Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 37-670 Shadow Meter Woes
#16

If you could open it and glue a thin metal strip to it?

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#17

Excuse me for asking what may be a dumb question but ,.. Why do you say half the vain is missing??
I've heard of them missing completely, but not pieces of them missing..
Correct me if I'm wrong,.. the vain pivots, not at the end but off center (from front to back) its both ends that make up the shadow.. The front end throwing one side and the back end throwing the other..
So there wouldn't be a right and left side to the vain.. At least that's the way I see it..

Stan
#18

I was wondering about that too.
My doubt was about this: if there is half missing (it is next to impossible to do anything to this meter without utterly destroying it to make it break in half in the first place), the meter is fairly enclosed space, the other half would still be inside.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#19

I can only describe what I see when I look into the back of the meter (where the lamp shines). The vane is there.  When there is no power applied to the coil, it looks like a thin vertical line.  If the lamp is replaced one sees a centered narrow line on the screen (I use the trick mentioned on the Phorum of taping a piece of discarded Philco dial material over the front so that I could see the generated shadow with the meter removed from the radio).

When power is applied to the coil (0-15 volts DC) I see a dark rectangle gradually appear from the CENTER of where the vane is mounted toward the right.  There is NO symmetrical rectangle on the left  side, and thus nothing to block the light on that side.  If the projection lamp is replaced the result is a thin dark centered line with zero volts.  With 15 volts gradually applied, the shadow expands to fill most of the meter screen on the right side.  There is no shadow on the left side (now looking at the FRONT of the meter).  The left side of the shadow does not move as the voltage is increased. The vane vibrates freely if power is suddenly cut off, so I assume that the vane is not binding up.

If part of the vane did indeed break off (I do not see how that could happen) it is surely lost, since the front of the meter is open once the meter is removed from the radio. 

I hesitate to try to disassemble the meter, since it sort of works as is.  And I have not found any information on disassembly of the new style meter, unlike the extensive (YouTube) videos and photos of the old boxy style.
#20

Well,.. I am not going to say it ain't so,.. just seems a bit odd.. What would have to happen, for a piece to break off..  Is there any way you can get a pic of that vain?? Maybe from the front looking in, off to one side?? Yeah I know what I'm asking, but in one of your pictures I can see the back end of the vain,.. I would like to see the front end..



Stan
#21

       
For you doubters, I have attached two photos.  My cheap camera cannot do a decent job that close with no lighting.  One photo is from the front, no voltage on the coil.  The other is with 9 volts connected, so the vane is tilted.  In both cases, note the bright line on the vane where the other half USED TO BE.  It's hard to see, but the rear vane (back side, closest to the lamp) is present.  The the front side of the vane is missing - broken off where the bright line is (bare metal - the remainder of the vane is dark).  Just my opinion.
#22

 Here is some pics of an old one I have. I took pic. of it and looked like yours with shiny end of vane.
https://www.dropbox.com/s/j95dsbq1n6scy1...8.JPG?dl=0
  I figured nothing to lose and decided to see if I could remove it.
https://www.dropbox.com/s/9mxb0to3lcnsm2...9.JPG?dl=0
 After carefully bending back the four tabs on the back I pulled it apart.
https://www.dropbox.com/s/zmqylmrb6lqxj1...1.JPG?dl=0
 Here is what it looks like after removal.
https://www.dropbox.com/s/10gb5ucm2l6enk...4.JPG?dl=0

https://www.dropbox.com/s/ybqic8wtckup01...2.JPG?dl=0

https://www.dropbox.com/s/exvbyk2ewd21na...3.JPG?dl=0

 You might want to try this to get a better look at yours. If you do don't get mad at me if it breaks Icon_e_surprised Icon_biggrin  Good luck.
#23

Huh,.. it looks gone.. I never said it wasn't.. Just seems that there would have to be some other sort of damage also.. I'd be willing to bet that someone stuck something in there and broke it..
I've bought a few Philco parts from a guy on another forum.. I'll look up his user name if you like..

Stan
#24

(04-08-2016, 04:54 PM)Stan the Man Wrote:  Huh,.. it looks gone.. I never said it wasn't.. Just seems that there would have to be some other sort of damage also.. I'd be willing to bet that someone stuck something in there and broke it..
I've bought a few Philco parts from a guy on another forum.. I'll look up his user name if you like..

Stan
Yes, about the only way the damage could happen is someone stuck something in the front, perhaps to see if the vane was free to move.  Thanks to the photos provided by Mike, I may try to take it apart and repair it by attaching a thin piece of metal. I'll have to check if the existing vane (other side) is ferrous or not.  I have some very thin brass, but I don't know if I have very thin and light iron/steel. Or I could try to obtain another meter with a bad coil, since my coil and magnet are OK.  

Thanks to all that have helped!
#25

Thanks to Mike's photos, I got the nerve to take the shadow meter apart.  As suspected, one half of the vane was missing - obviously broken off. Checking with a small magnet, the remaining half of the vane appeared not to be ferrous, or at least it was not attracted by the magnet.  I cut a small piece of paper thin brass and glued it in place (approximately) - not an easy task if your hands shake! I finally was able to tack it in place using fast setting epoxy.  Once dried, I painted it with flat black enamel like the rest of the parts. I did notice that the brass half of the vane was heavier than the original half.

In any case, it works perfectly now!  Thanks for all the help and advice.  I'm guessing that someone stuck something into the open front of the meter and in the process broke off the front half of the vane (the half that faces the back of the dial opening). The weight difference and resulting unbalance apparently did not matter.
#26

That's great, your perseverance really paid off.  The pictures and info in this thread will help someone else fighting a shadow meter problem in the future.

Edit:  now you can edit the title and remove the "I give up"!

John KK4ZLF
Lexington, KY
"illegitimis non carborundum"
#27

Great job!
Icon_thumbup Icon_thumbup Icon_thumbup
#28

Good job, Dave.

Crist
#29

Excellent! I look forward to having My "baby" in two weeks.




Users browsing this thread: 1 Guest(s)