Monday, January 12, 2015


Today I took the Driveby System on the road for the first test.  For some reason I couldn't get the GPS to work so I didn't get any mapping data.  HOWEVER, I was able to locate a 49Mhz Baby Monitor!  And some weak Power Line noise.

I didn't connect the planned large 25-1300Mhz Discone antenna for this test.  So I am rather impressed that the 1 meter long whip antenna I used was enough to detect what it did.

In the chart below I was driving around and once I saw the first spike on 49Mhz and NONE on 50 Mhz I knew I was close to a Baby Monitor.  There are about 5-6 of them in the town I live in.  This is the first time I've pin pointed one of them 'to the house'.  So please remember as creepy as this sounds the idea is to locate them, then ask the owner if they'd be willing to accept a 900Mhz or 2.4Ghz baby monitor as a swap.  The idea is to move them off these monitors that effect my 50 Mhz Radio operation.  And that's all.  Nothing creepy or sinister there.

I was also able to spot what may possibly be one of the main sources of Power Line noise that's local to me.  At the end of my street the graphs gradually rose up and then sank again as I was driving along.  On my return pass (always have to pass source at least twice to three times to verify it) It once again began to raise up again.  Looking briefly I noticed a power line leading from a pole to a home.  The line is rubbing on a large dead branch.  (probably dead from AC exposure if you ask me!).  I suspect now that this is one of my larger noise sources and probably and easy one to cure!

Here's the graph....the next time I take this on the road I'm going to make sure the GPS is functional.  This is the first time it's failed to work for I'll have to research what's going on there.

Jan 13th 2015 I hope to retest with the GPS working.  If successful I'll drive the entire town I live in and post the results here.  I didn't do a Video today because I decided without the GPS and the mapping working it wouldn't be all that interesting to most folks.  I got the GPS working again tonight back at home, so it's just something simple.  All I had to do what disconnect and reconnect the USB cable once, and it started right up.

A note to self: service gpsd restart 

Outputs more interesting command line results than service gpsd stop and then service gpsd start which returns nothing at all.  "restart" at least provides the typical Linux 'service' command line result with a satisfying "OK" message.  LOL