开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育
  1. Fa-Va5-Users
  2. Topics

Can the Fa-Va5 be used like a signal generator ?

 

Newbie just starting out -

I heard that the Fa-Va5 can be used like a signal generator ?

I looked at the operation manual and it looks like it has a very steep learning curve.

Can anyone out there tell me how to just set up a single HF frequency to be be generated ?

Appreciate any help

Frank
 

开云体育

Frank,

it is easy:

  1. Start FA-VA5
  2. Press and hold the left button (about 2 seconds) until the main menu "Operating Mode" is shown
  3. Press middle button [Dwn] quickly three times to move down to "Frequency Generator"
  4. Press left button [Sel] quickly to start the generator
  5. Press left button [D/S] quickly to cycle through the frequency digits
  6. Press middle [-] or right [+] buttons quickly to step the selected digit down or up
  7. Alternatively, press an hold middle [-] or right [+] buttons for "autorepeat" on selected digit
  8. When finished, press and hold left button [D/S] to stop the generator and return to the main menu

Please note that the output signal is a squarewave which contains odd harmonics (i.e. 3f, 5f, 7f etc.)

73 Johan SM6LKM


Frank KF2YD wrote:

Newbie just starting out -

I heard that the Fa-Va5 can be used like a signal generator ?

I looked at the operation manual and it looks like it has a very steep learning curve.

Can anyone out there tell me how to just set up a single HF frequency to be be generated ?

Appreciate any help

Frank

 

Thank you so much Johan
?
I apologize for being so late responding back to you. I never received a message from groups.io telling me that you responded back to my question.
?
If you do not mind, I have another question.
?
I know that the FA-VA5 can not do everything but I was wondering if it is capable of reading the fr (resonate frequency of a IF intermediate frequency of a IF filter ?
 
Edited

Frank,
yes, it is possible. At fr, the IF filter will change it's impedance significantly. However, most IF filters are designed for other system impedances than the 'normal' 50 Ohms, which makes SWR not the based method to test it. Just take a frequency sweep along the expected range (455 kHz, 9 MHz or whatever it is) and measure impedance |z| or retun loss s11 in dB at the input of the filter, while terminating the output of the filter with 100 Ohm or 200 Ohm. At fr, you should see a significant change. Sometimes these filters are so sharp that you will miss the change between samples. The same problems arrives with magnetic loops. The only solution is to narrow the frequency sweep, e.g. 400 kHz - 600 kHz for an expected 455 kHz IF filter, or take more samples. Using VNWA software you can extend the number of samples to 1000, 10000 or even more. Locally, the FA-VA 5 takes 100 samples.
Regards
Michael

1 - 4 of 4