Date   

Re: LightAPRS-W (WSPR) Tracker: attaching capacitors and solar panel

Robert Rabin
 

Hi Mustafa,

From the photos in "Tips and tricks for Pico Balloons", it appears that the solar panel and capacitors are each connected to the "raw" and "ground" pins on each side of the LightAPRS-W board. Is this correct? Does "raw" refer to the input positive DC voltage?

Thank you!

-Bob KA5MIZ


Re: What are you QRP guys using to measure power?

Dave VE3LHO
 

Mini? Do you mean micro?  I think the thing you call "fat mini" is really a miniUSB and the the thing you call "mini" is really microUSB.

micro has been pretty much standard for consumer portable electronics for coming up to a decade. Certainly the first device I had with a micro was in 2010 (Sony Ericson X10 phone). As I recall around about then the EU mandated that phone manufacturers needed to standardize on some connector (to reduce e-waste every time a new phone was purchased). Apple was the exception to that but since when did Apple follow anyone else's rules. I don't know how they got sround this requirement.

Mini lived on for a couple of years but I'll bet any device using mini was designed more than 6 or 7 years back. (Note I'm not saying you bought it that long ago. Some companies will keep succesfull products around as long they can milk them.) Case in point is the Arduino nano many of us will know. Yes it uses a miniUSB but it is a fairly old design they simply haven't updated (except for a few clone makers AFAIK)

USB-C is not only ambidextrous (can be plugged in either way) the connector is also supposed to be more robust than the micro and survive more plug-unplug cycles. Time will tell I guess.

Of less interest to many of us is that it brings higher speed to a small form factor connector.


On Sun, May 31, 2020 at 05:21 PM, James Daldry W4JED wrote:

Hi, Arv

Last year I bought a Motorola E5 Tracfone to get myself into a more recent Android version. Since it had problems with my favorite podcast player, I bought its big brother, the G6, and gave the E5 to my wife. The G6 solved the podcast problem, but, instead of using the common mini USB connector like every phone that I had ever had before that, it had a USBC connector, same size as the mini, but reversible. I guess they come up with the higher current capacity by having 2 connections for each wire, arranged abcddcba, so it reads the same right side up and upside down. Or else 2 rows of 4 over and under, with the top row reversed. So, here at my living room end table, I have 3 wall warts with USB cables - C for the phone, mini for the Amazon Fire, and "fat mini" for the Kobi ebook reader.

73

Jim W4JED

On 5/30/20 10:43 PM, Arv Evans wrote:
Alison
 
Thanks for all the info.  It will come in handy.  Especially appreciate the comment about the reversable USB connector.  That relieves my concern about possibly backwards connection.
 
Arv
_-_
 

On Sat, May 30, 2020, 7:54 PM ajparent1/KB1GMX <kb1gmx@...> wrote:
Arv,

A wonderful instrument to have if your doing any RF measurement.
Team it up with a SA and RF measurements get very interesting.

Yes, the prices are all over the map as it here are clones like crazy.
There are at least three versions as well  (mostly different firmware).

However as a long term user of HP and Agilent VNA and PNA machines
costing tens of kilobucks the nanoVNA is a remarkable tool for pennies.

The number of things you can worth one is nothing short of RF multitools
category.  I use it for filters of all sorts well into UHF, crystal filter testing
and adjustment, amplifier gain, port reflections and such, and cable checks
just to scratch the surface.  When working with power amps you can sort
out input mismatch, output mismatch, and even loss through TR relays
and leakage around them.  My favorite use is S21 mode as output to
reference antenna (simple dipole) and input from antenna under test
(after doing it with reference dipole in the input too).  Collect the data
from that and you can determine the antenna gain in DBD, patterns
of the antenna in any inclination or azimuth at least for antennas 
that you can handle like smaller than 6M beam (really handy for 432
and up).

Once your into smith charts and the  theory it becomes easy to see
how input or output matching works and how to move around the
impedance circle.

The connector used is polarized but symmetrical dual contacts so there
is no upside down.   Or as I call it yet another USB connector (YAUC).

Allison





-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


Re: QCX DX QSO!

George Korper
 

We should try a sked sometime. At least i can listen for you. I reach Japan with 200 mW on WSPR about that time in Mexico. 


On Sun, May 31, 2020, 8:23 PM Saku JP3OUG <jp3oug599@...> wrote:

Thank you.

Well, it was 08:30 P.M. in Japan ( =11:30 A.M. at UTC) .
I often hear signals from U.S. on 7MHz at that time.
But the one from Central America was new for me.
( I think that's because my antenna is very poor...hi )

JP3OUG Saku


Re: QCX-20 ... low output power (~1.5 W) #20m #qcx

Mike Easterbrook
 

Hi Rob
This sounds very similar to my experience. Using a straight key l get 4W most times but occasionally >1W - in this condition total current if I dare keep key down long enough is 900mA versus 450mA for "normal" i.e. 4W output.  All these at 13.8 v at input connector. Compressing turns or adding one turn to L3 or reducing supply volts to 12 eliminates problem. If I change to paddle & key a series of dits I can can see about 1in20 dits on the power meter (analogue) where the output drops. This avoids trying to troubleshoot key-down with rapidly frying finals!

What total current are you drawing when output is low or high?

My best guess is that something in the PA or shaping is on the edge of self-oscillation.


Re: [help] Only noise being seen while IQ balance / phase lo / phase hi.

Jose Tent
 

OK.   Took out c22. 

Voltage on IC10 has returned  closer to the expected value. 

    Measured voltage for IC10 are:   pin  1  ~ 8   :   5.90 / 5.93 / 5.93 / 0  ==  6.08 / 5.90 / 5.93 / 11.87    (Volts) 
    Manual indicates :                       pin  1  ~ 8   :   5.8    / 5.8   / 5.8   / 0  ==  4.2  / 3.94  / 5.83 / 11.67    (Volts) 

Pin 5,6 has a higher voltage than expected.   But, it's not as bad as the 12 volts I was seeing on pin 1,2,3. 

I have to go source a 10uF cap now.  With all the small electronics stores closed around NJ, I guess I have to go to digikey ?  I don't imagine Homedepot sells these.

Will report back when I get it in. 


Re: [help] Only noise being seen while IQ balance / phase lo / phase hi.

Don VE3IDS
 

Jose
If you clip the top lead of R37, that should separate R37 and C22 so you can do resistance checks of both without disturbing the board joints at this time. The cap should have infinite resistance. 

Don ve3ids


On Sun., May 31, 2020, 9:06 p.m. Jose Tent, <ksaito2@...> wrote:
Mutimeter:
    I'm using a 10030S Southwire digital multimeter.  Cheap, but not the absolute bottom of the barrel either.   

R37 Voltage REDUX:
I rechecked the voltage on R37 today again.   Well, the voltage on the top connected to IC10 Pin 5 is always higher by a bit through the swing of the volume pot. 
   Voltage top of R37 (IC10 pin 5) :     0.93v (@low Vol)    / 2.36v (@med Vol)    / 2.98v (Full vol) 
   Voltage bottom of R37 (C22)     :      0.8 V                    /  1.72v                     /   2.47v

Q7
I checked Q7 confirmed correct insertation.  Soldering looks good as far as I can see without any soldering whiskers. But it's hard to see since it's under the Volume pot. 

C22:
Ajparent1 is the second person mentioning installing C22 incorrectly. C22 doesn't have polarity. It is installed at the correct place. 

----

SO I guess we seem to have concurence that C22 may be bad and to proceed with taking it out and measuring IC10 voltage per Alan's post ??
(I'd rather remove c22 than IC10, so that is kind of a good news among the bad news) 

BTW, I want to thank everyone for helping me.   This has been educational.  




Re: QCX DX QSO!

Saku JP3OUG
 


Thank you.

Well, it was 08:30 P.M. in Japan ( =11:30 A.M. at UTC) .
I often hear signals from U.S. on 7MHz at that time.
But the one from Central America was new for me.
( I think that's because my antenna is very poor...hi )

JP3OUG Saku


Re: QCX DX QSO!

George Korper
 

Wow. Congrats. What was the time in Japan?


On Sun, May 31, 2020 at 8:26 PM Gary Bernard via groups.io <garybernard2=aol.com@groups.io> wrote:
Good job Saku. Nice case also.
73 Gary


-----Original Message-----
From: Saku JP3OUG <jp3oug599@...>
To: QRPLabs@groups.io
Sent: Sun, May 31, 2020 5:54 pm
Subject: [QRPLabs] QCX DX QSO!

Hello from Japan.

Yesterday, I heard a "CQ TEST" of a call sign with a prefix that I don't know.
I looked up the call sign, TI7W, on the QRZ.COM, and I realized it was a signal from Costa Rica!
Then I called him again and again.
Eventually, he copied my call sign correctly.
We exchanged the contest number. 
It is my record with my QCX-40.
About 13360 km with 3W !

The antenna I was using was a wire dipole, up about 6 meters high.
(Please visit my QRZ.COM page and see my set up.)

I heard that Costa Rica was the number one country in the World Happiness Index.
But now, 'I' am feeling happiest ever!

73 DE JP3OUG Nishigaki Sakutaro (Saku)


Re: [help] Only noise being seen while IQ balance / phase lo / phase hi.

Jose Tent
 

Mutimeter:
    I'm using a 10030S Southwire digital multimeter.  Cheap, but not the absolute bottom of the barrel either.   

R37 Voltage REDUX:
I rechecked the voltage on R37 today again.   Well, the voltage on the top connected to IC10 Pin 5 is always higher by a bit through the swing of the volume pot. 
   Voltage top of R37 (IC10 pin 5) :     0.93v (@low Vol)    / 2.36v (@med Vol)    / 2.98v (Full vol) 
   Voltage bottom of R37 (C22)     :      0.8 V                    /  1.72v                     /   2.47v

Q7
I checked Q7 confirmed correct insertation.  Soldering looks good as far as I can see without any soldering whiskers. But it's hard to see since it's under the Volume pot. 

C22:
Ajparent1 is the second person mentioning installing C22 incorrectly. C22 doesn't have polarity. It is installed at the correct place. 

----

SO I guess we seem to have concurence that C22 may be bad and to proceed with taking it out and measuring IC10 voltage per Alan's post ??
(I'd rather remove c22 than IC10, so that is kind of a good news among the bad news) 

BTW, I want to thank everyone for helping me.   This has been educational.  




Re: Fuse settings question

James Daldry W4JED
 

Hi, Jack

Sorry it took so long to get back to you. I was playing with, first, the Arduino IDE, then the avrgcc, avrgdb, avrdude, etc to find out what happened when you changed a simple program with one variable and 1 if statement, and, with the Arduino, the Serial.begin(9600); incantation. In the end I found that with either the Arduino IDE or avrgcc (which Arduino uses) the size of an empty int main(void) is exactly the same size with one variable added, and still the same size with an if comparison added, a little over 400 bytes. The Serial.begin(9600) puffed it up to over 1600 bytes. So I guess you could add the "if" without using up any precious bytes.

Maybe some day I'll try adding stuff to the simple program until it actually makes the .hex bigger.

73

Jim W4JED

On 5/24/20 10:26 AM, jjpurdum via groups.io wrote:
Jim:

How do you know the QCX is not programmed in C? Actually, there could be a Serial.begin(9600) in it for debugging purposes. I use scaffolding code all the time:

#define DEBUG
// ...a bunch of statements, then in setup()...

   #ifdef DEBUG
      Serial.begin(9600);
   #endif
// ...the rest of the sketch

When I'm debugging the code, I leave the #define for DEBUG active. When I'm done and ready for distribution, I comment out DEBUG , which means all of my calls to the Serial object are not compiled into the sketch. If I later find I missed a bug, I remove the comment characters for the DEBUG symbolic constant, recompile, and all my debug code is back in the executable without typing a single new line.

I'm pretty sure the QCX does use C and likely some assembler as well.

Jack, W8TEE

On Sunday, May 24, 2020, 9:54:29 AM EDT, James Daldry W4JED <jim@...> wrote:


Hi, Arv

The QCX is not an Arduino. The QCX is not an Arduino. The QCX is not an Arduino. Should I write it a few more times?

The QCX is not programmed in C. There has been no Serial.begin(9600) code written into it. Your "simple" string has to be written a half-byte at a time to the LCD. The code to make the comparison and goto a do-nothing loop will be probably 20 bytes. _THERE_  _ISN'T_  _20_  _BYTES_  _TO_  _SPARE_.

Jim W4JED

On 5/23/20 8:28 PM, Arv Evans wrote:

Larry

if (a != b) { Serial.println ("security code violated");
exit(1);  // product validation is simple!
}

Possibly was in the code from the time when an Ebay vendor tried to sell U3 
boards and expected QRP-Labs to support their marginal products.

Arv
_._

On Sat, May 23, 2020 at 6:02 PM Larry Howell <larry.howell.47@...> wrote:
Arv,
Any non-trivial decryption would require additional flash resources that do not exist.  I'm sure Hans is down to counting bits at this point.
Larry AC8YE

On Sat, May 23, 2020 at 7:54 PM Arv Evans <arvid.evans@...> wrote:
If I were trying to protect my proprietary software from being plagiarized
I would probably copy a key (maybe the CPU serial number) into the .eep 
file and then include code in flash memory to test for a match between 
CPU serial number and that key in the .eep space.  There are several other 
ways to do this.  Multiple tests could be done, or even encrypt the 
embedded key and test for proper decryption.  

Arv
_._


On Sat, May 23, 2020 at 5:07 PM Ham Radio <bernard.murphy@...> wrote:
The documentation on the QRP-LABS site should be updated regarding checking the HI fuse for X’D1’ for the first re-flash of the firmware.

If the HI  fuse is not correct, is the micro totally bricked or can the problem  be fixed using the  .eep file?
--
73, Bernie, VE3FWF


Re: What are you QRP guys using to measure power?

James Daldry W4JED
 

Hi, Arv

I seem to recall (over 60 years of playing with electronics some of the "recalls" are "seems") that the "standard cells" were mercury batteries. They lasted much longer than carbon - zinc and had stable voltage to the very end. Kind of went away when people suddenly got scared of mercury. As a teenager I used to rub mercury on my pocket change to make the dimes and quarters real shiny. Then again, for the past 60 years I've been inhaling hot lead fumes and eating sandwiches at the workbench after handling solder. Maybe that's where all the memories are going.

73

Jim W4JED

On 5/31/20 7:53 PM, Arv Evans wrote:
Jim

Evidently carbon cell batteries have changed over the years.  In 1956 when I built 
my Knight Kit VTVM the instructions said to assume that a new D-cell would be 
1.54 volts.  I don't know if the new cells which have much thinner carbon center 
cores have different nominal voltages.  

I wonder if a zenner with current controlled source could be relied on as a voltage 
reference?  Calibration vans that visited places where I worked usually had 
something called a "standard cell" that they used as a DC reference, but I have 
no idea what its makeup might have been.  Modern standard cells seem to be 
something different from what we had back in the bad-old-days.

Arv
_._


On Sun, May 31, 2020 at 5:40 PM James Daldry W4JED <jim@...> wrote:

Hi, Arv

The construction manual to my Eico VTVM said the new D cell was 1.55 volts. Didn't make a difference whether it was carbon post or cathodic envelope (Energizer).

My new box of 100 AA cells (Delco, from Amazon for a little over $20) seem to all read 1.611 on the Fluke 111.

73

Jim W4JED

On 5/30/20 5:49 PM, Arv Evans wrote:
Jack

I was thinking more about the measurement process and equipment that 
a ham might need to calibrate and maintain his or her own test equipment.
This may be an issue of expensive commercial test gear versus homemade 
test equipment.  The go-to instrument for commercial RF calibration might 
be an oscilloscope with UHF capability for measuring voltages versus 
waveform across a highly accurate non-inductive resistance, but the ham 
out in the wilds of middle Wyoming really does not have that option.  This 
takes us to typical ham radio ingenuity to develop an accurate way to 
measure current, voltage, and resistance at HF or VHF frequencies.  

In the bad-old-days we used to start with a new D-cell that was assumed 
to be exactly 1.54 volts and work up from there.  Today that is not adequate 
as a standard because we regularly measure voltage to 3 decimal points and 
expect our measurements to be as accurate as the display.

Arv
_._


On Sat, May 30, 2020 at 1:07 PM jjpurdum via groups.io <jjpurdum=yahoo.com@groups.io> wrote:
Arv:

A lot of universities, junior colleges, and even some high school physics labs have good quality (i.e., accurate) instruments for measuring almost anything a ham might need. Call those and check with the department head to see if they would let you bring your rig over for testing. Most will bend over backwards to help you.

Also, ask the members of your club if they have any of the required test equipment. Our club has a scope and watt meter for member use. (We even have a 100W HF station a member can borrow to see if they want to get on the HF frequencies.) There's more resources out there for the asking.

Jack, W8TEE

On Saturday, May 30, 2020, 2:42:41 PM EDT, Arv Evans <arvid.evans@...> wrote:


Hello

This thread has gone on for a while, but I wonder if we may be asking 
the wrong question.  Should the question really be "How accurate is 
your power measuring method?"?   What you use is immaterial if it is 
not accurate.  How would a ham with limited means insure that his/her 
RF power measuring device or method is really accurate?

Arv
_._


On Sat, May 30, 2020 at 12:33 PM lajes67 <jsmale859@...> wrote:
https://www.tindie.com/products/NM0S_qrp/qrpometer/

Last year I found this kit, it has an internal dummy load, checks power and shows VSWR, as far as I can tell it checks everything with accuracy.

73 John K2IZ


Re: QCX DX QSO!

Gary Bernard
 

Good job Saku. Nice case also.
73 Gary


-----Original Message-----
From: Saku JP3OUG <jp3oug599@...>
To: QRPLabs@groups.io
Sent: Sun, May 31, 2020 5:54 pm
Subject: [QRPLabs] QCX DX QSO!

Hello from Japan.

Yesterday, I heard a "CQ TEST" of a call sign with a prefix that I don't know.
I looked up the call sign, TI7W, on the QRZ.COM, and I realized it was a signal from Costa Rica!
Then I called him again and again.
Eventually, he copied my call sign correctly.
We exchanged the contest number. 
It is my record with my QCX-40.
About 13360 km with 3W !

The antenna I was using was a wire dipole, up about 6 meters high.
(Please visit my QRZ.COM page and see my set up.)

I heard that Costa Rica was the number one country in the World Happiness Index.
But now, 'I' am feeling happiest ever!

73 DE JP3OUG Nishigaki Sakutaro (Saku)


Re: What are you QRP guys using to measure power?

James Daldry W4JED
 

Hi, Arv

Last year I bought a Motorola E5 Tracfone to get myself into a more recent Android version. Since it had problems with my favorite podcast player, I bought its big brother, the G6, and gave the E5 to my wife. The G6 solved the podcast problem, but, instead of using the common mini USB connector like every phone that I had ever had before that, it had a USBC connector, same size as the mini, but reversible. I guess they come up with the higher current capacity by having 2 connections for each wire, arranged abcddcba, so it reads the same right side up and upside down. Or else 2 rows of 4 over and under, with the top row reversed. So, here at my living room end table, I have 3 wall warts with USB cables - C for the phone, mini for the Amazon Fire, and "fat mini" for the Kobi ebook reader.

73

Jim W4JED

On 5/30/20 10:43 PM, Arv Evans wrote:
Alison

Thanks for all the info.  It will come in handy.  Especially appreciate the comment about the reversable USB connector.  That relieves my concern about possibly backwards connection.

Arv
_-_


On Sat, May 30, 2020, 7:54 PM ajparent1/KB1GMX <kb1gmx@...> wrote:
Arv,

A wonderful instrument to have if your doing any RF measurement.
Team it up with a SA and RF measurements get very interesting.

Yes, the prices are all over the map as it here are clones like crazy.
There are at least three versions as well  (mostly different firmware).

However as a long term user of HP and Agilent VNA and PNA machines
costing tens of kilobucks the nanoVNA is a remarkable tool for pennies.

The number of things you can worth one is nothing short of RF multitools
category.  I use it for filters of all sorts well into UHF, crystal filter testing
and adjustment, amplifier gain, port reflections and such, and cable checks
just to scratch the surface.  When working with power amps you can sort
out input mismatch, output mismatch, and even loss through TR relays
and leakage around them.  My favorite use is S21 mode as output to
reference antenna (simple dipole) and input from antenna under test
(after doing it with reference dipole in the input too).  Collect the data
from that and you can determine the antenna gain in DBD, patterns
of the antenna in any inclination or azimuth at least for antennas 
that you can handle like smaller than 6M beam (really handy for 432
and up).

Once your into smith charts and the  theory it becomes easy to see
how input or output matching works and how to move around the
impedance circle.

The connector used is polarized but symmetrical dual contacts so there
is no upside down.   Or as I call it yet another USB connector (YAUC).

Allison





-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


QCX DX QSO!

Saku JP3OUG
 

Hello from Japan.

Yesterday, I heard a "CQ TEST" of a call sign with a prefix that I don't know.
I looked up the call sign, TI7W, on the QRZ.COM, and I realized it was a signal from Costa Rica!
Then I called him again and again.
Eventually, he copied my call sign correctly.
We exchanged the contest number. 
It is my record with my QCX-40.
About 13360 km with 3W !

The antenna I was using was a wire dipole, up about 6 meters high.
(Please visit my QRZ.COM page and see my set up.)

I heard that Costa Rica was the number one country in the World Happiness Index.
But now, 'I' am feeling happiest ever!

73 DE JP3OUG Nishigaki Sakutaro (Saku)


Re: What are you QRP guys using to measure power?

Arv Evans
 

Jim

Evidently carbon cell batteries have changed over the years.  In 1956 when I built 
my Knight Kit VTVM the instructions said to assume that a new D-cell would be 
1.54 volts.  I don't know if the new cells which have much thinner carbon center 
cores have different nominal voltages.  

I wonder if a zenner with current controlled source could be relied on as a voltage 
reference?  Calibration vans that visited places where I worked usually had 
something called a "standard cell" that they used as a DC reference, but I have 
no idea what its makeup might have been.  Modern standard cells seem to be 
something different from what we had back in the bad-old-days.

Arv
_._


On Sun, May 31, 2020 at 5:40 PM James Daldry W4JED <jim@...> wrote:

Hi, Arv

The construction manual to my Eico VTVM said the new D cell was 1.55 volts. Didn't make a difference whether it was carbon post or cathodic envelope (Energizer).

My new box of 100 AA cells (Delco, from Amazon for a little over $20) seem to all read 1.611 on the Fluke 111.

73

Jim W4JED

On 5/30/20 5:49 PM, Arv Evans wrote:
Jack

I was thinking more about the measurement process and equipment that 
a ham might need to calibrate and maintain his or her own test equipment.
This may be an issue of expensive commercial test gear versus homemade 
test equipment.  The go-to instrument for commercial RF calibration might 
be an oscilloscope with UHF capability for measuring voltages versus 
waveform across a highly accurate non-inductive resistance, but the ham 
out in the wilds of middle Wyoming really does not have that option.  This 
takes us to typical ham radio ingenuity to develop an accurate way to 
measure current, voltage, and resistance at HF or VHF frequencies.  

In the bad-old-days we used to start with a new D-cell that was assumed 
to be exactly 1.54 volts and work up from there.  Today that is not adequate 
as a standard because we regularly measure voltage to 3 decimal points and 
expect our measurements to be as accurate as the display.

Arv
_._


On Sat, May 30, 2020 at 1:07 PM jjpurdum via groups.io <jjpurdum=yahoo.com@groups.io> wrote:
Arv:

A lot of universities, junior colleges, and even some high school physics labs have good quality (i.e., accurate) instruments for measuring almost anything a ham might need. Call those and check with the department head to see if they would let you bring your rig over for testing. Most will bend over backwards to help you.

Also, ask the members of your club if they have any of the required test equipment. Our club has a scope and watt meter for member use. (We even have a 100W HF station a member can borrow to see if they want to get on the HF frequencies.) There's more resources out there for the asking.

Jack, W8TEE

On Saturday, May 30, 2020, 2:42:41 PM EDT, Arv Evans <arvid.evans@...> wrote:


Hello

This thread has gone on for a while, but I wonder if we may be asking 
the wrong question.  Should the question really be "How accurate is 
your power measuring method?"?   What you use is immaterial if it is 
not accurate.  How would a ham with limited means insure that his/her 
RF power measuring device or method is really accurate?

Arv
_._


On Sat, May 30, 2020 at 12:33 PM lajes67 <jsmale859@...> wrote:
https://www.tindie.com/products/NM0S_qrp/qrpometer/

Last year I found this kit, it has an internal dummy load, checks power and shows VSWR, as far as I can tell it checks everything with accuracy.

73 John K2IZ


Re: What are you QRP guys using to measure power?

James Daldry W4JED
 

Hi, Arv

The construction manual to my Eico VTVM said the new D cell was 1.55 volts. Didn't make a difference whether it was carbon post or cathodic envelope (Energizer).

My new box of 100 AA cells (Delco, from Amazon for a little over $20) seem to all read 1.611 on the Fluke 111.

73

Jim W4JED

On 5/30/20 5:49 PM, Arv Evans wrote:
Jack

I was thinking more about the measurement process and equipment that 
a ham might need to calibrate and maintain his or her own test equipment.
This may be an issue of expensive commercial test gear versus homemade 
test equipment.  The go-to instrument for commercial RF calibration might 
be an oscilloscope with UHF capability for measuring voltages versus 
waveform across a highly accurate non-inductive resistance, but the ham 
out in the wilds of middle Wyoming really does not have that option.  This 
takes us to typical ham radio ingenuity to develop an accurate way to 
measure current, voltage, and resistance at HF or VHF frequencies.  

In the bad-old-days we used to start with a new D-cell that was assumed 
to be exactly 1.54 volts and work up from there.  Today that is not adequate 
as a standard because we regularly measure voltage to 3 decimal points and 
expect our measurements to be as accurate as the display.

Arv
_._


On Sat, May 30, 2020 at 1:07 PM jjpurdum via groups.io <jjpurdum=yahoo.com@groups.io> wrote:
Arv:

A lot of universities, junior colleges, and even some high school physics labs have good quality (i.e., accurate) instruments for measuring almost anything a ham might need. Call those and check with the department head to see if they would let you bring your rig over for testing. Most will bend over backwards to help you.

Also, ask the members of your club if they have any of the required test equipment. Our club has a scope and watt meter for member use. (We even have a 100W HF station a member can borrow to see if they want to get on the HF frequencies.) There's more resources out there for the asking.

Jack, W8TEE

On Saturday, May 30, 2020, 2:42:41 PM EDT, Arv Evans <arvid.evans@...> wrote:


Hello

This thread has gone on for a while, but I wonder if we may be asking 
the wrong question.  Should the question really be "How accurate is 
your power measuring method?"?   What you use is immaterial if it is 
not accurate.  How would a ham with limited means insure that his/her 
RF power measuring device or method is really accurate?

Arv
_._


On Sat, May 30, 2020 at 12:33 PM lajes67 <jsmale859@...> wrote:
https://www.tindie.com/products/NM0S_qrp/qrpometer/

Last year I found this kit, it has an internal dummy load, checks power and shows VSWR, as far as I can tell it checks everything with accuracy.

73 John K2IZ


#Balloon #wspr #LightAPRS Launch Announcement #Balloon #wspr #lightaprs

BrianB
 

Hi,

We launched two balloons this morning from Rosamond, CA USA. Both had been tested multiple times on the ground before launch.

The first was a SBS balloon and a LightAPRS-W transmitter. APRS call is N6CVO-12 and 20m WSPR as N6CVO on 14,097,025. After launch the balloon was visually spotted to over 1,000' and APRS packets were received at the launch site but nothing got posted to aprs.fi  One hour into the flight we lost contact with the balloon and nothing has been heard since.

The second balloon used two cheep Chinese party balloons with a LightAPRS tracker and N6JED as the call. It worked great and is currently cruising along happily at 30,000' and posting to http://aprs.fi (enter the call sign and change Tail Length to 7-days).

Please keep an ear out for N6CVO just in case it shows up.

73,
BrianB
N6CVO


Re: [help] Only noise being seen while IQ balance / phase lo / phase hi.

ajparent1/KB1GMX
 

A large votlage drop would take a terrible meter to produce that its something on
the board likely C22 backward or solder whisker maybe even a bad part.

Maybe Q7 inserted wrongly.

Allison
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Re: [help] Only noise being seen while IQ balance / phase lo / phase hi.

g4edg
 

Just wondering if the voltage drop across R37 is due to the quality of the meter being used for the measurement?

Also wondering if Q7 is OK and not short circuit? Could be shunting the audio to ground? Any voltage on the gate that would cause this?

Just saying, as these things have not been mentioned before.

Watching with interest!

73 Steve G4EDG


Re: [help] Only noise being seen while IQ balance / phase lo / phase hi.

Alan G4ZFQ
 

Jose,

C22 is installed and confirmed that it is the correct capacitor. This
one doesn't have a polarity does it ?
No, as others have said the schematic shows an older version.

R37 bottom (connected to C22) 1.73v
top (Connected to IC10 Pin 5) : 2.32v
This shows current is flowing through R37. It should not.
It could be due to dirt or connection to somewhere else by a whisker of solder.
Or, a leaky C22. Look carefully with a glass, if the connection looks clean then remove C22. (Break it and remove each leg separately.) Then measure the IC10 voltages. They should be correct.
If so fit a new C22.

73 Alan G4ZFQ