Tag Archives: MTR-4B

Guest Post: Field Day – 200 QSOs with a Flashlight Battery

The PowerFilm LightSaver (Image: PowerFilm Solar)

Many thanks to Jim Cluett (W1PID) who has kindly allowed me to share this recent post from his website:


Field Day – 200 QSOs with a Flashlight Battery

June 2021

by Jim Cluett (W1PID)

Field Day was an experiment this year. I operated for nine hours using a 5V 18650 battery and made 200 QSOs before calling it quits.

I operated on the deck with an MTR 4-B designed by KD1JV. The antenna was an 88 foot doublet up about 45 feet. I used the ZM-2 tuner. For power I used the PowerFilm LightSaver. This is a 5 watt roll-up solar panel that charges a 3.7V 18650 battery rated at 3.2 Ahr. The battery inside the Powerfilm product is commonly used in flashlights. The combination of the rig and the power supply is crucial.

The MTR rigs will operate from 6 to 12 volts. The Powerfilm puts out 5V to a USB socket. The secret ingredient required to bring the USB voltage up to the operating voltage of the rig is a Baofeng USB charging dongle. This device takes a 5V input and outputs 10.3 volts… perfect for the MTR transceiver. With this voltage the MTR puts out a little less than 3 watts.

The PowerFilm LightSaver is designed to charge cell phones for hikers and campers. It weighs only about 5 oz. and rolls up into a tiny package. Any USB 5V cell phone charging battery could be used with the Baofeng dongle.

This year my whole station operated on 5V. I used a Samsung tablet for logging.

In New Hampshire it was cloudy for most of Field Day, but fortunately the amorphous solar panel provides some charging even when it’s cloudy. I’m guessing that after 9 hours of operating the battery was down to about half capacity. The beauty of this system is that one could operate indefinitely with moderate sunshine.

I’ve been experimenting with this setup during hikes and bike rides for the last couple of months with a view to using it for Field Day. This year’s emergency exercise proves that it is viable for an extended grid-down power outage.

Click here to check out Jim’s website!


What a brilliant challenge and test for Field Day, Jim! Thank you for allowing me to share it here on QRPer. Also, a hat tip to Eric (WD8RIF) for bringing this article to my attention!

The new Mountain Topper MTR-4B V2 by LnR Precision

The venerable Mountain Topper MTR-3B

I’ve just noticed that LnR Precision has announced their new Mountain Topper MTR-4B V2.

They’ve released a few details with the promise of photos soon. Looks like the MTR-4B will of course sport four bands (80, 40, 30, and 20 meters) but adds two valuable tools its predecessors lacked: an SWR and RF power meter.

A full 5 watts output power is attained with a 12V supply, but the voltage operating range is 5.5 to 13volts.  The MTR-3B’s (photo above) has an upper operating range of 12V.

I look forward to checking out the MTR-4B and we’ll post photos as soon as they are available.

Here are the details from the LnR Precision Website:


MTR-4B V2

Photos COMING SOON

“The Mountain Topper”

The LnR Precision MTR transceivers are designed to be efficient portable CW rigs. Whether climbing a mountain and operating SOTA or just out for an afternoon in the park, the MTR’s small size, light weight and meager battery requirements makes it a great choice for these activities.

Features:

  • Four bands – 80M, 40M, 30M and 20M
  • Very low receiver noise floor
  • Low current for maximum battery life
  • Wide operating voltage range – 5.5V to 13V
  • Full 5W “QRP” gallon with 12.0 Volt supply
  • 2 line, back lighted LCD display
  • SWR – RF Power display
  • Built in Real Time Clock
  • Internal Iambic B mode keyer, 5 to 31 WPM in 1 WMP increments.
  • Three Morse message memories with beacon mode.
  • Specifications: coming soon