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Electronics => Repair => Topic started by: feedback.loop on February 13, 2023, 01:04:06 am

Title: Agilent 33250A function gen output amp replacement
Post by: feedback.loop on February 13, 2023, 01:04:06 am

This is an attempt to come up with a replacement for Agilent hybrid output amplifier in 33250A function generator. The prototype almost works, but shows some sort of instability at the very limit at 80MHz and 10Vpp output.

https://www.youtube.com/watch?v=MVSbVt8pdcU (https://www.youtube.com/watch?v=MVSbVt8pdcU)

Title: Re: Agilent 33250A function gen output amp replacement
Post by: w1k on February 13, 2023, 09:11:48 am

Maybe the adjustment can help? It requires additionall power meter and 20db att.

Title: Re: Agilent 33250A function gen output amp replacement
Post by: HighVoltage on February 13, 2023, 10:58:07 am

Very nice repair!

At these frequencies the perf board might have a big influence and it will look much different, when you design your new PCB.

Looking forward to your next step.

Title: Re: Agilent 33250A function gen output amp replacement
Post by: anotherlin on February 13, 2023, 06:18:15 pm

Very nice repair video.

As a follow on project, it would be great to make it an open-source standalone module, that can be build by anyone in need of a 80MHz (maybe make it up to 100MHz since the IC looks like capable of more) signal output driver.

Title: Re: Agilent 33250A function gen output amp replacement
Post by: feedback.loop on April 18, 2023, 07:04:27 pm

Part 2. A board was designed, and the new version of the amp was tested. After some tweaks it seems to work.

https://www.youtube.com/watch?v=xyJm-F2zBfc (https://www.youtube.com/watch?v=xyJm-F2zBfc)

Title: Re: Agilent 33250A function gen output amp replacement
Post by: HighVoltage on April 18, 2023, 09:43:53 pm

Very nice work you did here with the replacement !