icom ps125 whine 50 Lookers and nobody knows??

[N1QOQ]

O.k I'm about to use my ps125 as a parts kit. Anybody have a fix for this inncessant high pitched whistle. I'm guessing it's the caps? It drives me nuts.
Its only 2yrs old.

Thanks
Paul

[wa4cch]

O.k I'm about to use my ps125 as a parts kit. Anybody have a fix for this inncessant high pitched whistle. I'm guessing it's the caps? It drives me nuts.
Its only 2yrs old.

Thanks
Paul

yea donate it to an old guy like me with a high freqency hearing loss it wont bother me hi hi

73 de chuck

[N9LCD]

Paul:

Is the PS125 a switching power supply or is it a linear supply?

Does the power supply emit a whine or is it in you rig's output?

Do you have an o'scope to check the output voltage for ripple?

JERRY

N9LCD

[N1QOQ]

I believe it is a switching supply.
The noise is from the supply.
No I don't have a scope.
It varies in intensity, sometimes it stops.
I have read of this before in a post on this board, but with no solution.
I fiqured I would ask some opinions here before I "fixed" it with a hammer.

Thanks for the responce
Paul

[N1QOQ]

So I got motivated and pulled the ps apart . Now it's been a few years since I took electronics and I don't know every thing (don't tell my wife). But I got a nice tingle off the TOPS of the two 1200uF caps with a reading of158vdc between the two. This does not sound right or do I know less than I think?

Thanks
Paul

[wa4cch]

So I got motivated and pulled the ps apart . Now it's been a few years since I took electronics and I don't know every thing (don't tell my wife). But I got a nice tingle off the TOPS of the two 1200uF caps with a reading of158vdc between the two. This does not sound right or do I know less than I think?

Thanks
Paul

send me that thing quick before you hurt your self

73 chuck

[N4JNE]

What I remember from science class, in order to produce a sound wave something has to move the air to create the sound wave!

So this is how I find the whine in a switcher. Take to cover off and push on the parts with a insulated stick. When you find the vibrating part, get some glue.

Some times it is a cap. that is making the noise, so just change it.

Or maybe trade it to one of us older guys that have lost our high freq hearing

Hope this helps

[k9yli]

posting most ly as a test.

Any way. correct. noise needs vibration of something.
"singing" sound can come from transfomrer windings vibrating.

You can get the sticks you need for troublshooting things you dont want to touch with your fingers or a meta tool, get a couple of chopsticks, and also some shish-ke-bob sticks from wally world.
handy to push on relay contacts that may be failing etc.

your problem could be a noisy fan. if it has one.

also save a paper towel roll.

makes an "ear trumpet" to localize sound.

k9yli