Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
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
Need to purchase some accessories for restoration of my Old Philco Radio
Here is a list of resources found in our online library that you might find useful. Mike's Gobs of Knobs email addres...klondike98 — 01:46 PM
First Radio restoration
Hi Tubeman, Welcome to the Philco Phorum.  Phamily Phriendly Pfun with Phine Pholks Phull of Philco Phacts. (See a p...MrFixr55 — 12:33 PM
First Radio restoration
You could post in the WANTED ADs section here on the Phorum and see if anyone has an RF generator that they want to sell...klondike98 — 11:55 AM
Zenith H725
Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately. More ...EdHolland — 10:18 AM
Graphics for majestic 1050 dial glass.
Murf; I found this thread on the ARF, the first photo has a pretty good view of the dial glass. Regards ArranArran — 01:12 AM
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM

[-]
Who's Online
There are currently no members online.

>