QRP On Deck

We had a little light snow today and the temperature was hovering just below freezing, but I wanted to get outside and check out one of my old QRP rigs. The radio of the day was my Hendricks PFR-3. The “PFR” stands for Portable Field Radio. The PFR-3 is (or was; I’m not sure if it is still available) sold as a kit, but I bought mine fully-assembled from a ham who is now a silent key. This radio is a very fine little QRP rig. I can’t understand why it isn’t more popular.

This was the perfect opportunity to test a portable setup I have been planning for outdoor winter radio operations. My shelter is a lightweight pop-up tent that can be carried to the field to provide a wind break and to keep the snow off operator and radio. I cleared the snow from my backyard deck and set up the tent in just a couple of minutes.

My QRP backpack and a camping stool were dropped inside the tent, then it was time to erect the antenna. I chose a random wire antenna (home made, of course, like all my antennas). I don’t usually like non-resonant antennas, but the PFR-3 has a built in manual tuner with LED SWR indicator so the random wire is a perfect match.

The radiating element is 29.5 feet long and the ground-mounted counterpoise is 21 feet – both coiled on the same winder. The 9:1 unun wound on a type-2 core is also mounted on the winder (see picture). The wire lengths were carefully chosen after a lot of experimentation to allow the PFR-3’s internal tuner to find a match on 20m, 30m and 40m – the three bands supported by the radio.

I tied a length of bricklayers twine to one of the sand-filled balloons that I use as a throwing weight and tossed it up over the limb of a tree about 25ft high, then pulled the end of the radiating element up and laid the counterpoise on the ground.

After tuning up on 20m I found a POTA activator in Indiana calling QRZ and threw out my callsign. Several stations were trying to contact him but my humble little QRP station beat the pile-up and the QSO was made. He even gave me a 599. I’m not sure if that was a contest-style report or a true signal report. Either way I was very pleased to make the contact.

You can see the station details in the pictures. Note my home made Bulldog Clip paddle. I have made several of these; they are actually very smooth and easy to use. Not visible is the battery pack (mounted under the radio). I use three 18650 LiIon cells that seem to last forever. I modified the PFR-3 to accept Anderson Powerpole connectors. I really didn’t like the barrel connector that was originally fitted.

The PFR-3 has two keyer memories and therein lies a story. The version of firmware installed in my radio does not allow the memories to be erased once recorded! They can be modified. When I wanted to erase them, the best I could do was record a single “dit” over the previous memory content. And why did I want to erase keyer memories? My PFR-3 is very sensitive to common mode current and it manifests this weakness by playing keyer memory #1 spontaneously – during an active QSO! I have inserted a common mode current choke at the rig end of the coax to help stop this annoying glitch.

I am beginning to remember how much fun it used to be when I was a dedicated QRP operator. I love the lightweight equipment and low-capacity batteries that power the station for a long operating session. Now that the new solar cycle has improved propagation conditions considerably, I think my PFR-3 and my rejuvenated FT-817 QRP stations will be seeing regular use.