¿ªÔÆÌåÓý

Date

Re: uBITX Display Emulation / Screen Capture

 

Thanks for the tip Jack.

To compare a string literal, do you recommend using strcmp or strncmp ?
e.g.?
if (!strcmp(buffer,"d")) {?
--or --
if (!strncmp(buffer,"d",11)) {? <-- this would appear to be more robust, and show that the first 10 chars + NULL string termination are being compared.?

or some other way?

Either works for this small test case.

Rgds,
Gary


Re: uBITX Display Emulation / Screen Capture

 

It works!

Thanks so much for the screen dump code. I added it to my sketch, changing it to just return binary image data. I wrote a Python script to capture the data and convert it to an image. The result is attached.

73,
Mark, N8ME


bitx20 3C SBL - Bandpass filter inductor issue

 

I've got this kit I've had around for 4 years and it is mostly working though there is an issue with the three inductors not "adjusting." The tuning plugs move just fine, but I have to put an absurd amount of pressure on them, then they start to pass RF. I've actually picked up stations after fussing with them, but I would like to know if anyone else had a similar issue with the bandpass filter and any guidance to correcting the lack of tunability.

Thanks!
--
Jason Pirok
W4UNX


Re: bitx-ver-3c LCD PIC processor code #bitx20 #bitx20help

 

I think you missed what the man is saying. He's working with the original bitx20 kit that was around before the Raduino and uses an FLL board with a PIC and LCD display. The FLL also supplies stabilizing pulses to the analog VFO.?

Greg, you need to message Sunil from to see if he can help you with troubleshooting your FLL board. He will be the best person to help with replacement parts as well. I recently bought a brand new FLL from his store not long ago.

W4UNX?

On Mon, Jan 11, 2021 at 7:21 PM Arv Evans <arvid.evans@...> wrote:
Greg

Unless you have something that is really strange, the processor is not a PIC device.?
It is an Atmel microcontroller on an Arduino Nano PCB which plugs into the Raduino PCB that drives the LCD display.? The code for your rig and lots of instructions are all available at </g/BITX20>? and more specifically at <>.? I am assuming that you have a uBITX V-3.? The current version is V-6, but older units are still usable...with
some modifications that have been discussed on the group web site.?

Having no indication on the display can be caused by several different things.? If no backlight then possibly part, or all, of the circuit is not getting power.? If only the top line if characters is viewable with no characters and the lower line blanked, then the Arduino Nano is not initializing the LCD display.? There is a contrast control on the display driver circuit that controls the display bias.? It can give the display a washed-out appearance if it is set too high.

Specific questions can be asked on the BITX20 discussion group.? There are a number of experts there who should be able to answer questions and/or suggest places to look for troubleshooting and repair.?

Arv? K7HKL
_._


On Sun, Jan 10, 2021 at 2:10 PM Greg Lind <gregg@...> wrote:
I have a?bitx-ver-3c-SBL with the? 2 line LCD that is not working. I suspect it is the PIC processor as I tried other LCD.? The symptom is no characters on the display.

The unit work at one time years ago --- the display lights up ---- nothing on the display.?

I am looking for the code for the processor pic16F628A to reprogram or if some one has one that replaced there's with a dds I would like the processor?

Also some have suggested to replace with a dds - is there a board for board replacement. Please let me know..

Any help much appreciate --??



--
Jason Pirok
W4UNX


Re: uBITX Display Emulation / Screen Capture

Jack, W8TEE
 

Hi Gary:

I would like to discourage you from using the String class in the Arduino environment. It can lead to fragmentation and other nasties. Try this an see if it works for your use:

??? char buffer[11];
??? int eos;
??? // more of your code...
??? while (Serial.available()) {
??????? eos = Serial.readBytesUntil('\n', buffer, 10);??? // Read max of 10 chars
??????? buffer[eos] = '\0';?????????????????????????????? // Make it a string
??????? // continue processing as you wish...
??? }
??
This should work and still not fragment your limited memory.

Jack, W8TEE ?

On Tuesday, January 12, 2021, 5:12:35 PM EST, Gary Anderson <gary.ag5tx@...> wrote:


The test was using Reed's code and replacing the ubitx_cat.cpp. Code space is at a premium.? I have extra flash space with the Optiboot bootloader. (32234 bytes used)
output format of x,y,color was for a QND bitmap, and it matches.? Color codes also match.
Rgds,
Gary

#include <Arduino.h>
#include <SPI.h>
#include "pin_definitions.h"
?
#define COLMAX 319
#define PAGMAX 239
?
void checkCAT(){
? ? String GetString;
? ? uint16_t R = 0;
? ? uint16_t G = 0;
? ? uint16_t B = 0;
?
? ? while (Serial.available() > 0) {
? ? ? ? GetString = Serial.readStringUntil(10); // 10 is a return
? ? ? ? if (GetString.equals("d")) {
? ? ? ? ? ? SPI.begin();
? ? ? ? ? ? SPI.setClockDivider(SPI_CLOCK_DIV4); // 4 MHz (half speed)
? ? ? ? ? ? SPI.setBitOrder(MSBFIRST);
? ? ? ? ? ? SPI.setDataMode(SPI_MODE0);?
?
? ? ? ? ? ? pinMode(PIN_TFT_CS,OUTPUT);
? ? ? ? ? ? pinMode(PIN_TFT_DC,OUTPUT);
? ? ? ? ? ? digitalWrite(PIN_TFT_CS, LOW);
? ? ? ? ? ??
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2A); // CASET
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer16(0);? ?//start
? ? ? ? ? ? SPI.transfer16(COLMAX); // stop
?
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2B); // PASET
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer16(0);? //start
? ? ? ? ? ? SPI.transfer16(PAGMAX); //stop
?
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2E); // RAMRD
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer(0x0); // dummy
?
? ? ? ? ? ? for (int y = 0; y <= PAGMAX; y++){
? ? ? ? ? ? ? for (int x = 0; x <= COLMAX; x++){
? ? ? ? ? ? ? ? //capture 8 bit from SPI
? ? ? ? ? ? ? ? R = SPI.transfer(0x0) >> 3; // 5 RED
? ? ? ? ? ? ? ? G = SPI.transfer(0x0) >> 2; // 6 GREEN
? ? ? ? ? ? ? ? B = SPI.transfer(0x0) >> 3; // 5 BLUE
? ? ? ? ? ? ? ? Serial.print(x);
? ? ? ? ? ? ? ? Serial.print(",");
? ? ? ? ? ? ? ? Serial.print(y);
? ? ? ? ? ? ? ? Serial.print(",");
? ? ? ? ? ? ? ? //display as 16 bit in 565 format
? ? ? ? ? ? ? ? Serial.println((R << 11) | (G << 5) | B);? ? ? ??
? ? ? ? ? ? ? }
? ? ? ? ? ? }
? ? ? ? ? ??
? ? ? ? ? ? digitalWrite(PIN_TFT_CS, HIGH);
? ? ? ? ? ? SPI.endTransaction();
? ? ? ? }
? ? }
}

--
Jack, W8TEE


Re: uBITX Display Emulation / Screen Capture

 

The test was using Reed's code and replacing the ubitx_cat.cpp. Code space is at a premium.? I have extra flash space with the Optiboot bootloader. (32234 bytes used)
output format of x,y,color was for a QND bitmap, and it matches.? Color codes also match.
Rgds,
Gary

#include <Arduino.h>
#include <SPI.h>
#include "pin_definitions.h"
?
#define COLMAX 319
#define PAGMAX 239
?
void checkCAT(){
? ? String GetString;
? ? uint16_t R = 0;
? ? uint16_t G = 0;
? ? uint16_t B = 0;
?
? ? while (Serial.available() > 0) {
? ? ? ? GetString = Serial.readStringUntil(10); // 10 is a return
? ? ? ? if (GetString.equals("d")) {
? ? ? ? ? ? SPI.begin();
? ? ? ? ? ? SPI.setClockDivider(SPI_CLOCK_DIV4); // 4 MHz (half speed)
? ? ? ? ? ? SPI.setBitOrder(MSBFIRST);
? ? ? ? ? ? SPI.setDataMode(SPI_MODE0);?
?
? ? ? ? ? ? pinMode(PIN_TFT_CS,OUTPUT);
? ? ? ? ? ? pinMode(PIN_TFT_DC,OUTPUT);
? ? ? ? ? ? digitalWrite(PIN_TFT_CS, LOW);
? ? ? ? ? ??
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2A); // CASET
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer16(0);? ?//start
? ? ? ? ? ? SPI.transfer16(COLMAX); // stop
?
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2B); // PASET
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer16(0);? //start
? ? ? ? ? ? SPI.transfer16(PAGMAX); //stop
?
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2E); // RAMRD
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer(0x0); // dummy
?
? ? ? ? ? ? for (int y = 0; y <= PAGMAX; y++){
? ? ? ? ? ? ? for (int x = 0; x <= COLMAX; x++){
? ? ? ? ? ? ? ? //capture 8 bit from SPI
? ? ? ? ? ? ? ? R = SPI.transfer(0x0) >> 3; // 5 RED
? ? ? ? ? ? ? ? G = SPI.transfer(0x0) >> 2; // 6 GREEN
? ? ? ? ? ? ? ? B = SPI.transfer(0x0) >> 3; // 5 BLUE
? ? ? ? ? ? ? ? Serial.print(x);
? ? ? ? ? ? ? ? Serial.print(",");
? ? ? ? ? ? ? ? Serial.print(y);
? ? ? ? ? ? ? ? Serial.print(",");
? ? ? ? ? ? ? ? //display as 16 bit in 565 format
? ? ? ? ? ? ? ? Serial.println((R << 11) | (G << 5) | B);? ? ? ??
? ? ? ? ? ? ? }
? ? ? ? ? ? }
? ? ? ? ? ??
? ? ? ? ? ? digitalWrite(PIN_TFT_CS, HIGH);
? ? ? ? ? ? SPI.endTransaction();
? ? ? ? }
? ? }
}


Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer

 

Gordon

Same here.? Those integrated diode IC's are a big improvement but even
ones from the same corner of the same die are probably not perfectly
matched after they have been manually soldered onto a PCB.? Even for
those it seems better to have a balancing network to insure we get the
best balance after everything is assembled.? Maybe this is just a feel-good
situation but part of optimizing a build is feeling good about how it went
together and how it was adjusted after the build.? This seems especially
true if the mixer is a 2-diode version instead of the full ring of 4 diodes.

Arv
_._


On Tue, Jan 12, 2021 at 2:40 PM Gordon Gibby <docvacuumtubes@...> wrote:
In the old days, I think we used a potentiometer and maybe a variable capacitor to balance out these mixers. I¡¯ve got a Heathkit SB 102 that I soldered together as a high school kid, and it has four individual diodes and I remember nulling out the carrier

Surely it can still be successful with all of the advanced semiconductors we have now.?




On Jan 12, 2021, at 16:29, Bob Lunsford via <nocrud222=[email protected]> wrote:

?
It is always better to use diodes and transistors made on the same substrate.

I remember replacing the PA transistor on an HW-8 with a dual transistor placed in parallel, doubled the power capability and since the? two transistors were on the same substrate, they were perfectly matched. If an IC can be found with four diodes, then finding matched diodes will not be required, if done on the same substrate ... IF such a thing exists.

Bob ¡ª KK5R

On Tuesday, January 12, 2021, 8:09:17 AM EST, Cristian Radulescu via <criradul2001=[email protected]> wrote:


Hi all,
Sorry to barge in like this.
12-13 years ago when I assembled my first, ugly style, BitX, I remember experimenting a lot with these mixers.
What I found is, one can not match the matched mixer rings that exist, produced by various companies.
What I ended up using was a diode ring IC "extracted" from a Motorola CP040 or GP300 VHF handy placed under a small shield close to the receiver part, between two trifilar transformers (obviously a mixer configuration), 8 pin IC chip produced by NEC or JRC.
I am sure one can recover boards from these old handies for parts recovery.
I had excellent results with it.
73's de YO3IAZ, Cristian

On Tuesday, January 12, 2021, 02:18:30 PM GMT+2, Loris IW4AJR via <lorisbollina=[email protected]> wrote:


Hi Rafael,

It will not be easy to combine four diodes, but I have to buy the BAT41s, while I have the HP2835s in the drawer (at least forty) ... I hope to be able to find two groups of 4 diodes at least very similar.
The HP gave a margin of plus or minus 20mV of Vf between two diodes in match pair, is this an acceptable term? that is, what can be the maximum deviation between two diodes for a match pair?

On Tue, Jan 12, 2021 at 12:37 PM, <rafaelgcpp@...> wrote:
Loris,

By looking at the datasheet, you can use it. The thing is you will have to match the diodes Vf very carefully. Using matched diodes like the BAT41 halfs your work!??

73

Rafael - PU1OWL

--
IW4AJR Loris


Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer

 

¿ªÔÆÌåÓý

In the old days, I think we used a potentiometer and maybe a variable capacitor to balance out these mixers. I¡¯ve got a Heathkit SB 102 that I soldered together as a high school kid, and it has four individual diodes and I remember nulling out the carrier

Surely it can still be successful with all of the advanced semiconductors we have now.?




On Jan 12, 2021, at 16:29, Bob Lunsford via groups.io <nocrud222@...> wrote:

?
It is always better to use diodes and transistors made on the same substrate.

I remember replacing the PA transistor on an HW-8 with a dual transistor placed in parallel, doubled the power capability and since the? two transistors were on the same substrate, they were perfectly matched. If an IC can be found with four diodes, then finding matched diodes will not be required, if done on the same substrate ... IF such a thing exists.

Bob ¡ª KK5R

On Tuesday, January 12, 2021, 8:09:17 AM EST, Cristian Radulescu via groups.io <criradul2001@...> wrote:


Hi all,
Sorry to barge in like this.
12-13 years ago when I assembled my first, ugly style, BitX, I remember experimenting a lot with these mixers.
What I found is, one can not match the matched mixer rings that exist, produced by various companies.
What I ended up using was a diode ring IC "extracted" from a Motorola CP040 or GP300 VHF handy placed under a small shield close to the receiver part, between two trifilar transformers (obviously a mixer configuration), 8 pin IC chip produced by NEC or JRC.
I am sure one can recover boards from these old handies for parts recovery.
I had excellent results with it.
73's de YO3IAZ, Cristian

On Tuesday, January 12, 2021, 02:18:30 PM GMT+2, Loris IW4AJR via groups.io <lorisbollina@...> wrote:


Hi Rafael,

It will not be easy to combine four diodes, but I have to buy the BAT41s, while I have the HP2835s in the drawer (at least forty) ... I hope to be able to find two groups of 4 diodes at least very similar.
The HP gave a margin of plus or minus 20mV of Vf between two diodes in match pair, is this an acceptable term? that is, what can be the maximum deviation between two diodes for a match pair?

On Tue, Jan 12, 2021 at 12:37 PM, <rafaelgcpp@...> wrote:
Loris,

By looking at the datasheet, you can use it. The thing is you will have to match the diodes Vf very carefully. Using matched diodes like the BAT41 halfs your work!??

73

Rafael - PU1OWL

--
IW4AJR Loris


Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer

 

It is always better to use diodes and transistors made on the same substrate.

I remember replacing the PA transistor on an HW-8 with a dual transistor placed in parallel, doubled the power capability and since the? two transistors were on the same substrate, they were perfectly matched. If an IC can be found with four diodes, then finding matched diodes will not be required, if done on the same substrate ... IF such a thing exists.

Bob ¡ª KK5R

On Tuesday, January 12, 2021, 8:09:17 AM EST, Cristian Radulescu via groups.io <criradul2001@...> wrote:


Hi all,
Sorry to barge in like this.
12-13 years ago when I assembled my first, ugly style, BitX, I remember experimenting a lot with these mixers.
What I found is, one can not match the matched mixer rings that exist, produced by various companies.
What I ended up using was a diode ring IC "extracted" from a Motorola CP040 or GP300 VHF handy placed under a small shield close to the receiver part, between two trifilar transformers (obviously a mixer configuration), 8 pin IC chip produced by NEC or JRC.
I am sure one can recover boards from these old handies for parts recovery.
I had excellent results with it.
73's de YO3IAZ, Cristian

On Tuesday, January 12, 2021, 02:18:30 PM GMT+2, Loris IW4AJR via groups.io <lorisbollina@...> wrote:


Hi Rafael,

It will not be easy to combine four diodes, but I have to buy the BAT41s, while I have the HP2835s in the drawer (at least forty) ... I hope to be able to find two groups of 4 diodes at least very similar.
The HP gave a margin of plus or minus 20mV of Vf between two diodes in match pair, is this an acceptable term? that is, what can be the maximum deviation between two diodes for a match pair?

On Tue, Jan 12, 2021 at 12:37 PM, <rafaelgcpp@...> wrote:
Loris,

By looking at the datasheet, you can use it. The thing is you will have to match the diodes Vf very carefully. Using matched diodes like the BAT41 halfs your work!??

73

Rafael - PU1OWL

--
IW4AJR Loris


Re: uBITX Display Emulation / Screen Capture

 

¿ªÔÆÌåÓý

Thanks for the tip.

Please post your code.

73,
Mark, N8ME


On Jan 12, 2021, at 12:10 PM, Gary Anderson <gary.ag5tx@...> wrote:

?On Sat, Jan 9, 2021 at 04:26 AM, Mark Erbaugh wrote:
Alternatively, I considered adding a routine to my sketch to dump the ILI9341 screen memory to the serial port, but I can't find a way to read the screen memory. Can that be done?
Hi Mark,
Yes it can be done.??0x2E command is RAMRD.?

If anyone is interested in a c function to dump screen memory, I can post? c code that outputs x,y,565color.
The starting program was Reed's V6 code.
Rgds,
Gary


Numerotation Arduino Nano

 

Hello,
Be careful if you use Kicad, the numbering is reversed compared to the Ubitx schema.
Number one becomes number 16.
So rotate the circuit 180% relative to the footprint on the PCB, Otherwise, it will smoke!

Ex D13 1 on Ubitx, 16 on Kicad



Re: Spectral analyser

 

Hello
Inside the TinySA


TinySA compared to a brand analyzer.


And many other videos...
Cdt


Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer

 

Over the years I have used my own matched diodes in mixers.? Matching is
usually at a fixed current with a high impedance VOM measuring forward
voltage drop.? On a few circuits I generated forward and reverse current (leakage)
curves at DC, and at RF but did not see much gained by excessive measurement.
Key for me has been matching the "knee point" where the diodes go into conduction, and matching the leakage curve if the diodes will be subject to high RF levels.

Arv
_._


On Tue, Jan 12, 2021 at 3:56 AM Loris IW4AJR via <lorisbollina=[email protected]> wrote:
I would like to know if I can use HP 2800 series Schottky diodes in the EASY BITX mixers circuits.
Can anyone give me answers?

73 de --
IW4AJR Loris


Re: TFT Display Interfacing

 

This anecdote certainly illustrates that Jack is not dumb.
In fact, he talks quite a bit.? ?;-)

Jerry, KE7ER



On Tue, Jan 12, 2021 at 10:40 AM, Arv Evans wrote:
Old people did not get old by being dumb!
?


Re: TFT Display Interfacing

 

Old people did not get old by being dumb!
_._


On Tue, Jan 12, 2021 at 9:47 AM Jack, W8TEE via <jjpurdum=[email protected]> wrote:
I have so much similar stuff that the XYL says she turns on her "cwap filter" when I talk. I love trivia! One time I was at the airport and a nice elderly lady was running the Information booth. I walked over to her and asked:

me: "Is this the Information booth?"
granny: "Why, yes it is, Dearie. What can I help you with?"
me: "What's the capital of Nepal?"
granny: "What?! I have no idea!"
me: "Well, what kind of information booth is this?"

I started walking away and she called out: "Well, what's the capital?" I answered: "Kathmandu", whereupon she asked me to spell it and she wrote it down!

Fast forward about five months and I'm at the airport again. Sure enough, there's granny at the Information booth. I walked up and asked: "What's the capital of Nepal?" She looked up, shook her finger at me, smiled, and said: "Just a minute" whereupon she went rummaging through a drawer, retrieved a piece of paper, and proudly called out: "Kathmandu!"

Ya gotta love her...


Jack, W8TEE


On Tuesday, January 12, 2021, 11:30:05 AM EST, Dean Souleles <dsouleles@...> wrote:


On Tue, Jan 12, 2021 at 08:51 AM, Jack, W8TEE wrote:
some TFT display drivers invert the color and the complement operator fixes it.
Excellent tribal knowledge and good to know next time I think a display is defective.

Dean

--
Jack, W8TEE


Re: Spectral analyser

 

I've been using a SDR dongle as a 'poor man's spectrum analyzer' for a few years now.? The one I have covers up to a 1 Mhz slice of the spectrum at a time (up to around a Ghz), although I can also zoom in to a few hundred hz, and with a upconverter mixer it works well with HF.? It's a bit frustrating if you want to look for spurious signals from a radio that may be beyond the 'window', but that also can be done.? (You just have to move the center frequency up through the range you're interested in.)

I've also used it to check deviation of voice and PL tones on a FM rig.? Knowing a bit of theory comes in handy when working on circuits - a balanced bridge can be used to determine a lot of characteristics about a signal or device, and you can easily 'trick' equipment to measure things that aren't what the equipment is designed for - for instance, using an antenna analyzer to determine the characteristics of a toroid core.? (They also can be tricked into giving information about capacitors and tuned circuits.)

I'm thinking about getting one of those tinySA units, once I can get enough money together, although I'd want to check the maximum frequency spread that it can display at one time.? I've also eyeballed some of the transistor curve tracer kits, but none of the affordable (for me) units really would do the job - and one of the more common kits could fry a component you're testing if hooked up wrong.

Bob
N4FBZ

On 1/11/21 7:52 PM, Arv Evans wrote:

Gerard

It takes a bit more than a signal generator and an oscilloscope to do
spectrum analysis.? In its most basic form your signal generator could
serve as the local oscillator for a mixer circuit and the oscilloscope as
the visual monitor at the output of that mixer.? Problem with this is that
you need some sort of tuned circuit at the RF input side of the mixer
to avoid seeing a very wide RF spectrum, and signals also detected
from harmonics of the local oscillator.? You could make your own
spectrum analyzer.? The learning curve for such a design and
construction would be steep, but maybe rewarding.

As an alternative, there are a number ot tiny spectrum analyzers that
would do the job for you at a price well below US$100.? There are
several VNA (Vector Network Analyzer) units, also under US$100, that
could be used to perform something similar.

Depending on what you are trying to do, it is possible to perform many
system tests using rather simple test equipment.

* Simple voltage presence tests can be done with an LED and a
resistor as a voltage probe.? (put a capacitor in series and this
unit can tell you if the voltage is AC or DC).

* An op-amp can be wired in a balanced input to determine if the
two inputs are equal or if one of the inputs is different from the
other.? Use an LED at the output to show which state is present.
A calibrated potentiometer on one input can be used to balance
that input with the unknown input.? Calibration on the pot knob
could then show the voltage on the other input.

* A very simple direct-conversion receiver circuit can be used
to locate and measure the level of an unknown frequency.
Also good for finding the frequency of an LC network.

* A balance bridge circuit (a center-tapped secondary on a
toroid) can be used to roughly measure the Q-factor of a component
or tuned circuit.? Also good for finding the value of L or C.
If you know any two of the LCF parts you can calculate the other.


There are many more examples of simple circuits being used in place of
expensive test equipment.? The usual trade-off is that you might have to
calculate some of the resulting values to arrive at the final answer.

Arv? K7HKL
_._


On Sun, Jan 10, 2021 at 1:24 PM Gerard <kabupos@... <mailto:kabupos@...>> wrote:

Good evening, I am a bit new in this field and I do not have all
the material for in-depth analysis
My first question is whether you can emulate a spectrum analyzer
with an oscilloscope and an HF generator
I have a 2*50MHZ oscillo and a FY6900 60MHZ generator that offers
a lot of possibilities (see doc)

Another possibility is to use a card and connect it to a PC
There¡¯s this one over there for 45$ (37€) Module de source de
signal, analyseur de spectre, carte de source de signal, outil
d'analyse de domaine de fr¨¦quence RF, avec interface USB, suivi:
Amazon.fr: Commerce, Industrie & Science
<>

I rely on your expertise
Thank's for your answers

cdt


Re: uBITX Display Emulation / Screen Capture

 

On Sat, Jan 9, 2021 at 04:26 AM, Mark Erbaugh wrote:
Alternatively, I considered adding a routine to my sketch to dump the ILI9341 screen memory to the serial port, but I can't find a way to read the screen memory. Can that be done?
Hi Mark,
Yes it can be done.??0x2E command is RAMRD.?

If anyone is interested in a c function to dump screen memory, I can post? c code that outputs x,y,565color.
The starting program was Reed's V6 code.
Rgds,
Gary


Re: TFT Display Interfacing

Jack, W8TEE
 

I have so much similar stuff that the XYL says she turns on her "cwap filter" when I talk. I love trivia! One time I was at the airport and a nice elderly lady was running the Information booth. I walked over to her and asked:

me: "Is this the Information booth?"
granny: "Why, yes it is, Dearie. What can I help you with?"
me: "What's the capital of Nepal?"
granny: "What?! I have no idea!"
me: "Well, what kind of information booth is this?"

I started walking away and she called out: "Well, what's the capital?" I answered: "Kathmandu", whereupon she asked me to spell it and she wrote it down!

Fast forward about five months and I'm at the airport again. Sure enough, there's granny at the Information booth. I walked up and asked: "What's the capital of Nepal?" She looked up, shook her finger at me, smiled, and said: "Just a minute" whereupon she went rummaging through a drawer, retrieved a piece of paper, and proudly called out: "Kathmandu!"

Ya gotta love her...


Jack, W8TEE


On Tuesday, January 12, 2021, 11:30:05 AM EST, Dean Souleles <dsouleles@...> wrote:


On Tue, Jan 12, 2021 at 08:51 AM, Jack, W8TEE wrote:
some TFT display drivers invert the color and the complement operator fixes it.
Excellent tribal knowledge and good to know next time I think a display is defective.

Dean

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Jack, W8TEE


Re: TFT Display Interfacing

 

On Tue, Jan 12, 2021 at 08:51 AM, Jack, W8TEE wrote:
some TFT display drivers invert the color and the complement operator fixes it.
Excellent tribal knowledge and good to know next time I think a display is defective.

Dean


Re: TFT Display Interfacing

Jack, W8TEE
 

Looks good! I just know that some TFT display drivers invert the color and the complement operator fixes it. When I saw the light gray background, I thought that might have been an issue.

Never mind! :>)


Jack, W8TEE

On Tuesday, January 12, 2021, 8:42:27 AM EST, Dean Souleles <dsouleles@...> wrote:


On Mon, Jan 11, 2021 at 04:54 PM, Jack, W8TEE wrote:
The colors look a little odd
Hi Jack,

Here's a color corrected image done using Adobe Lightroom. The phone's software gets confused by the color of the ambient room light and the blue cast of the screen.

When I used the compliment color, by the way, all I got was a gray background.

(In one of my other lives I am a professional photographer so I should know better. Check out www.dsoulphoto.com sometime)

Dean
KK4DAS
?

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Jack, W8TEE