Building a red system
#1
I meant to post this earlier but I kept getting distracted. My wife bought a weather station in 2006. She wanted to add a lightning detector to it soon after. This was our anniversary present to each other (12 years woo!). We are really happy with this system.

Before the kit arrived I ordered some other parts.
GPS Antenna http://www.ebay.com/itm/261553309782
Discovery board http://www.mouser.com/Search/Refine.aspx...4DISCOVERY
Shrink tube http://www.ebay.com/itm/111434272257
Magnet wire http://www.amazon.com/gp/product/B0082CUNVE/
R/C foam rubber http://www.amazon.com/gp/product/B0006NATXY/
12 50x7.5 mm ferrite rods http://www.surplussales.com/Inductors/Fe...rRods.html
Heat gun from Harbor Freight

I followed these directions to make 2 antennas http://www.wxforum.net/index.php?topic=19914.0. Well, I basically followed them. If you read through the comments you will find some changes to the process. I did not glue the ferrite rods together. I pressed them together and then put 1 wrap of electrical tape to hold them together. I put the rods in the shrink tube and used the heat gun. They are tightly held together. I wrapped the magnet wire on the outside of the shrink tube. I used electrical tape every so often. Ok, I actually deliberately spaced the electrical tape to be at the end and at the center of each rod so that the humps were evenly spaced. There is a tape hump where each rod touches the one next to it. After wrapping the wire I put the entire thing in another shrink tube and heated it up. I wrapped each antenna in the R/C foam (like in the directions) and then slid the antenna into 3/4" PVC. I did not use the metal foil shield. I used the ribbon cable shield. https://forum.blitzortung.org/showthread....01#pid4401

[Image: PICT_20140824_155838.JPG]
[Image: PICT_20140824_155934.JPG]
[Image: PICT_20140825_184238.JPG]

At this point I waited until Sep 24. Ok, the post office had it and gave me a note about it on the 23rd but I did not have it in my hand until the 24th. Woo.

The *wonderful* directions from W3DRM said to make the H-field amp first. I admit that I made the control board first. I soldered 1 module per night. The amp would not have been very entertaining by itself but the control board could be plugged into my network and I could play with the GPS and I could register the hardware. I also wanted to get a little bit of soldering in before I attempted those surface mount op-amps.

The control board soldering was pretty uneventful. I had already loaded the firmware on the discovery board the day it arrived so I was ready to plug them in and turn it all on. I had a little bit of Goldilocks fun with the phone chargers. The first one I plugged in was too low (4.0), the second too high (5.3) and the third was just right (5.1).

On Thursday I made the H-field amp. I had some trouble with the surface mount parts. It would take until the E-field amp before I remembered how I like to do those. I like to put a very small amount of solder on the pads before I put the component on. Ah well. I plugged everything in and had 1 working channel. I plugged the amp into the second input to see if I had messed up something on the controller board. Same results.

On Friday I decided to make the E-field amp instead of debugging the silent channel on the H-field. If I got the E-field working then the detector could use it while I was fixing the H-field. Alas once I was done the E-field did not work either. Crap.

Saturday I took the H-field amp offline and put a nice (less than 1 Vpp) quiet signal into the antenna inputs. Years ago my wife bought me a signal generator for I think $1 at a surplus auction from UTC. The General Radio 1210C and surplus oscilloscope did me good. I found that the signal went into IC7 but did not come out. A quick touch up and both channels worked.

On the to E-field! The pre-amp had power but the signal was not making it out. A continuity test showed that 2 of the 8 pins on IC1 were not connected to the board. That would be pins 3 and 6. I believe that is the input and the output. Yeah, I would mess up both of those. Some touch up work there and E-field works. Woo. I had a little bit of fun changing the frequency and watching the output change on the 3 output pins.

All in all this was much easier than my Elecraft K1.

A friend of mine gave me some 3/4" pvc so now to complete the installation I think I only need: 3 end caps, 1 junction box and 2 pieces of shielded cat 5/6 cable. Right now station 1181 still has its antennas in the computer room.
Stations: 1181
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Messages In This Thread
Building a red system - by Jack Zielke - 2014-10-09, 02:04
RE: Building a red system - by W3DRM - 2014-10-09, 04:19
RE: Building a red system - by Jack Zielke - 2014-10-09, 04:51
RE: Building a red system - by W3DRM - 2014-10-10, 16:02
RE: Building a red system - by Jack Zielke - 2014-10-26, 07:22
RE: Building a red system - by cutty - 2014-10-26, 10:15
RE: Building a red system - by Jack Zielke - 2014-10-26, 22:54

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