Fluke 6060A RF Signal Generator Troubleshooting - No Output <250 MHz - Page 1
Forum section: electronics / testgear

author: davefr
author_rank: Contributor
timestamp: September 12, 2021, 10:12:33 pm
content: I have a older Fluke 6060A RF Signal Generator. It powers up and completes self test with no errors. It seems to function just fine at frequencies above 250 MHz. But the instant I step it down one notch below 250 MHz output drops to zero. Anyone have one with a similar history. Any suggestions where to begin the troubleshooting process? TIA.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 12, 2021, 10:40:50 pm
content: Hi,RF generators like these generate the signals in bands. There are switches that switch between the bands. The symptoms you describe means part of the .1 - 245 MHz signal path is broken.This is from the manual:The manual is too big to attach here.Send me a PM if you can't find the manual.Regards,Jay_Diddy_B

author: TheDefpom
author_rank: Frequent Contributor
timestamp: September 13, 2021, 03:52:14 am
content: I repaired a 6060B about 5 years ago back in my very early youtube days, here is the playlist, it might be helpful as I remember a similar issue.

author: bob91343
author_rank: Super Contributor
timestamp: September 13, 2021, 05:47:39 am
content: Looks like a problem with the U201 mixer or associated circuitry.

author: wn1fju
author_rank: Frequent Contributor
timestamp: September 13, 2021, 12:15:58 pm
content: If I recall, the board layout of the 6060A pretty much followed the block diagram. Just probe along until you find the culprit. In my case, I had a problem with one of the amplifiers. The amplifier used several discrete transistor stages and one of the resistors surrounding the transistors in the amplifier burned up (they were underrated in my opinion and I replaced them with higher wattage versions).

author: davefr
author_rank: Contributor
timestamp: September 13, 2021, 01:10:53 pm
content: Thanks everyone!! This is a great head start. It sure looks like something in that portion of the block diagram will be the culprit. Hope it doesn't turn out to be some proprietary/unobtainium component.

author: davefr
author_rank: Contributor
timestamp: September 13, 2021, 05:59:18 pm
content: If I'm reading this right, HETL toggles the generator from low band to high band. When it toggles to low band, mixer U201 heterodynes the difference between 800-1045 MHz and 800 Mhz to create the frequencies below 245 MHz and that get's routed to the output.It sounds like the game plan is to confirm good 15 VDC going to Q202, Q204, Q206, Q207 and Q301. After that check that 800 MHz is being produced at TP5.My scope max's out at 300 MHz. Any creative ways to check 800 MHz other then purchasing a high end frequency counter?

author: bob91343
author_rank: Super Contributor
timestamp: September 13, 2021, 06:27:23 pm
content: Your scope may still have some usable sensitivity at 800 MHz. Or you can use the venerable HP 410B.

author: charlyd
author_rank: Frequent Contributor
timestamp: December 09, 2024, 06:16:30 pm
content: Nice topic... i have the same issue with my 6062A. i didn t do more research yet. next weekend i ll dive into..but thanks for the post history. 😉