Date   

Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

Yes, I will take another look this morning, but I see a small hole in the top of IC1 under magnification.
So I will send it over tp AZ for a second opinion. When the next QCX gets here I have decided to assemble in
several better ways for my manner of operation, including better solder, sockets for iIC's and an enclosure.
Gracias Amigo. Oh, and a new respect for voltage measurement. 

On Thu, Dec 12, 2019 at 6:48 AM Alan G4ZFQ <alan4alan@...> wrote:
> Game over as I don't have a replacement for IC3.

George,

OK, although they should be easy to source. But I am thinking that
further faults may be found if the voltages are checked.
Maybe look at again sometime, you learn more about how something works
when it does not work!

73 Alan G4ZFQ




New kit: 50W PA for QCX

Hans Summers
 


Hello all QRP Labbers... (don't forget to VOTE QRP LABS!)

Here is a new kit, this is a 50W PA kit for the QCX. See http://qrp-labs.com/50wpa . Price is $29.50 (approx £22 or 26€) which includes the PCB, all components and connectors, and two large black anodized aluminium heatsinks. The amplifier produces up to 50W power with full break-in (QSK), with 20V 5A supply. At 13.8V supply on 40m CW the measured power output is 25W. 

A beautiful enclosure for it is also available, price $16 (approx £12 or 14€), see http://qrp-labs.com/50wpabox . It is made from black anodized extruded aluminium with front and rear panels drilled and printed to match the 50W PA. 

A key feature of the kit is fast solid-state transmit/receive switching (relays!) - which allows full break-in (QSK) operation using the QCX. 

The kit can be built for 40, 30 or 20m bands, which covers 90% of QCX kits. It can also be built for other bands if you supply your own Low Pass Filter components. Multi-band would be possible if you connect your own switched external Low Pass Filters. 

Please refer to the FAQ on the 50W PA page http://qrp-labs.com/50wpa if you have any questions. The 68-page manual is very detailed making construction un-daunting, and the manual also also includes a substantial section detailing the circuit theory. 

Despite our dedication to QRP (5W and under), there are occasions when a bit more power is needed, and this kit provides it. For example, you want to QSO a particular station on a sked at a particular date and time; or when conditions are poor, or you want to work particular DX... any number of reasons. 

During the summer of 2019 the 40m version of this amplifier was tested extensively here in QTH KM46, with well over 500 QSOs in the log. Despite the poor band conditions and my very mediocre antenna and location, QSOs ranged from New Zealand and Japan in the East, to US in the West; Finland in the North, down to Saudi Arabia and everywhere in between. (500+ real QSOs averaging 10 minutes, not contest exchanges). During QSOs I estimate around 90% of correspondents are using power in the 50-100W range, the remaining 10% operate with higher power than that or a few of them, with QRP (5W and below). This 50W PA kit puts you and your QCX on a level playing field with the majority of CW operators on the bands.

So pimp your station, pump up the watts... have some fun with a new project... the 50W PA kit http://qrp-labs.com/50wpa 

73 Hans G0UPL


yahoo group changes

SkipF, NT1G <skip.flem@...>
 

QRPLABS  is NOT a YAHOO group..
It's like driving a Mercedes and Chevrolet says
they are dropping your warrentee.
 Whoop Dee Doo.


Re: yahoo group changes

Hans Summers
 

Hi Martin

We are not affected, because the QRP Labs group is not hosted on YahooGroups. It is hosted on groups.io. This has been the case for almost 2 years. All of the group content (archives, messages) were also moved from YahooGroups to groups.io at the same time. 

73 Hans G0UPL



On Thu, Dec 12, 2019 at 11:00 AM Martin <m.sellschopp@...> wrote:
Hi,

I just got a disturbing mail from Yahoo.

If I understand correctly all content of our group will be deleted and the group will become something not open to public.
Exchanges only be e-mail and new menbers only by invitation.

To me that looks like the end of our communication and as if all the usefull information stored in the history of this group to disappear.

Any remedy or chance to move the group somewhere else ?

73's
Martin


Re: yahoo group changes

Martin DK3UW
 

This is the mail I got

 
Privacy Policy | Terms of Service | Customer Support
701 First Avenue, Sunnyvale, CA 94089
©2019 Yahoo
Dear Group Moderators and Members,

Last month we notified you of the changes coming to Yahoo Groups that better align with user habits, and today we are providing an update to guide you through the next steps of the transition. Yahoo Groups is not going away - but we are making adjustments to ultimately serve you better. We are amazed at the vibrant community you’ve created through Yahoo Groups and we want to make sure you feel supported as we introduce these changes.

The following changes were made since our last communication:

   •   Users can now only join a Yahoo Group through an invite or group request approval by the Group Moderator.
   •   New Groups can’t be public. They can only be private (not listed in Groups directory, membership by invitation only) or restricted (listed in Groups directory, membership requests must be approved by a Group Moderator).
   •   Members must share all content via email, and can no longer upload or host new content on the Yahoo Groups website itself.

The following changes will be made on December 14, 2019:

   •   Public groups will no longer exist. All existing public Groups will become restricted Groups that require Group Moderator approval to join.
   •   Any content that was previously uploaded via the website will be removed.

If you would like to keep any of the content you’ve posted or stored within your Yahoo Group, please download it by December 14 by accessing the Groups Download Manager at this link. Once you provide your preferred email address, we will send you a confirmation of your download request and notify you once the download is complete.

You will receive a link to a downloadable zip file via email for each of your Groups organized into a separate folder. Download time varies depending on the amount of information and file size.

If your download request is made by 11:59pm PST on Saturday, December 14, 2019, your content will not be deleted until your download is complete. We are unable to accommodate any download requests made after this deadline.

This is the final reminder to download your content. You can find additional information about the upcoming changes here.

We have worked extensively with our customer support team to develop recommendations for tools that can help you with any download issues. See help article here.

We have watched the evolution of Yahoo Groups with awe, as we grew to a community of millions with over 10 million Groups. Every day, we witness the power of community and shared passions, and our mission is to provide a platform for the strong connections people make with each other around their interests.

We thank you for being part of the Yahoo Groups community and look forward to continuing to provide ways for you to connect with one another about your shared interests and passions.

Sincerely,
The Groups Team
 


yahoo group changes

Martin DK3UW
 

Hi,

I just got a disturbing mail from Yahoo.

If I understand correctly all content of our group will be deleted and the group will become something not open to public.
Exchanges only be e-mail and new menbers only by invitation.

To me that looks like the end of our communication and as if all the usefull information stored in the history of this group to disappear.

Any remedy or chance to move the group somewhere else ?

73's
Martin


Re: LightAPRS-W (WSPR) Tracker

Mustafa Tan
 

Hi Tim,

LightAPRS-W does not go sleep as much LightAPRS. It's because WSPR preparations and TX. WSPR TX takes 2 minutes and preparations starts 1 minute before. So no sleep nor APRS TX during this period. 

// preparations for HF starts one minute before TX time at minute 3, 7, 13, 17, 23, 27, 33, 37, 43, 47, 53 or 57. No APRS TX during this period...
if (readBatt() > WsprBattMin && timeStatus() == timeSet && ((minute() % 10 == 3) || (minute() % 10 == 7)) ) { 

On Thu, Dec 12, 2019 at 7:19 AM Tim Wiwel <tim.wiwel@...> wrote:
Mustafa:
I just received  my tracker and am very impressed.  Looks great.  Very easy to get running.  Doing power measurements,  the unit never draws more then about 320-350mA with Vbat at 7.4v or 5.5v.  DRA pin 7 is low.  On total power consumption,  the unit only goes to sleep (10mA)  about 3 minutes in 10.  It consumes 40mA almost always with 350mA during the 2s ARPS transmission.  Does this seem correct?  I see 3 APRS transmissions in 10 minutes.  These tests were preformed with no debug, no USB cable, a 19in wire connected to the VHF antenna, at about 21C using a Fluke 83 Meter.   

Before I hack on the code, is there a simple  Si5351 tuning program?

We plan to do a test flight next Thursday, 19 Sep using my call sign. 

Tim, KM4EFW 


Tim. 




Re: No output QCX 40 output drains show 1.6 watts in receive

Alan G4ZFQ
 

Game over as I don't have a replacement for IC3.
George,

OK, although they should be easy to source. But I am thinking that further faults may be found if the voltages are checked.
Maybe look at again sometime, you learn more about how something works when it does not work!

73 Alan G4ZFQ


Re: Two QCX kits (80m and 40) - both with shorts on Si5351A - fixed

ajparent1/KB1GMX
 

one last thing... soldering iron.

The average one I see in use by people is a reasonable quality temperature controlled
unit turned too far up with a cruddy tip with rough edges.  Replace the tip turn it down
and try to not use the tip as a chisel.   

Hint put it back in the holder without cleaning it after making a joint.  Clean it on the
way out and make sure its shiny clean before touching the joint.  If it gets dark and
grungy too fast its likely way to hot.


Or an el cheapo that run at 900 degrees or hotter, with a cruddy black tip.
Get a soldering iron!

Both users tend to have terrible soldering and complain they can't get the solder to melt
and they burn up boards in the process.  The tip has to be clean to transfer heat.  If you
beat it up or use poor solder and high heat (trying to get it to work) that tends to destroy
tips amazingly fast.  I've see a few kill a tip in hours.
 
I tend to use tips for literally thousands of hours (years) of build time.  Quality solder,
good care, and moderate temps.  

I bought the current Weller WES51 some 20 years ago and the current tip is more than
3 years old.  The only thing was to repair the cord to the handle.  My other iron is a
really old TCP60 (curie point temp control) from about 1979ish, the .25" wide tip on
that is maybe 10 or more years old.  I use that for SMT parts as its wide!

-------
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Re: LightAPRS-W (WSPR) Tracker

Tim Wiwel
 

Mustafa:
I just received  my tracker and am very impressed.  Looks great.  Very easy to get running.  Doing power measurements,  the unit never draws more then about 320-350mA with Vbat at 7.4v or 5.5v.  DRA pin 7 is low.  On total power consumption,  the unit only goes to sleep (10mA)  about 3 minutes in 10.  It consumes 40mA almost always with 350mA during the 2s ARPS transmission.  Does this seem correct?  I see 3 APRS transmissions in 10 minutes.  These tests were preformed with no debug, no USB cable, a 19in wire connected to the VHF antenna, at about 21C using a Fluke 83 Meter.   

Before I hack on the code, is there a simple  Si5351 tuning program?

We plan to do a test flight next Thursday, 19 Sep using my call sign. 

Tim, KM4EFW 


Tim. 


Re: Two QCX kits (80m and 40) - both with shorts on Si5351A - fixed

ajparent1/KB1GMX
 

What did you use?

I do not advise using any of the no-lead solders.  They do not rework well and
generally need more heat.  More pain that gain.

The standard here in my lab is the same for the last 40+ years Kester 44, 37/63 SN/PB alloy
in .031" diameter.  I also use the .020 and .040 diameter of the same at any given time
I have all three sizes in 1pound spools on the shelf.  Its not cheap.

KESTER part number  24-6337-0027 

An alternate some use is the 245 no clean in the .031 63/37 also kester.

https://www.amazon.com/Kester-24-6337-0027-Solder-Alloy-Diameter/dp/B0149K4JTY/ref=pd_cp_328_1/130-0155267-6249125?_encoding=UTF8&pd_rd_i=B0149K4JTY&pd_rd_r=1601493a-5f26-41c2-9b3c-65ccfb1d8bc2&pd_rd_w=iS80j&pd_rd_wg=98Cqk&pf_rd_p=0e5324e1-c848-4872-bbd5-5be6baedf80e&pf_rd_r=6MGM1H1D328D9YW4MACZ&psc=1&refRID=6MGM1H1D328D9YW4MACZ


--
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Re: Two QCX kits (80m and 40) - both with shorts on Si5351A - fixed

George Korper
 

Allison, 
I built my last QCX with  poor quality solder and had excessive sputtering and was not satisfied with it.  Please recommend a solder that you have had good performance with. Preferably available on Amazon.
George


On Wed, Dec 11, 2019, 9:29 PM ajparent1/KB1GMX <kb1gmx@...> wrote:
Us old farts that have been in the industry for 30 or 50 years have seen it.
Its common to hand soldered items.   You have to be looking for it.... Solder
with internal flux can often spatter.  It happens more so with some fluxes
and a hotter [than needed] irons as the flux heats up and goes from solid
to gas and the solder with it.  That sputter can end up everywhere and
anywhere.  That with modern tight lead spacing and traces close to each
other often shows as hairline shorts.   Little heat or solvent often breaks
them.

This is less common with wave soldering, radiant heating, and IR heated SMT
soldering systems as there is less solder and the flux is not inside it.  That
added to the thermal ramp to heating and cooling tends to avoid this.

Allison
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Re: Beware Buck converters

J68HZ
 

I use LM2596 DC to DC converters all the time.  Their performance is dependent upon load… so beware!

 

 

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com

Like us on Facebook!

 

Moderator – North American QRO Group at Groups.IO.

 

email:  bill@...

 

 


Re: Two QCX kits (80m and 40) - both with shorts on Si5351A - fixed

ajparent1/KB1GMX
 

Us old farts that have been in the industry for 30 or 50 years have seen it.
Its common to hand soldered items.   You have to be looking for it.... Solder
with internal flux can often spatter.  It happens more so with some fluxes
and a hotter [than needed] irons as the flux heats up and goes from solid
to gas and the solder with it.  That sputter can end up everywhere and
anywhere.  That with modern tight lead spacing and traces close to each
other often shows as hairline shorts.   Little heat or solvent often breaks
them.

This is less common with wave soldering, radiant heating, and IR heated SMT
soldering systems as there is less solder and the flux is not inside it.  That
added to the thermal ramp to heating and cooling tends to avoid this.

Allison
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Re: Beware Buck converters

ajparent1/KB1GMX
 

They are real.  Likely your asking them to do something they are not happy
with as supplied.

I have a bunch of them loose (spares) and more in service.  However I took
the time to do two things  optimize the inductor (inductance and type for the
current) and add two resistors to an external pot so its range is limited to a
narrow span.

The problem is the inductor size has to scaled for the current and voltages
or the efficiency goes down and the switching frequency gets pushed around
to the limits to try and regulate.  Switching regulators are not universal in
nature though they often exceed expected performance.  If the inductor is not
the right inductance they can go into a discontinuous mode and the external
switching frequency is the skipped cycles.  You see that if they optimized
for 2-3A and actually delivering maybe 100-150ma. 

Its a likely bet the current required by the QCX and U3S is too low for the
regulator to be efficient.

My QCX the TI part is running at 350khz and at the design center but then again
I did what the data sheet said and replaced the inductor.  The efficiency is 
92% and 14V and 87% at 9V (measured).   With the inductor they supplied it
would not regulate at all well and efficiency was below 70%.

Full datasheet included for the LM2596,
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Re: Beware Buck converters

Phil N6WKZ
 

Sverre,

I tested one of mine and found: 78 mv ripple at 68 KHZ. I guess that mine is a fake LM2596 too. Probably most of those $1.00 Buck converters are fake.

Thanks for the link! I used the same setup as in the link.

73

Phil N6WKZ

On 12/9/2019 12:04 AM, Sverre Holm wrote:

I use the cheap 2596 converters for my U3S also and the work well.

But there is something suspect about them. Mine have switching frequencies around 50 kHz, but an LM2596 is supposed to switch at 150 kHz. See https://k6jca.blogspot.com/2018/02/counterfeit-lm2596-regulator-boards.html

Whether this matters or not, I don’t know, but I think there is reason for suspicion when there is such a large discrepancy.

73, 
Sverre, LA3ZA

http://la3za.blogspot.com


Re: Two QCX kits (80m and 40) - both with shorts on Si5351A - fixed

Nick Austen
 

Hi Geoff

The stray resistor leg was one still floating around after clean-up - I have been building electronics things on and off for about 45 years :)
I had enjoyed the kit for about 24 hrs - and, through lack of self discipline, was listening to 40m on the QCX while cleaning up :) - a discarded lead was accidentally projected into the air and down onto the kit.

Thanks for reiterating the issue of meter voltages and their potential to cause damage. I typically use a CRO first and should take more case with the meter.
Interesting to note that for my cheap "Micron" (no-name) meter, I measure the following voltages across the probes for the selected resistance range settings:
  • Diode-check => 2.88 V
  • 200 ohms => 2.88 V
  • all other ranges => 560 mV 
Not 15 V but still worth keeping in mind.
Thanks.
Nick
VK6FABE


Re: Two QCX kits (80m and 40) - both with shorts on Si5351A - fixed

Arv Evans
 

Hans

Unfortunately it is impossible to perform quality control on assembled kits at the purchaser's location.  Also probably impossible to perform knowledge tests on those assembling the kits.  Even Heathkit never found a solution to assembler introduced problems.  

With over 8000 workinking kits out there it would seem that the design is solid.  Quality of shipped kits must be relatively good or the units would not be this popular.

Arv


On Wed, Dec 11, 2019, 2:11 PM Hans Summers <hans.summers@...> wrote:
Hi Geoff , Nick

Hans has mentioned in the past that the number of QCX's sold is around 4000 but given the number of builders who have purchased several units, the true number of purchasers must be only a few hundred!

You are far far out of date OM... current quantity is 8,885... 
Conclusion - don’t let it put you off - just check the legs of the Si5351A on the bare board before you start - it may save you some disappointment:

Still highly recommend - the best kit I have seen.
Thanks Nick... You should play the lottery OM. But avoid thunderstorms, they say lightening doesn't strike twice but... hi hi. 

Here we have assembled a large number of QCX kits for the shop http://shop.qrp-labs.com/assembled/qcx40 at a rate of 3-4 per week over the last 18 months or more... and I do not recall having seen a short on Si5351A pins once in all that time. I know it does happen occasionally, but I think it is pretty rare. Anyway I am glad you solved it and still enjoy the kits!

This does illustrate a problem with kits... it isn't easy to do a full Quality Control check before you ship it out. It isn't practical to examine the whole thing for every type of failure under a microscope, and count every resistor and capacitor, etc., for every kit shipped. When you have a completely manufactured product (not a kit), it is possible to power it up and do a Quality Control check which it either passes or it doesn't. Producing kits is a very tough business :-)

73 Hans G0UPL


Re: Two QCX kits (80m and 40) - both with shorts on Si5351A - fixed

Nick Austen
 

Hi Hans
All understood and appreciated. I was obviously unlucky and hope that I am the only one :)
Just thought it could help someone else - as, although I was disheartened (still excited like a young boy when the kit is completed), the solution was quick and simple.

On the previous kit, I was initially daunted at the prospect of trying to replace the the match-head size 10-lead surface mount device - but did it twice and it was relatively easy.

Thanks again,
Nick
VK6FABE


Re: New qcx build, and problems

Dave Edwards
 

Got mine many years ago. But I checked.....you can get small spools on Amazon, for a fair price.

Yellow, green, red on this page,

https://www.amazon.com/s?k=28+gauge+magnet+wire&crid=1XS537N4I1I8&sprefix=28+gauge+magn%2Caps%2C141&ref=nb_sb_ss_i_1_13

Here is my transformer. I used kaptan tape to hold the start and end of the big winding, alternate two colors so I could better see what I was doing

when pushing the wires into their correct locations. Forgot to remove the tape, but...doesn't matter...just looks messy!!

On 12/11/19 4:51 PM, SkipF, NT1G wrote:
Great news. I have several spools of 'Phelps Dodge' copper
 products. All HAPTZ (the good stuff).
Where did you buy this colored wire?
THANKS for the info.


On Wed, Dec 11, 2019, 4:46 PM Dave Edwards <kd2e@...> wrote:

Yellow, green, red...I have different colors in various gauges.

....Dave


On 12/11/19 4:19 PM, SkipF, NT1G wrote:
Never seen magnet wire available by color...
Perhaps a task for a 'sharpie' marker?

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