Ever wonder what the correct length for a random wire antenna is?
Random wire antennas are highly regarded for their simplicity, versatility, and cost-effectiveness. Their straightforward design allows for easy installation, making them an ideal choice for portable or emergency operations. One of the significant advantages of these antennas is their broadband capability, enabling operation across a wide range of frequencies and making them suitable for various applications. Furthermore, they are cost-effective to construct, requiring no specialized materials or components.
Setting up a mesh network is far easier and cheaper than you would think. It’s time you picked up a few devices and flashing the firmware. See thread for more links.
Some great info for GMRS radio.
GMRS, which stands for General Mobile Radio Service, is a type of two-way radio communication service primarily used for short-distance communications. It's a popular choice for families and small groups who want to stay in touch while camping, hiking, or participating in outdoor activities.
Here are the basics of GMRS radio:
1. Licensing:
- In the United States, you are required to obtain a GMRS license from the Federal Communications Commission (FCC) to use GMRS radios. The license covers your entire family or group, allowing them to operate GMRS radios under a single license. The cost of the license may vary, and it typically lasts for ten years.
2. Frequency Range:
- GMRS operates in the UHF (Ultra High Frequency) radio spectrum. It uses frequencies between 462 and 467 MHz. These frequencies provide relatively good range and penetration in urban and outdoor environments.
3. Number of Channels:
- GMRS radios offer 22 channels for communication. These channels are divided into two categories: the GMRS/FRS (Family Radio Service) shared channels and the GMRS-only channels.
- GMRS/FRS shared channels: Channels 1-7 are shared with FRS radios, which do not require a license. GMRS radios can operate at higher power levels on these channels when compared to FRS radios.
- GMRS-only channels: Channels 15-22 are exclusively for GMRS use. These channels allow for higher power levels and are often used for more reliable long-distance communication.
4. Power Levels:
- GMRS radios are allowed to transmit at higher power levels than FRS radios, which gives them a longer communication range. The maximum power output for GMRS radios is typically around 5 watts.
5. Privacy Codes:
- Many GMRS radios offer privacy codes, also known as sub-channels or CTCSS (Continuous Tone-Coded Squelch System) tones. These codes allow you to filter out unwanted conversations on the same channel by using a specific tone or code. Keep in mind that privacy codes do not provide absolute privacy; determined users can still hear your conversations.
6. Range:
- The effective range of GMRS radios can vary significantly depending on factors like terrain, obstructions, and the power output of the radios. In ideal conditions, GMRS radios can provide communication ranges of several miles.
7. Accessories:
- GMRS radios often come with various accessories, such as headsets, earpieces, and external microphones, to make communication more convenient and discreet.
8. Emergency Channels:
- Some GMRS radios also include dedicated emergency channels, such as channel 9, which can be used to communicate with emergency services or other GMRS users during urgent situations.
To use GMRS radios within the legal requirements, it's essential to obtain the necessary GMRS license from the FCC and follow the regulations and guidelines specified for GMRS operation. Family members can share the same license, allowing them to communicate with each other on the GMRS channels.
GM Nostr,
Here is some DIY ham radio antenna making ASMR to enjoy with your morning #coffechain coffee ☕️☕️☕️.
Have a great Saturday.
The software and release notes can be found here.
This is a great project for your old raspberry pis that you no longer use because your Bitcoin node performance needs have exceeded the pi’s capabilities.
What is the Pi-Star Project:
Pi-Star is a software solution used in amateur radio, specifically designed for digital voice hotspots and repeaters. It supports various digital modes such as DMR (Digital Mobile Radio), D-STAR (Digital Smart Technologies for Amateur Radio), System Fusion (C4FM), and P25 (Project 25). The new open source digital mode M17 is being implemented in a soon to be released update.
Pi-Star provides an easy-to-use interface and is often used with Raspberry Pi hardware, although it can run on other platforms as well. The software enables hams (amateur radio operators) to connect their radios to internet-linked networks, extending their communication capabilities far beyond local coverage.
👀 nostr:note1dzkz3ccjyq79kgvzs4h8ygk27a2hl4lf0h32qf8qkhkzdd563hgs4at5jl
⚡️⚡️ Did you know ham radio has a new digital radio protocol that has a lot of qualities that align with the Bitcoin/nostr ethos? It’s called M17, check it out.⚡️⚡️
🌽📻🌽📻🌽
The linked article has some great introductory information.
M17 is a new digital radio protocol designed for amateur radio use. It's distinctive for being completely open-source, contrasting with the proprietary nature of existing digital radio modes. The protocol employs Codec 2 vocoder for voice digitization and uses 4FSK modulation for transmission. It operates within a 9 kHz bandwidth, has a 12.5 kHz channel spacing, and a data rate of 9600 bits per second.
Key features of M17 include:
1. Open-Source Nature: It's developed and maintained by the community, with its code and documentation freely available on platforms like GitHub.
2. No User Registration Required: Unlike other systems that need specific user IDs, M17 uses the operator's callsign for identification.
3. Support for Data Services: M17 can transmit text messages and positioning data along with voice.
4. Wide Application: The protocol supports various devices and software, and can be used with modems, portable radios, and even Android apps.
5. Community Project: It's a collaborative project with contributions from amateur radio enthusiasts, fostering innovation and experimentation in digital radio communications.
The younger hams are more into doing thing digitally over the airwaves. Ham radio will have a completely different vibe in a few years. My goal is to get as many people with our values and technical proficiency in there to shift the culture and drive advancements in the radio arts.
The future belongs to those who show up.
Turn an unused/underused repeater into a decentralized local digital chat.
A look at the Module17 M17 Radio Modem Board.
This allows any 9600 Baud capable radio to transmit and receive M17.
Raspberry Pi’s are great for MMVDMs.
An MMVDM (MultiMode Voice and Data Modem) is a device or software that supports multiple digital modes used in amateur radio communications. These modes can include various forms of data and voice transmission, and the MMVDM allows for versatile communication across different digital protocols.
M17 is a new open source digital mode being added to the amateur radio communication spectrum. It's designed to be a free and open digital radio protocol, focusing on simplicity and efficiency. M17 aims to offer a viable alternative to proprietary digital modes, with an emphasis on voice communication.
By being open source, it encourages community involvement and innovation, allowing radio enthusiasts and developers to contribute to its development and improvement. The addition of M17 to devices like MMVDMs broadens the capabilities of these devices, giving users more options for digital communication.
If you like bitcoin or you like radio (or both), take a few minutes of your time to familiarize yourself with the ESP32:
Choosing simplex frequencies on the 2 meter ham band:
The article "Simplex Channel Confusion on 2 Meters" from AmateurRadio.com discusses challenges in selecting suitable simplex frequencies on the 2-meter (144 to 148 MHz) band. The main issue is the variation in channel spacing, with some areas using 15-kHz and others 20-kHz spacing. This discrepancy can cause confusion and interference problems. The article advises checking local VHF band plans for guidance on simplex frequencies and notes the importance of frequency coordination in amateur radio. It also mentions the National Simplex Calling Frequency (146.52 MHz) as a universally recognized channel. For more detailed information, you can read the full article.
https://www.amateurradio.com/simplex-channel-confusion-on-2-meters/
Winter Field Day is an annual event organized by the Winter Field Day Association (WFDA) for amateur radio enthusiasts. It's designed to encourage emergency communications preparedness among amateur radio operators. Participants set up temporary stations in various locations, often in challenging winter weather conditions, to demonstrate their ability to operate in various environmental settings and conditions.
The event is similar to the more well-known Field Day in summer, organized by the American Radio Relay League (ARRL). During Winter Field Day, operators attempt to make as many contacts as possible, using different modes of transmission and bands, enhancing their skills and readiness for emergency situations.
Winter Field Day in 2024 is scheduled for January 27th and 28th. This event is held on the last full weekend of January each year. It's a 24-hour exercise starting from 1900 UTC on Saturday and ending at 1900 UTC on Sunday. Participants can begin setting up their stations no earlier than 1900 UTC on the Friday before the event.
Build it: 2 meter Tape Measure Yagi Beam Antenna
Instructions & video by KB9VBR
Parts List
1 25 foot 1 inch wide steel tape measure
1 10 foot piece of 3/4 inch Schedule 40 PVC Tube
2 3/4 inch PVC Cross connectors
2 3/4 inch PVC T connector
6 3/4 to 1 1/2 inch stainless Hose Clamps
1 5 inch piece of 14 ga wire
1 length of RG-58 cable, approx 6 foot
Solder and Flux
Electrical Tape
Tools
Soldering Iron
Tin Snips
Wire Cutter
Screw driver or nut driver
PVC cutter or fine tooth saw
Sand paper or Dremel tool with sanding disk
Ruler or tape measure
Step 1
Cut three pieces of PVC tubing. One piece will be 11 1/4 inches long and the second will be 6 7/8 inches long. These pieces will make up the support boom for the antenna. The third piece can be any length, it will be the handle for the antenna, so give yourself about a foot or foot and a half. Whatever is comfortable.
Fit the pieces of PVC tube together with the crosses and the T. You may PVC cement if you wish to make the connections permanent, otherwise dry fitting them will be fine. The distance between the first cross and the middle cross has to be 8 inches and the distance between the middle cross and and the T has to be 12 1/2 inches. These are measured from the center points of the connectors. Make adjustment if necessary.
Step 2
Cut the tape measure into four pieces. One piece will be 41 3/8 inch and the second will be 35 1/8 inch. These are the reflector and director elements for your yagi. The driven element is made up of two pieces, so cut two pieces that are 17 3/4 inches long.
Step 3
On the two driven element pieces, sand or grind away the paint from one corner. This is where we will solder the the coax and the hairpin match. Apply flux and use your soldering iron to tin this area. It’s easier to tin this area now before attaching the elements to the support boom.
Step 4
Assemble the director and reflector elements. Making sure they are centered, use the hose clamps to attach the elements to the T and Cross connectors.
Step 5
Assemble the driven elements. Using the hose clamps, attach each half of the driven elements to the Cross connector. There should be a one inch gap between the two pieces.
Step 6
Attach the hairpin match. Take your 5 inch piece of wire and strip 1/4 inch off each end. Bend the wire so it is in a U shape with a 3/4 inch gap. Solder this to the tinned ends of the driven element.
Step 7
Attach the coax. I’ve got a six foot length prepared piece of RG-58 coax where I put a BNC connector on one end and stripped the braid and center conductor on the other. You’ll solder these two ends to the driven element of the antenna. It doesn’t make a difference which end goes where. Now before you solder, you can drill a hole in your boom and thread the coax inside the pipe. Otherwise just use a couple of cable ties or electrical tape to secure the coax to the antenna.
With that, your antenna is complete. With these dimensions the antenna should be resonant at about 146.5 Mhz. If you are going to use this as a receive antenna for fox hunting, tuning isn’t critical, but if you plan to transmit with it, then you can check it with an antenna analyzer or power meter and make any small adjustments by varying the gap between two parts of the driven element.