Cold – K7JLX's blog

Hello all, after leaving my last post in draft for a few months and not finishing it I figured I’d move right along and write another one! I had already set up my superantenna last night to do some SWL, but because the space weather is so good I decided to set up the Par EndFedz EFT-10/20/40 antenna to do some work on 20m. For today I used the arborist’s weight to hang the far end of the antenna in a tree in the back yard and connected the transformer end to the deck. The antenna was an estimated 20′ off the ground, and was oriented diagonally SE to NW across the yard. I had intended to run the antenna north to south but was unable to because the antenna was too long to be stretched from the deck to the right tree. I ended up moving it to another tree diagonally across the yard.

I made a partial contact with a Canadian ham out of Victoria, BC that suggested the solution to someone interfering with him was to “invoke the 2nd amendment” and solve the problem with a gun. Following that gem of a first partial contact of the day I decided to get off phone at that point and start operating JS8Call on 20m.

I connected the Raspberry Pi to the battery and Lab599 TX-500 and fired it all up. One of the first things I noticed was that the system clock was wrong. After using “timedatectl status” I saw that my hardware clock was right but on boot it failed to update the system clock. At that point I did it manually (“sudo hwclock –hctosys”). Since I had connected the Pi to the wifi at the house the previous night to run updates I was able to set my tablet up in the kitchen and leave the radio outside while I operated as there wasn’t enough cable to bring the radio inside. The family was around inside and it was considerably warmer in the house than it was outside so I could make QSOs and still talk with everyone that was inside. That’s one of the nice things about using keyboards and a slower mode like JS8Call – you can still talk with people while messages are being sent and received.

I made a few contacts but had a nice long QSO with W7SUA in AZ. Apart from that I was getting two way communications with stations over 1,800 miles away though they were generally automated requests for signal reports and locations.

Radio, Raspberry Pi, and a 4.5Ah Bioenno battery pack connected on a deck railing. — Radio set up with Rasbperry Pi connected.

Samsung Android tablet set up on a table showing a VNC session that's running JS8Call. — Tablet in the kitchen operating the radio while it’s outside.

Side view of the transformer end of the EFHW antenna connected to the deck with orange paracord and a coax cable. — Transformer end of trail-friend EFHW attached to the deck

Long view of the EFHW antenna connecting to a tree across a back yard. — View of the antenna running from the deck to the tree.

Image of https://pskreporter.info showing contacts from my station to others througout the US. — pskreporter.info screenshot showing stations that could hear mine throughout the day.

So, the weather in Portland has been pretty snowy which is a touch unusual! As most folks have been inside and not out attempting to drive on icy and snowy roads which are not plowed I decided I’d take my HT for a walk in the cold weather and test methods of keeping it warm enough to not have the battery fail as the temperature is dropping to ~18F with wind chill. My partner and I have been walking to the grocery store and taking our dog out so I decided to test an external antenna I’d built to mount on my backpack a year ago in the gnarly weather. I did some tests with APRS and some 5w FM phone as well. The theory here is that keeping the HT inside the fairly sealed bag would preserve some amount of air that’s warmer than the bag’s surroundings. It seemed to work as I was out with this setup for a few hours at a time and battery performance was within expectations.

Snow and ice covered backpack set on a snow-covered sidewalk with counterpoise extending down and antenna extending up. — Setup covered in ice and snow.

In order to not go stir crazy I’ve been taking walks with my partner and we’re close enough to a grocery store to just walk and pack our food in our bags which is very fortunate. I’ve taken the opportunity to test different ways of carrying the HT so it doesn’t get too cold, and to test a MOLLE antenna holder with a simple antenna and counterpoise setup. During the grocery store run pictured below I was able to reach stations in SE and NE Portland with a strong signal. I was between 2 and 9 S units into a station in Battelground, WA as well depending on structures around me. The antenna I’m using in this picture is a Nagoya NA-771. I used that instead of my Signal Stick because the signal stick doesn’t stay rigid in cold temperatures and will curve and lay over giving poorer performance. The speaker mic was used as both a speaker that I could hear outside the bag and as a sacrificial component in the event something gets too wet. A $30 speaker mic is much cheaper than a new HT. I did test the SWR on this setup and 2m performed very well near 1.2, but 70cm performance was poor with the SWR being near 2.8.

Backpack with anenna affixed in eggs in an attached cargo net. Bright orange paracord is tied in two spots to the backpack. — Small bit of paracord holds the mic in place, long bit holds the HT up in the bag.

Yaesu speaker microphone clipped to a backpack strap. — Small bit of paracord holds the mic in place, long bit holds the HT up in the bag.

The small bit of orange paracord is used to secure the speaker mic for cable routing purposes. When the mic comes un-clipped intentionally or on accident this cord makes it easier to grab and replace or remove and use. The longer orange paracord holds the weight of the HT in side the bag so the antenna cable and speaker mic don’t hold it up. It’s also necessary to hold it up in the bag to make sure there’s enough speaker mic cable to reach outside the bag and to my shoulder.

The HT holder inside the bag is suspended by the longer bit of paracord that runs through a loop on the HT holder. This suspension system also makes it easy to load the bottom of the bag with heavier items that might otherwise crush the HT or damage connectors.

The above gallery shows the antenna assembly set up but not mounted to the webbing on the backpack.

Tag: Cold

Working portable from WY

Cold weather backpack setup test