How would you mount this kind of meter?

[Opcom]

This is a meter of which there are several, with various markings, all from an old transmitter. I don't know what transmitter.

Maybe an RCA. They are the ame as I posted a pic. of earlier on a shelf. I have them handy now though and examined one. Here are
some pictures up close. Sorry they are cellphone pictures.

Westinghouse Type EX
Style NY-66146-6

Anyone got an old Westinghouse catalog?

The Panel cut-out would fit a body that is 3.75" wide and 4" tall, having radiused corners. No doubt the transmitter factory had an expensive punch. I don't!

The decorative bezel is 4" x 4.125" and 'snaps' on and off to reveal the working front panel with zero adjust screw and the four front access screws. This decorative bezel is cool because it hid the meter screws on a big BC TX, so everything looks right.

These four screws thread into the inside of the actual mounting bolts, which are each permanently affixed to the case, and each fits through a hole just outside the radius of each corner of the hole in the panel. Nuts go on the back to mount the meter in place.

Behind the working panel are the lamps, two candelabra base #40 types (6v), and the movement. The interior is white.

The lamps are on coaxial 'stalks' that can be pulled out for lamp replacement and just stuck back in. There is some spring pressure between the lamp bulbs and the inside of the working front panel. They touch that surface.

To remove the movement (which ought not really be neccessary, these things are taken out from the front and then the three screws on the back are removed.

Caution must be used as the gaskets are old cork-like material, likely had some 'stickum' on it, and will let go suddenly. So avoid having prying on it in such a ways that the movement pops loose suddenly out of the case ripping the gaskets.

A hole is going to be challenging due the not-round shape. It might be easy to use a plexiglass or plastic panel and a dremel-type 'router' bit. Then put the meters behind glass or something. These are not plastic but metal meters and a row of 4 of them will be weighty. They might also be intended to be used in a steel panel. I don't know the consequences of not doing that.

[Opcom]

more

[Opcom]

While I was at it I measured the case sizes of a few dozen round-body meters (not shown). It might be interesting to show the most typical large and small sizes, which would indicate approximately the more popular hole sizes. It has nothing to do with the big meters shown though.
Body diameters, inch:
1.5
2.0
2.17
2.25
2.75
2.81
2.9
3.0
3.125
4.5  (yeah a 2000 amp brass bezel RF ammeter. what to do...)

[KY4SP]

The radiuses at corners might be done with the appropriate size twist drill or hole saw- then cut the straight sides with your favorite saw or rotary tool.     

[W7TFO]

The radiuses at corners might be done with the appropriate size twist drill or hole saw- then cut the straight sides with your favorite saw or rotary tool.     

+1

73DG

[WBear2GCR]

agree - 4 holes and 4 straight cuts.

[Opcom]

Y'all are right.. I am always afraid of ruining a panel and that's why I am in these situations. Th overlap of the bezel is very small on these, 1/16" vertically and 1/8" horizontally, I will re-measure.

The original panels from the big ancient transmitters, which could be cut to 19", seem to never be around.

I made a carefully drawn template of the meter body and bezel. That's another reason I disassembled it. Need to scan it.

To figure the radius, I need to match up hole saws or find a compass I think it is called, having two legs one with a point and other with a pencil/pen tip. It has a scale on it, when opened the size is indicated for the circle drawn.

These may have to go on the shelf for a while. I want them for the future 3CX3000 project.

[K9PNP]

The original panels from the big ancient transmitters, which could be cut to 19", seem to never be around.

Don't forget street sign aluminum.  I use it for chassis and panels. Tough aluminum.  An angle grinder with sanding head will normally take off the wording, etc.  Try not to inhale the dust; not sure what is in the reflective stuff [like Scotchlite]. Get to know your local street department people.  Ours will give you some old signs before they get either thrown out or recycled.

[W1ADR]

Might I comment on the subject based on My Own personal experience. Whenever mounting instruments or meters in panels, I typically make a thin pressed board or cardboard template to match the outline shape or contour of the instrument. With this in hand I am now able to look at what would be the preferred layout for the main opening or hole and determine clearances with existing components, if any.. As to the mounting screw holes, the instrument itself is used as the template with a dab of paint on the end of the studs, if the instrument is so configured. If the through mounting holes are in the instrument, then these provide for the drill template. In short, without the need for extensive and precise layouts, the installation is easily accomplished without reaming or opening-up pre-drilled critical minimum clearance mounting holes. Furthermore; making individual templates allows for determining the physical layout or nesting of instruments for clearances necessary to accommodate components attached to the aft side of the jnstrument(s).   73, W1ADR Anthony

[WB4AM]

Y'all are right.. I am always afraid of ruining a panel and that's why I am in these situations. Th overlap of the bezel is very small on these, 1/16" vertically and 1/8" horizontally, I will re-measure.

The original panels from the big ancient transmitters, which could be cut to 19", seem to never be around.

I made a carefully drawn template of the meter body and bezel. That's another reason I disassembled it. Need to scan it.

To figure the radius, I need to match up hole saws or find a compass I think it is called, having two legs one with a point and other with a pencil/pen tip. It has a scale on it, when opened the size is indicated for the circle drawn.

These may have to go on the shelf for a while. I want them for the future 3CX3000 project.

Maybe to late to mention?  

How about cutting the hole so that the complete meter fits into the hole including the 4 mounting bolts with the meter trim removed.  Then cut a rectangle strip of metal long enough so that it goes from top to bottom of the of one side of the meter mounting bolts so that the ends of the metal strips rest against the inner front panel.  Of course holes would need to be drilled at the ends of the metal strips to allow the meter bolts to go through the metal strip and then add the meter screw down nuts in place to hold the meter against the inner panel.  One metal strip for the left and one for the right.  These would act as washer if you will?  The outer meter plate if strong enough would hold the meter to the outer side of the panel.  I don't know how sturdy the outer trim ring for the meter would be without having it here?  Anyway just another thought!

Edit: Looking back at that trim plate to meter housing looks pretty thin.  Looks to be a bad idea !!!