It isn't loud. It's like a little scratch on a new car that nobody else sees but you know where to look. It's 95% better than it was yesterday - most of the noise was coming from the loops between the computer (even though it's coax out somehow it's still grounded) and the grounded CD player. Next, I'll ground the player and connect it with isolation xfmrs to see if it can drive them.
The missing ground wire was the cause of the hum though. When switching on the cold phono section, it used to sound like a degauss along with a frequency sweep like on an old tape when you turned it on. Now it's silent...
The missing ground wire was the cause of the hum though. When switching on the cold phono section, it used to sound like a degauss along with a frequency sweep like on an old tape when you turned it on. Now it's silent...
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I meant how loud does it get when 9 amps are playing.
Or you use them one at a time?
Your hearing must be good if you can hear a quartz clock at 10 feet.
Silicon spray or grease in quartz clock movements works wonders for sound level and battery life.
Or you use them one at a time?
Your hearing must be good if you can hear a quartz clock at 10 feet.
Silicon spray or grease in quartz clock movements works wonders for sound level and battery life.
Oh! No. Only one at a time, but they are all connected - the outputs are switched.
Ya this clock doesn't even have a second hand. I can just hear it. I have to listen for it though. Right now the loudest thing in here is the refrigerator and still under the 30.1db my meter can measure - but it's loud AF if there's no sound playing LOL
I built an amp for my dad that had a slight 120Hz hum on it but I didn't notice until I was at his house. I built it in the summer and I have AC running so the winter is the only time I can hear and chase noise and hum. The AC is only 55db but that's far louder than the crap I'm chasing down.
He couldn't hear any hum at all though. If the furnace cycles in the night it'll wake him up but he can't hear a hum... I literally slept through the fire department and EMS coming in for my mother in the middle of the night when I was younger but I hear a bit of hum and it's like the end of the world.
Ya this clock doesn't even have a second hand. I can just hear it. I have to listen for it though. Right now the loudest thing in here is the refrigerator and still under the 30.1db my meter can measure - but it's loud AF if there's no sound playing LOL
I built an amp for my dad that had a slight 120Hz hum on it but I didn't notice until I was at his house. I built it in the summer and I have AC running so the winter is the only time I can hear and chase noise and hum. The AC is only 55db but that's far louder than the crap I'm chasing down.
He couldn't hear any hum at all though. If the furnace cycles in the night it'll wake him up but he can't hear a hum... I literally slept through the fire department and EMS coming in for my mother in the middle of the night when I was younger but I hear a bit of hum and it's like the end of the world.
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Designed a ESR meter.
Pretty straight forward a Oscillator and a precision rectifier into an A2D on a PIC micro.
A little bit of maths to work out ESR.
I then ventured into calibration mode where you attach a 47r resistor in place of the cap and use that as the calibration point.
I made the mistake of assuming a2d values would be linear.
But of course they are not due to the potential divider on the front end.
Had to do a divide by the calibrate value going through the potential divider.
Works a treat now.
Pretty straight forward a Oscillator and a precision rectifier into an A2D on a PIC micro.
A little bit of maths to work out ESR.
I then ventured into calibration mode where you attach a 47r resistor in place of the cap and use that as the calibration point.
I made the mistake of assuming a2d values would be linear.
But of course they are not due to the potential divider on the front end.
Had to do a divide by the calibrate value going through the potential divider.
Works a treat now.
Built a model railway DCC controller pcb.
IT powers up and puts power up message on the lcd display.
The menu then appears on the lcd display, so far so good.
Put train on track and software resets and goes through power up message.
Checked for overload and that was fine.
Power supplies were all correct voltage.
Replaced PIC micro. Replaced motor driver IC. Still the same.
If the PIC was resetting it must be a power supply glitch.
So changed 0.1uf cap on the PIC to 10uf and problem went away.
Looks like LM317 circuit is not functioning correctly and letting glitches through.
So did a rehash of the circuit and pcb.
Split 12 volts in through 2 diodes, one for motor driver and other for PIC supply via a 3v3 regulator.
An old problem with motor inductive spikes upsetting things.
Also split the ground for motor driver and PIC circuit.
IT powers up and puts power up message on the lcd display.
The menu then appears on the lcd display, so far so good.
Put train on track and software resets and goes through power up message.
Checked for overload and that was fine.
Power supplies were all correct voltage.
Replaced PIC micro. Replaced motor driver IC. Still the same.
If the PIC was resetting it must be a power supply glitch.
So changed 0.1uf cap on the PIC to 10uf and problem went away.
Looks like LM317 circuit is not functioning correctly and letting glitches through.
So did a rehash of the circuit and pcb.
Split 12 volts in through 2 diodes, one for motor driver and other for PIC supply via a 3v3 regulator.
An old problem with motor inductive spikes upsetting things.
Also split the ground for motor driver and PIC circuit.
Started on a new project of a model railway decoder that drives a couple of relays.
I usually work on the encoder side so this was a bit new to me.
Got stuck into reading in the data bits and got on ok.
I then found the data decoded wasnt right from my encoder.
I hadnt multiplied bit set function by 8 to go in correct data packet bit position.
So fixed it in my stand alone encoders before going any further.
The PC USB version was in fact ok, it looked like I had copied the code from that but missed the bit where the digit bit was multiplied.
So the lesson is take care when copying code that you copy all of it across.
I usually work on the encoder side so this was a bit new to me.
Got stuck into reading in the data bits and got on ok.
I then found the data decoded wasnt right from my encoder.
I hadnt multiplied bit set function by 8 to go in correct data packet bit position.
So fixed it in my stand alone encoders before going any further.
The PC USB version was in fact ok, it looked like I had copied the code from that but missed the bit where the digit bit was multiplied.
So the lesson is take care when copying code that you copy all of it across.
Stick blender, wire at brush holder came off the lug.
Soldered it back.
It is a series motor, armature and field coil, quite old.
Back in action.
Soldered it back.
It is a series motor, armature and field coil, quite old.
Back in action.
I managed to restore a wreck(former dynaco PAS3X) . The last thing was ti get and connect
the blend switch . Happy to successfully bring one of these alive again !
the blend switch . Happy to successfully bring one of these alive again !
A hand pump hydraulic standing exercise machine for an older friend who has
Pompey’s disease.
Started leaking and the company wants to sell you a complete unit (hydraulic cylinder )
For 570$ And no rebuild kits available..,.
Took the thing apart and found some o rings needing replacement and while in there polished
The shafts on my lathe and cleaned and replaced the fluid
Good as new for less than a dollar
Pompey’s disease.
Started leaking and the company wants to sell you a complete unit (hydraulic cylinder )
For 570$ And no rebuild kits available..,.
Took the thing apart and found some o rings needing replacement and while in there polished
The shafts on my lathe and cleaned and replaced the fluid
Good as new for less than a dollar
Picked up a pair of inoperable Audioengine A2 speakers at a thrift since they were cheaper than a McDonalds meal, were well built and had the psu. Spent a few hours removing the conductive black goo off of the amplifier board that was shorting things out and muting the output. Not sure that I like how they sound as they seem to be missing some midrange frequencies, but at least I got them working and they fill the gap of computer speakers in my office.
Newer Echo 490 chainsaw, less than 1 yr. old, after a large beech tree fell on it cleaning up after last February icestorm.
. Runs like new, only needed a new handle after cleanup and straightening. Saved a bundle over shop repair
. Runs like new, only needed a new handle after cleanup and straightening. Saved a bundle over shop repair
Erratic functioning on TVS Proton dot matrix printer, after checking the external power brick, I found a Chinese cap, 220 uF/35V or so, next to two Keltron 470/35V, on the internal PCB.
Took a chance, changed it, as it was not bulging or obviously faulty... back to normal.
It would suddenly stop printing at random, and then start again.
Took a chance, changed it, as it was not bulging or obviously faulty... back to normal.
It would suddenly stop printing at random, and then start again.
Crappy joint on an amp. 5R (main R in the CRC) one side fell out of the circuit! Soldered it back and retouched the rest of the board... All is good now. At least I remembered to discharge the first caps before I fixed it 🙂
I hate it when a power supply turns into a power suprise!
I hate it when a power supply turns into a power suprise!
So I finally got the boards for my 12AU7/6E2 meter - the first ones had the tubes facing 180° out which would be fine if I hadn't cut the chassis for it already.
I also found out that I swapped pins 7 and 8 on the 12AU7 but that was easy enough to correct.
I also found out that I swapped pins 7 and 8 on the 12AU7 but that was easy enough to correct.
Attachments
Been working on a model railway dcc controller.
Sold a few but had no feedback so assumed no problems.
I decided to increase loco addressing from 3 to 4 digits.
So got stuck into the code again.
Was horrified to find sending loco functions like lights and sound didnt work correctly.
I was sending 3 bytes instead of 2. The last 2 bytes needed adding together and put into 2nd byte.
To further complicate things some of the function numbers bits were wrong.
Sadly I dont have the luxury of a loco with lights and sound to test it.
If anyone complains they can have a free upgrade.
Sold a few but had no feedback so assumed no problems.
I decided to increase loco addressing from 3 to 4 digits.
So got stuck into the code again.
Was horrified to find sending loco functions like lights and sound didnt work correctly.
I was sending 3 bytes instead of 2. The last 2 bytes needed adding together and put into 2nd byte.
To further complicate things some of the function numbers bits were wrong.
Sadly I dont have the luxury of a loco with lights and sound to test it.
If anyone complains they can have a free upgrade.
Not so much of a "repair" pray tell, but more like an abrupt "eviction".... 
The dining room windows I rarely open, and usually keep the blinds mostly closed, it keeps the dining room dimmed.
I noticed a darkened "area" at the one window the other day, but didn't pay any mind to it, figuring it was a sun shadow.
Last year, I know that birds came around, chewing away at the nylon screens, creating a messy hole in that screen. - I had to replace all the screens on 4 of the upstairs windows over the past two years with metal screening, and I figured that I'll get to that damage later on this spring.
The birds use the nylon threads to build their nests, at my dismay.
So today, I hear a tapping crunching noise at that window, and opened the blinds to find a damn squirrel building it's nest in between the screen and window! - all in a 2 inch width maybe 5 inches high across the bottom of the window!
A whole bunch of tissues, paper, branches, twigs, and yes... even one of those light blue covid masks!
Crap!..... not in MY house!
A sharp bang on the window and the little stinker fled the scene, back through the hole in the screen.
Out comes the shop vac....
Cleaned up the mess, and used some Gorilla duct tape to make a temprorary patch over the screen hole until I can take the screen to the Ace Hardware for them to replace the screen with a metal one.
What is up with birds, and now squirrels these days?
The dining room windows I rarely open, and usually keep the blinds mostly closed, it keeps the dining room dimmed.
I noticed a darkened "area" at the one window the other day, but didn't pay any mind to it, figuring it was a sun shadow.
Last year, I know that birds came around, chewing away at the nylon screens, creating a messy hole in that screen. - I had to replace all the screens on 4 of the upstairs windows over the past two years with metal screening, and I figured that I'll get to that damage later on this spring.
The birds use the nylon threads to build their nests, at my dismay.
So today, I hear a tapping crunching noise at that window, and opened the blinds to find a damn squirrel building it's nest in between the screen and window! - all in a 2 inch width maybe 5 inches high across the bottom of the window!
A whole bunch of tissues, paper, branches, twigs, and yes... even one of those light blue covid masks!
Crap!..... not in MY house!
A sharp bang on the window and the little stinker fled the scene, back through the hole in the screen.
Out comes the shop vac....
Cleaned up the mess, and used some Gorilla duct tape to make a temprorary patch over the screen hole until I can take the screen to the Ace Hardware for them to replace the screen with a metal one.
What is up with birds, and now squirrels these days?