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Questions about Murania radio speaker mounting


Philip Karras <ke3fl@...>
 

I found four washers two are 1.25mm thick the other two are 0.75mm thick. All are metal so this will not protect the speaker frame from being connected to the traces in the holes. These holes are grounded.

Questions:
 1. Are the washers supposed to be two different thicknesses? If so which pair
    goes where? Thicker on top, bottom, left or right sides?
 2. Is the speaker case supposed to be grounded? The instructions say, "...washers between the speaker and the panel to space the speaker from the frame up from the traces that run on the surface..." Metal washers won't stop the speaker from touching the grounded hole traces.
 
Thanks for any clarification.

tnx es 73 de KE3FL,
Phil
-----


Robert
 

Phil
There is many different vendors that we get our washers from. There is no constancy in the thickness of the washers. It really does not matter, the only purpose of the washers is to space the speaker off of the board 

Good luck with your build

Bert
N0YJ

On Wed, Feb 10, 2021, 4:13 PM Philip Karras via groups.io <ke3fl=yahoo.com@groups.io> wrote:
I found four washers two are 1.25mm thick the other two are 0.75mm thick. All are metal so this will not protect the speaker frame from being connected to the traces in the holes. These holes are grounded.

Questions:
 1. Are the washers supposed to be two different thicknesses? If so which pair
    goes where? Thicker on top, bottom, left or right sides?
 2. Is the speaker case supposed to be grounded? The instructions say, "...washers between the speaker and the panel to space the speaker from the frame up from the traces that run on the surface..." Metal washers won't stop the speaker from touching the grounded hole traces.
 
Thanks for any clarification.

tnx es 73 de KE3FL,
Phil
-----


Jim, N5IB
 

Hi Phil,

It's OK for the metal speaker frame to touch and make electrical contact with the ground plane that surrounds the plated through mounting holes.
But there are active traces that run underneath the speaker.
Those the frame should not touch. But they are sufficiently far away from the washers.

Given that you have a mismatched pair of washer thicknesses - don't put the like-sized ones diagonally opposite, since that would torque the frame.
Put them on adjacent screws.

I cut up old dark socks (after washing!) to make cheap "grill cloth"

N5IB


Philip Karras <ke3fl@...>
 

Hi Jim,

Thanks I figured to match them as pairs on a side or top/bottom, not as you said not to opposite corners. I've done similar for grill cloth, I'll have to see what I have around for that. I have plenty of dark socks just not ready to be cut up ;-)

73 de KE3FL,
Phil
ARRL OES, ORS, & VE
ARRL Life Member


On Wednesday, February 10, 2021, 6:29:05 PM EST, Jim, N5IB <n5ib@...> wrote:


Hi Phil,

It's OK for the metal speaker frame to touch and make electrical contact with the ground plane that surrounds the plated through mounting holes.
But there are active traces that run underneath the speaker.
Those the frame should not touch. But they are sufficiently far away from the washers.

Given that you have a mismatched pair of washer thicknesses - don't put the like-sized ones diagonally opposite, since that would torque the frame.
Put them on adjacent screws.

I cut up old dark socks (after washing!) to make cheap "grill cloth"

N5IB











Philip Karras <ke3fl@...>
 

Thanks again Bert.

73 de KE3FL,
Phil
ARRL OES, ORS, & VE
ARRL Life Member


On Wednesday, February 10, 2021, 6:02:58 PM EST, Robert <e1dslr@...> wrote:


Phil
There is many different vendors that we get our washers from. There is no constancy in the thickness of the washers. It really does not matter, the only purpose of the washers is to space the speaker off of the board 

Good luck with your build

Bert
N0YJ

On Wed, Feb 10, 2021, 4:13 PM Philip Karras via groups.io <ke3fl=yahoo.com@groups.io> wrote:
I found four washers two are 1.25mm thick the other two are 0.75mm thick. All are metal so this will not protect the speaker frame from being connected to the traces in the holes. These holes are grounded.

Questions:
 1. Are the washers supposed to be two different thicknesses? If so which pair
    goes where? Thicker on top, bottom, left or right sides?
 2. Is the speaker case supposed to be grounded? The instructions say, "...washers between the speaker and the panel to space the speaker from the frame up from the traces that run on the surface..." Metal washers won't stop the speaker from touching the grounded hole traces.
 
Thanks for any clarification.

tnx es 73 de KE3FL,
Phil
-----