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

Shadow Meter Question
#1

I have a Philco Model 118 restored and playing great but I have no shadow meter vane action. I took the lens off and can see the vane. With the radio off the vane is facing the front (narrow side). I can move it with a toothpick and it appears to be spring loaded with the narrow side facing out as its rest position.  Is that right?
The part number is 2028 and it measures 1437 ohms so the coil is not open. The schematic indicates a 2900 ohm shunt but the as found one installed measures 1200 ohms. I have experimented with various shunt values (0 to 7K ohms) and there is no affect. No vane action ever.  Shouldn't the vane show its wide side (maximum shadow with the radio off, i.e. no station tuned in?  And what does it take to move the vane to the narrow position--more current or less current?
When I measure the voltage across the meter I get minimum voltage (and hence minimum current) on a strong station and a larger voltage (and hence larger current) when off station.  Does anyone know what the ma range is supposed to be, i.e. how much current to get the vane to move to cast a wide shadow vs. how much current to get the vane to face the front and cast a narrow shadow?
How do I fix this thing or do I need to look for a replacement? Maybe the vane is getting stuck on its pivot.  My next step will be disassemble it to see what is going on inside.
Here is the schematic:
http://www.nostalgiaair.org/pagesbymodel...013125.pdf

Thanks,
Joe
#2

When i tested the one on my 16b, i actually used a 9v battery to test the meter action (meter wires isolated from radio) Icon_smile

I noticed the meter action improved in the radio after i did the alignment procedure..

Steve
#3

Does the sm have a thumbscrew at the back of it?? If so it sets the tension on the vane. Too tight you have very little vane movement. Too loose the vane will bounce from side to side as you tune the set and will settle down after a few seconds.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 91 Speaker Replacement
The spider is glued on the cone and so is the voice coil. I think you can use a cotton swab dipped in acetone and carefu...RodB — 02:42 PM
Restoring Philco 37-604C
Yes I saw that. If I knew, I'd probably try to arrange for getting it myself. But I have just got one. Which does not m...morzh — 01:44 PM
Philco 38-2 Automatic Tuning
When you push the lever, you are supposed to rotate the disk to the desired station. Then the magnetic tuning will acqu...morzh — 01:42 PM
Philco 38-2 Automatic Tuning
I figure out the muting from another picture that helped. Now I need to know how the automatic tuning works. When I push...dconant — 12:11 PM
Philco 91 Speaker Replacement
How would I go about removing the spider from the cone?dconant — 12:04 PM
Philco 38-2 Automatic Tuning
Hello, I am having trouble getting my automatic tuning to stay unmuted. If I play with the tuning handle I can get it to...dconant — 10:51 AM
Does anyone make photofinish replacements?
Here’s the link to the DIY photofinish section of our site: klondike98 — 09:46 AM
Delco car radio Peko vibrator converstion issues
Hi Richard, Thx for posting the schematic.  As I remember as a kid, these were great performers for the time, likely...MrFixr55 — 08:56 AM
Delco car radio Peko vibrator converstion issues
hello mr Fixr, The Electro  Powersupply that I am powering the radio with has a huge choke plus a 10,000ufd electrolyti...radiorich — 10:58 PM
Delco car radio Peko vibrator converstion issues
How about putting a choke in the power supply? The big cap was likely an attempt to stabilize the DC. Kids who cre...MrFixr55 — 09:19 PM

[-]
Who's Online
There are currently 1868 online users. [Complete List]
» 1 Member(s) | 1867 Guest(s)
Avatar

>