Building this preamp is no different for grounding or system noises as in doing it for any other preamp. Its a matter of solving individual build or system issues. Nothing special.
Radiotron has a somewhat better paper then RCA with bigger curves (accuracy I have no clue). I printscreened them and did some plots in my tubes working. They run 20,1 bias at 274 V. Heres my loadline, almost superlinear (100 pixels in each direction +/- 5 v)
Ill post an empty one to if you guys are up to paint and loadlines😛
Ill post an empty one to if you guys are up to paint and loadlines😛
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Is there any chance just 1kHz poking up if you deselect sweep? Because now only 1/F near zero sticks up.
You don't drive the pre input from the Pico gen also? Just sampling the pre output to Pico scope when in spectral mode?
Yes, I had the gen to left channel in and pickup to left out. Curve responded when i moved on gen probe so I think it worked
Stajo you are welcome "down south" and hook it up to my HP3562 then you can take non reliable equipment out of the picture.
But i still think you have to find the source of your headache.....
A HV lab powersupply is another good tool when playing around.
But i still think you have to find the source of your headache.....
A HV lab powersupply is another good tool when playing around.
Flathead is nice and Iko is mean😀
Elvis is asleep so tell me if you want me to do some other measures. The Mighty One asked for some clipping level. How do I measure that with my excellent tools?🙂
Elvis is asleep so tell me if you want me to do some other measures. The Mighty One asked for some clipping level. How do I measure that with my excellent tools?🙂
You drive out of the Wavetek a sinewave (1kHz is OK, probe 1x) to pre in and you scope the pre's output on the Hameg. You start low on the Wavetek output knob and you wind it up until you see the sinewave start chopping off to flat top. Then you back down just a hair before the clipping. You read the screen divisions times the V/div switch. Then you state to Zen Mod "That X voltage is my max VPP".
Another nice signal for that is triangle where you can see the points exactly. You have your pre volume pot to max. Wavetek 182 has a max output of 20VP-P.
