[w4rtc]

Hi all
I have a Philco 37-675, I am having trouble getting the light to shine thru the plastic part that selects the band. If I remove that
part the light shines thru the dial no problem. If I leave it out then all of the square band indicators show up. I even
got some of those LED dial light bulbs, that helped, but I cannot see the dial numbers and the LED bulbs  are brighter
than the #55 bulbs. The bright line on the dial comes thru o k but I cannot see the dial numbers. It is one of the automatic
tuning dials. Any advice?
Joe

[morzh]

Joe

Since the system is the same with 37-116....

The glass (or clear plastic) cylindrical rod in front of the light is a lense, so if the distance is off or the glass is murky the light will dissipate instead of focusing in a thin vertical line.

Troubleshooting is easy - see where the light stops.
Unlike electrons, light is visible

[AI2V]

The light from pretty much any LED is broad; the light from the original incandescent bulb is a very tiny, concentrated light source. Hence the display with an LED will be very broad and spread after it goes through the lens but the old fashioned bulb will "shine" with a good, sharp line. Been there, done that.

[morzh]

Ugh...I did not appreciate the fact the LED was used instead, I somehow read it as it was used for diagnostics.....LED won't work as Pete said.
The reason being that the lense (and it is a lense and a matte surface, like in your SLR camera) at best focus can only achieve the image as thin as it gets to project, if it is wide like an LED spot, there won't be a thin Line.

[w4rtc]

I guess I did not explain good enough. I get the sharp thin bright line (pointer) o k . The problem is;
There is a square hole in the "mask" for each band  behind the dial that is suppose to let light thru the square hole to show the Dial number. I tried both kinds of bulbs they worked the same. The bulb is supposed to be a #55 which I am going to use. The light thru the round piece of glass is fine and bright. It seems that not enough light is getting thru the "mask" to the dial to show the numbers.
Thanks for the replies. 
Jo

[morzh]

Jo

I am a bit slow today....WHERE do you get "sharp thin bright light (pointer)? WHAT is the surface you see it on?
I mean, unless the lens projects it on something, there will be no thin pointer.
If it is not the dial disk you see it on, what then?

[w4rtc]

O K
The light bulb is behind the mask and dial. The mask has a oblong hole (or cutout) that the round glass lense fits into. The light hits the round lense and focuses on the dial that forms the bright marker that acts like a pointer on the dial. Also this light shines thru a square opening in the mask at the same size of the numbers on the dial to give light enough to see the numbers on the dial. The bright light ( pointer) is o k the problem is there is not enough light to illuminate the numbers on the dial.
This is hard to explain with out seeing it and even harder to get a picture that would help.
Joe

[morzh]

OK, got it.
I will look tonight on my 37-116, see if the numbers are illuminated. Actually I do not remember if they are. The very system might be designed to only create the pointer.
I also do not remember a whole lot of illumination on 37-640 which is smaller but similar in design (creates line).
But I no longer have it.

Wait 'till tonight, I will look.

[morzh]

Joe

I wish my iPad made photos I could post here.
In short, the figures on the dial are BARELY lighted, the line is bright but the narrow column lighting numbers is extremely faint.

The dial's background is lighted itself, and so the extra lighting has to be discerned on already lighted disk, and it is very little difference. So it is possible yours is working as designed.

[Ron Ramirez]

Here's a drawing of the front view of Philco's Automatic Tuning dial:

[Image: http://i326.photobucket.com/albums/k420/...g~original]

Light has to pass through the dial screen holder assembly (26), which includes one sheet of amber plastic with a slot in the middle and the glass rod in the center; through another sheet of amber plastic (11), the mask assembly; and finally, onto the dial scale (12).

All of these parts have to be clean. You have to be careful with the dial scale, of course; usually, careful wiping with mineral spirits (never water, never glass cleaners such as Windex or any other brand - only mineral spirits) will clean the dial and prevent the numbers from washing off. As always, test in an inconspicuous area first; such as a part number that may be printed away from the scale itself. If these numbers do not wash off, you should be good to go.

The mask assembly and dial screen holder assembly can be cleaned more aggressively, since there are no numbers printed on these. Clean, clean, clean. You can't make the old plastic lighter, so you have to be sure the pieces are clean so you can get as much light through the individual elements of the puzzle as you can.

Not long ago, the 37-690 I used to own went to its new home in the great collection of y2k Bruce. Before it left here, I was experiencing a similar issue in that the lamp behind the dial was barely effective. A 4-chip LED lamp made a big difference in the illumination of the 37-690 dial. YMMV.

I used this LED bulb from Pinball Life:
http://www.pinballlife.com/index.php?p=product&id=2561

I also have one of these in my 610T (630 chassis), and I am having excellent results with them. Again, YMMV.

[AI2V]

If you have a replacement dial, that is easily the problem. The replacements are much denser than the originals. Originals are kind of a light orange in color and the new replacements are thick and brown in color.

The LED's that Ron recommends are great! Even so they aren't the best for a sharp dial "line".

[w4rtc]

Thanks for all the replies. I have tried the led lights and they show thru the dial mask about the same bightness as the
correct #55 bulb. There are some on youtube that show up better than mine do. My dial is the orignal, it looks to be in
good shape. Thanks for the info Ron, Chuck sent that to me with the packet on 37-675 I got from him. Maybe the plastic
the dial is made from is just to dark due to the age of it. But thanks to all for the reply.
The light thru the glass rod gives me a good bright line (pointer) but when you have the square centered on the light
rod mark l think the light should show thru the square and light up the dial frequency number, refer to the picture in Rons
attachment. The square also determines what band is in use the light comes thru the glass rod and as the band is changed
the marker moves with the square.

Thanks Guys
Joe