Date   

Re: vfo/signal generator

Mont Pierce KM6WT
 

On Fri, Sep 24, 2021 at 11:39 AM, Arv Evans wrote:
Mont, and others
 
Arv, 

I commented on your post, but moved to a new topic (click here) so as not to hijack Syd's discussion.  :)  :)


73
km6wt


UProc Reset / Micro"Processors" vs Micro"Controllers"

Mont Pierce KM6WT
 

I didn't want to hi-jack Syd's thread, so moved this to a new topic.

First, before I forget, one comment on the ATmega328a Reset Pin.

Many microcontrollers have a reset pin.

The reset pin is often on a pin that is shared or could be configured for other purposes.
The ATmegaXXX family has a fuse setting which will disable the reset function of the pin so it can be used as a regular port pin.

What a microcontroller does on Reset varies depending on its Manufacturer's design .  Many ATmegaXXX circuits have this pin hardwired to VCC, as the option described in detail for the VFO/SigGen assembly manual page 7 (click here) and more details on page 12 (click here).

For the ATmegaXXX, if you want to be able to use the "In System Programming" feature, the Reset must be able to be pulled low by the Programmer plugged into the ISP port.

Another feature of the ATmegaXXX is it has a sleep mode, where everything can be shutdown to save battery power.  The Reset pin can be used to awaken it from sleep mode.  (Many microcontrollers have this feature).

In the VFO/SigGen assembly manual, Hans describes the "8) Optional In-circuit programming header" (same as ISP port) on page 9 (click here).   If you install a 2x3 header (as shown in the picture) and a 100K resistor at R3, then you can program or update your VFO's firmware in place.  (also detailed on page 12)

And, finally, for most (all?) of the QL Kits with  the ATmega328 processor, this is the MAIN use of the Reset pin, i.e. to enable the use of the 2x3 header for In-circuit Programming (aka In-System Programming, or ISP for short). 


On Fri, Sep 24, 2021 at 11:39 AM, Arv Evans wrote:
When things go badly...REBOOT sounds like earlier versions of Microsoft
Windows.  There are UNIX and Linux systems out there that have not been
rebooted for years. 
This reminds me of a VCR I owned years ago.  Every few months, it would just Hang.  I swear, it must of had an Embedded MS Windows operating system.  I would have to unplug it to totally power off, let rest for 10-20 minutes, and plug it back in.  Afterwards it would run fine for another few months... and I'd have to repeat the unplug power off sequence.

What this does bring to mind is that with a little bit of free memory it might
be possible to add some self test routines to the startup or run-once part
of microcontroller code so that the bootup self-tests provided indications
of the state of hardware and software during a boot process.  This could
probably be turned on and off via a word in EEPROM (make it a number
so that the value could control the level of test or debug during the next
bootup).
 
On the avr or Arduino system a reset is activated during power-up by
having a capacitor to ground and a 10K to +5V on the RESET pin.  The
cap holds the reset lead close to ground for long enough to effect a
boot (JMP to memory address Zero), while the 10K charges the capacitor
to +5V and holds it there after the reboot has occurred. 
 
What would we want included in a talkative reboot/reset process?  Well,
maybe some basic things like power supply voltage check (displayed or
just a minimum and maximum and light a red LED if out of range. 
Network connection might be interesting to know.  Confirmation of date
and time from an RTC, and other hardware interface confirmations?
 
Lots of possibilities if one wants to add boot time information like the old
Microsoft systems provided. 

A micro"Processor" and a micro"Controller" live in two very different worlds.

A microprocessor, as used in full blown "general" purpose computers like the PC on your desk, has a myriad of optional additional hardware peripheral devices.  At boot up, there are certain peripherals it needs and expects, but for the most part the "boot up" code has to search it's environments to "discover" what's available.  And it loads drivers to communicate with the attached peripherals, and usually runs some diagnostics to make sure these attached peripherals are functioning as expected.

There are several boot steps the processor runs through before finally being ready to be used by a user for an infinite number of various tasks.


The "world" of a microcontroller is Very Different.  There are myriads of variations of microcontrollers for any purpose you can think of under the sun (and beyond). 

The microcontroller usually has many of it's needed peripherals Built In.  And the programmer of a microcontroller already knows the environment the code will be running in, i.e. how much internal ram is available, internal program space available, what port pins are available and if they have internal optional purposes, etc.  It's already a known environment, doesn't have to be "discovered". 

Practically any device you have now has some kind of microcontroller taking the place of what used to be implemented in complex circuits of discreet components.  From  your TV, to the TV Remote, to the Microwave Oven, to the DVD player, and on and on.

Every general purpose full blown personal computer also has many components in the case that have their own specific purpose microcontroller.  The Keyboard has it's own microcontroller, the disk drive, and every card plugged into the PC bus, each one has it's own special purpose or programmed microcontroller to perform it's specific tasks.


Many microcontrollers are design for physical size limitations, manufacturing cost savings, and many many more considerations.

When designing a device, the design engineer has available many choices.  One is what is the minimum capability needed in a microcontroller to perform the task at hand.  This option greatly reduces the cost of the product being engineered, which can influence whether this product will be a success or failure in a very competitive market place...

As a hobbyist, we often will choose a microcontroller by familiarity, features that will exceed our future requirements or at least one that is part of a family of microcontrollers with same/greater features (i.e. least code change, etc).


Anyways, this is just a very small glimpse of the Two Very Different worlds of MicroProcessor VS MicroController...

So, have at it everyone...  let the comments (flames?  hope not...) begin...


Or better yet:  Google   "microcontroller vs microprocessor"   for your own mind blowing edification.   :)  :)


73
km6wt


10W HF Linear PA Heatsink Mounting Holes, Chassis Drilling Dimensions

Al Holt
 

Does anyone have the dimensional layout of the mounting holes in the heatsink for the 10W HF Linear Power Amp?

I'm planning on mounting it on the outside of an aluminum enclosure and would love to get the mounting holes accurately placed before taking it apart.
I haven't been able to find any reference to it here or QRP Labs' website. Did I miss it?

Thanks!

--Al
WD4AH


Finally on the air #wspr #u3s #loveit

Bertel Andresen - SM6OES
 

Hi all.

How on earth is this possible?
From what I *thought* I knew about distance vs power, it is not, but I'm still doing it...
I have my newly built U3S finally on the air, temporarily hooked up on my kitchen table, not even boxed yet.
A couple of lab cables to the PS and such.
A fairly simple HFJ-350M antenna on the balcony, grounded in the railing, tuned with a simple analyzer.

At for example 20m, with about 180mW out to the antenna.
I'm getting spots from all over Europe, Moscow, Crete, Iceland, The Canary Islands AND North Eastern US.
I'm living in Gothenburg, Sweden.
6147km (WZ7I) on 180mW, 29uW/km, OK.....

I find this truly amazing.
What can one do with such simple equipment?

Many thanks to a lot of You guys that has guided me to get this far.

73 SM6OES, Bertel


Re: 10W HF Linear PA - Gain Flatness

Andrew Lenton
 

Hi, The gain of this amp is is high in any case and it is is an HF amp 3-30 MHz, for  MF 300Khz to 3MHz amp different materials are used, HF transceivers manufactures hide the drop off at lower frequencies with gain control. I would expect a drop off below 3MHz. Gain control of HF linear amplifiers would require a level detector and a means of controlling the gain of the amplifier, or controlling the input level to the amplifier. This would triple the complexity of the HF amplifier. 

For a broadband keeping the input impendence at a constant 50 Ohm, is tricky. if the input impendence of this amp is playing a part in drop off of gain at the low end then try a 3dB or 6dB attenuator at the from end and increase the drive a little bit, I use a 17dB attenuator as the output from the  U3S is a healthy 350mW at 14MHz, this to alters across the enormous frequency range!

10W = 40dBm - 27.5dB = 12.5dBm so a very low drive level required. If the U3S 23dBm output, a minimum of 10.5dB attenuator required. I have no idea of what you are using the linear amp for, but to use it with the U3S for example and have it running 6 bands is tricky due the variation of the drive level coming in the the U3S.

I noticed the on the 10 Watt amp, if you increase the voltage to 14V it is far cleaner than 12V, however, the power does increase. I thick it is safe up to 20W, so it will require even less input.

Broadband amp for bench use, you can Monolithic microwave integrated circuit, these are designed to be flat.

BR

Andrew


Re: QCX 50W T1&T2

Tony Britton <Tonymail001@...>
 

hello Peter, I guess you're right. I only use bondic as a temporary 'hold' before finally soldering some components. some of the QRPGuys kits are designed to use a tyrap to secure certain things. I haven't yet completed the QRPLabs kits I have so can't comment on specifict of these but  If I wanted to secure a component with significant mass particularly in a device which might be subject to shock or vibration in use then I'd look for either a mechanical support or use a final conformal coat or potting compound.


On Sat, 25 Sept 2021 at 09:27, Peter GM0EUL <gm0eul@...> wrote:
Have you successfully used Bondic on a toroid?  My experience is that it won't stick if the UV light can't get to it so it may hold the toroid just at the very edge but 99 percent of the contract area will not be polymerised and there is no strength to the repair.

You can get superglues with a few seconds delay to allow positioning.

I find Bondic is brilliant as a clamp to hold an epoxy joint.  I use epoxy to fix something, hold it tightly in position then squeeze Bondic bridges across the join and polymerise it with the UV.  The Bondic holds the joint while the epoxy cures then picks of the surface quite easily if you want a smooth finish.

73
Peter GM0EUL





--
Tony Britton
Mail; tonymail001@..., mail@...


Re: QCX 50W T1&T2

Peter GM0EUL
 

Have you successfully used Bondic on a toroid?  My experience is that it won't stick if the UV light can't get to it so it may hold the toroid just at the very edge but 99 percent of the contract area will not be polymerised and there is no strength to the repair.

You can get superglues with a few seconds delay to allow positioning.

I find Bondic is brilliant as a clamp to hold an epoxy joint.  I use epoxy to fix something, hold it tightly in position then squeeze Bondic bridges across the join and polymerise it with the UV.  The Bondic holds the joint while the epoxy cures then picks of the surface quite easily if you want a smooth finish.

73
Peter GM0EUL




Re: 10W HF Linear PA - Gain Flatness

geoff M0ORE
 

The input to this amp is not 50 ohm so the gain variation is due to mis-match on the input.


Re: Shack clock - serial output?

Jim Allyn - N7JA
 

Don't know of any reason a new PCB would be required; there are a half dozen unused pins on the microcontroller on the current PCB.  But Hans is pretty busy and it seems unlikely that he would want to add another bit of code (although probably trivial) to his task list.


Re: QCX 50W T1&T2

Claus, OE6CLD
 

Hi Toni,

Great idea. I still have plenty of Bondic from their Kickstarter campaign.

Will give it a try first.

73,
Claus, OE6CLD, DJ0DX, EI7JZ 


Re: vfo/signal generator

Arv Evans <arvid.evans@...>
 

Mont, and others

When things go badly...REBOOT sounds like earlier versions of Microsoft
Windows.  There are UNIX and Linux systems out there that have not been
rebooted for years. 

What this does bring to mind is that with a little bit of free memory it might
be possible to add some self test routines to the startup or run-once part
of microcontroller code so that the bootup self-tests provided indications
of the state of hardware and software during a boot process.  This could
probably be turned on and off via a word in EEPROM (make it a number
so that the value could control the level of test or debug during the next
bootup).

On the avr or Arduino system a reset is activated during power-up by
having a capacitor to ground and a 10K to +5V on the RESET pin.  The
cap holds the reset lead close to ground for long enough to effect a
boot (JMP to memory address Zero), while the 10K charges the capacitor
to +5V and holds it there after the reboot has occurred. 

What would we want included in a talkative reboot/reset process?  Well,
maybe some basic things like power supply voltage check (displayed or
just a minimum and maximum and light a red LED if out of range. 
Network connection might be interesting to know.  Confirmation of date
and time from an RTC, and other hardware interface confirmations?

Lots of possibilities if one wants to add boot time information like the old
Microsoft systems provided. 

Arv
_._


On Thu, Sep 23, 2021 at 5:32 PM Mont Pierce KM6WT <de.km6wt@...> wrote:
On Thu, Sep 23, 2021 at 11:29 AM, Syd wrote:
from and old computer adage, when things go awry reboot, and that has worked for me and my computers quite a few times in the past. Since rebooting a computer is no more than doing a software reset of it's UProc I decided what can I lose? Resetting a UProc just tells the embedded binary code to start at the very beginning of the program and since that should include checking the RAM contents and going into the "diagnostic" mode and that  would prove that the UProc is still working. Incidentally, if I were writing this code the first thing I would do is set a T/F flag, do the RAM check (diagnostic menu) and then reset the flag so that the code would skip over this step from then on when the program is run from then on, which is exactly what this code is doing. 
I remember the old days too, when you could sit and watch the PC going through it's diagnostics, doing ram check, hardware checks, etc, etc.  And then finally booting.


On the ATMega328p, there is not much room for diagnostics.  QL does some simple tests, like checking if EEPROM is valid, and if it can talk to the Si5351a, (and probably a couple more quick tests I don't know about).  Since these tests are very limited, and run quickly, they are done at every power on.  So as Hans stated, doing a reset or a power cycle, the same code will be executed.


Your comments brought back some fond memories of decades ago...  Thanks.


73
km6wt


Shack clock - serial output?

Stephen Farthing G0XAR JO92ON97
 

Hans, 

Hope all is well. I wonder if it would be possible to add a serial output to the shack clock. 

i have a few very nice VFDs with a serial input one of which would look great as a larger shack clock. I’d be happy with the current time out only. Clearly this requires a code change and possibly a new PCB. 

I’m not sure if other people would want this. It might be useful for providing serial time out for other lab equipment..

if you don’t think it’s worthwhile I can always write my own.

73s Steve G0XAR  

 


Re: #50w #case #building #pa Fitting PCB to upper case half #50w #case #building #pa

Kevin Luxford
 

Hello Hans,
"The 4 holes in the corners of the enclosure are not used. There are not supposed to be any holes for them in the top half of the enclosure. None at all. Those four corner holes are merely there in case anybody wanted to mount the PCB somehow in their own enclosure arrangements." -- Ah now the penny has dropped!  Thank you, and apologies for taking up so much of your precious time.

73,
Kevin VK3DAP / ZL2DAP



On Sat, 25 Sep 2021, at 02:42, Hans Summers wrote:
Hi Kevin
 
I was wondering if there may possibly have been a manufacturing defect in the top case.  Such as the four  PCB holes for the fixing screws inadvertently not drilled and tapped.  You perhaps will recall that these two kits were originally shipped without the heat sinks, which you supplied subsequently.  The 6 mm screws will not start when put in the corner holes of the PCB. I have looked carefully with a bright light and magnifying glass and am unable to see anywhere near the ends of the top case where a 6 mm M3 screw could "take".

And in assembling, I have followed your very clear instructions carefully, in the exact sequence.

However, with the end plates screwed to the case, the PCB won't go anywhere.

With all due immense respect, and apologies in advance, I still respectfully suspect that you might have misunderstood the assembly sequence, sorry ;-)   



There are supposed to be SIX holes in the enclosure. They are untapped. When the two heatsinks are correctly positioned, these six holes line up with some of the holes in the heatsink. The heatsink holes are M3-tapped. I am attaching my drawing of the top half of the 50W PA enclosure to this email. Two of these six holes attach the IRF510 mounting tabs to the heatsink, and the other 4 bolt the two ends of the heatsink to the enclosure lid tightly. 

The only thing holding the PCB assembly fixed to the enclosure lid, is the tabs of the IRF510s. However, the PCB is supposed to be slid into the rails in the aluminium extrusion which forms the enclosure lid, so that it is securely fixed in place once the end panels are fixed on.  

The PCB will slide into the enclosure only if the correct sequence is followed. Don't screw the IRF510 tabs at first. You have to screw the heatsinks to the enclosure at only one end. Then slide in the PCB from the OTHER end (as the IRF510 tabs won't pass the screw heads). Then you can insert the screws for the IRF510, through large holes in the PCB that line up above the IRF510 tabs; and you can insert the two final screws holding the enclosure and heatsinks together, through the two large holes at the Western end of the PCB, the end near the two LEDs. Of course all the while you have to ensure the heatsinks remain desirably square against the top of the lid, and you have to make sure that the silicone pads are properly aligned under the tabs so that the metal tabs of the IRF510s don't touch the aluminium enclosure, and you have to remember the little white spacing washers so that the IRF510 tab screws are insulated from the IRF510 tabs. 

But when it all fits together you will feel a nice sense of achievement :-) 

73 Hans G0UPL




Attachments:
  • TopHalfDrawing.png

-- 
  Kevin B. G. Luxford



--
Kevington


Re: vfo/signal generator

Syd
 

Since I really can't remember which buttons are 1 & 2, I did your sequence assuming 1 and repeated the sequence assuming it was 2.  Still no results!  Will replace UProc!
73 wt1v


Re: #50w #case #building #pa Fitting PCB to upper case half #50w #case #building #pa

Hans Summers
 

Hi Kevin
 
I was wondering if there may possibly have been a manufacturing defect in the top case.  Such as the four  PCB holes for the fixing screws inadvertently not drilled and tapped.  You perhaps will recall that these two kits were originally shipped without the heat sinks, which you supplied subsequently.  The 6 mm screws will not start when put in the corner holes of the PCB. I have looked carefully with a bright light and magnifying glass and am unable to see anywhere near the ends of the top case where a 6 mm M3 screw could "take".

And in assembling, I have followed your very clear instructions carefully, in the exact sequence.

However, with the end plates screwed to the case, the PCB won't go anywhere.

With all due immense respect, and apologies in advance, I still respectfully suspect that you might have misunderstood the assembly sequence, sorry ;-)   

The 4 holes in the corners of the enclosure are not used. There are not supposed to be any holes for them in the top half of the enclosure. None at all. Those four corner holes are merely there in case anybody wanted to mount the PCB somehow in their own enclosure arrangements. 

There are supposed to be SIX holes in the enclosure. They are untapped. When the two heatsinks are correctly positioned, these six holes line up with some of the holes in the heatsink. The heatsink holes are M3-tapped. I am attaching my drawing of the top half of the 50W PA enclosure to this email. Two of these six holes attach the IRF510 mounting tabs to the heatsink, and the other 4 bolt the two ends of the heatsink to the enclosure lid tightly. 

The only thing holding the PCB assembly fixed to the enclosure lid, is the tabs of the IRF510s. However, the PCB is supposed to be slid into the rails in the aluminium extrusion which forms the enclosure lid, so that it is securely fixed in place once the end panels are fixed on.  

The PCB will slide into the enclosure only if the correct sequence is followed. Don't screw the IRF510 tabs at first. You have to screw the heatsinks to the enclosure at only one end. Then slide in the PCB from the OTHER end (as the IRF510 tabs won't pass the screw heads). Then you can insert the screws for the IRF510, through large holes in the PCB that line up above the IRF510 tabs; and you can insert the two final screws holding the enclosure and heatsinks together, through the two large holes at the Western end of the PCB, the end near the two LEDs. Of course all the while you have to ensure the heatsinks remain desirably square against the top of the lid, and you have to make sure that the silicone pads are properly aligned under the tabs so that the metal tabs of the IRF510s don't touch the aluminium enclosure, and you have to remember the little white spacing washers so that the IRF510 tab screws are insulated from the IRF510 tabs. 

But when it all fits together you will feel a nice sense of achievement :-) 

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


Re: #50w #case #building #pa Fitting PCB to upper case half #50w #case #building #pa

Kevin Luxford
 

Hi Hans,
I was wondering if there may possibly have been a manufacturing defect in the top case.  Such as the four  PCB holes for the fixing screws inadvertently not drilled and tapped.  You perhaps will recall that these two kits were originally shipped without the heat sinks, which you supplied subsequently.  The 6 mm screws will not start when put in the corner holes of the PCB. I have looked carefully with a bright light and magnifying glass and am unable to see anywhere near the ends of the top case where a 6 mm M3 screw could "take".

And in assembling, I have followed your very clear instructions carefully, in the exact sequence.

However, with the end plates screwed to the case, the PCB won't go anywhere.

Started on the 40 m QCX 50 W amp assembly having used a marker pen to mark every bag and container with "40 m", and I also wrote the value of components on their bandolier.  However, a minor disaster struck as I was deburring a transformer toroid -- it broke apart into two nearly equal pieces.  I could not find the specs of these toroids so that I could perhaps source a replacement locally, so a small dab of superglue on the faces of the break, followed by applied pressure until the glue had taken hold.  The repaired toroid put in a safe place for at least 12 hours before making the trifilar winding.  I hope that the repair does not render the completed transformer useless.

The motto of my university is "Ancora imparo", Italian (not Latin) "I am still learning" attributed to Leonardo da Vinci, and thanks to Hans and his great designs and kits, it is still true for me in my old age.

Here in Melbourne, we have been living under stay at home orders and a nightly curfew for around a year, and assembling kits is one way of keeping relatively sane and harmless to others.

vy 73,

Kevin VK3DAP / ZL2DAP

On Fri, 24 Sep 2021, at 16:22, Hans Summers wrote:
Hi Kevin

It should not be necessary to drill and tap anything. The enclosure should all be properly drilled and everything correctly placed. 

HOWEVER - it can be confusing, installing the 50W PA PCB in its case because a certain sequence of assembly is required, and if you deviate from that then you find that the thing does not appear to fit properly, holes in the wrong place, screws blocking the PCB sliding in, etc. 

I say this because... I am the one who designed this amp and its enclosure. I am the one that wrote the instructions. But when I was writing the instructions, even then I got confused and did things incorrectly and had to dismantle and take photos again. Then to make sure I had written the instructions properly, I built another one... and even THEN, I still got it wrong... imagine... the designer... LOL. 

So please check again and again - it is quite possible (likely, even) that there is just a misunderstanding in the sequence of assembly steps. 

73 Hans G0UPL






--
Kevington


Re: vfo/signal generator

Mont Pierce KM6WT
 

On Fri, Sep 24, 2021 at 05:36 AM, Rob Giuliano wrote:
then hit left button, then cycle power
I'd add 1 more thing...  don't immediately cycle power. 
It takes about 6-8 seconds to program the EEPROM to default settings.

So wait at least 10-15 seconds before cycling power so you don't interrupt the reset programming.


Ok, I lied... 2 more things:

After resetting the EEPROM, on power up it WILL display "Diagnotic Mode". 
To clear this:

  1. click left button.  Splash screen will be displayed.
  2. click right button to enter config mode.
  3. set any config item to something.
  4. exit config to save edit to EEPROM
Subsequent power cycles will then go straight to Splash screen.


73
km6wt


Re: vfo/signal generator

Mont Pierce KM6WT
 

On Fri, Sep 24, 2021 at 05:36 AM, Rob Giuliano wrote:
It is a quick test and doesn't hurt anything.
Except... any previous settings will be erased.

So if anyone has spent much time getting their VFO configured just right, they probably won't want to do this.


On Fri, Sep 24, 2021 at 05:36 AM, Rob Giuliano wrote:
Immediately on powering the unit, right button, then the left button.
Since the LCD is the issue and you are 'hoping' the reset helps,  you will have to experiment a bit.
  Hold right button on power up - ensure it is quick enough - then hit left button, then cycle power
     If LCD comes back, RESET worked!
  Hit right button within ~1 second of power up then hit left button, then cycle power
     If LCD comes back, RESET worked!
  Hit right button after 2 count of power up then hit left button, then cycle power
     If LCD comes back, RESET worked!
There's one state Rob left out:

If it says "Diagnostics Mode"or you cannot tell what it says,
then Left click, Right click, Left click, Right click   should do it.
     ( this should work even if you're confused like me about
       which button is Right or Left...  as it depends on how
       you're holding/looking at the PCB )

If you can see the LCD, and it says "Setting up..." or "Reseting...",
then the EEPROM is being set to Factory Defaults.


73
km6wt


Re: Another one put together! #40m #build

mike/w1mt
 

Not quite identical.

See https://groups.io/g/QRPLabs/message/58387


Re: Another one put together! #40m #build

Dave Esquer
 

I believe 1.07 and 1.07a are identical. If I remember, I bought a firmware upgrade to 1.07 for an original QCX20 which came with 1.02. I received a 1.07a chip with my new QCXMini 20. Somewhere in this group.io is a message from Hans that states they are the same.  (Dave, K6WDE)