the audio peak filter and its like narrow slices of the band.  Found the RX to b e really good on the lower bands.  More than holds it own during contests.
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ex MN Radio Officer, Portishead Radio GKA, BT Radio Amateur Morse Tester.  Licensed as G3YCP ZL1DAB, now taken over my father (sk) call as ZL1BBW.

G4AON

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Re: New rig that's great on CW especially QSK
« Reply #3 on: September 30, 2022, 02:27:30 AM »

Rick, I have to agree with ZL1BBW, true QSK can only really work if you have a very wide frequency split or with remote transmitters (as used in the past commercially).

The expectation is that you can easily hear QRM, or when the station you are working wants to bring something to your attention. With my K4D on QSK you can "sense" a carrier between dots at 30 wpm, but it's nowhere near as nice to use QSK as it is with a short delay where you can hear between words.

Also, you mentioned DSP noise reduction. On CW I find being able to adjust the bandwidth "mid QSO" by simply turning a knob is far more effective than noise reduction, which tends to work better in wider bandwidths such as on SSB.

A feature you didn't mention is diversity receive, the K4D does this brilliantly and it is especially easy to turn on/off, just press and hold the "SUB" button and it's instantly there. Using a horizontal antenna as the TX antenna and a vertical as the RX antenna on 40m, the signal will swap between your left and right ear on headphones surprisingly often, with no loss of received signal. Obviously, your mileage may vary depending on available antennas.

Everyone will have their own personal radio choice, the wider the question, the more varied the replies. Unfortunately, it's not easy to really evaluate a radio without having one in your shack for a week or two, which may explain why some hams seem to change radios more often than most...

73 Dave
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K7JQ

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Re: New rig that's great on CW especially QSK
« Reply #4 on: September 30, 2022, 06:02:03 AM »

A world-class contest station (staffed by world-class CW contesters) here in Arizona uses two Icom IC-7610’s. At $3,200, they’re reasonably priced, reliable, ergonomically friendly, no nonsense radios. You won’t be constantly plagued with bug fixes and firmware updates (Flex), unnecessarily high priced (Elecraft), and quirky (Yaesu) offerings.

Just my $.02…good luck with your choice.

Bob K7JQ
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K1VSK

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Re: New rig that's great on CW especially QSK
« Reply #5 on: September 30, 2022, 06:43:53 AM »

Elecraft K4. Second place - everything else
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W9AC

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Re: New rig that's great on CW especially QSK
« Reply #6 on: September 30, 2022, 06:52:45 AM »

Consider a used Elecraft K3s, P3, and KPA500, KPA1500, or RF-KIT 2K-S amplifier.  That gets you real QSK performance from PIN diode T/R switching. You'll experience true QSK being able to hear between keyed elements few artifacts. I think the K4 is a long way off for comparable QSK performance. 

Among several transceivers I own, I wouldn't classify the IC-7610 as a true QSK transceiver with fast break-in performance.  It's good, not great. 

Unfortunately, Flex's amp has automotive frame relays for T/R switching. I don't think QSK was much of a design factor. 

I've taken a different route with ANAN and Hermes transceivers that is unmatched by anything else I've used but it takes software and hardware changes to get there.  QSK is true full duplex.  When QSK is engaged, there's no internally-generated CW sidetone. The sidetone comes from the receiver and the receiver is always active, albeit at reduced sensitivity during transmit.  Split operation up the band?  No problem, in fact it's super easy with an Elgato Stream Deck device and MIDI control surface.  Macros allow for "one button" split operation.  I have several splits set up in Stream Deck. It's the one transceiver with knobs and buttons configured the way I want them, where I want them. 

The band can be heard between keyed elements at 60 wpm without any keying artifacts heard.  No clicks. no pops, no AGC pumping.  I'm just another CW signal on the band while transmitting. With 30 dB of LDMOS amplification, 1500W is possible in one step from 2W to 1500W.   

But to achieve this level of QSK performance required modifying the T/R system and use of fast ASIO audio drivers with clocking synchronized between the sound interface and radio with a 10 MHz GPSO.  This kind of QSK performance was once thought to be impossible with a "fat Ethernet" architecture but here we are.  It is indeed possible. 

Paul, W9AC
« Last Edit: September 30, 2022, 06:56:49 AM by W9AC »
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WA3SKN

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Re: New rig that's great on CW especially QSK
« Reply #7 on: September 30, 2022, 11:46:18 AM »

Gotta budget?

-Mike.
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KA2DDX

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Re: New rig that's great on CW especially QSK
« Reply #8 on: September 30, 2022, 02:01:35 PM »

Find a used Yaesu ftdx3000 ... Terrific cw rig.
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K9AO

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Re: New rig that's great on CW especially QSK
« Reply #9 on: October 01, 2022, 09:49:56 AM »

Thanks for the thoughts everyone that replied :)

I have saved enough for a top of the line radio and amp. I had been waiting to pop for the hardware until I fully retired and I did that at the end of August. So, time for the radios now.

I have been following the K4 refinements and was hoping they'd be farther along and at the K3 QSK performance by now. COVID has impacted all of that I am sure and I know they'll get there. When would be the question. I do like the idea of PIN diode switching, not just for CW but some of the new digital modes retransmit often too, VARA comes to mind. I used to do AMTOR back in the day but the relay clacking drove me nuts. But the newer rigs likely have a lot quieter relays now.

Paul, W9AC, I appreciate your comments and I'd be interested in any links that point to what you are describing with your Hermes and ANAN hardware. I'm well versed in computers, did hardware and software engineering as a career, so wrangling all of that would be another fun side of the new radio project I know FLEX always touts the wide pipe vs thin pipe aspect of their design. But since I an not planning to do any remoting of the rig there really isn't any issue with a wide pipe for me locally on the radio LAN here, and actually I think I like the idea of the computing part being separately replaceable from the RF part. Also no problem with getting a replacement PC, that's something I had also been saving for but had held off on doing until retirement and the new rig was on the way. Likely I'll replace this workstation too, though it's no slouch, 8-core AMD and water cooled, 32 GB RAM, fast video card and all of that. But, it's a bit long in the tooth by today's bus standards. I'm curious what amp you're using with your setup Paul? PIN diode switched? But then I'm thinking maybe that's not really an issue with the full duplex method that you are using?

Thanks again to all for the thoughts...

Rick, K9AO

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W9AC

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Re: New rig that's great on CW especially QSK
« Reply #10 on: October 01, 2022, 12:25:06 PM »

>Paul, W9AC, I appreciate your comments and I'd be interested in any links that point to what you are describing with your Hermes and ANAN hardware.

Links to more info below.  The third link has a .WAV file upload from my ANAN 7000DLE in full duplex QSK mode.  Unfortuinately, the Apache site would not allow a linear, uncompressed audio upload.  So, what you hear sounds a bit fuzzy due to the .WAV file compression.  Still, it provides an idea as to QSK performance in full duplex mode. 

The audio clip starts with band noise and a carrier to simulate a breaking station.  Keyer speed is then slowly increased to 50 WPM.  The carrier and the band can be heard between keyed elements at 50 WPM. 

Someone is bound to ask about ear-to-hand latency and it's a good question.  Depending on the DSP Rx filter selected, the sidetone is heard about 25 ms later after key closure.  Latency with ASIO drivers is low enough that I can send without any timing restrictions up to my personal limit of about 42 WPM.  Beyond that, I can't send very well with iambic paddles with no latency. 

https://community.apache-labs.com/viewtopic.php?f=14&t=3965&p=20920&hilit=w9ac#p20920

https://community.apache-labs.com/viewtopic.php?f=17&t=4033&p=20511&hilit=w9ac#p20511

https://community.apache-labs.com/viewtopic.php?f=14&t=3920&p=19664&hilit=w9ac#p19664

Paul, W9AC

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K9AO

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Re: New rig that's great on CW especially QSK
« Reply #11 on: October 01, 2022, 01:18:48 PM »

Thank you for the links Paul.

I listened to the QSK wav file and it totally blew me away. I'm going to spend some time getting educated on the hardware and software you're using.

Looking forward to this a lot.

Thanks again...

Rick, K9AO
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N4RSS

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Re: New rig that's great on CW especially QSK
« Reply #12 on: November 15, 2022, 08:17:23 AM »

Consider a used Elecraft K3s, P3, and KPA500, KPA1500, or RF-KIT 2K-S amplifier.  That gets you real QSK performance from PIN diode T/R switching. You'll experience true QSK being able to hear between keyed elements few artifacts. I think the K4 is a long way off for comparable QSK performance. 

Among several transceivers I own, I wouldn't classify the IC-7610 as a true QSK transceiver with fast break-in performance.  It's good, not great. 

Unfortunately, Flex's amp has automotive frame relays for T/R switching. I don't think QSK was much of a design factor. 

I've taken a different route with ANAN and Hermes transceivers that is unmatched by anything else I've used but it takes software and hardware changes to get there.  QSK is true full duplex.  When QSK is engaged, there's no internally-generated CW sidetone. The sidetone comes from the receiver and the receiver is always active, albeit at reduced sensitivity during transmit.  Split operation up the band?  No problem, in fact it's super easy with an Elgato Stream Deck device and MIDI control surface.  Macros allow for "one button" split operation.  I have several splits set up in Stream Deck. It's the one transceiver with knobs and buttons configured the way I want them, where I want them. 

The band can be heard between keyed elements at 60 wpm without any keying artifacts heard.  No clicks. no pops, no AGC pumping.  I'm just another CW signal on the band while transmitting. With 30 dB of LDMOS amplification, 1500W is possible in one step from 2W to 1500W.   

But to achieve this level of QSK performance required modifying the T/R system and use of fast ASIO audio drivers with clocking synchronized between the sound interface and radio with a 10 MHz GPSO.  This kind of QSK performance was once thought to be impossible with a "fat Ethernet" architecture but here we are.  It is indeed possible. 

Paul, W9AC

True full duplex means when I'm talking to you face-to-face I can hear you interrupt me as I utter a sound.

Are you saying you can hear the other operator interrupt you during the transmission of a code element while both on the same frequency ?   How does that work ?
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W9AC

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Re: New rig that's great on CW especially QSK
« Reply #13 on: November 15, 2022, 08:54:14 AM »

True full duplex means when I'm talking to you face-to-face I can hear you interrupt me as I utter a sound.

But if you scream loud enough, you won't hear me.  That's full duplex too, but not effective in breaking through a message. 

When sending CW on the same frequency, my signal overwhelms the strongest breaking signal on receive just like you screaming.   In my QSK system, the T/R transitions are so fast without artifacts, that in effect it's full duplex although it may not strictly comply with the full duplex definition.   Listen to the audio file.

Paul, W9AC   
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G4AON

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Re: New rig that's great on CW especially QSK
« Reply #14 on: November 15, 2022, 09:22:47 AM »

I have recently been measuring latency on transmit and receive through my Elecraft K4D. These timings are done with a pulse of audio on DATA mode and may not relate to QSK performance.
TX latency 23 mS
RX latency 32 mS

By comparison, my humble IC-7300 measures.
TX latency 4.2 mS
RX latency 3.3 mS

In terms of TX/RX switching times the ARRL reviews show the IC-7300 as being one of the fastest.

Whether latency on DATA relates to QSK timing is debatable, but what is surprising is the huge difference between the humble IC-7300 and a K4D at around 5 times the price!

To save anyone searching for “dit” timing, the dit time in mS = 1200/speed in WPM. 30 WPM has 40 mS dits.

73 Dave
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