Greetings, That noise source has a history of large power output. To me it would have been good to use an inline attenuator, 20-30db, to make sure you do not damage the Spectrum Analyzer until you know what the total power levels are.
yes you are right I did a video on protecting your spectrum analyzer: th-cam.com/video/2dKaHbvb7GA/w-d-xo.htmlsi=Iv4GZ_4WHgB6MWeJ This HP 8921 has a 60watt front end so no way to kill it.
Hi, I have the same noise source but the problem is that this board becomes very very hot if you supply it with 12Vdc - 10,8 V are enough, the output will not anymore rise up if you increase the voltage. After a few month it will die. For this reason I added on the backside of this board a heatsink.
Another application that I found is to get the Body plot of gain magnitude -- not the phase- of opamps. Of course the noise generator has to be modified to optimized for lower Frequencies, since most opamps have Unity Gain Frequency (UGF) of few MHz. Putting the circuit under test between noise generator and oscilloscope with FFT, since most RF spectrum analyzers do not go down to DC. This made me interested to think about designing a circuit that can do both gain and phase Body plots. Stay tuned. Do you guys know how do they measure phase in Vector Network Analyzers?
@@IMSAIGuy I have a hallicrafters SX100 with a first IF of 1650 Khz. There is a radio station about 100 miles away on 1650 Khz am. Time to wind a custom notch filter and a noise source like this would make that a bit easier. I cant believe hallicrafters didnot see this coming :)
Greetings,
That noise source has a history of large power output. To me it would have been good to use an inline attenuator, 20-30db, to make sure you do not damage the Spectrum Analyzer until you know what the total power levels are.
yes you are right I did a video on protecting your spectrum analyzer: th-cam.com/video/2dKaHbvb7GA/w-d-xo.htmlsi=Iv4GZ_4WHgB6MWeJ
This HP 8921 has a 60watt front end so no way to kill it.
Hi, I have the same noise source but the problem is that this board becomes very very hot if you supply it with 12Vdc - 10,8 V are enough, the output will not anymore rise up if you increase the voltage. After a few month it will die. For this reason I added on the backside of this board a heatsink.
@@rmontgomery4340 I fixed with thermal adhesive small heatsinks on each of the 3 amplifier and on the other side of the pcb a bigger one.
Another application that I found is to get the Body plot of gain magnitude -- not the phase- of opamps. Of course the noise generator has to be modified to optimized for lower Frequencies, since most opamps have Unity Gain Frequency (UGF) of few MHz. Putting the circuit under test between noise generator and oscilloscope with FFT, since most RF spectrum analyzers do not go down to DC.
This made me interested to think about designing a circuit that can do both gain and phase Body plots. Stay tuned.
Do you guys know how do they measure phase in Vector Network Analyzers?
yes: th-cam.com/video/cU05VVFl0N0/w-d-xo.html
phase: th-cam.com/video/yGKWBpgN8PU/w-d-xo.html
Will that noise source go down to say 500 Khz? Thanks :)
i think so
@@IMSAIGuy I have a hallicrafters SX100 with a first IF of 1650 Khz. There is a radio station about 100 miles away on 1650 Khz am. Time to wind a custom notch filter and a noise source like this would make that a bit easier. I cant believe hallicrafters didnot see this coming :)
Nose source? Does Pinocchio have one of these?
quite possibly