Date   

Re: tuners for experimental antennas and the QCX

Karl Schwab
 

I have only 1 antenna tuner at KO8S and it is a Dentron MT-3000a manual tuner that I have had here for years!  I use it for all my radios, QRP and QRO up to the legal limit tuning all my HF antennas; center fed Zepp and Yagi's.  Using this tuner, I have never damaged any of my radios!  Some of my newer radios have a built in auto tuner and I never use them.  I tried stand alone auto tuners, and I am a bit leery of them, i.e., might damage a radio that does not have PA protection. I have been at this hobby for many years, and I am sticking with what works for me and I am just passing my experience along.  Karl


Re: QCX Challenge Feb 2021

ON7DQ Luc
 

My 19:00Z session
Only QRV on 40m.
Good to see several people using the sked page, very easy to find their frequency.
But  alas, I couldn't hear any of the others (and no other QCX called me). 
I worked 5 stations that I saw on the bandmap (https://dxcluster.ha8tks.hu/rbn_ct1boh/), but none were QCX. More luck next time.

Rig: same setup as in the 13:00 session, power 50W

Luc ON7DQ


Talk: “Cherokee Challenge Flight – London to Sydney the slow way – by Andy Hardy G1AJH (ex VK2CHA)”

Trystan G0KAY
 

Tuesday 23rd 8 pm (2000 UTC) 

“Cherokee Challenge Flight – London to Sydney the slow way – by Andy Hardy G1AJH (ex VK2CHA)”

Join us on this amazing adventure of a lifetime. Two chaps, a light aircraft and an HF radio piloting their way from Blighty to Oz, the slow way! Andy Hardy G1AJH (ex VK2CHA). So make sure your seats and tray tables are in the upright position, make sure your seat belt is securely fastened and that your carry-on luggage is stowed in the overhead lockers. Get ready for takeoff! Chocks away. 

This event is hosted on Zoom: https://zoom.us/j/7730730073 (Meeting ID: 773 073 0073 )

Also Live-streaming on YouTube with live chat: https://tinyurl.com/buryradio 

(Bury Radio Society, with Warrington ARC)


Re: Qcx keyer erratic

Hans Summers
 

Hi Jim

I use my QCXs at 15wpm and they always work perfectly. I'm using the latest firmware 1.07a.

I had 9 QSOs today on 20m in the 1300Z session of the QCX QSO party and a few minutes after the hour ended. Since I've had almost no QSOs in the last 3 months (just two I think), I reduced the speed to 14wpm after the first QSO to give myself a chance to get in practice again, gently. 

I do wonder if you have problems with RF getting into your paddle cable. Coax common mode currents and grounding issues can wreak havoc. 

73 Hans G0UPL 


On Mon, Feb 22, 2021, 23:12 Jim Painter via groups.io <Jfpainter=yahoo.com@groups.io> wrote:
Trying to do QCX challenge on 20m. My keyer was so screwed up I couldn’t answer anyone. Decided to do a reset on the QCX. Started working fine. Reset had set speed back to 12wpm. When I crank up to 15 wpm starts giving extra dit and dahs. Sometimes misses dits and dahs. I have no problem with 15wpm on my other rigs. Guess I’ll just leave it at 12wpm.

Hans, do you have any ideas. My fist is not great but I’ve always been able to handle 15wpm.

73...Jim....KQ3S



On Feb 22, 2021, at 10:30 AM, Daniel Walter via groups.io <nm3a=yahoo.com@groups.io> wrote:

Auto Space off? Typo?
--
73, Dan  NM3A


Re: QCX+ SSB mod documentation

cq@...
 

Hello,
i try to build the QCX+ with Guido's mods and I'm running out of ideas. Thanks for this latest documentation, very helpull, but still, I can not bring it alive.  I have it done as shown, wire by wire. When I start it the SW reports two errors:
!!V5.0=2.76V and
!!Vadc1=1.38V

When verifying the mods as documented with the schema that Guido published I particularly see one thing that is inconsistent in the docu: The white wire from lower C39 to middle R27: That basically is a wire from IC5 Pin 1 (output of OpAmp) to R53 which goes directly into ADC of the ATMega , Pin 24. I do not see such a link in Guidos schema. The outputs of the two OpAmps go into a capaciter C39 and C40 but not into a resistor R53. The Guido schema is different then the described mods on the PCB. Help would highly be apreciated. Thanks


Re: tuners for experimental antennas and the QCX

N3MNT
 

I am using the Elecraft T1. .  It is small quick and matches most anything albeit not the lowest price.  Simple one button tune.


Re: Qcx keyer erratic

Jim Painter
 

Trying to do QCX challenge on 20m. My keyer was so screwed up I couldn’t answer anyone. Decided to do a reset on the QCX. Started working fine. Reset had set speed back to 12wpm. When I crank up to 15 wpm starts giving extra dit and dahs. Sometimes misses dits and dahs. I have no problem with 15wpm on my other rigs. Guess I’ll just leave it at 12wpm.

Hans, do you have any ideas. My fist is not great but I’ve always been able to handle 15wpm.

73...Jim....KQ3S



On Feb 22, 2021, at 10:30 AM, Daniel Walter via groups.io <nm3a@...> wrote:

Auto Space off? Typo?
--
73, Dan  NM3A


Re: tuners for experimental antennas and the QCX

Fred Spinner
 

Anecdotal, but the LDG AT-11 I built years ago matched better than the built in tuner in a TS-440SAT did. 

I am presently building a ATU-100 because I couldn't resist the kit for the about $50 price.  (A little more with a box, etc.). But I am doing it very slowly because life has been severely been getting in the way.  So I am close but not quite done.  It is a fun build so far though. 

Most reports are that it works well for the cost, but you can tell it's not quite as robust the older AT-11 just by looking at the two.  However, for $50 I can suggest that you won't be wasting your money on the ATU-100, it is easily converted to a QRP tuner by changing the turns ratio on the tandem match if anything else.  It would be oversized for that use. 

As for balanced tuners having a narrow matching range, that is at least true for my vintage Johnson Matchbox... But they are known to be lower loss as well... Different tools for different jobs... 


On Mon, Feb 22, 2021, 12:06 PM <namerati@...> wrote:
Has anyone got experience with different antenna tuners for the QCX?

I am looking for something that will work well with a variety of home
brew and improvised antennas.

Right now the best options look like:
- a Z-match manual tuner like the Emtech ZM-2 or QRPproject ZM-4 (which
   is an improved ZM-2)
- a 7x7 L-network automatic tuner like the Elecraft T1 or (much cheaper)
   ATU-100

The z-match tuners have the obvious benefit they can tune balanced
antennas as well.

However I have also read they have a more limited matching range (ca
30-500 ohms for a Z-match vs ca 40-4000 ohms for a 7x7 L-network
automatic tuner.

Does anyone have actual experience with both, can you comment if this is
correct? can the automatic tuners really match a 10 times wider
impedance range?








Re: tuners for experimental antennas and the QCX

Michael N6MST
 

Z match, L match, T match. Lots of experimenting one could do with those three.


tuners for experimental antennas and the QCX

namerati@...
 

Has anyone got experience with different antenna tuners for the QCX?

I am looking for something that will work well with a variety of home brew and improvised antennas.

Right now the best options look like:
- a Z-match manual tuner like the Emtech ZM-2 or QRPproject ZM-4 (which is an improved ZM-2)
- a 7x7 L-network automatic tuner like the Elecraft T1 or (much cheaper) ATU-100

The z-match tuners have the obvious benefit they can tune balanced antennas as well.

However I have also read they have a more limited matching range (ca 30-500 ohms for a Z-match vs ca 40-4000 ohms for a 7x7 L-network automatic tuner.

Does anyone have actual experience with both, can you comment if this is correct? can the automatic tuners really match a 10 times wider impedance range?


Re: QCX Challenge Feb 2021

Martin DK3UW
 

Hi,

I could hear Hans all the time but noch chance for a QSO
one QSO to aRussian /m station and one to Spain which was QRP but no QCX.

Will try19:00UTC


Re: No audio in headset after pressing switch before beginning alignment

Dave VE3GSO
 

Absolutely!  Check the soldering! Remove the flux using a Qtip and Isopropyl alcohol, or a good spray flux remover and then go over the soldering again with a good magnification loop! A very high percentage of errors are down to poor or shorted joints.

If all that is good, check the crazy things, like 3.3k resistors in places reserved for the 33k resistors and vice versa. Again, a good full spectrum light and magnifying light. (Ask me why I chose that specific example!)

If all of that comes up empty, then start worrying about brand new faulty components.

Dave

On Feb 22, 2021, at 10:28, Greg <gberenato@...> wrote:

Since you are trying to align the QCX, it sounds like you just finished building it and it has never worked.  By far the most likely problem is a construction fault.  Construction errors are far more likely than a component failure on a rig that has just been built and has never worked.  I found a solder bridge on a friend's QCX using a jeweler's loupe.  He had a similar problem with a low tone and the three potentiometers would not adjust properly.  As soon as the solder bridge was fixed, the radio aligned perfectly.  Good luck.


Re: QCX Mini Alignment Issues #qcx20mini

Rod Smith
 

Hi Dave.  I had the same problem - it turned out to be a faulty op amp IC7.  Checking voltages around ICs 6 and7 could be useful for you, although I'd check T1 carefully first..

Allison's advice is of course could - however the effort applied could have been applied by a now-"fired" board fabricator rather than by your good self.  I'm sure that's how it was in my case and at least a few others.  Good luck!

Rod
G0VKX


Re: Qcx keyer erratic

Daniel Walter
 

Auto Space off? Typo?
--
73, Dan  NM3A


Re: QCX Challenge Feb 2021

ON7DQ Luc
 

My 13:00Z session

First called CQ on 20m for half an hour.
Despite good spots on RBN all over EU and 3 in USA) NIL replies.
I heard TA4/G0UPL, but just too weak for QSO.
Then went to 40m, had three QSO's there, and thanks to DD6DO for the only QCX QSO.
 
Rigs : QCX 'Classic' 20m and 40m
Homebrew Chinese amplifier 40W(20m), 50W(40m).
Antennas : GP on 20m, Random endfed wire (33m long) on 40m.
Key: Himound straight key.

73,
Luc ON7DQ


Re: QCX Challenge Feb 2021

Hans Summers
 

Hi Peter, Luc, all

I had a busy hour, QCX+ 20m with 50W PA kit about 40W, had 7 QSOs RW3KE/P, DL2NAI, IK5PWJ, PG4I, UA3TCQ, RK3DY, RN6HFZ, none of which were QCXs. 

Right after the party, I worked DD6DO 2-way QCX, and then UR4QAA (not QCX). 

73 Hans G0UPL

On Mon, Feb 22, 2021 at 4:34 PM Peter GM0EUL <gm0eul@...> wrote:
Hi All
Called CQ for the last half hour or so and nothing except two weak hits on the RBN.  I can see a few familiar calls on the band-plan but can't hear anything.  Switched to KX3 just to check it wasn't the QCX playing up.  No appreciable difference so I'm giving up but will probably try again this evening.  Back to work

73
 
Peter GM0EUL

CWops 1899. FISTS 18888, SKCC 16307T, GQRP 15056



On Mon, 22 Feb 2021 at 12:44, Hans Summers <hans.summers@...> wrote:
Hi Luc, all

Well there comes a point where the workload is evidently and undeniably so overwhelmingly enormous, and it is apparent that abstinence from QCX QSO parties would hardly even inflict a minor dent on the mountain. At which point it makes sense to throw one's hands up in the air, and in the interests of avoidance of insanity, to take an hour to relax at the key. So expect me around 14056+/-some with QCX+ and QRP Labs 50W PA, output power on 20m is about 43W to the dummy load, as measured just now. I have logged into http://n8fq.org/sked/index.php?board=qrp too. 

73 Hans TA4/G0UPL
http://qrp-labs.com


On Sat, Feb 20, 2021 at 10:54 AM ON7DQ Luc <on7dq@...> wrote:
Hi Folks,

coming up next Monday, Feb 22nd, is the next edition of the QCX Challenge

more info: https://www.qrp-labs.com/party.html

please log in to this sked page: http://n8fq.org/sked/index.php?board=qrp
Use your callsign (a password is optional, but it will protect your Profile data)
Press the "Back" button to appear on the list at the right.

It will make it easier to find other QCX operators.

Last time I blew a FET in my amplifier just before the Chalenge, ouch.
I had switched the wrong LPF (stupid me)... so I had to operate QRP.
It's now repaired (and I'm looking into an automatic SWR protection for the future ... hi), so I will be running 40W on 20m and 50W on 40m.

GL es 73,
Luc ON7DQ


Re: Latest QCX-mini pcb rev.2 and C38 mod #c38 #qcxmini #manual #mods #pcbversion

john@...
 

Hi Hans,
No smoke (!), all calibration adjustments behaved exactly as documented, 4W out at 12V. 

It was a pleasure to build, and I can see some fun ahead!
I cannot tell you how impressed I am.  Thank you so much. 

73
John G3ZTU 

 


Re: Iambic CW?

Kwacka
 

As I understand it, the the IARU High Speed Telegraphy contests winners use single paddles to send at up to 300 characters/minute.

I would imagine that, at those sort of speeds the chance of an added dot or dash could mean the difference between winning and losing.

BTW, keyboards are NOT allowed


Re: QCX Challenge Feb 2021

Peter GM0EUL
 

Hi All
Called CQ for the last half hour or so and nothing except two weak hits on the RBN.  I can see a few familiar calls on the band-plan but can't hear anything.  Switched to KX3 just to check it wasn't the QCX playing up.  No appreciable difference so I'm giving up but will probably try again this evening.  Back to work

73
 
Peter GM0EUL

CWops 1899. FISTS 18888, SKCC 16307T, GQRP 15056



On Mon, 22 Feb 2021 at 12:44, Hans Summers <hans.summers@...> wrote:
Hi Luc, all

Well there comes a point where the workload is evidently and undeniably so overwhelmingly enormous, and it is apparent that abstinence from QCX QSO parties would hardly even inflict a minor dent on the mountain. At which point it makes sense to throw one's hands up in the air, and in the interests of avoidance of insanity, to take an hour to relax at the key. So expect me around 14056+/-some with QCX+ and QRP Labs 50W PA, output power on 20m is about 43W to the dummy load, as measured just now. I have logged into http://n8fq.org/sked/index.php?board=qrp too. 

73 Hans TA4/G0UPL
http://qrp-labs.com


On Sat, Feb 20, 2021 at 10:54 AM ON7DQ Luc <on7dq@...> wrote:
Hi Folks,

coming up next Monday, Feb 22nd, is the next edition of the QCX Challenge

more info: https://www.qrp-labs.com/party.html

please log in to this sked page: http://n8fq.org/sked/index.php?board=qrp
Use your callsign (a password is optional, but it will protect your Profile data)
Press the "Back" button to appear on the list at the right.

It will make it easier to find other QCX operators.

Last time I blew a FET in my amplifier just before the Chalenge, ouch.
I had switched the wrong LPF (stupid me)... so I had to operate QRP.
It's now repaired (and I'm looking into an automatic SWR protection for the future ... hi), so I will be running 40W on 20m and 50W on 40m.

GL es 73,
Luc ON7DQ


Re: QCX+ Audio Eventually Fades Away

Ted 2E0THH
 

Hi Dave

Have a browse through this thread, it may give you some pointers.
https://groups.io/g/QRPLabs/topic/28995685?p=Created,,,20,1,0,0

73s Ted
2E0THH

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