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Andrew Wyard · 16th Jun 2021, 6:31 pm

Hi Chaps hope you can help.

I have an E2 sig gen bought from a rally some time back.
From the start it had issues, most of which haven't been that much improved.
The lower three frequency ranges (D,E,F) are pretty much as they should be with good amplitude. The upper three get successively worse with frequency.
Across the range- F=2.5V E=2V, D=1V to 2V, C=1V, B=0.6V to 0.08V, A staggers in to life mid range at about 0.1V All measured at full RF OP and also on tag strip.

Initially it had low HT, so replacement 6X5 and filter caps that helped that. Voltages quoted on diagram pretty much match.
I also ordered a new ECC91 this has possibly helped a little.
I have thoroughly cleaned the wafer switch.
I have replaced the C and R connected to the osc grid.
I have checked the VC for leakage.
I have tried disconnecting the attenuator stage to see if that was loading it.
I have also checked and changed some other resistors around the circuit that weren't that close to value

My last thought is the possibility that the ECC91 is the problem, even though it and the original perform in a similar way.

Any way that's probably enough waffle for now, hopefully there's somebody that's gone through some of this before and has some ideas.

Many thanks, Andrew Wyard. PS if I don't come back to responses for a bit, its just work etc getting in the way. Thanks.

16th Jun 2021, 6:31 pm	#1
Andrew Wyard Diode Join Date: Mar 2021 Location: Bracknell, Berkshire, UK Posts: 4	Advance E2 Signal Generator fault Hi Chaps hope you can help. I have an E2 sig gen bought from a rally some time back. From the start it had issues, most of which haven't been that much improved. The lower three frequency ranges (D,E,F) are pretty much as they should be with good amplitude. The upper three get successively worse with frequency. Across the range- F=2.5V E=2V, D=1V to 2V, C=1V, B=0.6V to 0.08V, A staggers in to life mid range at about 0.1V All measured at full RF OP and also on tag strip. Initially it had low HT, so replacement 6X5 and filter caps that helped that. Voltages quoted on diagram pretty much match. I also ordered a new ECC91 this has possibly helped a little. I have thoroughly cleaned the wafer switch. I have replaced the C and R connected to the osc grid. I have checked the VC for leakage. I have tried disconnecting the attenuator stage to see if that was loading it. I have also checked and changed some other resistors around the circuit that weren't that close to value My last thought is the possibility that the ECC91 is the problem, even though it and the original perform in a similar way. Any way that's probably enough waffle for now, hopefully there's somebody that's gone through some of this before and has some ideas. Many thanks, Andrew Wyard. PS if I don't come back to responses for a bit, its just work etc getting in the way. Thanks.