View single post by Slider2732
 Posted: Mar 4th, 2008 01:24 PM
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Joined: Mar 3rd, 2008
Location: Muskogee, Oklahoma USA
Posts: 349
I joined this site to help further the thoughts by Keith that I read about, on working together in this area. No point me building a version of the Frank's box/Spiricom/Spirit Telephone and keeping it quiet ! Secondly, i've learned so much from reading posts here that to not post would be remiss.

Here's mine:

Functions are:
Frank's Box derivative, with variable scan rate and LED notifications of signal reception and rate scan.
Infra red sense
Static electricity sense

This shot shows from left to right: audio out, internal/external sound switch, on/off switch, flashlight button. On the top are infra-red sense LED, scan rate dial (speed of scan LED above, received audio LED underneath) and BF245A static electricity sensor LED.
The unit uses an external wall plug 3V-6V supply or rechargeable battery. Bridge rectified and smoothed to allow practically any wall adaptor. A USB supply is enabled by using a simple build lead, to change the flat plug to round plug.
The design is based on an old HP mouse, my current favourite boxes of choice while not having employment (Immigration Visa to the USA from England).
My Para-meter's feature several proven useful devices and are diode seperated to minimise possible function interferance.
Audio out is either through the small horizontal gap in the reworked mouse case, or through the earphone port, for recording to PC/portable recorder. Internal space is maximised to allow for some bass and the slit approach on the top works well in conjunction.

More pics (early stage and apologies about the purple camera trouble)
Left side, showing the power port.

Underneath, showing the speaker (handy for sticking the unit to metal objects when hands free listening).

Powered up and pressing the flashlight button.

One area I have to work on, unless it's a bonus, is the scanning. While it works great for a few seconds, depending on scan rate, the unit then finds no stations. It results in a background noise each scan. This should mean, you'd think, that audio after that point would be clear of is.
So this audio recording has me perplexed.

Over the build period and testing, the unit would go quiet of found stations after the first few seconds, staying like that. At the point this audio was recorded, it had been switched on for a good couple of minutes. I went to record, to show the speed scanning in operation and noted the interferance...followed immediately by the robot voice and then the crash cymbal type noise. The robot is the second sound piece at the start of the recording.
We've recorded a robot here at the house before now, when, perhaps similarly, we had introduced several new pieces of electronics to our webcam setup.

Am interested in your thoughts of the Para-meter and the recording :)