Adding a SWR function to BITX40

Status
Not open for further replies.

beamin

Member
Premium Subscriber
Joined
Jan 27, 2012
Messages
108
I was reading through the code and saw this:
/**
* Display Routines
* These two display routines print a line of characters to the upper and lower lines of the 16x2 display
*/

void printLine1(char *c){
if (strcmp(c, printBuff)){
lcd.setCursor(0, 0);
lcd.print(c);
strcpy(printBuff, c);
count++;
}
}

void printLine2(char *c){
lcd.setCursor(0, 1);
lcd.print(c);
}

/**
* Building upon the previous two functions,
* update Display paints the first line as per current state of the radio
*
* At present, we are not using the second line. YOu could add a CW decoder or SWR/Signal strength
* indicator




How would you add a SWR function to the second line? This would be very handy since i make my own antennas!
 

Kb2Jpd

Member
Joined
May 6, 2016
Messages
207
Location
New York City, NY
I was reading through the code and saw this:

/**

* Display Routines

* These two display routines print a line of characters to the upper and lower lines of the 16x2 display

*/



void printLine1(char *c){

if (strcmp(c, printBuff)){

lcd.setCursor(0, 0);

lcd.print(c);

strcpy(printBuff, c);

count++;

}

}



void printLine2(char *c){

lcd.setCursor(0, 1);

lcd.print(c);

}



/**

* Building upon the previous two functions,

* update Display paints the first line as per current state of the radio

*

* At present, we are not using the second line. YOu could add a CW decoder or SWR/Signal strength

* indicator









How would you add a SWR function to the second line? This would be very handy since i make my own antennas!



Start here: http://www.na0tc.org/lib/exe/fetch.php?media=technical:homebrew_swr_meter.pdf

I would design the circuit just for reflected power back, not SWR. Tune your tuner or prune your antenna for minimum reflected power and you are good.

All you need is a ADC (analogue to digital convertor) and some way for it to be read by the microcontroller running the display.


Sent from my iPhone using Tapatalk
 

beamin

Member
Premium Subscriber
Joined
Jan 27, 2012
Messages
108
So this is the circuit you add?
BITX Hacks

Im legally blind so im having a bit of trouble finding the code and parts list.
 

beamin

Member
Premium Subscriber
Joined
Jan 27, 2012
Messages
108
i forgot to add Im really new to arduino and electronics so that first example seems a "bit " over my head.

But I did figure out how to build a power supply from scratch as well as the antenna.
 

Kb2Jpd

Member
Joined
May 6, 2016
Messages
207
Location
New York City, NY
So this is the circuit you add?

BITX Hacks



Im legally blind so im having a bit of trouble finding the code and parts list.



Then your solution is a simple one.

I worked with Dan Kb2Mlh with making audible SWR/Power meters for him. He is also a blind ham. I used to make a circuit called a Voltage Controlled Oscillator and connect the circuit across the meter movement.

Tuned it for lowest SWR. The circuit I used in the past was a 555 connected to a speaker and the power switch was a mercury switch. You tilted the meter upward, you did the tune, then rested back down and the circuitry would shut off.

http://www.learningaboutelectronics...d-oscillator-VCO-circuit-with-a-555-timer.php

Maybe it's time for that circuit to make a reprise.




Sent from my iPhone using Tapatalk
 
Status
Not open for further replies.
Top