Here’s the parts list:

1.   1-2n2222 or similar (2n3904,2n4401, etc.)                                  $0.20 Affiliated

2.   1-33KOhm resistor org-org-org-gld                                            $0.100 Affiliated

3.   1-15KOhm resistor brn-grn-org-gld                                            $0.10 Affiliated

4.   2-10 Ohm resistor brn-blk-blk-gld                                              $0.20 Affiliated

5.   1-150 Ohm resistor brn-grn-brn-gld                                           $0.10 Affiliated

6.   1-small trimmer capacitor for tuning the crystal                           $0.55 Affiliated

7.   2-0.1uF (104) capacitors                                                       ~$0.40 Affiliated

8.   1-4.7uF 16v electrolytic capacitor                                             $1.00 Affiliated

9.   1-150pF (151) capacitor                                                          $0.20 Affiliated

10. 1-100pF (101) capacitor                                                           $0.20 Affiliated

11. 1-270pF (271) capacitor                                                           $0.20 Affiliated

12. 1-40m crystal (For tech and general class its 7025-7125kc)          ~$2.00 Affiliated

13. 1-22mH choke red-red-blk-red                                                 $0.25 Affiliated

14. 1-pkg of chokes                                                     $1.97 Radioshack prt #273-0108

15. 1-pkg project boards                                             $1.99 Radioshack prt #276-148

Total:                                                                                        ~$10.36+tax

Click on the images above to view them and see the schematic and descrition

they are from the W1FB’s QRP NOTEBOOK by sk Doug DeMaw W1FB

Myself, KE5SWU, Scott, KD5NKR, and Curtis, KF5ECI have been talking about building out a mesh network using WIFI. Here is my first attempt at a node for the network. Currently the solar panel is not being used. I need to get a solar panel controller before it can be introduced into the system.  The end goal will be a self contained unit that could be easily installed at any repeater site or someones home. So this is a call to the rest of the club, we have cool projects going on and if you want to join in on the fun do. Here are some links about the project:

This is the source for the firmware we load onto the wifi routers:

http://hsmm-mesh.org/

We are trying to standardize on the WRT54 models. All models below v5 should work.

http://wiki.openwrt.org/oldwiki/openwrtdocs/hardware/linksys/wrt54g

If you have one collecting dust, join in on the fun and we will help you set it up.

Here is the dish setup I am currently using:

http://www.qdg.org.au/qdgmod.htm

Ping any of us if you have any questions or want to help.

With an inexpensive FM scanner and a pc anyone can receive and decode images from the National Oceanic and Atmospheric Administration Polar Orbiting Environmental Satellites.

NOAA 15 Northbound 29° W on 137.62MHz, Multi-Spectral Analysis Enhancement, Normal Projection, Channel A: 2 (Near Infrared), Channel B: 4 (Thermal Infrared)

These satellites offer the advantage of daily global coverage, by making nearly polar orbits roughly 14.1 times daily. Currently in orbit there is a morning and afternoon satellite, which provide global coverage four times daily.  

The data we want to receive from these satellites is encoded in an audio signal called an Automatic Picture Transmission (APT).  The broadcast transmission is composed of two image channels, telemetry information, and synchronization data.. All this data is transmitted as a horizontal scan line. A complete line is 2080 pixels long, with each image using 909 pixels and the remainder going to the telemetry and synchronization. Lines are transmitted at 2 per second, which equates to a 4160 words per second, or 4160 baud.

On NOAA POES system satellites, the two images are 4 km / pixel smoothed 8-bit images derived from two channels of the Advanced Very High Resolution Radiometer (AVHRR) sensor.  Of the two images, one is typically long-wave infrared (10.8 micrometers) with the second switching between near-visible (0.86 micrometers) and mid-wave infrared (3.75 micrometers) depending on whether the ground is illuminated by sunlight. 

Included in the transmission are a series of synchronization pulses, minute markers, and telemetry information.

Diagram showing the Automatic Picture Transmission system's transmission frame format.

The synchronization information, transmitted at the start of each video channel, allows the receiving software to align its sampling with the baud rate of the signal, which can vary slightly over time. The minute markers are four lines of alternating black then white lines which repeat every 60 seconds (120 lines)

The signal itself is a 256-level amplitude modulated 2400Hz subcarrier, which is then frequency modulated onto the 137 MHz-band RF carrier. Maximum subcarrier modulation is 87% (±5%), and overall RF bandwidth is 34 kHz. On NOAA POES satellites, the signal is broadcast at approximately 40dBm (10 watts) effective radiated power

An APT signal is continuously broadcast, with reception beginning at the start of the next line when the receiver is within radio range. Images can be received in real-time by relatively unsophisticated, inexpensive receivers during the time the satellite is within radio range, which typically lasts 8 to 15 minutes.

Now that we have a basic understanding of the signal let’s get down to the actually process of receiving and decoding that signal. 

The Equipment you will need:

• FM Scanner that can receive on the 137 MHz-band.
• Antenna
• PC with WXtoImg software
• Cables to connect scanner to pc.

WXtoImg Software

There are several software products to decode the ATP signal; the one we will be discussing is WXtoImg. This software comes in a freeware version that is very feature rich and will do everything you will need to receive and decode the images from the satellites. You can download WXtoImg from http://www.wxtoimg.com/ . Once you have it installed and your scanner connected to your sound card there are a few steps to setting up the software. First you will configure your receiving location by longitude and latitude so that the software can track satellite passes.  Second you will click on help and read the entry on required calibrations. This will teach you how to set your volume levels and other calibrations that will need to be made on your first satellite pass.

Once you have the software setup you will need to program your scan with the frequencies used by the satellites. These frequencies are 137.6200, 137.5000, 137.9125, 137.1000.

Now that you are ready to receive the signal you can tell WXtoImg to wait for the next pass and auto decode. This is started simply by clicking on the file menu and then clicking on Record, the record dialog box will appear and you will click “Auto Record”. WXtoImg will now be in standby mode waiting for the next satellite to appear on the horizon. The bottom status bar will indicate when the next pass is with info about the satellite and what frequency it will be on. You can set your scanner to scan those frequencies and walk away or you can just set the frequency for the next pass.

When the satellite comes up on the horizon you should be able to hear the easy to identify sound of the signal. Once WXtoImg starts recording the signal you will see the image begain to apeair one line at a time. This will last from 5 -15 minutes depending on the elevation of the satellite pass. Once the pass is complete WXtoImg will attempt to decode the image and create false color and enhanced images from the original signal. WXtoImg will also add map overlays and an “X” marks the spot for your location.

Eggbeater Antenna

Now that you are able to receive and decode APT signals from Weather Satellites let’s discuss what can be done to improve reception of the signal. Now you can receive and decode signals with a simple vertical antenna but there will be dips in the signal strength as the satellite passes over. Plus the antenna that is uses on the transmitter is right-hand circularly polarized so for best reception you will need an antenna that is right-hand circularly polarized and will not have many dip-outs as the antenna passes from horizon to horizon. A popular antenna for this uses is the Eggbeater design and it will work with a right or left hand circularly polarized signal and is great for receiving overhead signals. You can also use the crossed dipole and the quadrifilar helix antenna (QHA). 

Also this will work with just about any receiver capable of reception in the 137-138MHz FM band but for best results requires a scanner with 30kHz – 50kHz bandwidth. It is not advisable to use just any scanner (most of which only support 15kHz or 230kHz bandwidths) if you intend to use it for weather satellite reception as the image quality will suffer, but you will still produce a picture.

There are many resources online that you can review for information about the status of the satellites in operation. http://www.oso.noaa.gov/poesstatus/ list the current satellites and their operation details.

Now you can operate your own weather satellite receiving station and get live images of the earth from space without the need of the internet or television.

Img RX'ed with a Yaesu FT-7800, Mag mount 2m Whip, and WXtoImg.

Click here for a PDF doc with information on building an APT ground station in an article from GEO Quarterly No 1 by Less Hamliton.

(Thanks to Jay ad5pe, and Jeff kc5ert for assembling this info and making it available to us.)

Parts: 

A Conduit – base (1) 4’6” 
B Conduit – 10m (1) 3’6 13/16” 
C Conduit – 12m (1) 1’3 11/16” 
D Conduit – 15m (1) 1’6 15/16” 
E Conduit – 17m (1) 1’11 3/8” 
F Conduit – 20m (1) 3’5 3/4 ” 
Couplers (5) 
Star washer (1) 
Screws (6) 
Ring Terminal (2) 
Board (1) 
Clamps (2) 
Radials (8) 18’ of network cable 

The A conduit is the base – it fastens to the board with the 2 clamps and 4 screws. Positioning is not critical, but keep the base end up about 2” from the end of the board. The board will sit on the ground with the antenna erected, and is the “base insulator” to keep the vertical radiator off the ground. Pre-drill a hole in the lower end of the A conduit for the coax. Put this slightly below the bottom clamp ,positioned out.

Strip a couple of inches of your coax pigtail jacket. Fold the braid back and pull the center conductor (with dialectric) out through the braid. Leave the dialectric in place. Strip ¼” of the dialectric off the center conductor.

Instal a ring terminal on the center conductor, and fasten to the predrilled hole in the A conduit with a star washer and screw.Strip the jacket off the network cable. Untwist the inner conductors, yielding 8, 18’ wires. Fasten all 8 wires to the coax pigtail braid. Use a ring terminal and a screw into the board for a strain relief. Coil the wires up to keep them out of the way until you set up the antenna. 

For 10m operation, attach the B conduit to the A base conduit with one coupler. Guy the antenna approx. 2/3 of the way up (any nonconductive rope with work). You will need the appropriate connector to match your radio on the other end of the coax. 

For lower bands, add the appropriate conduit stubs using the additional couplers. For 20m, you need all six pieces. You will have to move your guys up, keeping them 2/3 of the way up the vertical radiator. Also, unless you need to frequently switch bands, (in which add them in order by band) the antenna is more stable with the longest stubs towards the bottom. In other words, for a day of 20m operations, A, B, F, then C, D, and E stubs puts the shortest stubs up top and makes the antenna flex less, but to change to 17m you have to break the antenna at both ends of the F stub, and then reconnect C to B. 

The below spreadsheet was contributed by Edd, kk5edd. 

Band	Lo Freq.	Hi Freq.	Freq.	Avg.	LnthFt.
20	14.225	14.350	14.288	16.378	3.478
17	18.110	18.168	18.139	12.900	1.947
15	21.275	21.450	21.363	10.954	1.579
12	24.930	24.990	24.960	9.375	1.306
10	28.300	29.700	29.000	8.069	3.569
Base				4.500
Band							Total	Mine	Jay’s
20	4.500	3.569	1.306	1.579	1.947	3.478	16.379	16’4 9/16″	16′ 51/16″
									12′ 10
17	4.500	3.569	1.306	1.579	1.947		12.901	12’10 13/16″	13/16″
15	4.500	3.569	1.306	1.579			10.954	10’11 7/16″	10′ 11 1/2″
12	4.500	3.569	1.306				9.375	9’4 1/2″	9′ 4 1/2″
10	4.500	3.569					8.069	8’0 13/16″	8′ 2 7/8″
Base	4.500						4.500	4’6″	4’6″

3’6			1’3	1’6
20	4’6″	13/16″	11/16″	15/16″	1’11 3/8″	3’5 3/4″
		3’6	1’3	1’6
17	4’6″	13/16″	11/16″	15/16″	1’11 3/8″
		3’6	1’3	1’6
15	4’6″	13/16″	11/16″	15/16″
		3’6	1’3
12	4’6″	13/16″	11/16″
		3’6
10	4’6″	13/16″
Base	4’6″

Edd also contributed his illustration on how he configured the assembly of the antenna to suit his needs

 

 

  

 

 

 

I have made several launches, lost 2 balls, but the launcher seems to work great. I have put 22 pennies in the ball to help it fall back down when caught in tree branches.  The only thing left to do is tie the line from the reel to the ball. I will do this sometime this weekend and I will try to get some video of it in action.

I am getting closer to completing the launcher. I bored out the end cap for the transition from 1.25 PVC elbow to the 2.5 PVC pipe. All that is remaining is to get some JB Weld for the before mentioned joint.

Here I am getting ready to bore out the hole in the cap:

The highlighted part is what I am making in the above picture.

Antenna launcher, step 1

Started on my launcher for Field Day. I did as much as I could tonight. I will have to wait till Tuesday for my shipment from McMaster-Carr to finish it up(had to mail order the right pvc pipe). I will post up more pictures as the project progresses. I am using these instructions as the bases: http://www.antennalaunchers.com/csv19/csv19asm.html