Actually, if you place the blade of a screw driver on the body of a working diode and the handle end in your ear, you can hear the 50 or 60 cycle noise clearly.
So there!
Jan
PS I kid you not!
Well, I just fixed the Jfet pin order, but that hasn't changed the noise either. Still exactly the same noise level.
It's a BF862 LTP frontend with ~8.7mA per Jfet, 4V tracking cascode. Carbon film 39k/470R feedback network.
It's a BF862 LTP frontend with ~8.7mA per Jfet, 4V tracking cascode. Carbon film 39k/470R feedback network.
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Keantoken, Brad has a point. I'd try a gate stopper - 50-100 ohms. Better yet, a small ferrite beam out right next to the device.
Separately, I had a helluva oscillation problem on me e-Amp diff pair cascodes at 182 MHZ. Fix was 470 ohm SMD resistor right at the base of the cascode transistors. I have a write up about it and some sims on my website.
It looked like noise because my scope could not trigger properly. I hooked up one of those cheap Rigol digital scopes and it became clear what the waveform was.
Separately, I had a helluva oscillation problem on me e-Amp diff pair cascodes at 182 MHZ. Fix was 470 ohm SMD resistor right at the base of the cascode transistors. I have a write up about it and some sims on my website.
It looked like noise because my scope could not trigger properly. I hooked up one of those cheap Rigol digital scopes and it became clear what the waveform was.
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You can't hear the sea? damn. I'll let others put a piece of metal onto something where one slip could cause bad things(tm) to circuit or user. But I understand the noise bit. I used to find that you could gauge the load on telco switches by the noise in the switch room. In that case SMPS transformers. For the diodes pot them and screw then to the chassis I say to kill the noise. Ah they already do! How nice of the manufacturers 🙂
I couldn't affect the noise any by touching different leads with a pencil lead. Nothing I do seems to change the noise level.
Hear the sea??
My g/f has a shell tattoo high on the inside of her thigh. If you put your ear on it you can smell the sea 😎
Jan
My g/f has a shell tattoo high on the inside of her thigh. If you put your ear on it you can smell the sea 😎
Jan
Exactly. Nothing weird or wonderful going on, nothing to see here, just straightforward engineering...
I'll definitely have to verify that up close on the next rencontre.
I have a tattoo of Curaçao, I'm on the isle if I smell or eyeball it, 2 months left for the next ten-hour flight over.
(then again, I have an eidetic memory, I only think in images, sounds and scents. Numbers are pictures, as are words, and smells)
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That has so cheered me before starting the tedious job of the day I have been putting off for 6 months 🙂
Mowing the lawn ?
(Up close, could possibly smell like a silky smooth and salty sea. 'Ziltig' in Dutch is more to the point, English is so general that it's not accurate)
(Up close, could possibly smell like a silky smooth and salty sea. 'Ziltig' in Dutch is more to the point, English is so general that it's not accurate)
No lawn was yesterday. Today is carpet cleaning. Cat is away so mouse gets to deal with backlog.
Aside: Always intrigued me that in UK its 'gardening' a pleasurable hobby and in USA its 'yardwork' a chore.
Well, by no fault of my own, noise has dropped to 1/4th it's last amount. I added several gate stoppers, but at first it didn't seem to have done anything. Then after messing around I look at the scope again and 3/4 of the noise is gone. I'm wondering if something got "reset" after a burst of oscillation since I was adjusting the compensation.
Bill,
Gardening is pruning the roses, planting a few pots, watering the garden. Yard work is racking piles of leaves, pulling weeds, cutting branches of trees up high. Gardening can be a nice small plot for your vegetable garden, yard work is taking care of a 1/3 acres plot some on a steep hill where you soaking wet with sweat!
Gardening is pruning the roses, planting a few pots, watering the garden. Yard work is racking piles of leaves, pulling weeds, cutting branches of trees up high. Gardening can be a nice small plot for your vegetable garden, yard work is taking care of a 1/3 acres plot some on a steep hill where you soaking wet with sweat!
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