Date   

Re: Keyer Issue with QCX - missing or short dahs

dbauer@...
 

My call is VE7AHT and often the T is shortened by about 1 bit length. For those of us who actually use Iambic keying instead of making unrelated comments, there is no opportunity to use the “squeeze key” function when sending the letter T My QCX 20 speed is set to 25 wpm which matches my average keying speed. Varying the QCX speed and my keying rate does not eliminate the occasional shortening of Dahs. The dahs occasionally also go MIA, which completely throws off my sending cantor.
No other of my rigs has this issue, but admittedly they are much pricier commercial units. Still, I am sure Hans can duplicate/resolve the issue once it is recognized as legitimate.
I love my QCX 20, and continue to be amazed by its overall performance.
 
Dave. Licenced 1958 CW favourite mode.


Re: ProgRock not working #progrock

w7qjq
 

Regarding 'latency'...it is my understanding that the value of the latency of the 1PPS has no relevence to the CLK0 frequency accuracy. What is revalent is that the latency be a constant value and that the 1PPS pulse width be at least several mS (the QLG1, and many other GPS receivers' 1PPS is 100 mS),  and very importantly that the positive-going leading edge be very fast and clean.

 

73,  Sid  W7QJQ


Re: 5watt amp/u3s

Alan de G1FXB
 

Hi Paul,

If there is any risk, then sacrifice the component not the pcb tracks.
"A pair of sturdy pliers crush all known capacitors, dead." or whatever the Domestos advert said.? :-)

Also, I don't know if your are using multi band LPF's.
If so, it's really advised to get spots on all band using the barefoot U3 & filters to prove that works first.
if in the unlikely event it needs debugging, it is far far easier knowing it's just something Amp related.....
For instance the V5 filter PCB has evolved in all it's uses with 1001 options for wire links & Coax interconnects depending,
LPF, multi antenna switching, etc.

Have Fun!
Alan


On 20/07/2019 21:59, m0bmn via Groups.Io wrote:

Thanks Alan,

Will get the iron hot, look out C5!

73/4 Paul M0BMN

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From: Alan de G1FXB via Groups.Io
Sent: 20 July 2019 15:10
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] 5watt amp/u3s

?

Hi Paul,
Yep, Still pull C5
In doing so you create a breakout point for the PA.

Hans recommends using one of the conveniently positioned vacant Q3 BS170 pads where you can find RF and GND connection both close by and send it to the PA input.

PA output gets patched back onto the U3S
Hans suggests RFI and the adjacent GND pads where amplified RF now gets routed into the inbuilt LPF position
and 10 way backbone connector for the expansion LPF positions if fitted, as normal.

As you noted, over time AN004 layouts have not kept up with the PCB revisions.
Not a show stopper the pads are still there, just not exactly in the same place.

Alan

On 20/07/2019 00:13, m0bmn via Groups.Io wrote:

?

Think I have just realised how this is done, a zoom in on the newer PCb shows? on the 10 way (5 x2) socket

GND/RFI and GND/RFO which are the connections I need I guess. Do I still chop c5 as before.

73 Paul

Sent from Mail for Windows 10

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Virus-free. www.avast.com

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Re: Pico Balloon Launch LightAPRS N6CVO-11

BrianB
 

Flight Day 1 20-JUL-2019 13:02 UTC

 

Launched at 06:02 PDT (local time)

  Location 34.8 -118.1 (Rosamond, CA USA)

  Altitude 727m 2,385’

  Voltage 0.0v (Sun was just rising)

 

First contact was received at 07:30 PDT (14:30 UTC)

  Location 34.9458 -117.8176 ( Directly over Edwards Dry Lake)

  Altitude 6,866meter or 22,527’

  Voltage 4.55v (Sun was just starting to hot the solar panel)

 

Last contact of the day at 18:18 PDT (21-JUL-2019 01:18 UTC)

  Location 37.10983 -116.11933 (Middle of Nevada)

  Altitude 9757m or 32,012’

  Voltage 4.60v (Sunset on the solar panel)

 

Notes:

- Launch was sketchy due to the high ground winds and balloon was almost immediatly lost in a downdraft.

- Tracker came to life very close to the time it was projected to get sun on the solar panel.

- Balloon reached cruising altitude and leveled off in an hour and fourtyfive minutes.

- Sucessfully received transmissions averaged 108seconds apart.

- Expecting payload to wake up around 08:00 PDT over Salt Lake City.

- Future times will all be reported using UTC

 


Re: clear tape on GPS kit chip

Hans Summers
 

Hi all

The tape is only stick on for the purposes of preventing damage during shipping. You can remove it or not, as you wish.

73 Hans G0UPL 

On Sun, Jul 21, 2019, 01:27 Don--AE4DW <dwinflorida@...> wrote:
I left the tape on both boards I built, they work fine.

Sounds like, no effect either way.


Re: #QCX : Keyer issue solved (?) #qcx

Axel
 

Hi,

I apparently solved my RF-interfernce problem into my paddles now, even with my SOTA antenna. What I did:

* replaced the 200Ohm resistors in my previous fix by 2.2KOhm resistors
* added another two 100nF capacitors directly at the inputs of the Atmega
* halved the length of the hacksaw blades of my paddles
* used shielded cable between paddles and keyer input

Unfortunately, I have the non-RF-interference problem described in "Keyer Issue with QCX - missing or short dahs": dahs are quite often shorter than 3 dits.


73
Axel, DF1ET


Re: Keyer Issue with QCX - missing or short dahs

Axel
 

That's the point. Dahs should ever be as long as three dots, never shorter, regardless of what the operator does.

Unfortunately, this hits me quite often (QCX20).

Axel


Re: i was dreaming

KEN G4APB
 

I guess for one person in particular, QSX = nightmare. :( 
Ken g4apb 


Re: ProgRock not working #progrock

Robin Midgett
 

Hans & the group,
An update: Exchanging the RC values on the 555 has shown that the 555 latency isn't causing the frequency error I'm experiencing. I'm now in the region of 400nS latency at the 555 stage with a 33mS long output pulse (2.75nF cap & 10MOhm resistor), and I still have a 18-19 Hz. discrepancy (low) in the output frequency. The output frequency is very stable, just low. This is with reg. 3 set to 0, and reg. 2 is recorded at 27,003,057, which is bogus. I say it's bogus because if I take the GPS correction out of the picture by setting reg. 3=50, which gives me time to experimentally find the correct value for reg. 2, then the ProgRock will run spot on frequency, temperature changes not withstanding. That value is 2=27003024 for my ProgRock. 

Whenever I put the GPS back into the scheme (reg. 3=0) regardless of the pulse width above 11mS going into the ProgRock, it drives reg 2 to 27,003,057, and the result is a very stable 18-19 Hz. low 15 MHz output.

To be clear without a schematic, the wire up is:
Trimble Resolution T GPS 1PPS output (positive going 2.8V logic 1mS wide) driving the base of a 2N3904 for an inverted output at 5v logic level;
Inverted 5v logic into 555 monostable pulse stretcher giving 33mS high output for every 1mS pulse from the GPS; this output drives the 1PPS input of the ProgRock.
Using a modern oscilloscope I measure a 400nS latency in the 555, which would be irrelevant in the ProgRock output based on 1 Hz.error/µS latency.
I then decided it'd be better to measure the overall latency from the GPS pulse to the 555 output; ~750nS, so not even 1 Hz. output error, based on 1 Hz./µS. In the photo below, the yellow trace is GPS output, blue trace is 555 output going into ProgRock.

It'll be interesting to see if the QLG1 solves the 18 Hz. discrepancy I'm measuring repeatedly. 
If only my rifle marksmanship was as repeatable as this....

And just to reiterate...I can live with the error for my application. I'll either make the adjustment in the frequency programming or leave it as is. I just really wonder what's going on...curious, ya' know.


 

Robin Midgett K4IDC


On Fri, Jul 19, 2019 at 9:28 AM Robin Midgett <K4IDC@...> wrote:
Hi Hans,
The inverter & level shifter are the same stage..a simple 2N3904. The shifter is needed to bring the 2.8V logic 1PPS from the GPS to 5V logic level, and the coincidence is that it's inverted logic is needed by the input to the 555. Propagation delay for a 2n3904 is specified in the 40nS range. There are no caps on this stage.

There is a latency associated with the 555 and that's the time shown in the oscilloscope photograph in my previous post. That latency scales with the chosen RC value for the 555 one shot. In that photo I was using 10uF & 10K which gave a ~110mS pulse width.

You'd indicated in an earlier email exchange that the minimum acceptable pulse width of the 1PPS ProgRock input is unknown. I'm experimenting with different RC values on the 555 & can report that, latency issues notwithstanding, 14mS seems to work well thus far, using 1uF & 10k on the 555.

Yes, I suspect the QLG1 will make my ProgRock work properly.
Thanks,
Robin Midgett K4IDC


On Fri, Jul 19, 2019 at 1:37 AM Hans Summers <hans.summers@...> wrote:
Hi Robin

If you have an inverter in there as well... then that's also a problem :-/     The leading edge of the 1pps from the GPS is the one that is considered accurate. There's no guarantee about the trailing edge. 

If there was a latency that was fixed precisely, then all would be well. But if you have Resistors and Capacitors in there that are generating the stretching, and triggering off the wrong edges... then all bets are off.... 

I suspect that when you get your QLG1 you will find all works as expected. 

73 Hans G0UPL

On Thu, Jul 18, 2019 at 6:24 PM Robin Midgett <K4IDC@...> wrote:
Hi Hans,
Do you mean like this? :>)
This morning the error at 16.686600 MHz was 14 Hz. In other words, I set register 8 to 16,686,614 to obtain a measured output of 16,686,600. Doubling that output frequency resulted in a doubling of the error, doubling again, same error factor. Then I set about measuring the latency...probe 1 is the output of the level shifter/inverter stage that is connected to the input of the 555. Probe 2 is the 555 output.



Now....what to do about it? Perhaps a pulse stretcher with a Schmitt trigger input? 
I'm more of an analog guy, so this experience is really helping me learn. This is fun!
Thank you, Hans! 
Thanks,
Robin Midgett K4IDC


On Wed, Jul 17, 2019 at 10:40 PM Hans Summers <hans.summers@...> wrote:
Hi Robin

Is there a possibility your 555 pulse extender circuit could also be adding variable latency to the pulse? It would not take very much error... bear in mind, every 1us is 1 part-per-million error at the output. 

Anyway it will be interesting to see how things go once you get your QLG1

73 Hans G0UPL

On Thu, Jul 18, 2019 at 12:44 AM Robin Midgett <K4IDC@...> wrote:
Hi Hans,
Thanks for the response.
I'd really like to understand what's causing this issue & what to do about it.
Presently I have the Trimble GPS 1PPS 2.8V logic 1mS pulse driving a level shifter to a 5V logic level and also providing the needed inversion for driving a non-retriggerable 555 one shot. The 555 is giving a 112mS long positive going 5volt pulse for every 1PPS from the Trimble GPS. I'm applying the 112mS pulse to the GPS input on the ProgRock. In this configuration, register 2 is being updated to a value that causes the output frequency to run low of the desired by ~18 Hz.
If I remove the 1PPS, ground the 1PPS input on the ProgRock & reboot the ProgRock, then manually dial in register 2 to give the proper output frequency, it'll stay there within a couple of Hz. over a period of many hours if not days, thermal effects not withstanding.
It seems to me that under GPS discipline the frequency of the crystal is being mis-read, or there's some magic in register 28 that needs to be adjusted; these are my guesses at this point.

My primary reason for the 555 is to allow me the opportunity to experiment with different pulse widths. Since the QLG1 gives 100ms, I started with a value near that. I can trim it to be spot on later, but 112mS is where my particular RC value came to land late last night. I know from experience that 1mS doesn't work, nor does 11mS, at least not as my ProgRock sits currently.

My QLG1 and the OCXO from QRPLabs are in the mail. Once I have those we can see if anything changes. If you have any further suggestions, I'm all ears.

Thanks,
Robin Midgett K4IDC


On Mon, Jul 15, 2019 at 3:33 PM Hans Summers <hans.summers@...> wrote:
Hi Robin, Graham, Sid, all

There have been a lot of posts on this topic and being on vacation at the moment I kind of lost track of where this got to.

ProgRock should work as advertised on the web page and documentation. If it doesn't, something is wrong. 

A GPS disciplined ProgRock should be accurate well within 0.05ppm (note that this parts-per-million specification means that the absolute precision in Hz, scales with frequency). This is what I have seen in all my tests and has been verified by other constructors too. To get the system working does require:

1. GPS correction threshold register must he understood properly. To get maximum precision requires setting the GPS correction threshold register to zero (default is 5Hz). 

2. The 1pps signal needs to be at 5V logic level. Many GPS units have 2.8V logic level outputs and need level conversion. This can be done with pull-up resistors with some care and some inevitable degradation in noise immunity. Or with proper level conversion.

3. The GPS pulse needs to be long enough for the processor to handle it properly. I'm not actually sure what the minimum is. Many common modern GPS modules have 0.1 second positive pulses, these work fine. Some modules with very short pulses e.g. 1 microsecond wouldn't work.

Note that the QRP Labs QLG1 GPS kit http://qrp-labs.com/qlg1 was used in all my testing and works very well. It has 0.1 second positive pulse and it has proper logic level conversion. The QLG1 has a very accurate 1pps specified with max 11 nanosecond r.m.s error.

If the ProgRock isn't performing as expected then something is wrong. That could be an electrical problem (soldering problem, dead component etc); or some issue with the characteristics of the 1 pulse-per-second signal input. 

If there's any question I haven't covered here, please let me know.

73 Hans G0UPL 







On Mon, Jul 15, 2019, 16:31 Robin Midgett <K4IDC@...> wrote:
Hi Graham & the group,
The issue Sid & I and possibly others who aren't reading the mail on this subject isn't about stability with the TCXO or OCXO. The stability with those optional oscillators is well documented and not in question, and for a broad range of applications, mine included, well more than sufficient.
The issue here is making the ProgRock work reliably with GPS discipline, and why that isn't happening reliably.
Diatribes about the NEED for GPS discipline in anyone's application are irrelevant simply because the fact is the product doesn't perform reliably as advertised with GPS discipline, and, very importantly, within the context of kit building and the price of the kit, this is not a deal breaker or terribly surprising. This is part of the value of kit building; the builder has the opportunity to improve the kit as they see fit, or not.
What is perhaps more interesting and worth studying is why the GPS discipline isn't as reliable as it should be, and what's to be done to mitigate that deficiency. Based on the current responses to our (Sid & my) posts, Hans may be the only person qualified to really answer the questions regarding the apparent deficiency.
Further, personal attacks are not helpful, Andy Brilleaux. Let's leave those for the elementary school playground. Let's approach this issue scientifically and see if a successful solution can be had. I suspect it can and will.
Thanks,
Robin Midgett K4IDC


On Sun, Jul 14, 2019 at 3:15 PM Graham W <gram.warrington@...> wrote:
I have built a few prog rocks. I did not use the 27 mhz crystal as supplied, but installed a TCXO as suggested in the manual. I find ,even without GPS control that it is very stable. The pads are already there for the TCXO.
Graham VE3WGW


Re: i was dreaming

Don--AE4DW
 

@John Rabson...my original call ended in QXM (WD8QXM) so you can imagine all the variations on QRM jokes that I heard.


Re: clear tape on GPS kit chip

Don--AE4DW
 

I left the tape on both boards I built, they work fine.

Sounds like, no effect either way.


Re: 5watt amp/u3s

m0bmn
 

Thanks Alan,

Will get the iron hot, look out C5!

73/4 Paul M0BMN

 

 

Sent from Mail for Windows 10

 

From: Alan de G1FXB via Groups.Io
Sent: 20 July 2019 15:10
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] 5watt amp/u3s

 

Hi Paul,
Yep, Still pull C5
In doing so you create a breakout point for the PA.

Hans recommends using one of the conveniently positioned vacant Q3 BS170 pads where you can find RF and GND connection both close by and send it to the PA input.

PA output gets patched back onto the U3S
Hans suggests RFI and the adjacent GND pads where amplified RF now gets routed into the inbuilt LPF position
and 10 way backbone connector for the expansion LPF positions if fitted, as normal.

As you noted, over time AN004 layouts have not kept up with the PCB revisions.
Not a show stopper the pads are still there, just not exactly in the same place.

Alan

On 20/07/2019 00:13, m0bmn via Groups.Io wrote:

?

Think I have just realised how this is done, a zoom in on the newer PCb shows? on the 10 way (5 x2) socket

GND/RFI and GND/RFO which are the connections I need I guess. Do I still chop c5 as before.

73 Paul

Sent from Mail for Windows 10

?

 

Virus-free. www.avast.com

 

 


Re: Keyer Issue with QCX - missing or short dahs

Rex Vokey
 

Both of you clearly didn't read the whole string. The short dahs are the issue and are a design flaw that has to be worked around if treating the paddle as single-lever (or actually using a single lever). 

73,
Rex KE6MT


Re: clear tape on GPS kit chip

DON MAYHALL
 

AC2GW,

I removed the tape...no apparent operational effect.
I'm using an external GPS antenna with my unit.

Don / N5DM


Re: Help ! My U3S behaves badly.... #u3s

PA3CRZ
 

Hi Don,

Miracles do happen from time to time....
I put it all together again, and now it's working perfectly. Didn't change anything....

It must have been something like you said, maybe a short against the metal case.
Just made sure this time that the connectors to the pins on the PCB were bent slightly more away from the
bottom of the case (although I used heat shrink, so no visible exposed connectors).
Possibly, this was the cause of the trouble.

Anyway, U3S is working fine now, and I have my first long distance report (to ZS1LS, almost 10,000 km), using only 200 mW in
 a small dipole antenna. Not the best of circumstances here, but a nice result.

Thank you, and everyone else, for the support.
On to my next project!

Regards and 73,
Hans
PA3CRZ


Re: Keyer Issue with QCX - missing or short dahs

Kees T
 

.....OR, "if I want to speed up the process and hold up two nails, my hammer only hits one .....why is that ?" 


Pico Balloon Launch LightAPRS N6CVO-11

BrianB
 

We launched a balloon this morning and it came to life once the sun came up. What a way to celebrate the moon landing anniversary. Woo hoo...

https://aprs.fi/#!call=a%2FN6CVO-11&timerange=604800&tail=3600

BrianB
N6CVO


Re: i was dreaming

Alan de G1FXB
 


Perhaps consume some cheese at bedtime,
it may make the time fly by?

With each sleep,
the QSX becomes a day nearer becoming a reality.?


Alan

On 18/07/2019 22:31, Mike wrote:
On 18 Jul 2019 at 14:09, Mike wrote:

I  was dreaming in morse last night. The other station was sending quite
badly 
and I was trying to hear him through the qrm on 40m. I thought he was sending
GDAD, GD1D with cw abbreviations for the 1, but he kept repeating his
callsign 
over and over again. In the end I gave up and in my dream qsy'ed somewhere 
else.
When I woke up The cw was clear in my mind, he was sending QSX.
No wonder I did'nt get it.....

QSX was just a dream..................





Re: clear tape on GPS kit chip

Stephen
 

thanks. i wasn’t sure if any soldering nearby would bother the tape
--
Stephen - AC2GW


Re: 5watt amp/u3s

Alan de G1FXB
 

Hi Paul,
Yep, Still pull C5
In doing so you create a breakout point for the PA.

Hans recommends using one of the conveniently positioned vacant Q3 BS170 pads where you can find RF and GND connection both close by and send it to the PA input.

PA output gets patched back onto the U3S
Hans suggests RFI and the adjacent GND pads where amplified RF now gets routed into the inbuilt LPF position
and 10 way backbone connector for the expansion LPF positions if fitted, as normal.

As you noted, over time AN004 layouts have not kept up with the PCB revisions.
Not a show stopper the pads are still there, just not exactly in the same place.

Alan


On 20/07/2019 00:13, m0bmn via Groups.Io wrote:

?

Think I have just realised how this is done, a zoom in on the newer PCb shows? on the 10 way (5 x2) socket

GND/RFI and GND/RFO which are the connections I need I guess. Do I still chop c5 as before.

73 Paul

Sent from Mail for Windows 10

?


Virus-free. www.avast.com