Midland High School Radio Club

Pictures from the new Midland High School Radio Club in Midland Mi.

The radio shack isnt complete yet. The class is held in a science /physics class room.
I believe there are about 12-18 students in the class now.

RFI on SDR

Trying to troubleshoot noise or RFI can be hard, but being able to “see” signals with an SDR dongle, makes it a lot easier, and kinda cool.

I tried to pick up one of the new Ham Radio Satellites, FunCube-1 on 145.935Mhz. I saw a ton of noise and I couldnt hear the satellite. I decided to hunt down the noise source(s).

I found out that my 8 port ethernet switch was one source of noise. I swapped it our for a metal case model, instead of plastic, but no luck. I then unplugged all my cables and plugged them in one at a time. I already had 3 shielded cables on it, and those were fine. I then found 3 other cables that caused a lot of noise. These were un-shielded cables. I replaced 2 of them and it got a lot better. I have a long ~100′ cable that is un-shielded that goes into my garage for my radio servers that causes a big problem. I’ll have to replace it soon.

Here is a pic of the noise from the ethernet cables. The bottom of the waterfall is with the switch on, and the top is with the switch off. You can see a lot of lines or signals disappear, by simply unplugging the switch.

 

 

Here I tried to use 2 different USB ports.
The bottom of the waterfall shows my front USB port. The top shows the back. Maybe they dont use a shielded cable inside the PC, or it just pics up a lot of noise.

 

ADS-B receiver with MLAT

ADS-B MLAT Receiver

New ADS-B MLAT receiver from FlightRadar24.
This unit has new MLAT technology, similar to cell phone tower and GPS triangulation.
The new callsign / identifier for this receiver is F-KMBS1

Here is the old setup, before the new MLAT unit. http://www.mark-rodgers.com/ads-b/

 

 

 

ADS-B MLAT Receiver
ADS-B MLAT Receiver Back

New Garage Server Rack

Radio / Electronics Server Rack

I found a great deal on a 19″ rack cabinet when the local school was selling their PA system. I got it for $10 including a 120w PA amp and phone control system. I just wanted the cabinet and its worth a lot kore than what I paid for it. I brought it home, removed the equipment from my old DIY wood rack and replaced it.

Here is the basic setup layout, before wiring.
Here is what the rack will hold.

I’ve also drilled a new bigger hole in the wall of my garage for more antenna coax feeds.

Radio / Electronics Server Rack

The old rack unit. It served it purpose for a while.

 

Satellite Antennas

Satellite Yagi Antennas

After having some yagi antennas collecting dust for a few months, I finally decided to get off my butt and get them in the air. A friend on Twitter @2e0sql has been talking about his satellite contacts and it was kinda like rubbing it in my face, so I got mine installed. I’m glad that I did.

Visiplex Transmitter TX2000U Info

TXF-2000U 330x108

This page serves as a historical data archive for the Visiplex VS40 transmitter module.

Units are made by Wireless Devices Taiwan.
http://www.wdit.com.tw/0211%20products%20list.htm

They no longer appear on the web site, but I found a old page, using the “WayBack Machine”
http://web.archive.org/web/20050228145658/http://www.wdit.com.tw/Specification%20of%20TXF-2000U.htm

PDF Info Sheet
TXF-2000U 0402S

Hamfest Equipment Test Stations

As our local Hamfest is coming up soon, and the person who has been running it for years wants to resign from the position, it has got me thinking about what it actually takes to run a swap / hamfest.

I got to thinking about all the swaps I’ve been to and how sometimes I’m afraid to buy a radio or equipment, because I don’t know if it works or not. As a kid I would carry a backpack for goodies I bought and also a 12v 7ah battery to power test radios. I found a few radios or items that they claimed worked, but wouldn’t even power up, its a good thing I didn’t buy them.

What if clubs offered a free “Equipment Test Table” ? This could benefit both buyers and sellers, by proving that the used equipment works. Here is what I would like to see at a table.

  • 110v outlets / surge strip
  • 12volt – 30 amp power supply
    including power pole, banana jacks, standard mobile connectors & alligator clips.
  • Dummy Load for HF & VHF
  • Basic antenna for HF receive (ex. 40/20 dipole)
  • Basic antenna for VHF/UHF receive
  • Multimeter
  • Watt Meter

Most clubs could easily find this equipment to be loaned for the day. It could be watched at the raffle ticket table easily. This would be enough to test most radio related items found at a swap, and would make buyers feel a lot better about spending their hard earned money.

I will be bringing this idea up to our club and will offer to loan my equipment for the cause for our swap. I hope other clubs will do the same.

APRS digipeater in a box

APRS Digipeater in a box

I am planning on deploying a few more APRS digipeaters in the Mid-Michigan area.
I hope to be able to fit everything inside a 12 x 12 x 6″ outdoor weatherproof box, for each site. The only external connections will be 110v power and antenna. I still have do do all the wiring and solder up some connectors, but this will give an idea of how it will look inside.

Contents:

  • 110v outlet
  • 12v 3amp power supply
  • 12v 7ah battery
  • MFJ-1207C TNC
  • Vertex FTM-2011 commercial VHF mobile
  • Wiring for power / data

I hope to get some much smaller TNC’s like the Byonics TinyTrack4 for some future kits.
I am not sure which site this will be installed at, but I will update my website with the new location and installation pics, when done.

WSPR Receiver

WSPR 20Meter RX

Since I’m not big into HF and I have a Yaesu FT-747GX radio just sitting here collecting dust, I figured I would put it to use. I haven’t touched it since I removed it to take to our club’s Field Day site in 2011. I just placed it back on my desk and forgot about it, so I had to search for the power cord and jumper coax to go to my filter and coax switch.

I installed K1JT’s WSPR software on a Win XP computer and wired up the audio line out from the radio to the line in on the PC. After tweeking some settings in the software, I was receiving WSPR beacons from all over the place. I figure I might as well put it to good use in RX mode, to help other people know how the band propagation is.

Currently I only have it set up to my 10/11M Antron 99 vertical antenna, only 10′ off the ground and partially blocked by my house. It is mounted on my kid’s trampoline for now, until it gets warmer and I get install it either back in my tree at 40′ off the ground or on a tripod on my garage roof. It feeds to the radio with about 50′ of RG-8 coax.

I plan to leave this running on either 10 or 20 meter bands, and leave it on 24/7.

WSPR 20Meter RX

A-99 WSPR

 

Raspberry Pi Text To Speech

Making Raspberry Pi talk, using Google’s Translation API
This is written in PHP, as I needed that to do some other projects.

You will need to install a few things.

  • PHP-5
  • cURL
  • PHP5-curl
  • mpg123
  • internet connection

This will download the audio file from Google and play it as soon as it processes.
the nice thing about this is that its very simple & no TTS program needs to be on your R-Pi.
There is a max of 100 characters to use for text.
Click below to view the code.

<?php

$output = shell_exec('wget -U Mozilla -q -0 - "$@" translate.google.com/translate_tts?tl=en\&q=This+is+a+example+of+text+to+speech|mpg123 -q - ');

echo $output;

?>

 

 

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