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

What was the correct DC ohms of a good coil on these??


I have been told 900 ohms 1000 ohms 1500 ohms

I have one from a Philco Model 17 and the coil checks out good at 670 DC ohms.

one from a Model 16 125-126 45-2028 OPEN COIL
one from a Model 650 45-2086 OPEN COIL

All the links I find leaves it up in the Air. Nothing as to what Philco intended them to be in DC ohms


Any Help appreciated

Bob T
#2

1. 1000 feet of #40 gauge enameled copper wire will be needed to rewind the coil in the Shadow Meter assembly. It just so happens that #40 gauge wire has a resistance of about 1.1 ohms per foot. So in a typical radio, a current draw of 10ma. will give the 10 volt drop across the coil that it takes to operate the shadow vane correctly.

(calculates at 1,100 Ohms)




http://www.philcorepairbench.com/tips/svctip01.htm

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.
#3

Yes Thank You

I did find an original that measured 960 ohms, so that is close enough.

Bob T
#4

Found another P/N 6497 Original from early 16B
Coil measures 848 DC Ohms

Functions well, not tried in Radio.



Bob T
#5

As long as it functions well, plus minus 20% or so does not matter. It is a DC magnet, they are way simpler and not critical to things like a turn short.

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.




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
New member
Hello jeff, Welcome aboard ! Sincerely Riochardradiorich — 06:53 PM
New member
Good picture, When was it taken? You don't look in it like a guy who has a teenage son :)morzh — 06:13 PM
New member
Love the pic! I'm southern IL, so wouldn't be much help and Bob Anderson is very good on those, but lives in Chicago are...TV MAN — 05:25 PM
Philco 40-120C Filament Wiring
:thumbup:klondike98 — 04:56 PM
Philco 40-120C Filament Wiring
With these values I think you are OK; the Cmax for this tube is 40uF. Your Vbb could rise a bit, but probably not too mu...morzh — 04:53 PM
Philco 40-120C Filament Wiring
BTW, someone had replaced the original 20uF/20uF filter cap with a 47uF/33uF cap. Do you think these values are safe on ...bluecap — 04:33 PM
Philco 40-120C Filament Wiring
You're correct. I was misinterpreting the key position. I now know where it is, and things are making sense. I appreciat...bluecap — 04:29 PM
Philco 40-120C Filament Wiring
I think Morzh has a good thought. Check the key position. The under chassis diagram in the Philco info shows an “H” for ...klondike98 — 04:25 PM
Philco 630csx power cord
Yes, the third wire goes to the stud on the side and is separate from the other two. I've usually used cloth covered ...Tynwald — 03:09 PM
New member
Have you tried Alabama Historical Radio Society? They possibly could recommend someone. I remember a name of Dee Hanes...morzh — 03:08 PM

[-]
Who's Online
There are currently 4819 online users. [Complete List]
» 3 Member(s) | 4816 Guest(s)
AvatarAvatarAvatar

>