The Wilderness Protocol is a suggestion that those outside of repeater range should monitor standard simplex channels at specific times in case others have Emergency or priority calls. The primary frequency is 146.52 MHz with 52.525, 223.5, 446.0 and 1294.5 MHz serving as secondary frequencies. This system was conceived to facilitate communications between hams that were hiking or backpacking in uninhabited areas, outside repeater range. However, the Wilderness Protocol should not be viewed as something just for hikers. It can (and should) be used by everyone anywhere repeater coverage is unavailable. The protocol only becomes effective when many people use it.

The Wilderness Protocol recommends that those stations able to do so should monitor the primary (and secondary, if possible) frequency every three hours starting at:

• 7 AM, local time, for 5 minutes…
• 10 AM
• 1 PM
• 4 PM
• 7 PM
• 10 PM

Additionally, those stations that have sufficient power resources should monitor for 5 minutes starting at the top of every hour, or even continuously.

NOTE*** Placing 146.52 MHz , 52.525, 223.5, 446.0 and 1294.5 MHz in your Scanner would help.

Priority transmissions should begin with the LiTZ signal. ( LONG TONE ZERO )
CQ-like calls (to see who is out there) should not take place until four minutes after the hour.

UHF/VHF Simplex Wilderness Protocol

The Wilderness Protocol is simply a recommendation that those outside of repeater range monitor standard simplex channels at specific times in case others have priority or emergency calls. “FM & Repeaters”, June 1996 QST, p. 85.

Simplex frequencies:
146.52  <-- primary
446.0
223.5
52.525
1294.5

Monitor at least
07:00 - 07:05
10:00 - 10:05
13:00 - 13:05
16:00 - 16:05
etc.; if possible, monitor every hour.

Priority/Emergency transmission: begin with 10 seconds of DTMF "0" (this
is called LiTZ, "Long Tone Zero", and is a good idea for repeaters as well).

Routine transmission: wait until four minutes after the hour.

The Wilderness Protocol --

The Wilderness Protocol is a dedicated effort to insure emergency communications help either in areas beyond normal repeater coverage, or in the event local repeaters are off-the-air and not reachable
in an emergency situation.

The purpose of this initiative is to offer stations outside or without repeater range capability an opportunity to be heard when needed the most!

The Wilderness Protocol suggests that radio operators in the Amateur service monitor standard simplex channels at specific times in case of Emergency or priority calls.

The primary frequency to monitor is 146.52 MHz; secondarily or alternatively 52.525, 223.5, 446.0 and 1294.5 MHz respectively. The idea is to allow communications between hams that are hiking or backpacking in uninhabited areas, or outside repeater range an alternative opportunity to be heard.

NOTE- Though it’s mainly used in the wilderness settings, it’s NOT just for hikers, back packers, or similar situations….it is also available for ANYONE to use at ANYTIME assistance is needed.

Recommended procedures for “Wilderness Protocol”

MONITOR THE STANDARD CALLING FREQS: *146.520* and/or any of the SECONDARY FREQUENCIES.(52.525, 223.500, 446.00, 1294.500)

MONITOR TIMING: Every 3 hours starting from 0700 HRS ..on the hour until 5 (five) minutes past the hour.(7:00-7:05 AM, 10:00-10:05 AM, …, 10:00-10:05 PM).

ALTERNATE TIMING: 0655 to 0705, Etc 5 before till 5 after.. (to allow for differences in peoples watch settings). You can always listen for longer if you want.

ENHANCED MONITORING: Fixed stations or portable stations with enough battery power levels LISTEN EVERY HOUR. (Obviously Continuous Monitoring is also an option.)

LISTENING / MONITORING: Listen to the calling frequencies until 4 minutes past the hour, then make a few calls asking if there are stations listening that may need assistance. This calling traffic should only start at 4 minutes after the hour preceded by listening for 30 seconds… Unless of course you’re the one making an emergency call. LISTEN FIRST- CALL CQ with short transmissions. LISTEN FIRST! – always a good idea!

NOTE- 146.52 IS A CALLING FREQUENCY…. Make your Calls, and then move off the frequency so others can use the frequency. Suggested frequencies to move to; 146.55, 146.43, etc. etc.

PRIORITY TONE SIGNALS: Suggested for Priority Radio Transmissions ONLY.

USE the LONG TONE ZERO (abbreviated LiTZ). Begin calls for assistance with about 10 seconds of TONE with the LiTZ signal. Do this by keying up and holding down the zero key to continuously transmit the zero DTMF tone ( hence: LONG TONE ZERO ). Then proceed to make your emergency call. This should help those listening to recognize that an emergency or priority call is coming through.

Lastly, remind people of the protocol at your club meetings and on radio nets. It a good thing to know.

Source Credit: Tcares

Let’s take a look at several different power supply technologies to power your rig. How do you get a low-noise, high-current 13.8 volts? Price, performance, power, and even weight are things to consider.

How many amps does your rig draw? Do you need to over-provision current? Is that cheap ebay-supply going to smoke your expensive radio? No everyone can afford an expensive linear power supply, so let’s take a look at some reliable alternatives.

[NOTE: this originated as a Linux User Net discussion topic for Aug. 5, 2019]

Indroduction

The term “SDR” — Software Defined Radio — has been widely used and misused, both for descriptive and marketing purposes. As a result, it has can mean many things, depending on the context in which it is used, as well as the perspecive of the speaker.

If someone tells you, “I have an SDR”, you have to dig deeper to discover what that “SDR” actually is. Part of the confusion comes from the fact that “software-defined radio” originally described a process, not an object.

Usage

I have come up with a list of seven possibile meanings — there may be more.

1) A radio with DSP

People sometimes cofuse Digital Signal Processing with SDR. The difference is that DSP works on audio signals, not radio signals. Many analog radios use DSP in their audio stages. Note that a true SDR almost always will encorporate DSP. So, this is not actually SDR.

2) Digital control of a radio

Again, not really SDR. I hear this most often applied to QRP rigs, such as the uBitx. The radio itself is fully analog, but it is controlled by a digital device, such as an Arduino or similar microcontroller board. This is nothing new, of course — virtually every ham rig produced in recent years has come with a digital interface. What is new is that the control device is open to be programmed by the user. I believe this is the source of confusion with SDR.

3) A USB device

• Here we get into radios are true SDRs, with full analog-to-digital (and possibly vice-versa) at the RF stage.
• This includes a large range of devices, from inexpensive plug-in dongles to sophisticated radio development devices.
• Most commonly receive-only, but could be a transceiver
• Output might be an I/Q stream for processing by another device. E.G., RTL-SDR.
• Might include a FPGA (Field Programmable Gate Array) to process the I/Q from the ADC, so the output is audio, plus perhaps metadata such as spectrum data for display. In a development device, the FPGA could be open for programming by the user.

4) SDR-in-a-box

Here the radio is fully software-defined in the inside, but externally appears to be, and functions as, a traditional radio. These rigs are essentially designed to be drop-in replacements for older analog units, sporting the cutomary knob and button controls, along with legacy interfaces such as serial ports. It looks and feels so much like an analog radio that you wouldn’t know it’s digital inside without being told. Examples: Icom IC-7300, Yaesu FTDX-101D.

5) SDR box + built-in Windows PC

This is an all-in-one rig that includes a full MS Windows PC internally. That gives it the capability of running various ham software inside the box, rather than in a connected PC. Hook up monitor, keyboard, and mouse, and you have a complete shack-in-a-box. Example: Expert Electronics MB1.

6) SDR box + server

• Again, a single box with traditional controls, but it also acts as a network server so that other digital boxes can connect to it, either to remotely control or be controlled.
• All signal conversion and processing is done onboard, with audio and metadata transferred over a computer network.
• Example: Elecraft K4 (I think with a Linux server inside).

7) SDR server only

• As above, all signal conversion and processing is done on board, with audio and metadata transferred over a computer network.
• No external user controls. All control is performed on networked computers.
• In essence, the network is the radio.
• Possible advantage is open API or software that allows anyone to program interfaces for them.
• Examples:
  • FlexRadio. Linux server inside. They produce a custom control unit, built around a Windows CE tablet. Also have grafted that unit to the front of servers to produce an all-in-one unit; still connected via Ethernet. Control software (SmartSDR) is proprietary, but the API (Application Programming Interface) it uses is open and well-documented.
  • ANAN transceivers: Fully open source software, inside and out. Apache Labs offers a Raspberry Pi-based control unit.

An aside

“SDR radio” — another redundant acronym?

I’m always on the lookout for new examples of redundant acronyms, where people pronounce the acronym as a word and follow it with the word that the final letter of the acronym stands for. Examples are “PIN number” and “ATM machine”. I recently added “NIC card” to my list (thanks to KA7PLE).

“SDR radio” might be one — or it might not. It can be argued that if “SDR” describes the process of manipulating RF signals with software and the word “radio” describes an object that functions within the accepted meaning of “a radio”, then “radio” has two different meanings – and so there is no redundancy, even though it sounds that way.

Source Credit: KC7MM Wiki