Date   
Re: QCX output power drops when input voltage is above 10 volts

geoff M0ORE
 

I think altering the values of components in a filter will alter more than just the frequency response.

Has anybody measured the Z before and after changing component values? This is physically measuring, not computer simulation.


On 02/09/2019 09:44, Alan G4ZFQ wrote:
By right, the capacitor values should probably be reduced as well if someone really wants to push the cut off point much higher in frequency.


John,

But from previous posts people say that by removing a turn or maybe two brings the inductance to the design value.
Just about everybody that measures them finds they are higher than the specified value, including me..
If that is so then removing turns just brings the cutoff to the required frequency.

73 Alan G4ZFQ




Re: QCX output power drops when input voltage is above 10 volts

Alan G4ZFQ
 

By right, the capacitor values should probably be reduced as well if someone really wants to push the cut off point much higher in frequency.
John,

But from previous posts people say that by removing a turn or maybe two brings the inductance to the design value.
Just about everybody that measures them finds they are higher than the specified value, including me..
If that is so then removing turns just brings the cutoff to the required frequency.

73 Alan G4ZFQ

Re: QCX output power drops when input voltage is above 10 volts

John Desmond
 

That's an interesting result Jon. 

Looking at the manual, it calls for 16 turns for L1 and L3 so reducing it by two is a fair bit. By right, the capacitor values should probably be reduced as well if someone really wants to push the cut off point much higher in frequency.

To answer your question, the output filter will have a certain impedance. As you change the values of the components then the impedance will change as well. If a PA stage is prone to oscillation then this can be a factor.

The old joke is that all amplifiers want to be oscillators so you have to be careful when changing values. 

John, EI7GL

Re: OT Electrolytic caps

MIKE WILLMAN
 

Thanks Everyone for the input, Put in the correct caps. and all is well

Re: LightAPRS

Ron Yates <yatesvilleron@...>
 

Are there any preferred solar powered units that are used with LightAPRS-W (+WSPR) tracker?  Please note I am not a kit builder, more of an “off shelf” talent…lol

 

Is it too simplified to think I could acquire a Pico, the LightAPRS-W, solar power then launch?  Be gentle…lol

 

Ron AR4RY

 

From: QRPLabs@groups.io <QRPLabs@groups.io> On Behalf Of Mustafa Tan
Sent: Sunday, September 1, 2019 12:58 PM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] LightAPRS

 

Hi Brian,

 

Ignore the warnings, they don't break the build.

 

By the way I'd like to contribute to your project if needed and you can always contact us via support@... 

 

TA2MUN

 

On Sun, Sep 1, 2019 at 5:41 PM B C <k9wis@...> wrote:

I tried to compile the LightAPRS-pico balloon program using the latest version of the Arduino IDE and I did not get any errors. but I did get several warning about passing constant strings as parameters to several functions. Strings like 'Wide-1' etc. Is there a compile switch that I should have set to allow this? Can these warnings be ignored? What did you use to build this project? 

 

I am in the process of reverse engineering and documenting the code so I can understand it better and use it for the curriculum I am setting up for a STEM workshop I hope to hold next summer using a pico balloon as the center of focus. I am a retired embedded systems design engineer from Rockwell Automation now serving as an educator at the planetarium. 

 

Brian K9WIS

Horwitz DeRemer Planetarium

Waukesha, WI 

-----------------------------------------

From: "Mustafa Tan"
To: QRPLabs@groups.io
Cc:
Sent: Monday August 26 2019 4:02:45PM
Subject: Re: [QRPLabs] LightAPRS

Hi Brian,

 

Yes it does. 

 

CNSP launched a Super Pressure Balloon last week using a LightAPRS tracker with float altitude of 45.000 feet. (http://www.cnsp-inc.com/cnsp-31/)

 

 

TA2MUN

 

On Mon, Aug 26, 2019 at 9:44 PM B C <k9wis@...> wrote:

Does the GPS work over 40,000 feet? We are putting together a STEM project at the planetarium that I work at so kids can track a balloon, hopefully as it circumnavigates the globe. We are planning a curriculum so they can decode WSPR packets and us APRS.fi to follow and monitor the status of the mission.

Brian K9WIS
Horwitz-DeRemer Planetarium 
Waukesha WI


 

--


 

--

Re: U3S + 5 watt PA troubleshooting help needed.

Liam Kingsmill <lumetters1@...>
 

Compared the measured characteristic of the BS170 from the U3S kit to one of three shipped from DigiKey.  They are nearly identical.  2.6 V and 65nF vs  2.5 V and 73nF.

Conclusion:  The original BS170 that came from QRP-labs still works.  That narrows the problem to the Si5351A or the other IC on the U3S board.

I have ordered another U3S kit with filter and Si5351.

Liam KI7UPZ

Re: LightAPRS

Garry48
 

Brian, Post a couple of the warning messages. Do you have PREFERENCES -> WARNINGS "ALL" set for compile options?  I suspect you do.
Here is how I removed some warnings recently:
/* original code that produced a warning */
//char *menuSend[]    = {" By two's", " Mix     ", " CopyCat ", "Flashcard", " Exit    "}; /* modified line that removed the warning */
char const *menuSend[]    = {" ", " Mix     ", " CopyCat ", "Flashcard", " Exit    "};
I had to add 'const' to the string declatations and type them in function calls using (const char).

Garry




Re: LightAPRS

K9WIS
 


OK...that's good to know it will still work despite the warnings.
Thanks for the offer to support the project..I am sure I will have a lot of questions as we go along. I will be ordering a board from QRPlabs in the next week or so to experiment with. I have several arduino platforms to play with. I am really happy that you and Hans created the hardware and made the code open source.

The target date for the our launch will be next summer...Also any documentation we create we will make available to you. This is going to be fun. 

Brian K9WIS

-----------------------------------------

From: "Mustafa Tan"
To: QRPLabs@groups.io
Cc:
Sent: Sunday September 1 2019 12:58:02PM
Subject: Re: [QRPLabs] LightAPRS

Hi Brian,

Ignore the warnings, they don't break the build.

By the way I'd like to contribute to your project if needed and you can always contact us via support@... 

TA2MUN


On Sun, Sep 1, 2019 at 5:41 PM B C <k9wis@...> wrote:
I tried to compile the LightAPRS-pico balloon program using the latest version of the Arduino IDE and I did not get any errors. but I did get several warning about passing constant strings as parameters to several functions. Strings like 'Wide-1' etc. Is there a compile switch that I should have set to allow this? Can these warnings be ignored? What did you use to build this project? 

I am in the process of reverse engineering and documenting the code so I can understand it better and use it for the curriculum I am setting up for a STEM workshop I hope to hold next summer using a pico balloon as the center of focus. I am a retired embedded systems design engineer from Rockwell Automation now serving as an educator at the planetarium. 

Brian K9WIS
Horwitz DeRemer Planetarium
Waukesha, WI 

-----------------------------------------

From: "Mustafa Tan"
To: QRPLabs@groups.io
Cc:
Sent: Monday August 26 2019 4:02:45PM
Subject: Re: [QRPLabs] LightAPRS

Hi Brian,

Yes it does. 

CNSP launched a Super Pressure Balloon last week using a LightAPRS tracker with float altitude of 45.000 feet. (http://www.cnsp-inc.com/cnsp-31/)


TA2MUN

On Mon, Aug 26, 2019 at 9:44 PM B C <k9wis@...> wrote:
Does the GPS work over 40,000 feet? We are putting together a STEM project at the planetarium that I work at so kids can track a balloon, hopefully as it circumnavigates the globe. We are planning a curriculum so they can decode WSPR packets and us APRS.fi to follow and monitor the status of the mission.

Brian K9WIS
Horwitz-DeRemer Planetarium 
Waukesha WI



--



Re: QCX output power drops when input voltage is above 10 volts

Jon Reck W8REA
 

I messed around some more with turns and discovered that, yes indeed, the oscillation (if that's what it is) happens when I remove 2 turns from L1 and L3. I put a turn back and removed one turn from L2 and no oscillation and a power increase from the original 2W to about 2.75W. Just to be clear, that's removing 1 turn each toroid from the specified number of turns in the manual.

At this point, I'm leaving well enough alone. Just relieved that it works.

Jon, W8REA

Re: Ultimate 3S #u3s

Sverre Holm
 

I agree cell phone chargers are good for what they are intended for, but may be too noisy as a power supply driving e.g. an U3S. On the other hand, many have found, like I, that the switch-mode power supply modules using LM2596 do a good job, despite their very low price on eBay. Just search for LM2596S Power DC-DC Buck Converter Step Down Module 5V 3A and you'll find modules for slightly more than 1 USD.

--
Sverre

 

LA3ZA, http://la3za.blogspot.com

Re: LightAPRS

Mustafa Tan
 

Hi Brian,

Ignore the warnings, they don't break the build.

By the way I'd like to contribute to your project if needed and you can always contact us via support@... 

TA2MUN


On Sun, Sep 1, 2019 at 5:41 PM B C <k9wis@...> wrote:
I tried to compile the LightAPRS-pico balloon program using the latest version of the Arduino IDE and I did not get any errors. but I did get several warning about passing constant strings as parameters to several functions. Strings like 'Wide-1' etc. Is there a compile switch that I should have set to allow this? Can these warnings be ignored? What did you use to build this project? 

I am in the process of reverse engineering and documenting the code so I can understand it better and use it for the curriculum I am setting up for a STEM workshop I hope to hold next summer using a pico balloon as the center of focus. I am a retired embedded systems design engineer from Rockwell Automation now serving as an educator at the planetarium. 

Brian K9WIS
Horwitz DeRemer Planetarium
Waukesha, WI 

-----------------------------------------

From: "Mustafa Tan"
To: QRPLabs@groups.io
Cc:
Sent: Monday August 26 2019 4:02:45PM
Subject: Re: [QRPLabs] LightAPRS

Hi Brian,

Yes it does. 

CNSP launched a Super Pressure Balloon last week using a LightAPRS tracker with float altitude of 45.000 feet. (http://www.cnsp-inc.com/cnsp-31/)


TA2MUN

On Mon, Aug 26, 2019 at 9:44 PM B C <k9wis@...> wrote:
Does the GPS work over 40,000 feet? We are putting together a STEM project at the planetarium that I work at so kids can track a balloon, hopefully as it circumnavigates the globe. We are planning a curriculum so they can decode WSPR packets and us APRS.fi to follow and monitor the status of the mission.

Brian K9WIS
Horwitz-DeRemer Planetarium 
Waukesha WI



--



Re: LightAPRS

K9WIS
 

I tried to compile the LightAPRS-pico balloon program using the latest version of the Arduino IDE and I did not get any errors. but I did get several warning about passing constant strings as parameters to several functions. Strings like 'Wide-1' etc. Is there a compile switch that I should have set to allow this? Can these warnings be ignored? What did you use to build this project? 

I am in the process of reverse engineering and documenting the code so I can understand it better and use it for the curriculum I am setting up for a STEM workshop I hope to hold next summer using a pico balloon as the center of focus. I am a retired embedded systems design engineer from Rockwell Automation now serving as an educator at the planetarium. 

Brian K9WIS
Horwitz DeRemer Planetarium
Waukesha, WI 

-----------------------------------------

From: "Mustafa Tan"
To: QRPLabs@groups.io
Cc:
Sent: Monday August 26 2019 4:02:45PM
Subject: Re: [QRPLabs] LightAPRS

Hi Brian,

Yes it does. 

CNSP launched a Super Pressure Balloon last week using a LightAPRS tracker with float altitude of 45.000 feet. (http://www.cnsp-inc.com/cnsp-31/)


TA2MUN

On Mon, Aug 26, 2019 at 9:44 PM B C <k9wis@...> wrote:
Does the GPS work over 40,000 feet? We are putting together a STEM project at the planetarium that I work at so kids can track a balloon, hopefully as it circumnavigates the globe. We are planning a curriculum so they can decode WSPR packets and us APRS.fi to follow and monitor the status of the mission.

Brian K9WIS
Horwitz-DeRemer Planetarium 
Waukesha WI



Re: Ultimate 3S #u3s

Don--AE4DW
 

On Sat, Aug 31, 2019 at 07:50 AM, Don wrote:
Hello Group,

As my summer build project of a multi-band Ultimate 3S approaches completion, I'm wondering what others are using for their 5 VDC power supply?  I haven't managed to find a current requirement for this interesting project running only 5 vdc and (at most) three BS170 PA transistors. Any ideas?
 
I was planning on using one of the ubiquitous cell phone chargers but while the one I had in mind was clearly marked DC, it really isn't. A simple series 1N4148 diode seems to make a huge difference, but is this a sufficient power source for a three output transistor U3S?

FWIW, it is always nice to receive an interesting kit with excellent build instructions and no parts shortages. Thank you QRP-Labs.

Thanks for any input,
... Don K3RLL  

I've been doing some testing with multiple BS170s, and even with 3, you're easily less than a 1A draw. if you're running everything on 5V (as opposed to a higher PA supply V) just use a good clean regulated 5V supply, rated at an amp or better. Cell phone chargers are a crap shoot, as is a lot of the cheap garbage you find on ebay, or even Amazon. The quality definitely matches the price. 

Dependent on what i'm doing and where I'm testing, I've used my bench supply, a repurposed PC supply, or a small 5V usb battery back with a hacked cable.

And you are definitely correct..Hans' kits are a fun build, good build instructions, and a ton of support as needed.

Re: Ultimate 3S #u3s

Sverre Holm
 

I'm using regulators based on the L;2596, cheap on Ebay. A fixed one for the processor and a variable one for the PA.. See https://la3za.blogspot.com/2017/02/comparing-two-antennas-with-wspr.html



--
Sverre

 

LA3ZA, http://la3za.blogspot.com

Re: U3S + 5 watt PA troubleshooting help needed.

Liam Kingsmill <lumetters1@...>
 

Alan,

BS170's arrived today.  Installed one.  U3S still does not function.  The PicoScope shows what I believe is instability or oscillation at a varitey of frequencies.  None of which the scope likes well enough to trigger on consistently.  (Operator sips another mouthful of his vodka-tonic.)  Therefore, I will order another U3S.  The order will be for 14MHz version.

GPS sets, time, date, frequency. 

This U3S worked when first built and when first had power applied.  Then, I added the 5 watt amp and that short (one strand of stranded wire across the 5V power supply).  That short seems to have done more than blow the 1 amp fuse.

Gabby Hays quote:  "Dag Nab It"

Liam

Re: Ultimate 3S #u3s

James Daldry W4JED
 

Hi, Bruce

Even more fun is the XK-700 trainer. I built one in the early '90's and the lid is very seldom closed. Plus and minus fixed and variable power supplies, function generator, "stimulus" switches, "reaction" LED's, double row 80 pin solderless breadboard. The only thing it doesn't have is meters on the supplies. It runs on the same transformer, and uses the same regulators, as the bench supply.

Jim W4JED


On 8/31/19 12:01 PM, Bruce K1FFX wrote:
This is what I've been using for all my QRP Kits activity:

https://www.amazon.com/Elenco-Triple-Output-Power-Supply/dp/B0002DT0GU/

Reviewed in the April, 2018, issue of QST.

And you get to have more kit building fun as well.

Best -

Bruce K1FFX

Re: Ultimate 3S #u3s

Mike Berg
 

My Elenco power supply has been going for 25+ years and it gets used every day.

Glad to see it's still in production.

Mike N0QBH

Re: Ultimate 3S #u3s

Bruce K1FFX
 

This is what I've been using for all my QRP Kits activity:

https://www.amazon.com/Elenco-Triple-Output-Power-Supply/dp/B0002DT0GU/

Reviewed in the April, 2018, issue of QST.

And you get to have more kit building fun as well.

Best -

Bruce K1FFX

Re: Ultimate 3S #u3s

John Canfield
 

My U3S runs off one of my shack's two 12V power supplies and I use a LM7805 on a little prototype board inside the U3S case. The heat from the 7805 keeps the board thermally stable. I think I measured maximum current consumption of the U3S about 500-600 Ma. By the way, I have a fairly large heat sink on the regulator, it's been running for several months with this configuration.
--
John, WB5THT

Re: QCX output power drops when input voltage is above 10 volts

Jon Reck W8REA
 

Thank you, John-

I first noticed the problem after I removed 2 turns from L2. (this was after removing 2 turns from both L1 and L3)  At that time I had also mistakenly de-soldered one of the leads from an adjacent resistor. I re-soldered the resistor and re-wound L2 with fresh wire, back to the original full winding.

Could oscillation be caused by removing too many turns form L1 and L3?

Jon, W8REA