I tried Ted's open, no change, save CAL technique (on HFLAT only) but it does not seem to have worked; at some point, the values that self-populated for the steps took a jump from 16's to -2's. I get significant drop in output level (Vpp) when going up to 100 MHz and more at 200 MHz. I guess I'll have to do a real CAL
Gandalf:
Please read all of the below so that you know what to expect:
For a DG4202 the CW RF Output should be flat up to 200MHZ within +/- 0.8dB after the Calibration recovery has been completed. Note that the Sine Sweep Mode is still limited to a maximum frequency of 160.000,000 MHz for a flat RF Output. Any Stop frequency above this at all, will screw up the frequency response even below 160MHz. So if want to go beyond 160.000,00MHz do it in Sine CW mode only.
Still think your DG4202 has a problem:
Check that your DG4202 is Set for (under Utility, Settings) 'Power, Default', Not 'Power, Last'. Then I suggest going back to FW 00.01.06. Verify that you still have a DG4202 model installed per the DG's 'Utility', 'System', 'Information' menu. If not use the appropriate CEN file to change it to one. Perform the Calibration Recovery routine for Amp-AC*, LFLAT*, and HFLAT. Then go back up to to FW 00.01.08. How is it now?
Note: * Cal for Amp-AC and LFLAT Cal. may not be required, but I do it to prevent other potential glitches. I had a few people tell me that doing this fixed some issues for them, but I don't have any conclusive evidence. It's easy to do, but you can always go back and do these two later (if you chose to) after you have determined your unit is now working Ok in manual CW mode to 200MHz.
The above is what I have successfully done and has worked for others, but if there is something unusual with your unit (i.e. FW/hardware) I'm NOT responsible. I think you will be OK, but I live far, far away, so don't come looking for me.
If you have questions, but no bitching please (Ha Ha), feel free to contact me via a PM.
Good luck, Ted572