Date   
Re: need better eyes

Phil/K3UT (ex W3HZZ)
 

I take a picture of the toroid with my iPhone. Then I blow it up on the screen and count the turns with a pencil. 
Works for my 75 year old eyes

Phil, K3UT 
--
Philip L. Graitcer
204 Cater Street
St Simons Island
404-245-9780 (mobile)

Re: Extreme thumping when keying

ajparent1/KB1GMX
 

what version firmware?  there have been improvements.

Also there have been suggestions and improvements in the sidetone circuit
Check the QRPlabs site for those.

the waveform your seeing on pin15 is about right.  Also check that the right
resistor was placed at R59.

Allison
-------------------------------
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Re: Extreme thumping when keying

g4edg
 

Hi Greg

Sorry if I didnt make it clear what I'm seeing on pin 15, its just the keying waveform, i.e. key up key down about 3v in amplitude....yes I would have expected a square wave of 600Hz (my sidetone frequency) to be rounded later in the filter to a sinewave.....

I'll investigate further!

Thanks for your reply

Steve G4EDG

Re: Extreme thumping when keying

Gregg Myers
 

Hi Steve,

The sidetone is indeed a square wave coming out of the processor. It gets converted to a sine wave by passing it through the 200Hz CW filter. So your observation of the square wave seems normal to me.

73,
Gregg W7GRM

On Sun, Jan 5, 2020 at 3:16 PM g4edg via Groups.Io <G4edg=aol.com@groups.io> wrote:
Hi

A classic case of "If it ain't broke dont fix it"

My attempts at upgrading the firmware in my QCX have ended in frustration and failure...I have ordered a pre programmed chip from Hans!

With all this messing about I managed to toast the finals and Q6....I dont know why, I wasnt even touching anything when smoke poured out from under the display...OK so with the blown items replaced I have now restored the RF output.

I had previously changed C21 from 10uf to 0.1uf as recommended which was to remove a thumping while keying, which it did perfectly, my QCX was the best QSK I had ever experienced...perfect!

I took the opportunity while I had the PCB out of its case to change the PAs and Q6 of changing C21 and C22 to 1uf as per the latest circuit revision...

However now I have the most terrible thumping when keying making the rig almost unusable.

I changed the values of C21 and C22 back to 0.1uf and 10uf respectively, but the thump continues.

Q5 (front end muting) checks out OK, as does Q7 (Audio muting)

The problem does not seem to be related to RF output as the thumping continues in practice mode.

The only thing I can find which I find a bit odd is the sidetone pin of the processor (15)...is just an on/off square wave in time with the keying...no sine wave as I would have expected...strangely a good sine wave side tone is heard in the headphones.

It kind of points to the processor, but in my experience processors either work 100% or not at all.

Ive had a pretty good look at the PCB for solder bridges and can see anything...although a dry joint on C1 was found, which got rid of an annoying crackle on RX when the case was tapped!

I wonder if anyone has any thoughts on this problem?

Meanwhile I await the arrival of my new v1.03 chip

Thanks for reading!

73 Steve G4EDG

Extreme thumping when keying

g4edg
 

Hi

A classic case of "If it ain't broke dont fix it"

My attempts at upgrading the firmware in my QCX have ended in frustration and failure...I have ordered a pre programmed chip from Hans!

With all this messing about I managed to toast the finals and Q6....I dont know why, I wasnt even touching anything when smoke poured out from under the display...OK so with the blown items replaced I have now restored the RF output.

I had previously changed C21 from 10uf to 0.1uf as recommended which was to remove a thumping while keying, which it did perfectly, my QCX was the best QSK I had ever experienced...perfect!

I took the opportunity while I had the PCB out of its case to change the PAs and Q6 of changing C21 and C22 to 1uf as per the latest circuit revision...

However now I have the most terrible thumping when keying making the rig almost unusable.

I changed the values of C21 and C22 back to 0.1uf and 10uf respectively, but the thump continues.

Q5 (front end muting) checks out OK, as does Q7 (Audio muting)

The problem does not seem to be related to RF output as the thumping continues in practice mode.

The only thing I can find which I find a bit odd is the sidetone pin of the processor (15)...is just an on/off square wave in time with the keying...no sine wave as I would have expected...strangely a good sine wave side tone is heard in the headphones.

It kind of points to the processor, but in my experience processors either work 100% or not at all.

Ive had a pretty good look at the PCB for solder bridges and can see anything...although a dry joint on C1 was found, which got rid of an annoying crackle on RX when the case was tapped!

I wonder if anyone has any thoughts on this problem?

Meanwhile I await the arrival of my new v1.03 chip

Thanks for reading!

73 Steve G4EDG

Re: #progrock #problem #si5351a #test #progrock #problem #si5351a #test

Carl conrad Maeder
 

Thank you for support!
I found the mistake: It was a bad solderid pin from the preassebled Si5351 chip!

73 Carl

Re: 50W PA 0.1uF capacitor markings / manual error

ajparent1/KB1GMX
 

However the BOM and the schematic are correct.

The statement 3.11:
These are 0.1uF 50V ceramic capacitors, code “105”.

Yes, they are 1uf and the statement is half right as 105 as the marking code.
Minor typo.

Saw that while assembling mine.  

Allison
-------------------------------
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Re: Anyone have a dead QCX with a good receiver?

ajparent1/KB1GMX
 

Dean,

The good news is the only parts that don't like more than 3.3 or 5V are...

atmega328P micro
LCD
si5351
74ACT00
FST3251 
They are all easily had.

The opamps will tolerate 12V or more (but not reverse polarity)

With care, there is no part that should during removal damage the board.
That means often using enough heat but not a torch.  For example a I
use a .25" wide tip of an old WPT60 (old weller 60W temp controlled)
so I can heat all the leads sufficiently at the same time as it wide and
holds heat.  The other trick is building a puddle of solder to heat
them all.  The excess solder can easily be removed later.

Parts like the 5351 and FST3231 are removed with no intent to
salvage other than the board.  the flat packs the easy way is a
hot iron and a dental hook to lift the leads until its loose.  Then use 
a bit of Solderwik to clean the pads.  Some people using
solder wick "scrub " with it and that generally rips up the board.
If it doesn't wick it up when hot enough get some fresh
or maybe a better iron.  For removal a puddle of solder
across one side then heat and lift, repeat for the other.

That also means thing like fine tweezers (not junky ones)
and maybe a few repurposed dental hooks and a sharp
precision knife (EXacto). 

Generally pulling a plated though hole means you have nowhere 
near enough heat (usually the ground pin!) so things like  three
terminal regulators I cut loose and extract pins one at a time.
The parts are often are cheap, the board is not.  I've seen people
destroy a board trying to save a $0.79 part.

Once you break it for any reason the best course is a cup of
joe (or tea), a rest break, and then carefully proceeding.  its easy
to see someone over tired or distraught proceeding to compound
errors unintentionally.

I say this as I've worked on machines and radios where parts
are unobtainium and the board it self is very valuable and
hard to find even non functioning.   Proceeding carefully and
methodically is the only course. 

Recently I watched a series of videos of a few guys that are part
of the Computer history museum restoring a Apollo guidance
computer to full function (old, rare, complex, and valuable) and
during that they had to "open up" sections that were potted in
epoxy to replace a bad diode.  It takes great care, precision,
and study so that one does not create more problems.

Allison
-------------------------------
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Re: 50W PA 0.1uF capacitor markings / manual error

Paul AI4EE
 

According to the schematic, these capacitors are 1 uF. The .1uF must be a typo.

On 1/5/2020 10:54 AM, Chris Smith wrote:
Hi,

The kit instructions state C1, 2, 3, 6, 7, 13 and 16 are 0.1uF capacitors according to manual revision i page 21. However marking is listed as 105 and the capacitors are definitely 1uF (measured on Peak LCR45).

Can this be clarified in the instructions and/or kitting?

Best regards,

Chris M0XTE

Re: MSF or DCF clock module instead of GPS

Armin, DJ2AG
 

Razvan,

have a Conrad DCF77 module sitting around here with currently not much work to do. If you are not in a hurry, I will try to build something around an Arduino. As I don’t know what exact NMEA information U3 needs to work properly, I ordered an U3S today, to have something to play with. Something I wanted to do since a long time, but now I have an excuse.

Armin, DJ2AG

Re: QCX CW Memory Progsigns #qcx #firmware

ink3n
 

Good news , thx for the info :)

73, Axel

Re: QCX CW Memory Progsigns #qcx #firmware

Hans Summers
 

Hi Axel

Prosigns aren't supported at the moment. They are on the wish-list.

73 Hans G0UPL 

On Sun, Jan 5, 2020, 14:53 <inkiiin@...> wrote:
Hi,
Can't find anything in the manual ... Is it possible to add special characters for Progsigns ? If I try to enter a progsign to the memory the qcx only shows a * ... 

There are many special characters that could be stored in a messagememory - are this characters reserved for the Progsigns? 

Best regards,
Axel

50W PA 0.1uF capacitor markings / manual error

Chris Smith <me@...>
 

Hi,

The kit instructions state C1, 2, 3, 6, 7, 13 and 16 are 0.1uF capacitors according to manual revision i page 21. However marking is listed as 105 and the capacitors are definitely 1uF (measured on Peak LCR45).

Can this be clarified in the instructions and/or kitting?

Best regards,

Chris M0XTE

Re: QCX CW Memory Progsigns #qcx #firmware

George Korper
 

In a pinch I combine letters. 

Re: Anyone have a dead QCX with a good receiver?

George Korper
 

Pity sakes, why don't you have Hans send you the chip?
I have the board here and I can send it to you but it will take as long as Hans.

From MX to USA these days,
It's like getting funds from a check while your on "Vacation": "10 working days."

That was a great full story. Especially that Q6 Pix, just send it to Hans
I would order new firmware from him and have him toss in a couple of SMD's
Without the new firmware you can end up a member of the Q6 club. 
Just put your request in the comment section and in an email getting approval before you pay.
Or put it back in the drawer and get a new one, the problem is you have to build it!

Re: Anyone have a dead QCX with a good receiver?

K5DH
 

Here is a linkto the full story.  The event occurred back in 2017.  I ran across my dead QCX recently and decided to try bringing it back to life.   

https://groups.io/g/QRPLabs/topic/7431371#19203

--

73/72,
Dean K5DH
20m QCX msn 612

QCX CW Memory Progsigns #qcx #firmware

ink3n
 

Hi,
Can't find anything in the manual ... Is it possible to add special characters for Progsigns ? If I try to enter a progsign to the memory the qcx only shows a * ... 

There are many special characters that could be stored in a messagememory - are this characters reserved for the Progsigns? 

Best regards,
Axel

#progrock #problem #si5351a #test #progrock #problem #si5351a #test

Carl conrad Maeder
 

Prog-Rock with a strange error !

I bought two prog rock sets. With one SI5351 module I only get a frequency when I switch on for the first time. When I switch off and on again, the LED is permanently on.  So the start-up test is not successful.

One more time after a longer wait (1 day) I made it a second time, after that not anymore. Everything re-soldered and checked with a magnifying glass.....

 If I put the second SI5351 module on the same processor board, it works fine.

An identical picture with the second processor board. So there must be something with the first SI5351 module!

 Does anyone have a idea ?
73 Carl

Re: 4 line display for qrplabs clock

Bobby
 

Jim,

Hi!  Case was designed by me using a great 3D printing file from Thingiverse.com.  https://www.thingiverse.com/thing:2938921.

See attached photos of the case in early  stages before wiring components.

Final build included a micro usb port along with the 12v input to Buck converter.  This way I could power the clock using a portable USB Power Bank or a 12v DC supply.

If you have any questions please feel free to contact me anytime...:))

73
W2RWM
Bob.....








-----Original Message-----
From: Jim Samuels, Jr., W3BG <jimsam@...>
To: QRPLabs <QRPLabs@groups.io>
Sent: Sat, Jan 4, 2020 3:25 pm
Subject: Re: [QRPLabs] 4 line display for qrplabs clock

Hi Bob,
Very nice case for the 4-line display. Did you make it? If it is available online I’d appreciate the link or any addl info. Many thanks. 
de Jim W3BG

Re: 50w amp

ron mcmurray
 

thanks allison, that answered my question. i'm using the lpf-100 from hf projects.
ron, kc0tdj