Date   

Re: Wood: the other case alternative. #case

Tom Gundlach <ks5x@...>
 

Beautiful Job!


On 7/14/2018 7:26 AM, Braden Glett wrote:
Attaching pics of my retro 1930-style QCX case for 40m, completed yesterday. Wood is a viable alternative for those who like to putter around with tools. 
All controls and hook-ups are on the PCB, except for the power jack and the two push buttons. Works very well, and has the old timey radio look I was looking for.
Naturally, it won't work if you are looking for a space-age high tech look. lol
Many thanks to Jim W7EED for his help in thinking through my volume control issue, rig works perfectly and have made some nice contacts.
73,
Brady KD8ZM

-- 
Have a GREAT Day

Tom KS5X@...







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Re: Wood: the other case alternative. #case

Andy G0FTD
 

I like !

73 de Andy


Re: Transmitter Hang-up

g4sra
 

On 13/07/18 14:17, Tim Glennon wrote:
When I key the QRP X with an external Key (SK) the transmitter will hang 
and it seems like the final is oscillating.  any cures?
You don't say which band or board build version this is.

a) PA Stability modification (if not already present)

b) RF Feedback (proximity, bad match, etc.) evaluate behaviour when
TXing into dummy load. Shorten Key lead and choke with ferrite close to
QCX key socket.


Re: help needed trouble shooing QCX 40-LCD Contrast

Alan G4ZFQ
 

There are two test points just to the left of IC1, I think labelled CLK0 and CLK1. These are used to check that the Si5351 is producing a signal from the two outputs.
Ken,

I'm not sure this will prove anything.
If the Si5351 is not working it is either faulty OR it has not been initialised by the controller.

R47 has the full 5
volt range, but adjustment moves from all blocks to all
blanks and never any alpha or numeric characters on the
display. We performed all other tests in that section and
found all ok with 1 exception.  Pin 1 on the LCD is ground
with pins 5 and 16 measured at ground as well.  The guide
leads me to beleive that pins 5 and 16 should not be at
ground although they appear to be at ground on the
schematic.
I've not looked but I'd believe the schematic, thousands have seen it, I cannot imagine it's wrong.

I also need to say that when we first powered up
the QCX, the DC supply was connected in reverse for at least
a minute before we caught it.  I dont think this
caused any harm as D3 seems do have done its' job,
It should have. You could check it is not shorted.

Right now we are looking at the Si5351A Synthesizer chip
IC1.  Using a loop, it appears that the pins on the crystal
side of the chip are a bit curled and corroded, as
oppposed to  the pins on the opposite side that are flat
against the pcb and shiny.
Not easy. If I remember correctly if the Si5351 does not respond you do get your situation with the LCD. If you are bold flood that side of the Si5351 with solder and remove it with desoldering wick. That's the standard way of hand-soldering that sort of chip.

73 Alan G4ZFQ


Re: QRPLabs QCX Enclosure Dimensions

Allen Poland
 

About the best I’ve seen so far!!

 

From: QRPLabs@groups.io [mailto:QRPLabs@groups.io] On Behalf Of rentwist@...
Sent: Friday, July 13, 2018 6:37 PM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] QRPLabs QCX Enclosure Dimensions

 

LOL Al.  Here's my result using the opposite of laziness, OCD!: https://groups.io/g/QRPLabs/attachment/24853/2




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Re: QRPLabs QCX Enclosure Dimensions

Al Clark
 

Very nice!


Re: help needed trouble shooing QCX 40-LCD Contrast

Simon G0FCU
 

Hi Ken

There are two test points just to the left of IC1, I think labelled CLK0 and CLK1. These are used to check that the Si5351 is producing a signal from the two outputs. With an oscilloscope you should see a sine wave (of sorts) from each test point. They should be at the same frequency but 90° out of phase.

If you can check this you can rule out or not that the Si5351 has a problem. From your description of the pins on one side it sounds suspect.

73 Simon
G0FCU.


On Sat, 14 Jul 2018, 00:08 Ken Evans, <w4du@...> wrote:
We just completed a 40 meter QCX build with my 13 year old grandson.We are stuck on step 1 "LCD contrast adjustment".  We are following the current Trouble Shooting page under "Digital Section"and are getting the resutts as listed under"LCD all Blocks or all Blanks".  R47 has the full 5 volt range, but adjustment moves from all blocks to all blanks and never any alpha or numeric characters on the display. We performed all other tests in that section and found all ok with 1 exception.  Pin 1 on the LCD is ground with pins 5 and 16 measured at ground as well.  The guide leads me to beleive that pins 5 and 16 should not be at ground although they appear to be at ground on the schematic.I also need to say that when we first powered up the QCX, the DC supply was connected in reverse for at least a minute before we caught it.  Youthful enthusiasm makes a few errors!!  Old guys simply miss them!!  I dont think this caused any harm as D3 seems do have done its' job,  but I would appreciate any thought on where else to look.
 
Right now we are looking at the Si5351A Synthesizer chip IC1Using a loop, it appears that the pins on the crystal side of the chip are a bit curled and corroded, as oppposed to  the pins on the opposite side that are flat against the pcb and shiny.  So right now I am thinking a malfunction in IC1.  But Im not sure how to confirm it.I cannot put test leads on the chip and am unsure enough of its operation to know what to expect at any test point.  Any thoughts on how to determine if IC1 is good or bad?
 
I installed the following mods
 
*moved inductor L5 to between pins 20 & 7
*Installed 10K resistor ffrom Q5 drain to +12Volts
*added 6.8K resistor from wiper R7 to ground
 
Any suggestions greatly appreciated.
 
Ken
W4DU


help needed trouble shooing QCX 40-LCD Contrast

Ken Evans
 

We just completed a 40 meter QCX build with my 13 year old grandson.We are stuck on step 1 "LCD contrast adjustment".  We are following the current Trouble Shooting page under "Digital Section"and are getting the resutts as listed under"LCD all Blocks or all Blanks".  R47 has the full 5 volt range, but adjustment moves from all blocks to all blanks and never any alpha or numeric characters on the display. We performed all other tests in that section and found all ok with 1 exception.  Pin 1 on the LCD is ground with pins 5 and 16 measured at ground as well.  The guide leads me to beleive that pins 5 and 16 should not be at ground although they appear to be at ground on the schematic.I also need to say that when we first powered up the QCX, the DC supply was connected in reverse for at least a minute before we caught it.  Youthful enthusiasm makes a few errors!!  Old guys simply miss them!!  I dont think this caused any harm as D3 seems do have done its' job,  but I would appreciate any thought on where else to look.
 
Right now we are looking at the Si5351A Synthesizer chip IC1Using a loop, it appears that the pins on the crystal side of the chip are a bit curled and corroded, as oppposed to  the pins on the opposite side that are flat against the pcb and shiny.  So right now I am thinking a malfunction in IC1.  But Im not sure how to confirm it.I cannot put test leads on the chip and am unsure enough of its operation to know what to expect at any test point.  Any thoughts on how to determine if IC1 is good or bad?
 
I installed the following mods
 
*moved inductor L5 to between pins 20 & 7
*Installed 10K resistor ffrom Q5 drain to +12Volts
*added 6.8K resistor from wiper R7 to ground
 
Any suggestions greatly appreciated.
 
Ken
W4DU


Re: QRPLabs QCX Enclosure Dimensions

rentwist@...
 

LOL Al.  Here's my result using the opposite of laziness, OCD!: https://groups.io/g/QRPLabs/attachment/24853/2


Re: U3S & OLG1 new version drifting in Altitude

Clint Sharp <cjaysharp@...>
 

Pretty sure it’s a feature of the GPS module but initiated by the controlling device

On Fri, 13 Jul 2018 at 17:24, Alan G4ZFQ <alan4alan@...> wrote:
> It may be possible to imprvoe the accuracy if the module supports a
> 'survey' mode but that can take days to run...

I think this is in PC software, not in a GPS module?

73 Alan G4ZFQ




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Re: U3S & OLG1 new version drifting in Altitude

Arv Evans <arvid.evans@...>
 

Improving accuracy could be accomplished by establishing your own local DGPS (Differential
GPS station) using a second GPS receiver.  The DGPS concept involves using a GPS receiver
that is located at a proven fixed location and comparing information received from satellites
versus the known location.  The differences are then used as dynamic correction factors to be
applied to the locations given by the portable GPS receiver unit.  This provides a way to correct
for atmospherics, signal reflections, and other strange phenomena.

You may have a nearby DGPS station that can be used.  They are usually on an LF frequency
(the closest one here is on 325 KHz). 

https://www.navcen.uscg.gov/?pageName=SiteLocations

Arv
_._


On Fri, Jul 13, 2018 at 10:24 AM Alan G4ZFQ <alan4alan@...> wrote:
> It may be possible to imprvoe the accuracy if the module supports a
> 'survey' mode but that can take days to run...

I think this is in PC software, not in a GPS module?

73 Alan G4ZFQ





Re: U3S & OLG1 new version drifting in Altitude

Alan G4ZFQ
 

It may be possible to imprvoe the accuracy if the module supports a 'survey' mode but that can take days to run...
I think this is in PC software, not in a GPS module?

73 Alan G4ZFQ


Re: 3D printed QCX case

Bob Bennett
 

Jira,
    I would be interested in one. This may be the incentive I need to start using the printer :-)
--
Bob/NZ2Z


Re: U3S & OLG1 new version drifting in Altitude

Clint Sharp <cjaysharp@...>
 

It may be possible to imprvoe the accuracy if the module supports a 'survey' mode but that can take days to run...

On 13 July 2018 at 15:12, Peter LB0K <lb0k@...> wrote:

To add to the comments from Arv-

Any GPS/GNSS receiver will find its position in a series of single fixes, each resulting in Time, Lat, Long, and Height.
The position is resolved for Time, Latitude, and Longitude. the computing of Height is used as a trade off allowing the Lat and Long to be most accurate. The Height will not normally be as accurate as Lat and Long and can wander around, esp. when the signal path is affected by multipath or whatever.
Another factor is that the position fix is resolved from a collection of Lines Of Position, (LOP) each coming from one of those satellites in view. These LOPs will seldom intersect exactly over each other, in fact estimating the small errors of each LOP in each fix is a major part of the computation process. In successive fixes these LOPs will be seen to move to-and-fro, as the small irregularities of transmission have effect as well as noise. See 'Least Mean Squares Solution'.
Also the geometry of these LOPS has a major effect. If the shape generated by the LOPs is regular and approaches a circle/spheroid then errors are small and accuracy much better.
If the shape is elongated, a triangle, then some of the errors are large and accuracy be poorer, and remember these effects are ALL occurring in 3 dimensions. The result will easily appear to jump around in these circumstances, Maybe as seen by Stuart?

These small errors or residuals are labelled 'Dilution of Precision' or DOPs, the HDOP values and GDOP values are the most commonly used quality figures .

Regarding changes from fix to fix. 'Normal' GNSS receivers are made to plot from A-B so they will always look for the direction and speed towards the next points, or Target. They will hunt for this and the heading and speed values will constantly change a little to-and-fro.
Prof GNSS units for surveying can treat the data in a different manner and then they tend towards a static solution. 

GNSS units can easily be affected by digital noise from other units so one should aim to get a good separation from any of these other units, one can't say at least XXcm but instead 'the further, the better'.  I use a 1mtr minimum.
Hans' use of the small ground plane with this QLG1 means one can place these directly over a digital unit at smaller separations.

Spheroids. These are mathematical models that allow us to make computations and get reasonable answers. They are NOT 100% accurate shapes for good old Earth. The Earth has an irregular shape with some bits sticking out and some bits sunken in, depending on gravity and density of the rocks. So one can well see negative height values in some areas even when one is sitting on a beach. E.g. the Dead Sea area is about 200m below mean sea level (on the spheroid). After all they are only numbers, the reality is around you!

Accuracy?  Read the specs of the systems and the receivers used and you'll see - as good as +/-10m in Lat/Long for a single fix, Height will be more.
These are general worst case values, and can be easily improved on, with monitoring over time, with sophisticated statistical analysis, or with using something better than a QLG1.  
The QLG1 are nice little units, I have three, but not quite up to Topcon or Trimble units that use antennas 10 times as big.

For deeper understanding one can TRY reading-
https://en.wikipedia.org/wiki/Satellite_navigation#Positioning_calculation
https://en.wikipedia.org/wiki/GNSS_positioning_calculation
https://en.wikipedia.org/wiki/Geodesy
https://gssc.esa.int/navipedia/index.php/GNSS_Performances
Heavy stuff I'm afraid, and there is lots and lots more listed in the Reference sections.




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Re: U3S & OLG1 new version drifting in Altitude

Peter LB0K
 

To add to the comments from Arv-

Any GPS/GNSS receiver will find its position in a series of single fixes, each resulting in Time, Lat, Long, and Height.
The position is resolved for Time, Latitude, and Longitude. the computing of Height is used as a trade off allowing the Lat and Long to be most accurate. The Height will not normally be as accurate as Lat and Long and can wander around, esp. when the signal path is affected by multipath or whatever.
Another factor is that the position fix is resolved from a collection of Lines Of Position, (LOP) each coming from one of those satellites in view. These LOPs will seldom intersect exactly over each other, in fact estimating the small errors of each LOP in each fix is a major part of the computation process. In successive fixes these LOPs will be seen to move to-and-fro, as the small irregularities of transmission have effect as well as noise. See 'Least Mean Squares Solution'.
Also the geometry of these LOPS has a major effect. If the shape generated by the LOPs is regular and approaches a circle/spheroid then errors are small and accuracy much better.
If the shape is elongated, a triangle, then some of the errors are large and accuracy be poorer, and remember these effects are ALL occurring in 3 dimensions. The result will easily appear to jump around in these circumstances, Maybe as seen by Stuart?

These small errors or residuals are labelled 'Dilution of Precision' or DOPs, the HDOP values and GDOP values are the most commonly used quality figures .

Regarding changes from fix to fix. 'Normal' GNSS receivers are made to plot from A-B so they will always look for the direction and speed towards the next points, or Target. They will hunt for this and the heading and speed values will constantly change a little to-and-fro.
Prof GNSS units for surveying can treat the data in a different manner and then they tend towards a static solution. 

GNSS units can easily be affected by digital noise from other units so one should aim to get a good separation from any of these other units, one can't say at least XXcm but instead 'the further, the better'.  I use a 1mtr minimum.
Hans' use of the small ground plane with this QLG1 means one can place these directly over a digital unit at smaller separations.

Spheroids. These are mathematical models that allow us to make computations and get reasonable answers. They are NOT 100% accurate shapes for good old Earth. The Earth has an irregular shape with some bits sticking out and some bits sunken in, depending on gravity and density of the rocks. So one can well see negative height values in some areas even when one is sitting on a beach. E.g. the Dead Sea area is about 200m below mean sea level (on the spheroid). After all they are only numbers, the reality is around you!

Accuracy?  Read the specs of the systems and the receivers used and you'll see - as good as +/-10m in Lat/Long for a single fix, Height will be more.
These are general worst case values, and can be easily improved on, with monitoring over time, with sophisticated statistical analysis, or with using something better than a QLG1.  
The QLG1 are nice little units, I have three, but not quite up to Topcon or Trimble units that use antennas 10 times as big.

For deeper understanding one can TRY reading-
https://en.wikipedia.org/wiki/Satellite_navigation#Positioning_calculation
https://en.wikipedia.org/wiki/GNSS_positioning_calculation
https://en.wikipedia.org/wiki/Geodesy
https://gssc.esa.int/navipedia/index.php/GNSS_Performances
Heavy stuff I'm afraid, and there is lots and lots more listed in the Reference sections.


Re: Transmitter Hang-up

Kārlis Goba
 

My first thought - check your supply. Check for unusual voltage swing when you're keying. The supply usually has to have fairly low internal resistance for finals to work properly.


Transmitter Hang-up

Tim Glennon
 

When I key the QRP X with an external Key (SK) the transmitter will hang 
and it seems like the final is oscillating.  any cures?


Re: Historical Maritime CW station event #kph

John Rabson
 

Hi Wes,

The information on historical coast stations Is very interesting. In the mid-1970s, after a break for university studies, I decided my CW ability needed improving. Casting around the HF spectrum, I found WCC on 13034(?) kHz sending weather warning traffic to NAVAREAS at a useful speed. This was just what I was looking for and I continued to listen to that station from time to time until it ceased operation.

I then moved to the CW segment of 40 m and found that there was plenty of good CW. Some years later, when Morse was no longer required for a UK amateur licence, I noticed an upsurge in very well-formed sending from stations with M3 calls. These were holders of the new Foundation Licence but I suspect many of them were former Radio Officers. it was a great pleasure to listen to them.

My only other involvement with official MF stations was when I was setting up the transmitter for University Radio Essex. Its assigned frequency was 998 kHz AM but something went wrong and we came out on 499. Fortunately GNF did not notice before I corrected matters.

73 John G3PAI and F5VLF


Re: Wacky voltage readings

Clint Sharp <cjaysharp@...>
 

Sounds likely, IC4 is a nice large SMD so it’s easy to remove and replace with nothing more than a soldering Iron and care. If you’ve a pin chuck and a sewing needle you can put them to good use in the process 

On Fri, 13 Jul 2018 at 03:30, Charles W. Powell via Groups.Io <doctorcwp=yahoo.com@groups.io> wrote:
Alan (G4ZFQ),

I did more pondering on the QCX I am trying to repair and did some experimenting.  I removed the transformer leads that go to pins 7 and 9, and I now get an expected voltage division between R1 and R2 at 2 volts. Shy of the published voltage but exactly half of what is supplied to R2. Regulator output is 5.01 volts but I’m still getting exactly 4 volts at R2 - not sure why.  The LCD seems to operate just fine.  There is obviously a trace or a bus that spans the board but wow! Trying to find that is going to be tough.

With T1, C45, and R9 fully removed, I no longer get high voltages on the ICs, 5, 6, 7, etc.  Rather the voltage that were ridiculously high drop down to about 0.5 to 1.5 volts in most instances.  I no longer have 11 volts anywhere on the IC pins.  Even with C45 and R9 removed, pins 5 and 12 on IC4 still show nearly a dead short to ground (about 10 ohms in the path). If there is a solder bridge somewhere, it’s beyond my capability to see it.  I am beginning to think strongly that IC4 has at least a bad segment in it.  Some of it must be working or the radio wouldn’t receive anything.

At this point in time, I am supposing that there is very little to lose by trying to replace IC4, surface mount be damned.

Thanks for your help with trying to track things down, Alan.  I’m open for more suggestions (from anyone!) if they are out there.  Since it would be ridiculous to try to remount T1 with the existing wiring, I will re-wind the transformer.  Then I can be certain it is mounted correctly.

73,

Charles - NK8O


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Re: QCX firmware empty #qcx #firmware

Hans Summers
 

Hi Karlis

I'm sorry, I don't know how that happened - somehow you must have been sent a blank AVR chip. 

I will contact you off-list now. 

73 Hans G0UPL

On Fri, Jul 13, 2018 at 9:46 AM Kārlis Goba <karlis.goba@...> wrote:
Hi,

I have just received my QCX (20m), and already assembled myself. The kit came with an AVR with a sticker 'T1.00e' on it.

However, after turning it on, it showed the dreaded one filled line (uninitialized LCD). Checking the contents of AVR via ISP, I saw an empty FLASH and empty EEPROM, and also the fuses seemed to be at the defaults (20MHz clock was not working). I fixed the fuses according to suggestion here (ext: FC, high: D1, low: F7), and at least the clock is now running.

I flashed the QCX flash .hex file, but as expected, now it shows "Use original IC". As I understand, it is caused by the empty EEPROM. Reading through the forum, I guess I should contact Hans directly, am I right?

Kind regards,
Karlis