Re: ATU-10: an alternative PCB layout?
Robbie,
blonde is the new forgetful! Try , where AN-691 () discusses LF operation of the AD8361, and various other chips.
HTH, 73, Stay Safe,
Robin, G8DQX
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On 01/03/2022 11:30, Robbie M1ROK wrote: I'm probably having a blonde moment here but as the?AD8361 is an RF detector for the 100MHz-2GHz range how can it be accurate at the lower HF frequencies? Just curious...
Robbie M1ROK
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Re: ATU-10: an alternative PCB layout?
I'm probably having a blonde moment here but as the?AD8361 is an RF detector for the 100MHz-2GHz range how can it be accurate at the lower HF frequencies? Just curious...
Robbie M1ROK
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Re: ATU-10: an alternative PCB layout?
Hello!
The PCB is designed to accept SOT-23-6.
My point of view - because the capacitors and inductors have only 128 steps (just seven relays, so 2[sup]7[/sup] available values), there is no sense in higher resolution ADCs. The built-in are 12 bits and David adjusts the reference voltage to accomodate the input signal level: for coarse measurements there is 2-volts VREF, for finer measurements of lower signals he switches to 1-volt VREF. This should be more than enough (I think).
I'm winding the coils trying to have them doubling the inductance, so that the "power of two" set of values would be obtained. This is VERY difficult to achieve. The first three coils are easy, from there on - even a slightest movement of individual wires changes the resulting inductance severely - way much more that the by the value of the first (Least Significant Bit) coil. To obtain a smooth and monotonous "inductance vs control code" characteristic I need to somehow glue the wires to the cores. With capacitors it is possible to choose the values for the "power of two" set, and hope that the C0G material will be stable enough to keep it. Initially I was looking for 1% capacitors but higher-voltage ones are very expensive (not all values are available even at Mouser!). Now I'm peeking among those I've got so far.
Regards,
Tony
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Re: ATU-10: an alternative PCB layout?
The AD8361 is a great part and ideal for this application or as a mWattmeter. Are you testing the SOIC or SOT23 package ? You might have to add a better (more bits) ADC with a I2C interface like the MCP3422A0.
73 Kees K5BCQ
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Re: ATU-10: an alternative PCB layout?
Hi, I think that it is a very interesting concept and as soon as I can get hold of a PCB I will definitely try that.? Vy 73 de?
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Am 28.02.2022 um 18:07 schrieb ZAO via groups.io <zao@...>:
?Dear Michael,
My goal is an attempt to make it possible to tune with as little RF-power as possible.
The original project (just as most other SWR-meters and ATUs) employs diodes as RF-detectors. This is OK for higher-power devices, and it requires some sort of diodes' Volt-Amp curve linearisation - because diodes do not rectify well if small signal is applied.
The quality of any ATU is (among other things) rated by its' ability to determinate the between the forward and the reflected RF-power; and by the insertion loss it causes. These parameters are called the directivity and the isolation factors. Both of them depend on design of the RF-transformer called the Trandem Match or the binocular".
The Tandem Match or equivalent transformers' in the high-power ATUs have windings ratio around 1:20 which provides for better isolation factor (less losses in the direct path).
The original ATU-10 has 1:5 ratio - because of QRP nature of that project. The isolation factor is not sufficient (by my liking!). The 1:5 ratio is - as I think - a compromise between the isolation and sensitivity. Make it 1:10 - the isolation improves but the RF-power to be rectified by diodes gets too low (in this QRP project).
By using the AD8361 RF-detector instead of more common diodes allows (as I hope) to achieve good isolation and have good sensitivity as well. David has built an ATU with AD8361 before, he recommends to wind 1:10 ratio at the Tandem Match. By guarding the AD8361 inputs with 15dB attenuators it is possible to achieve very good balance of the windings - this assures high directivity factor in the ATU.
The directivity is THE factor most important for an ATU because in the process of tuning the less and less power reflects from the load. If it were diodes - they would stop giving the voltage sooner. The AD8361 RF-detectors will provide signals at much lower reflected power levels - thus THEORETICALLY the ATU could tune to better SWRs.
Hope to get the PCBs from the factory soonest to give that modification a try.
Regards,
Tony
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Re: ATU-10: an alternative PCB layout?
Dear Michael,
My goal is an attempt to make it possible to tune with as little RF-power as possible.
The original project (just as most other SWR-meters and ATUs) employs diodes as RF-detectors. This is OK for higher-power devices, and it requires some sort of diodes' Volt-Amp curve linearisation - because diodes do not rectify well if small signal is applied.
The quality of any ATU is (among other things) rated by its' ability to determinate the between the forward and the reflected RF-power; and by the insertion loss it causes. These parameters are called the directivity and the isolation factors. Both of them depend on design of the RF-transformer called the Trandem Match or the binocular".
The Tandem Match or equivalent transformers' in the high-power ATUs have windings ratio around 1:20 which provides for better isolation factor (less losses in the direct path).
The original ATU-10 has 1:5 ratio - because of QRP nature of that project. The isolation factor is not sufficient (by my liking!). The 1:5 ratio is - as I think - a compromise between the isolation and sensitivity. Make it 1:10 - the isolation improves but the RF-power to be rectified by diodes gets too low (in this QRP project).
By using the AD8361 RF-detector instead of more common diodes allows (as I hope) to achieve good isolation and have good sensitivity as well. David has built an ATU with AD8361 before, he recommends to wind 1:10 ratio at the Tandem Match. By guarding the AD8361 inputs with 15dB attenuators it is possible to achieve very good balance of the windings - this assures high directivity factor in the ATU.
The directivity is THE factor most important for an ATU because in the process of tuning the less and less power reflects from the load. If it were diodes - they would stop giving the voltage sooner. The AD8361 RF-detectors will provide signals at much lower reflected power levels - thus THEORETICALLY the ATU could tune to better SWRs.
Hope to get the PCBs from the factory soonest to give that modification a try.
Regards,
Tony
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Re: ATU-10: an alternative PCB layout?
Thanks Tony - Forgive my ignorance, how does this improve the
system?? I'm learning as I go here.
On 2/24/2022 11:40 AM, ZAO via
groups.io wrote:
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Dear Michael,
I did not change much - there are the same 0603 capacitors and
resistors, the board is mostly the same as the original.
Only the diodes are replaced with the AD8361 detectors and an
additional PCB trace is provided to control them.
This change requires to amend the firmware, that's what I'm trying
to do right now as I wait for the PCBs to arrive.
Regards,
Tony
_._
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Re: ATU-10: an alternative PCB layout?
Dear Michael,
I did not change much - there are the same 0603 capacitors and resistors, the board is mostly the same as the original.
Only the diodes are replaced with the AD8361 detectors and an additional PCB trace is provided to control them.
This change requires to amend the firmware, that's what I'm trying to do right now as I wait for the PCBs to arrive.
Regards,
Tony
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I will try re-winding?binocular core.? I thought I was careful to get good connections, but you never know.? I also have some magnet wire that is a bit thicker I can use.
Does the phasing between the two sides make a difference?? I didn't really pay attention to this when I wound it.
--
Dennis
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Re: Site currently unavailable
Or you can go to David's github repo and grab the users manual which is the same thing.
Vince.
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On 02/23/2022 01:06 PM, Tony Magon wrote: Thanks for the help
On Thu, Feb 24, 2022 at 5:01 AM Karl Heinz Kremer - K5KHK <khk@...
<mailto:khk@...>> wrote:
Try the internet archive:
--
Michigan VHF Corporation -- nobucks dot net
K8ZW -
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I agree, the quality is by far not the same as Elecraft or QRP-Labs or Heathkit (used tobe). And I had to buy pcb from one supplyer and housing as well as diplay from another. Vy 73 de Rolf, DL8BAG ? ? A buyer should not have to reprogram a so called pre-programmed part! It should be ready to go. Isn't that why we buy kits with the processor pre-programmed? With all the different processors being used now days, It would be expensive to have programmers for all of them. On Wednesday, February 23, 2022, 08:55:24 AM CST, Rolf Schroeder <rolf@...> wrote: Hi, two things were wrong: display type and adress - obviously the display cannot show anything if you looking at the wrong adress and afterwards try to talk to it in a foreign language :-)
Thanks again for your hints. This reveals of course one thing: without a pickit3 you would consider the kit to be defect although it wasn't and you sometimes need to dig into the details.
Vy 73 de
Rolf, DL8BAG
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Re: Site currently unavailable
Try the internet archive:
?
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A buyer should not have to reprogram a so called pre-programmed part! It should be ready to go. Isn't that why we buy kits with the processor pre-programmed? With all the different processors being used now days, It would be expensive to have programmers for all of them.
Max KG4PID
On Wednesday, February 23, 2022, 08:55:24 AM CST, Rolf Schroeder <rolf@...> wrote:
Hi,
two things were wrong: display type and adress - obviously the display cannot show anything if you looking at the wrong adress and afterwards try to talk to it in a foreign language :-)
Thanks again for your hints. This reveals of course one thing: without a pickit3 you would consider the kit to be defect although it wasn't and you sometimes need to dig into the details.
Vy 73 de
Rolf, DL8BAG
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Site currently unavailable
A month or two ago I found a web page with the ATU info
It was
but it now says that the site is unavailable
Maybe someone can help? - I did not copy the full webpage and of course now it is unavailable
Regards
Tony VK2IC - Sydney
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Hi,
two things were wrong: display type and adress - obviously the display cannot show anything if you looking at the wrong adress and afterwards try to talk to it in a foreign language :-)
Thanks again for your hints. This reveals of course one thing: without a pickit3 you would consider the kit to be defect although it wasn't and you sometimes need to dig into the details.
Vy 73 de
Rolf, DL8BAG
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Re: PIC16f1938 and changing eeprom
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Re: PIC16f1938 and changing eeprom
You can reprogram them just fine. You just can't read what's currently in it. After the reprogram, you'll be able to read it without a problem.
Now somehow I managed to wipe out what's in my PIC, so I'll be re-writing it sooner than planned and might as well rewind them things now. Got the desoldering iron all warmed up to pull the old ones.
Vince - K8ZW.
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On 02/22/2022 05:45 PM, Diogenio via groups.io wrote: Hey Vince:
I saw your post on groups.io
How will these "Chinese protected" PICs affect us with our 1 kW kits?
Will we just be able to write over the existing software and not even
worry about it?
My toroid cores are on their way from "DIZ" but I did receive my Pickit3
programming setup already.
73,
-Dennis W1LJ
On Tuesday, February 22, 2022, 12:47:13 PM MST, Vince Vielhaber
<vev@...> wrote:
If it's a Chinese kit you'll probably find that they read protected the
PIC. The vendor I got my ATU-1000 from told me the factory does that on
all of them. There's a thread on here somewhere about someone else
having that same issue.
Vince - K8ZW.
On 02/22/2022 07:10 AM, Jo PG4I wrote:
Hi Onno,
I am experimenting with the atu-100 now (100W version) and I made a
backup of the hex file with pk2cmd and a PICKIT2 as follows:
*pk2cmd -PPIC16F1938 -A5 -T -R -J -GFN7DDC.hex
*
I can send you my backup file if you like.
I am currently looking into reading the EEPROM, no luck so far. It
should be something like:
*pk2cmd -PPIC16F1938 -R -J -GE00-3F*
But I get all zero's:
*Read successfully. *
*EEData Memory*
*0000 00 00 00 00 00 00 00 00 *
*0008 00 00 00 00 00 00 00 00 *
*0010 00 00 00 00 00 00 00 00 *
*0018 00 00 00 00 00 00 00 00 *
*0020 00 00 00 00 00 00 00 00 *
*0028 00 00 00 00 00 00 00 00 *
*0030 00 00 00 00 00 00 00 00 *
*0038 00 00 00 00 00 00 00 00 *
*Operation Succeeded*
73 Joop PG4I
--
Michigan VHF Corporation -- nobucks dot net
K8ZW -
--
Michigan VHF Corporation -- nobucks dot net
K8ZW -
|
Looking for a case for the ATU-1000.? Any suggestions or help finding a case for the ATU-1000 would be greatly appreciated.
Thank you? 73
Emory? WM3M
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Re: PIC16f1938 and changing eeprom
Hey Vince:
I saw your post on groups.io
How will these "Chinese protected" PICs affect us with our 1 kW kits? Will we just be able to write over the existing software and not even worry about it??
My toroid cores are on their way from "DIZ" but I did receive my Pickit3 programming setup already.
73, -Dennis? W1LJ
On Tuesday, February 22, 2022, 12:47:13 PM MST, Vince Vielhaber <vev@...> wrote:
If it's a Chinese kit you'll probably find that they read protected the
PIC.? The vendor I got my ATU-1000 from told me the factory does that on
all of them.? There's a thread on here somewhere about someone else
having that same issue.
Vince - K8ZW.
On 02/22/2022 07:10 AM, Jo PG4I wrote:
> Hi Onno,
>
> I am experimenting with the atu-100 now (100W version) and I made a
> backup of the hex file with pk2cmd and a PICKIT2 as follows:
>
> *pk2cmd -PPIC16F1938 -A5 -T -R -J -GFN7DDC.hex
> *
> I can send you my backup file if you like.
> I am currently looking into reading the EEPROM, no luck so far. It
> should be something like:
>
> *pk2cmd -PPIC16F1938 -R -J -GE00-3F*
>
> But I get all zero's:
> *Read successfully.? ? ? ? ? ? *
>
> *EEData Memory*
> *0000 00? 00? 00? 00? 00? 00? 00? 00? *
> *0008 00? 00? 00? 00? 00? 00? 00? 00? *
> *0010 00? 00? 00? 00? 00? 00? 00? 00? *
> *0018 00? 00? 00? 00? 00? 00? 00? 00? *
> *0020 00? 00? 00? 00? 00? 00? 00? 00? *
> *0028 00? 00? 00? 00? 00? 00? 00? 00? *
> *0030 00? 00? 00? 00? 00? 00? 00? 00? *
> *0038 00? 00? 00? 00? 00? 00? 00? 00? *
>
> *Operation Succeeded*
>
> 73 Joop PG4I
>
--
? ? ? ? Michigan VHF Corporation -- nobucks dot net
? ? ? ? ? ? ? K8ZW -
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Rolf Schroeder
Jo PG4I