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Unanswered Questions





Wireless Data To PC September/October 2018

I have a number of wireless temperature/humidity sensors made by Oregon Scientific for use as weather station sensors. I would like to use them for a data acquisition and monitoring application. Does anyone know what frequency and mode they operate on and how I might use them to send data to a PC to record seasonal trends? Would I need a microcontroller to interpret the output or could it be read directly by the PC and then logged and displayed using software such as MakerPlot?

#9184
Jai Hooley
Edmonton, AB


Something Strange With The Range September/October 2018

The effective range of the key FOB for my Ford F150 seems to have decreased over recent months. While it used to work from distances of 75-100 yards easy, now I need to be nearly right in front (10-20 yards) of my vehicle to operate the systems. I changed to a fresh battery, but no difference. Is it likely there is an antenna problem? If so, where is it located and is there a test procedure?

#9183
Les Waldroup
Charlotte, NC


Resonator Frequency September/October 2018

I have in my junkbox what I believe to be ceramic resonators. What is the best way to test them to determine their frequency?

#9182
Donald Frazier
Geneva, IL


Scoping Out Some Advise September/October 2018

Certain techs and engineers still have a need to sample and view composite/NTSC video in its three axes form, that is: X axis (horizontal), Y axis (vertical), and Z axis (intensity).

In the past, this was accomplished using a CRT o’scope: horiz sweep to H input; vert sweep to V input; and video to Z, or intensity modulation input. Since CRT scopes are bulky, heavy, and, in most cases, not battery powered, a PC/digital scope with capture capability would be very handy for field use.

None of the scope ads I’ve seen list these features. Can anyone make some recommendations?

#9181
Paul Dendrenos
Barstow, CA


PCBs With PTHs July/August 2018

Is there a hobbyist method for making circuit boards with plated through holes at home? Also curious by what is meant by multilayer boards. I'm just getting started, so forgive if this is an obvious newbie question.

#7185
Leonelo Márquez
Maplewood, MN


Show Me The Power July/August 2018

When renovating houses as a hobby, I need to locate powerlines inside the walls and also underground. What curcuit can I build that would be useful? Also, what is the theory of how such a detector would work?

#7184
Denzel Meier
Winnsboro, SC


Phone Line Intercom July/August 2018

We use our cell phones as our main phone service, so our “land line” is no longer being used. Is there a way to use the house phone wiring along with the old phones as a whole house intercom system? I have a detached garage/workshop away from the house where this would be especially useful, not to mention almost every room is wired. Would I need to disconnect from the phone company "grid" to do this?

#7183
Jay Bousquet
Lexington, NC


TV Image Capture July/August 2018

What’s the best way to capture images from my TV? I’m looking to do something like a computer “print screen.”

#7182
Sharon Fitzgerald
Chattanooga, TN


Smooth LEDs? July/August 2018

What makes some LED replacement bulbs dimmable, while others are not? Some of the replacements I have purchased do not dim very smoothly. They seem to dim in steps and then just turn off before lowering to where I need them to be. The previous incandesants dimmed much more smoothly down to a soft glow. Is there a different, (maybe more expensive) type/technology that  would more closely emulate the incandesants? I'm using an X10 controller for the dimming, could this be the problem?

#7181
Everett Barham
Elvaston, IL


Measuring Heat With Crystal Diodes May/June 2018

I have a bunch of crystal diodes in my junkbox that I want to use to measure heat. I seem to remember a circuit for it some years back that I’m trying to reconstruct from memory. It’s not working very well, so I must be missing something. Anyone have a simple circuit or explanation of how it should work?

#5185
John Marion
Bend, OR

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