How field-proven, economical FMeXtra fails vs. HD Radio. Possible FMeXtra rebirth as open FM digital SCA.
Possible 2G GSM shutdown impacts vis cheap replacement 4G modems. US 2G shutdown targeted for 2019.
Long-range license-free modems at VHF (151 MHz) MURS are compared with globally-usable 900 MHz modems.
9V batteries don’t have enough available energy to usefully charge modern smartphones. They will likely drain your phone’s charge.
WJIB is on 101.3 FM translator as well as 740AM. Here are solutions for issues faced by new FM translators.
How to install and use Radio Mobile Deluxe on Linux using WINE.
Wifi 2.4 GHz ranging is an important IoT application. Explore an early LoRa chip ranging & comms features.
The FCC’s 2009 ruling allowing AM stations to simulcast on FM permits Bloomberg Radio to escape interference endemic to AM radio with a 99 watt FM transmitter.
The old 800 MHz SMR spectrum that we used for taxi cab and police calls is now for Sprint broadband data as LTE Band 26.
First impressions of the LG Urbane Second Edition LTE smartwatch are highly favorable–let’s take a technical look at smartwatch RF performance.
Project Fi uses three LTE carriers plus VPN WiFi. Here are some practical details on how the Project Fi aggregating MVNO works.
Geoscience observatories in remote corners of the Earth need connectivity. We have LTE connectivity in many areas despite their remoteness, here are some rou...
In 2017, you’d think we’d have standards based ways to connect wirelessly to everything in our home. Not yet.
Qi falls short compared to modern quick-charging from USB-PD.
Google Pixel Phone has many LTE bands, allowing good international roaming–here are some details.
Understanding LTE smartwatch coverage by example of LTE Android Wear smartwatch in rural areas.
Technical explanation of paging coasters in the 27 MHz and UHF bands, including antennas and interference.
Detailed technical review of Verizon Mifi w.r.t. antennas and frequency
Many LTE bands experience tropospheric ducting, allowing interfering signals from unusually far away.
I wish someone would make a speaker-mic for mobile phones.
Are Motorola dual-band radios VHF/UHF/700/800 APX8000 worth the nearly $10K purchase price?
What does positive train control imply for short line railroads with considerable rural track miles now dark?
With text messaging in full bloom, have you ever wondered why the limit is 160 characters?
A simple voice scrambler using SSB techniques is discussed
Location of Nextel towers collected manually in Michigan via field test menu of phone.
We look at real-life overloading in an LTR UHF radio system and what can be done.
How to measure repeater desense step-by-step with example measurements.
Interference to a local emergency services 450 MHz repeater has been noted in the form of “kerchunks” every 10 seconds for about 1/4 second. The source of t...
I switch from Nextel to Sprint with Blackberry 8703e. Thoughts on critical need for STEM mentors, or those that can guide to STEM.
detailed example of how a radio system can suffer poor performance due to initial deployment or degradations, and how they can be fixed.
Picking a clear frequency on VHF (150 MHz) on which to frequently transmit with a high-level station can be a daunting task, one likely to create strife if c...
technical discussion of trunking radio system latency.
The Blackberry Nextel iDEN network is a vast advance from just a couple year ago.
How to find and fix 800 MHz two-way radio system interference from cellular carrier Nextel. Working with field engineers to reaim antennas and retest.
The distinct yet similar 2.3 GHz satellite radio broadcasts may be received indoors depending on building construction.
Verify your coverage predictions by drive testing and logging with sound card for repeatable results.
Detailed resolution to Nextel public safety radio interference.
Why are so many EF Johnson 800 MHz designs from 1980s-2000s microphonic?
Technical details of redesigning a poorly thought-out life-critical paging system.
Broadband interference from cable TV systems may not be directly audible due to the broadband TV emissions. Try a desense test to track interference.
more and more internet services, but adoption is low from most.
Youngest student at a number of Motorola courses, necessary for PSAP work, including R56, Centracom Gold Elite, and MOSCAD.
Save $10/month on Nextel Mobile Email by using text messaging to read/reply to emails.
The biggest investment in SMR/CMRS is the radio plant–don’t wait for total failure to recheck your channel performance!
Nextel spent a quarter billion buying 900 MHz Arch Wireless spectrum. FCC authorized 5 MHz more of 800 MHz for CMRS, when will it be our turn to be acquired?
Sunken cost, zero budgets, and mutual aid keep police/fire/EMS stuck with 1950s radio technology. Here’s why.
Going on a hilltop tower visit, we encounter deer hunters and failing brakes on the way down! Commercial repeater piracy methods.
Make sure your 800 MHz SMR system is more than a paper tiger–Nextel might snatch your license!
Even for mildly urban areas and forested areas, low-gain antennas can perform better than high gain antennas when the main signal is coming from overhead dif...
Wireless data or wireless WAN (WWAN) is growing rapidly. Going beyond two-way paging and package tracking to email for business.
EF Johnson 35 Watt Summit 800 MHz mobiles suffer from predictable solder failures at the output transistor. Here’s how to repair.
Describes experience of high-power car phone in the form of 800 MHz LTR SMR full-duplex telephone interconnect.
Getting a real radio system for our group on 800 MHz.
Saving time packing and money paying is an excellent tradeoff for 20 minutes of work.
There is still room to profit from SMR frequencies. Seek renewed avenues in mobile tracking and credit card transactions.
EF Johnson Challengers are a mid-1980s design, a first generation synthesized radio that requires manual tuning to change frequency significantly.