Very interesting. I was expecting something like this, since these resistors also look differnt than the other ones. I wonder if they had to measure tons of resistors to find a series that works in just the right way or if the datasheet actually had the parasitics given. My respect goes out to all the Anritsu engineers from the 80s. Btw. I would have given you some credit for using the Yokogawa multimeter on the japanese board... however you already did it yourself. Thanks for the second look at the amp, it was a very fascinating video.
I must be missing something, but is the impedance of the amplifier ~70ohms and why is that special? Warning, I will probably delete this comment if it turns out to be too dumb!!
It is not dumb! What is special is that the designers used the parasitics to control the flatness of the amplifier!! They used these through hope resistors on purpose
The amplifier is good up to 3GHz.. the ~70 ohm was the correct value for 1GHz, considering the rest of the circuit. They found through hole resistors that gave the gave the correct response. Why 70? We don't know for sure, the full behavior was only at the minds of the engineers
Really thank you for taking the time to explain this. It was only a few months ago that I grasped different voltages can exist on the same piece of wire at the same time!! Now I'm obsessed with all things RF 😊
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Cool video as expected... Let the vna heat up before calibration... Those old equipment need at least 20 minutes heating up.
Very interesting.
I was expecting something like this, since these resistors also look differnt than the other ones.
I wonder if they had to measure tons of resistors to find a series that works in just the right way
or if the datasheet actually had the parasitics given.
My respect goes out to all the Anritsu engineers from the 80s.
Btw. I would have given you some credit for using the Yokogawa multimeter on the japanese board...
however you already did it yourself.
Thanks for the second look at the amp, it was a very fascinating video.
Too top, VNA is another world.😁😁
🤭🤭🤭
Muy buen video Gregory.
podrias comparar con los VNA nano? son muy utiles y baratos.
saludos
Leo, LU3MKH
Hi Leo!! I still don't have a nano VNA hehe
@@AllElectronicsChannel deberiamos regalarte uno entre todos jajaja.
saludos y gracias por tu trabajo
Gracias Leo!!
I must be missing something, but is the impedance of the amplifier ~70ohms and why is that special? Warning, I will probably delete this comment if it turns out to be too dumb!!
It is not dumb! What is special is that the designers used the parasitics to control the flatness of the amplifier!! They used these through hope resistors on purpose
Thank you, but why 70 ohms and not 50? Is that close enough to give a reasonable match over a range of frequencies?
The amplifier is good up to 3GHz.. the ~70 ohm was the correct value for 1GHz, considering the rest of the circuit.
They found through hole resistors that gave the gave the correct response. Why 70? We don't know for sure, the full behavior was only at the minds of the engineers
Really thank you for taking the time to explain this. It was only a few months ago that I grasped different voltages can exist on the same piece of wire at the same time!! Now I'm obsessed with all things RF 😊
1:12 Jequiti
Fight club