Telco, Paris, and Fort Worth. Repairs under way.
A World Radiocommunication Conference 2023 (WRC-23) agenda item proposing to study a range of frequencies, including potentially reassigning 144 – 146 MHz as a primary Aeronautical Mobile Service allocation, drew little opposition at a meeting of the European Conference of Postal and Telecommunications Administrations (CEPT) Project Team A. The team is responsible for some aspects of CEPT WRC positions, and the meeting was held June 17 – 21 in Prague, Czech Republic. Introduced by France, the proposal targeting 144 – 146 MHz would be part of a broader consideration of spectrum allocated to the Aeronautical Mobile Service. Another issue addressed during the meeting concerned the sharing of the Amateur Radio 1240 – 1300 MHz band with Europe’s Galileo GPS system.
“We hear only one admin[istration] (Germany) opposed the 144 MHz proposal — no one else,” the UK Microwave Group tweeted following the meeting. Otherwise, it has been carried forward to the higher-level CEPT Conference Preparatory Group (CPG) meeting in August.
The International Amateur Radio Union (IARU), which was represented at the Prague meeting, expressed “grave concern” to any proposal that would include 144 – 146 MHz in the proposed Aeronautical Mobile Services agenda item. That comprises the entire available 2-meter band in ITU Region 1. IARU has pledged to make every effort to fully protect Amateur Radio interests and seek the support of regulators for their view.
IARU Region 1 President Don Beattie, G3BJ, said prior to the meeting that the IARU would “energetically” promote its opposition in Regional Telecommunications Organizations (RTOs) and the International Telecommunication Union (ITU) “to obtain assurances that the spectrum will remain a primary allocation for the amateur services.”
The 144 – 146 MHz band is allocated globally to the Amateur and Amateur Satellite services on a primary basis, and is the only globally harmonized Amateur Radio VHF band. A widely used segment of the Amateur Radio spectrum, 2 meters supports a broad base of terrestrial users, repeater systems, and satellite stations, including the International Space Station.
According to the meeting minutes, the proposal provides no justification for targeting 144 – 146 MHz, and the IARU believes that sharing with airborne systems likely would be difficult and lead to constraints on the development of the Amateur and Amateur Satellite services there. IARU suggested that alternative proposals might be developed that could provide further spectrum for the aeronautical applications without impacting this Amateur Service spectrum.
IARU is expected to brief member-societies, requesting that they discuss the French proposal with their governments in advance of the August CEPT-CPG meeting. France could seek to introduce the same proposal to study 144 – 146 MHz for aeronautical use into other RTOs.
Meanwhile, further discussion on the 23-centimeter band study proposal is anticipated prior to the Conference Preparatory Group meeting in August. The proposal was raised in the wake of reports of interference to the Galileo navigation system, but IARU has said it’s aware of only “a handful of cases” of reported interference to the Galileo E6 signal on 1278.750 MHz. Work on this issue will continue in other specialized CEPT forums in the interim.
Tomorrow at 3:30 pm KB5WB will be reinstalling the CAT800 controller at Arlington. There will be a interruption of service from East Bound to West bound during 3:00-4:00 pm. Allstar users will be disconnected and should connect back to KB5EDB Arlington node 47611. If the interference is gone, 443.850, Wires-x, and Plano will be back on line too.
Fort Worth is now connected to the system. It is a long RF putt and has two repeater tails. Leave plenty of time between key ups, if using Fort Worth. It will stay connected as long as no issues arise. That leaves Plano, Wires X, and DMR not connected. Plano and DMR work as stand alone.
There are system repairs underway. Arlington is down. East bound is connected via Allstar through Paris’ link radio. West bound is connected via Allstar through N5KOU Echolink. East and West bound are tied via Allstar. Fort Worth and Plano are not connected to the system, but are in standalone. Fort Worth should be linked via RF to Allstar later this weekend. It is not the best performance and there are extra repeater tails. This is temporary, so use the system for needed communications only.
Hotspot Offset Calibration
People using DMR/TGIF please take a few minutes and setup your hotspot-offset-calibration. On the analog side of the system, many of you are unintelligible. Below is K9NPX procedure on doing this with Pi-Star. For OpenSpots and other products, there are similar processes.
on February 05, 2019Most of the boards I’ve been getting lately have required adjusting the offset to function properly on DMR. Many boards are shipped with a sticker on the bottom with the required offset. These are usually pretty close. There is however a way to get this more exact and specific to your radio.
Luckily there is a utility built in to Pi Star that enables you to tune your offset. All it requires is pen and paper, a calculator and a little time.
Step one is to gain ssh access to your Pi. The easiest way to do this is go to “Configuration” then click “Expert” then “SSH Access” and log in with pi-star and your password.
Next set your radio to VFO Digital mode at 433.000mHz TS1 TG9
Then go back to SSH and type “sudo pistar-mmdvmcal” this will start the calibration program. Type “m” this sets a 1031 Hz test tone. Next press the “space bar” to start transmitting. You should hear the test tone on your radio at this point. Next press the “f” key repeatedly until the radio goes silent. After that press the “F” key multiple times until the tone comes back. Write down the frequency at which the tone comes back. Now you have to go the opposite way. Press “F” until the tone stops followed by “f” and write down the frequency where the tone comes back again. Next subtract the lower frequency from the higher frequency of the two you just wrote down. Divide that number by 2 and add the result to the lower frequency. Now the difference you get from 433mHz is your offset. To sum up
- sudo pistar-mmdvmcal
- space bar
- f (repeatedly until you lose the tone)
- F (repeatedly until the tone comes back)
- F (repeatedly until you lose the tone)
- f (repeatedly until the tone comes back)
- subtract lower frequency from higher frequency
- divide that number by 2
- add the result to lower frequency
- find difference between result and 433mHz
Once you have your offset you have to set it in Pi Star.
You’ll need to go to your pi-star dashboard, then “Configure” and “Expert” Now click on “MMDVMHost” Scroll down to “Modem” and enter your offset in RXOffset and TXOffset. Don’t forget to click “Apply Changes”
Still having trouble talking to your hotspot?
The above method will usually get you close enough but if it doesn’t there is a method to tune your hotspot for a minimal BER.
First, set your radio to 433.000mHz Talk Group 1 and Color Code 1.
Next, use the same command in SSH to start mmdvmcal “sudo pistar-mmdvmcal” then press “b” to start the BER tuning program. While pressing the PTT on your radio press the “f” key or “F” key to adjust the frequency until you get the smallest BER you can achieve. However far off you are from the starting frequency of 433mHz is what your RXOffset should be set to.
Tip: These are the instructions for DMR. When you start the mmdvmcal program it displays a list of codes for other tests and other modes you can test.