Basic radio:After enjoying numerous little QRP radios, I figured it's time to make a change so I purchased an Elecraft KX3 with the following options:
Roofing filter board
Internal battery charger w/clock
Built in auto tuner
Elecraft screw on CW paddles ( a gift from a good friend )
CW operating tip:
When the KX3 is tilted forward on its rear feet, I found that the CW paddles are a little too low and uncomfortable. When laying the rig flat on its
back I then found the paddles a little too high and again uncomfortable. To resolve this I placed a 3/4" think piece of white pine under the rig.
This places the paddles at a much more confortable and usable operating position.
The picture on the right shows the actual pad that I made out of wood that measures 3/4" x 7-9/16" x 3-3/4".
I cut a small grove on the top front of the pad so the rubber feet on the bottom of the KX3 rests in the slot. This
keeps the radio from sliding off of the pad if you hit the paddles too hard or bump the radio. A radial arm saw,
table saw or router can be used to cut the groove.
Palm Pico Paddles on the KX3
Hannes, DL9SCO and Dieter, DJ6TE have outdone themselves with this setup. The KX3 is a great radio but the Elecraft paddles are very questionable. Every so often the Elecraft paddles will miss a dit or a dah. I tried everything I could think of to resolve this issue and finally gave up. Other’s have had the same problem. After watching a YouTube video on the Pico Paddles I decided to give them a try. I can not put into words how much I like these little paddles. I was concerned about the size, I though they would be too small. I was wrong, they are perfect. They have a great feel, adjustable tension and adjustable contact gaps. When not in use you can swing the paddles to the side and tuck the paddles inside of the little square enclosure. These little guys don’t miss a beat.
The Pico Paddles also have a magnetic base. “Mores Express” sells a metal side panel for the KX3 so you can attach these little paddles to the right hand side of the radio if you don’t want them on the front of the radio. A bonus for me is, my little You Kits / Ten Tec R4020 has a metal enclosure so these little guys will also work with that rig.
Here's a YouTube video talking about CW paddles, KX3 platform and a note on batteries:
The Ni-Zn batteries (1.6 volt per cell) that are shown in this video can not be charged while they are in the radio. You MUST use the special charger that is designed for these batteries.
When it it comes to trimming an antenna, I found that the little MFJ-223 antenna analyzer does a great job. I needed a simple antenna analyzer that would fit in my shirt pocket and the 223 fits the bill. The frequency range is 160 to 6 meters. I also use other antenna analyzers, but I did not want to carry around a large antenna analyzer, like the MFJ 259B.
AD5X did an great product review of this unit. You can see it here: Click Here
If you'd like to see how the MFJ-223 works, first hand, you may find the video below very interesting.
12 foot long 20 meter micro antenna construction details
I like using very small resonant antennas when operating portable. The following You Tube video will give you instructions on how to make a very compact reson
tant 20 me
up to 100 watts of RF. er dipole. This antenna can handle
The coax I used in the video is a 15 foot length of RG 174. The maximum length I would use of this coax would be no more than 25 feet.
A word on coaxial cable
It's always nice to be able to use low loss coaxial cable, like RG 213, but it is really not practical to use this type of coax when operating portable. I feel RG 8X is great cable for portable operations. RG 58 is a little smaller in diameter but I always had issues when using PL 259 connectors on this cable. It seemed they had a very high failure rate. The center conductor would always fail inside of the connector. Having a coax fail when in the field makes for a bad day. Since the KX3 and my Ten Tec R4020 both use BNC's, I figured it’s time to make the change. Installing BNC's on RG 58 cable is not a fun job. First you must make sure your purchase the correct connector. I decided it would be a lot easier and, in this case, much better to look for assemblies already made. Amphenol Cables on Demand had just what I needed. They use low loss RG 58 cable and BNC's that are molded to the cable. I purchased two each pre made 25 foot lengths and one each pre made 50 foot length. You will also need to carry a BNC female coupler if longer lengths are needed.
I started to use RG-174 coax with BNC's on both ends. It's much smaller and easier to carry. The losses of a 25 foot run of RG-174 are very low.
Shown on the left is a pre made 25 foot length of RG 58 coax, with BNC molded connectors. The double female connector is shown laying in the middle.
Amphenol Cables on Demand. Cables on Demand
The labels on the coax were made using the Brady BMP 21 wire label maker. Since I bought the Brady I've labeled all of the cables in the shack. The Brother P-Touch has its place but there is nothing like a label maker designed for putting labels on wires and cables.
11.1 Volts @ 5 AH LiPo battery
Battery size: 5-1/2" x 1-1/4" x 1-5/8"
The LiPo battery, pictured right, is a great addition to my KX3 package. The fully charged three cell LiPo battery is around 12.2 volts. You can run the KX3 at 10 watts output power with this battery. Since I only run my KX3 at the 5 watt level, I can use this battery for a very long time when set up portable.
Hobby Express stocks a large selection of LiPo batteries.
The four cell pack will product too high of a voltage for the KX3, 16 volts fully charged. The Nickel Metal Hydride Battery, I have used on the Icom IC 703, is almost twice the size of this LiPo and only delivers 4200 mha. Nickel Metal Hydride Battery will also self discharge in a few weeks while just sitting on the shelf. The LiPo batteries will hold their charge, on the shelf, for an extened period of time. I added the fuse holder and the Anderson Power Poles to the battery.
Hobby Express has numerous sizes to choose from. When I compared the 4000 and the 4400 mah LiPo to the 5000 mha battery, there was very little difference in the physical dimensions. For me, the slight difference is physical size and price, the 5000 mah was the best choice.
Hobby King Is another place to purchase LiPo batteries. They seem to have the best price. They now have a stateside location so shipping is a lot faster.
The needed charger, purchased from Hobby Partz, was only $19.
This battery is also a great choice for other rigs like the Icom 703 and the You Kits / Ten Tec QRP rigs.
Portable QRP >