Thank you for the review, very informative. I've been looking for a sensibly priced VHF generator for some time, and these look just the job. Your spectrum analyser output with strong odd harmonics suggests it's got a square wave output, but your oscilloscope was displaying it as a sinewave because the frequency was close to the scopes limit. You'd probably see a more accurate waveform at a lower frequency.
Thanks for the feedback! Have a look at this screen grab of the output at 50MHz, the scope's bandwidth is 100MHz, so well within it's range.... drive.google.com/file/d/1uIkmP50tdH9LNoFCJA6Us_RvcphsLvnC/view?usp=sharing
I have one of these boards. A valuable tool for signal generation up to 4GHz++. However, each output are measured to 0dBm, with the +5dBm setting in the menu. It can perhaps be because of (1) a "dodgy" design of the output from the IC to the SMA. Or (2 - less probably) the nominal power is given when using both outputs in differential mode. The outputs are 180 degrees phase shifted too.
@@marko.692 No they are not; 68X smd markings indicate 49.9ohm resistor values. This PCB is a clone copy of the original Chinese (that one is ENIG and has a trash can logo beneath the switch). On that PCB R12/R13 are actually L2/L3 3.9nH inductors.
@@luisderivas6005 You’re correct, 68X smd resistor it’s 49.9Ohm, thank you for letting me know. I don’t have experience with smd marking standards and after magnifying Bill’s video I assumed the 2 resistors are 68Omh each :) I don’t own this generator, since it's square waves I passed. I’m using my TinySA as generator, it’s sine wave (LOW connector) up to 350MHz. If I need higher frequency I use harmonics from the HIGH connector square wave, or my NanoVNA.
@12:00...the spectrum shows that each odd harmonic is only a few dB down from the previous. The 3rd harmonic around 10dB down, then 15, 18, 20dB down, but the harmonic measurement table shows all odd harmonics after the 3rd to be over 90dB down. That doesn't make sense. Where have all the other odd harmonics gone?
Thank you for the review, very informative. I've been looking for a sensibly priced VHF generator for some time, and these look just the job. Your spectrum analyser output with strong odd harmonics suggests it's got a square wave output, but your oscilloscope was displaying it as a sinewave because the frequency was close to the scopes limit. You'd probably see a more accurate waveform at a lower frequency.
Thanks for the feedback!
Have a look at this screen grab of the output at 50MHz, the scope's bandwidth is 100MHz, so well within it's range....
drive.google.com/file/d/1uIkmP50tdH9LNoFCJA6Us_RvcphsLvnC/view?usp=sharing
The SMA connector in the center of the board on my unit is marked MUX.
I have one of these boards. A valuable tool for signal generation up to 4GHz++. However, each output are measured to 0dBm, with the +5dBm setting in the menu. It can perhaps be because of (1) a "dodgy" design of the output from the IC to the SMA. Or (2 - less probably) the nominal power is given when using both outputs in differential mode. The outputs are 180 degrees phase shifted too.
The collector resistors (R12 and R13) in the output are 68ohms, but they should be 50ohms each. I believe it's root cause of the problem.
@@marko.692 No they are not; 68X smd markings indicate 49.9ohm resistor values. This PCB is a clone copy of the original Chinese (that one is ENIG and has a trash can logo beneath the switch). On that PCB R12/R13 are actually L2/L3 3.9nH inductors.
@@luisderivas6005 You’re correct, 68X smd resistor it’s 49.9Ohm, thank you for letting me know. I don’t have experience with smd marking standards and after magnifying Bill’s video I assumed the 2 resistors are 68Omh each :)
I don’t own this generator, since it's square waves I passed. I’m using my TinySA as generator, it’s sine wave (LOW connector) up to 350MHz. If I need higher frequency I use harmonics from the HIGH connector square wave, or my NanoVNA.
Do you have a schematic diagram to understand the essence of its work?
There is a jumper selection in the center of the board for internal or external clock. Do you know where to connect the external signal?
@12:00...the spectrum shows that each odd harmonic is only a few dB down from the previous. The 3rd harmonic around 10dB down, then 15, 18, 20dB down, but the harmonic measurement table shows all odd harmonics after the 3rd to be over 90dB down. That doesn't make sense. Where have all the other odd harmonics gone?
Thank you for the review, very informative.
Can you measure the phase noise on 160Mhz at 1 KHz offset best regards
Brother, with this, can the signal of WiFi router be made long range?
Brother, with this, can the signal of WiFi router be made long range?