[AMRadio] LED Magnifying Lamp by Duratool


rbethman rbethman at comcast.net
Tue Sep 22 12:10:02 EDT 2015


Bought this.

I like the brightness & the magnifying glass. The lid for the glass is a 
nice touch.
It keeps the glass clean & protects it.  It even has a section of the 
Magnifying glass that works like a bifocal. It really is bright!  It has 
60 LEDs in a ring under the top, around the magnifying glass.  It is great!

Then as I found on another review on a different Emporium's Site:

    "But unfortunately, when the light is on, it gives off a fair bit of
    RF hash that can be heard in a radio. I added a 0.022uF 630V cap at
    the output terminals to the LEDs and that quieted it down a bit. I
    wish that the people that spec out these designs would pay more
    attention to spurious RF that some power supplies cause."

I took it apart when it got here.  The power supply is in the base. I 
went with a bigger value cap.  I went with a 0.068uF @ 630V one. Now I 
got rid of all the hash!

When you get one of these, open just the base.  Two screws hold the 
little switching supply.

Look at the DC end.  It has the + and - marked on the board.

Good news is the board uses screws to hold the wires!  A bit of teflon 
tubing to the cap leads, solder it across the DC end, tuck it where you 
can, and the hash is totally gone!

I went with a bigger cap simply because that reviewer commented, "that 
quieted it down a bit", and I wanted more than a "bit".




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