Philco Shadow Graph Rebuilt With Arduino
Posts: 109
Threads: 18
Joined: Mar 2015
City: Ann Arbor, Michigan
(This post was last modified: 09-25-2018, 08:48 AM by markmokris.)
Posts: 7,265
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Clever idea.
For me it's just easier to rewind the original.
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
Posts: 109
Threads: 18
Joined: Mar 2015
City: Ann Arbor, Michigan
09-25-2018, 12:31 PM
I was looking for something to use an Arduino for.
Mark
Posts: 15,502
Threads: 543
Joined: Oct 2011
City: Jackson, NJ
What's in the blue box?
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.
Posts: 358
Threads: 4
Joined: Aug 2015
City: Monteith, Ontario CA
(09-25-2018, 01:10 PM)morzh Wrote: What's in the blue box?
I don't know but I'd guess a signal controlled motor to adjust the vane of the indicator.
Posts: 15,502
Threads: 543
Joined: Oct 2011
City: Jackson, NJ
I thought it is a motor, but was wondering how fast the reaction would be: it needs to be very fast.
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.
Posts: 4,654
Threads: 51
Joined: Sep 2008
City: Sandwick, BC, CA
It's likely sluggish compared to the original movement, which was just a form of variometer like an analog Ohm or Volt meter, which just moves with changes in AGC voltage rather then having to think about things first.
Regards
Arran
Posts: 15,502
Threads: 543
Joined: Oct 2011
City: Jackson, NJ
>>which was just a form of variometer
you mean - galvanometer? It's a crude form of Weston/D'Arsonval galvanometer, indeed used in all analog meters.
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.
Posts: 358
Threads: 4
Joined: Aug 2015
City: Monteith, Ontario CA
(09-25-2018, 03:46 PM)morzh Wrote: I thought it is a motor, but was wondering how fast the reaction would be: it needs to be very fast.
They can be very fast. All of the gasoline powered inverter generators that I have worked on use the same sort of system for engine speed control, and that has to be at least as fast as this indicator.
Posts: 15,502
Threads: 543
Joined: Oct 2011
City: Jackson, NJ
I hope so.
Motor is not as reactive. It takes more time for the engine to rev up, then for a human hand to pass the station when rotating the dial while looking at the indicator: the angular speed could be quite high even with slow rotation, and very little needed to pass the tuning point.
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.
Posts: 109
Threads: 18
Joined: Mar 2015
City: Ann Arbor, Michigan
It's not a great solution. It is a little slow, and you can even hear the servo make a bit of motor noise as it turns. The servo, the little blue thing, takes commands from the Arduino microcontroller to turn to an angle between 0 and 360 degrees. I did it as more of a novelty than anything else.
I am usually one for authenticity, and this is reversible if I get a working shadow meter. I tried rewinding the coil twice, and I couldn't seem to get t to work very well.
Mark
Posts: 15,502
Threads: 543
Joined: Oct 2011
City: Jackson, NJ
Have you tried to re-magnetize the magnet?
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.
Posts: 4,654
Threads: 51
Joined: Sep 2008
City: Sandwick, BC, CA
A Galvanometer, yes, that's the word, I must have been a bit off when I typed that. But still, the shadow meter movement should react much like a magic eye tube if it's working properly, charging up the magnet is a good idea.
Regards
Arran
Users browsing this thread: 1 Guest(s)
|
Recent Posts
|
Bakelite crack repair - what is best epoxy?
|
Starting on a Philco 48-1401 Boomerang radio/phonograph. It has one crack on the left side running from the speaker ope...de371 — 07:17 PM |
Philco 89B code 123 newbie
|
Progress continues, finished blocks 9 and 26. I wonder for caps 23 and 24—can I get away with 100pf instead of 110pf?
...Kurt P — 03:43 PM |
Looking for place to donate unique Philco Philco J-1930 Prototype
|
Welcome to the Phorum, jeibner. Several of our members have connections with radio-related museums. I'm sure others wi...GarySP — 03:41 PM |
Looking for place to donate unique Philco Philco J-1930 Prototype
|
I'm looking for a museum or other permanent home where I can donate a unique Philco prototype of a very top of the line ...jeibner — 03:15 PM |
Test bench almost done...
|
Sweet! Yes, that's a lot of planning and work but will pay off! I built mine about 10 years ago using a radio book from ...TV MAN — 11:39 AM |
1950 Emerson TV resurrection attempt
|
Been awhile since I've even been in the radio room. Work work work, kids graduating, going into college, and the list go...TV MAN — 10:35 AM |
Philco 269 - 444 FIVE VALVE VERSION?
|
> So, given that this is a major refurb I don't have the time to spend on this, so happy to pass it on to someone who...Radioroslyn — 09:08 AM |
Philco 269 - 444 FIVE VALVE VERSION?
|
Thanks for this
Hi Chas,
Fix it, don't bin it! Don't sell your skills short. One step at a time and like the Home D...ChasL0001 — 01:48 AM |
Philco 84 antenna connection
|
Have a Philco 80 my long wire is app 30 feet, for a ground in my work shop have a ground rod that is used only for radio...David — 07:47 PM |
Philco 46-480 Cabinet Restoration
|
Thank you, Gary! I appreciate it.jrblasde — 07:24 PM |
Who's Online
|
There are currently 2716 online users. [Complete List] » 2 Member(s) | 2714 Guest(s)
|
|
|
|