The PHILCO Phorum
38-62 Line safety caps - Printable Version

+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Philco Radio Discussions (https://philcoradio.com/phorum/forumdisplay.php?fid=5)
+--- Forum: Philco Electronic Restoration (https://philcoradio.com/phorum/forumdisplay.php?fid=8)
+--- Thread: 38-62 Line safety caps (/showthread.php?tid=20677)


38-62 Line safety caps - jake wells - 11-30-2019

Should i use Y2 or X2? I am having a hard time choosing because i don't know which i need to use the values is .015 .

RE: 38-62 Line safety caps - Patrick - 11-30-2019

I always use Y2, because they can be used both line to ground, and across the line, whereas X2 shouldn't be used line to ground. Y2 are slightly larger, and cost $1 rather that 50¢, but I don't see that as much of a problem.

Besides, at my age, I don't want to have to try and remember which one I should use, or have to read the small writing on them.

Pat

RE: 38-62 Line safety caps - Steve Davis - 11-30-2019

Y2 and I would drop the value down to .01

Steve

RE: 38-62 Line safety caps - jake wells - 11-30-2019

Does dropping the value lead to a decrease in line interference?

RE: 38-62 Line safety caps - Steve Davis - 11-30-2019

Jake, the reason I suggest lowering the value of the caps is, they are connected in series across the line, with the mid point connected to the chassis. This creates a voltage divider, putting one half the line voltage on the chassis. By lowering the value, you decrease the current available. The main purpose of these caps is not to filter the line but, to provide a ground path for the antenna circuit, the lower value will do this just fine. 

Steve

RE: 38-62 Line safety caps - morzh - 11-30-2019

>>>>......they are connected in series across the line, with the mid point connected to the chassis.

Which means they are connected in parallel from the point of view of the chassis. So if from L to N two .01 uF caps present 0.005 uF equivalent then from L and N to Chassis they look like 0.02uF 6V AC source with the equivalent AC current.

This is called "touch current" in LVD safety regulations and should be limited.

0.01uF caps is what I use and it's more than enough.

As for Y2, as Steve also noted, those are the best.

Strictly across L - N X2 is fine but since more often than not caps are placed from L and N to chassis, Y is warranted.

RE: 38-62 Line safety caps - jake wells - 12-01-2019

.01 Y2 is what i am going to use.

RE: 38-62 Line safety caps - Ron Ramirez - 12-01-2019

I use these X1-Y2 caps from Mouser:

https://www.mouser.com/ProductDetail/Vishay-BC-Components/VY2103M63Y5US63L7?qs=sGAEpiMZZMu3dWSqd4Tl0JWsZCkrOTnx17haQC%252BZxV3YfgpVLdXR8Q%3D%3D

RE: 38-62 Line safety caps - morzh - 12-01-2019

I use the same.