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CW frequency in ubitx

CW frequency in ubitx

This article is about CW frequencies on uBITX radios. Maybe you already know.
If you already know, please refer to chapter 5 below only, This article is for beginners like me. 

1.The CW frequency display method in uBITX has been discussed for a long time.
Search for 'ubitx cw frequency' or 'bitx cw frequency' in Google.

In particular, mike, the operator of uBITX.net, has clarified the CW Frequency.
https://ubitx.net/2018/07/02/kd8cec-firmware-hint-cw-frequency-display/


2.About CW Frequency
Suppose that amateur radio Operator 'A' transmits radio waves at 1.000 Mhz
When I measured with the frequency counter, the frequency of exactly 1.000Mhz was measured.

Amateur radio operator 'B' will receive radio waves from 'A' in SSB receiver.
'B' knows that A transmits radio waves with a frequency of 1.000Mhz

'B' set the mode to LSB and tune the frequency to 1.000Mhz.
Can 'B' receive the CW sound transmitted by 'A'?


The answer is no.

Why?
In LSB mode, the lower the frequency, the higher the audio frequency

Below is the structure where A and B communicate.
Now you understand why B can not hear CW sounds?

So let's change the frequency of B's Transceiver a little bit?
Increased frequency by 100Hz, 1.000100Mhz.
The 1.000 000 MHz transmitted by A is 100 Hz lower than that of B.
B can hear the CW sound transmitted by A at 100Hz.



100Hz is too low for human to hear, let's increase the frequency a little more?
B set the frequency to 1.000 800Mhz.
CW sound transmitted by A is heard at 800Hz.


USB mode is also the same.
In USB mode, the higher the reference frequency, the higher the audio frequency


Below is the structure when B receives at 1.000 000 Mhz with mode USB
Can B hear the CW sound sent by 'A'?

Yes, B can not be received CW.
So what does 'B' have to do to receive the CW sound?

Will it increase frequency like LSB?
Below, 'B' is a slight increase in frequency by taking advantage of LSB mode experience
'B' could not receive any CW sound.


Let's lower the frequency.
'B' decreased the frequency by 500Hz -> 0.999500 Mhz


We learned about the frequency at which the CW is transmitted and the frequency at which it is received.
We will be able to receive the CW sound in the desired tone in LSB and USB mode.

3.About CW in uBITX Stock firmware
uBITX Stock Firmware can only select LSB and USB mode.

Set uBITX to USB mode and scan frequency.
CW sound is heard at frequency 14.030 000Mhz.
(The uBITX LCD displays 14.030 000Mhz)

It will be the following structure.

We know from chapter 2 above that the actual radio wave is not transmitted at 14.030 000 Mhz.

Decreasing the frequency will increase the audio frequency, and increasing the frequency will lower the audio frequency.

what frequency should we send radio waves to?
You do not have to worry about it.
uBITX Stock firmware automatically changes the frequency when transmitting.

Actual Transmit Frequency = Displayed Firequency + CW Side tone


In this way, you can communicate normally with most transceiver.

Below is the Stock firmware source for uBITX (Version 4.3)



When transmitting CW radio waves, you can see that it adds and subtracts sidetone.
We can understand the above sources through chapter 2 above.

4.What is the best Sidetone value?
When you listen to CW notes, you have to enter what you hear best.

When you are in CW communication, you will notice a change in the audible CW sound frequency when you increase or decrease the frequency.
In other words, by changing the frequency, you can choose the CW sound that you are most comfortable with, Enter the frequency for that sound to Sidetone.

Below is the situation when the side tone is set incorrectly.

'A' likes to hear a 500Hz CW sound.
However, the side tone is set to 1000

The receiving frequency is different from the transmitting frequency.
Of course, communication in this state is done without problems.

Below is the most comfortable CW Tone set to Side Toned.


What about the other transceiver?
Most transceiver, such as ICOM and YAESU, are this way.
After selecting CW mode, turn the frequency. The CW tone will go down or go up.

5.CW Frequency in uBITX CEC firmware
Now we know that the CW frequency is different between the receive and transmit frequencies, It will probably be as different as Sidetone in general.

Here a problem arises.

What frequency should be displayed on the screen?
Of course, no matter what frequency is displayed, there is no problem in qso.

CEC firmware supports all frequency display methods since version 1.03.
You can select it use uBITX Manager.

In 1.03, the default was to display the TX frequency.
However, there was a continuous inquiry of 'the frequency indication is strange'.

After all, I showed the RX frequency by default in Version 1.06

If uBITX Manager has the following settings, RX frequency is displayed.


If uBITX Manager has the following settings, TX frequency is displayed.


Of course, no matter what frequency is displayed, there will be no problem in communication, You can choose what you want.

6.CW Mode Receive Test
Generates 14.050 000Mhz frequency in RF Generator



Set USB, 14.050 000 Mhz in uBITX, We can not hear any sounds.




Set USB, 14.049 300 Mhz in uBITX, We can heard 700Hz Sound.



Change To LSB Mode


Set LSB, 14.050 000 Mhz in uBITX, We can not hear any sounds.




Set LSB, 14.049 300 Mhz in uBITX, We can not hear any sounds.





Set LSB, 14.051 000 Mhz in uBITX, We can heard 1000Hz Sound.



Change To CWL Mode


uBITX Status


We can not hear any sounds. It is the same as LSB.


Set LSB, 14.051 000 Mhz in uBITX, We can heard 1000Hz Sound. It is the same as LSB.

Change To CWL Mode


We can not hear any sounds. It is the same as LSB.


Set LSB, 14.049 000 Mhz in uBITX, We can heard 1000Hz Sound. It is the same as USB.


CW frequency display mode is selected as below.


We can not hear any sounds.


Change To CWL Mode


Set CWL, 14.050 000 Mhz in uBITX, We can heard 1000Hz Sound.

Set CWU, 14.050 000 Mhz in uBITX, We can heard 1000Hz Sound.


7.CW Mode Transmit Test

Press the CW-Key, TX

TX Freq Error -1.000Khz -> 14.0490 000 Mhz
14.050 000 Mhz - 1000Hz(Side tone) = 14.0490 000 Mhz


Change mode to USB


Press the CW-Key, TX


TX Freq Error 1.000Khz(0.995) -> 14.051 000 Mhz
14.051 000 Mhz + 1000Hz(Side tone) = 14.051 000 Mhz
(3hz is calibration error)


Change to CWL Mode


uBITX Manager Status, and Side tone change -> 700Hz


Press the CW-Key, TX


TX Freq Error - 0.700Khz (Side tone), it is same LSB Mode.


Change to CWL Mode


Press the CW-Key, TX


TX Freq Error 0.700Khz(0.695KHz) (Side tone), it is same LSB Mode.
(Calibration Error : 5Hz)



Change to CW Frequency Type using uBITX Manager.


Change to CWL Mode
Press the CW-Key, TX


Error : 0
(5Hz : Calibration Error)


Change to CWU Mode




Press the CW-Key, TX


Error : 0
(-5Hz : Calibration Error)



The video below is taken from this document.


Comments

  1. Thank you again dear Ian it works fine for my ubitx. I see in your video that the values in s meter blocks are to low.

    ReplyDelete
    Replies
    1. I am preparing a post for another S-Meter sensor. It seems a little more fun.

      Delete
  2. I think the method of offsetting the transmit frequency is backwards to how CW offset should be done. Although this works, it can have bad consequences. If the other station is transmitting on 14.100 I will not hear him unless I tune the uBitX to 14.099300 if I am particular about hearing a 700Hz tone and I am using CWU, so that means I actually will be transmitting on 14.100 when I send back and he will hear me. Similarly, if I have selected CWL I won’t hear him until I set the receiver to 14.100700 and I will be transmitting back on his frequency. However, we should be indicating the actual transmit frequency, not where I have offset to hear the other station. If I was close to the lower band edge, and I wanted to call CQ on 14.000500, I would actually be transmitting 200Hz below the band limit if I have selected CWL mode. Other rigs I have used, even Allard's sketch for the BitX40, offset the receiver by the amount of the desired tone (offset), either up or down based on if CWU or CWL is selected, so the transmitter always is sending on the dial frequency.

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