First outing for my Elecraft KX1

Saturday 16 March was an excellent opportunity for me to give my new Elecraft KX1 its baptism of fire. The occasion was the John Moyle Field Day, so I packed up my gear and headed for a nearby park.
I decided to use a long wire and counterpoise for an antenna, which I would tune up with my BLT tuner. I haven’t build and installed the automatic tuner yet; that is my next project.
I attached a heavy nut onto the end of a long piece of string, tied it to the end of the long wire, and threw it up across the branch of a tall gum tree. It went up first time. Talk about beginner’s luck!
I had decided to also give my newly-built touchkeyer a run. I only operated for an hour and made three good contacts. I was more than pleased.

The KX1, BLT tuner and P3K touchkeyer in place and ready for action.

Elecraft KX1 mod

I have now replaced R11 (now 5.6 Ohms) and R30 (now 30.8 Ohms), and squeezed the turns of L2 together more. The result has been most satisfying.

L2 in position before L1 was installed.

The power output is now as follows:
20m
9V = 1.87W
12V = 3.14W
13.8V = 3.92W

40m
9V = 1.66W
12V = 3.07W
13.8V = 3.98W

Measuring power levels.

The rig is now performing as it should according to the specifications.

Completing my Elecraft KX1 and first on air QSOs

The final stage of the build process involved final assemble and testing. The last few resistors, a zener diode and a trimmer pot were soldered in. Then it was time to wind and install toroidal inductors. The only tricky one was the transformer, which has two windings.
Next came inserting the metal standoffs onto the PCB.

With the standoffs in place, it is beginning to look like a radio.

Once that was done, it was time to scrape off the paint on the enclosure so that there is a good earth between it and the standoffs. I did this with a rotary tool.

Having the right tools makes the job easier. Sand paper will also do.

I then installed the red filter over the LED display opening, soldered in the final transistor and carried out some voltage checks to see if all was okay. I then attended to the installation and wiring of the internal battery holders. This was a little tricky but didn’t present any problems, except that I applied too much solder to one of the crimp terminals and so ruined it. A quick email to Elecraft resulted in two new ones being mailed out to me that same day. Awesome service.

The PCB in place mounted to the upper part of the enclosure.

Time now for final alignment and testing.

Testing the transmitter requires taking power readings on both bands with an accurate power meter; one that can read power at QRP levels. I have two; a QRPometer, and a Hendricks dummy load/power meter. I used both.

QRPometer on the left, Hendricks dummy load/power meter on the right.

This is what I read:
QPR0meter
20m @ 13.8V: 3.8W
40m @ 13.8V: 2.66W

Hendricks dummy load/power meter
20m @ 13.8V: 3.5145W
40m @ 13.8V: 2.66W

The formula I used to calculate power with the Hendricks meter is as follows:
P=([Vx0.707]+0.3)squared/50

The instruction manual says that power on both bands should be between 3 and 4 Watts, so clearly my 40m readings are a bit low. I emailed Elecraft and was told the readings look typical, but I want a little more power, especially on 40m as Down Under it was come in handy. I was told to change the values of R11 and R30 to between 4.7 and 5.6 Ohms, and 27 to 33 Ohms respectively. That is the next thing I will attend to, when I can source such low value resistors.

The rig complete and ready for the first on air test.

Time for the first real test. I plugged in my Touchkeyer P3K and tuned around on 40m on 1 March 2013 and heard ZL1IG Robin calling. I answered and completed my first QSO with this rig. He gave me a 339, which I was pleased about, especially since the distance between us was 1,549 miles. He is in Invercargill and I am in Brisbane.

Two days later, I decided to try 20m and answered FK8CE Dominique, who was calling from New Caledonia, a distance of 891 miles away. He replied and we had a satisfying QSO. He gave me a 599. After that, I tuned around and heard HB9BQR Roland calling from Solothurn in Switzerland. I answered and he gave me a 579. That was fantastic because the distance between us was 10,133 miles. We had a long QSO, so it wasn’t just a case of luck.

The antenna I was using was a simple dipole up at around 15 feet.
Now to wait for the crimp connectors to arrive and then to source some resistors, and the rig will be complete. Perhaps I don’t really need that additional Watt of power!

Elecraft KX1: Alignment and Test

I hit a snag while running through the testing stage of the build. On 20m, I could align the receiver as called for in the build instructions. All that was needed was to fire up my FT-450, connect it to a dummy load and wind back the power to 5W. Then, while listening to the KX1 with earbuds, send a signal via the FT-450 and peak two trimmers for maximum noise.

That was easily done.

Then what I needed to do was repeat the process for 40m. This was where I hit a snag. I couldn’t hear anything in the earbuds.

Time to start troubleshooting. I reheated all the solder connections, looked for solder bridges and anything else that might be wrong. I double checked the components but all seemed OK. So I shot off an email to Elecraft seeking advice.

Gary, AB7MY responded with a heap of good advice. I pulled out crystal X5 just to make sure I didn’t have any soldering problems but all seemed OK, so back in it went.

I could find nothing wrong so enlisted the help of Wallace, VK4CBW, who has some good test equipment (and sound knowledge). We ran though some basic checks first and then hooked up his oscilloscope and started signal tracing. Within minutes he found that I had soldered in one of the RF chokes (L4) into a wrong hole. I wondered how we would remove this as I had never been particularly good at using solder braid. But Wallace had a better idea, and good tools. He pulled out a desoldering vacuum machine and boy did this thing work! Did the job in no time at all and left beautifully clean holes.

Back in the shack I dug out a spare 2.2uH choke (luckily I had one in my spares cupboard), soldered it back in and proceeded to align the rig on 40m without further problems.

This little mistake was also causing the encoder Z1 to be very noisy when changing frequency. I would hear loud clicks in the earbuds. That has now gone too and changing frequency is now silently achieved.

So on now with the build …

Started building an Elecraft KX1

I have just received KX1 Serial No 2711 and started building. I couldn’t believe just how ‘professional’ the kit is. Apart from the wonderful set of instructions, it contained paper envelopes with the components, each with a label stating who had packed it, and even a sheet of sand paper for stripping the ends of the torroid leads!

The kit as it arrived.

Following the detailed instructions was quite straight forward. I completed Part 1 of the build over two evening sessions.

I use a vice to hold the PCB nice and steady.

Careful attention needs to be paid to ESD precautions as there are a number of static sensitive components in the kit. The three surface-mount components came already installed.

The PCB being populated in an orderly fashion.

At the end of Part 1 of the build process came the first test. A series of resistance tests with a DMM were done and when readings obtained indicated there were no short circuits or other mistakes, power was supplies and voltage checks done. Then it was time to access and test the configuration menu and the digital display.

The PCB positioned next to the top cover of the enclosure so that the legends identifying the switches and their functions can be seen.

Everything tested according to plan, so now it’s time for Part 2 of the build; the receiver circuit.

Building and using a CW Touch Paddle

I have just completed building a CW Touch Paddle, Model P3K, that I obtained from http://www.cwtouchkeyer.com. The kit took an impressive 6 days to arrive Down Under and was excellently packaged. The instructions were also first class.

The PCB took about half an hour to assemble and test. Worked first time. What did take a little longer was construction of a suitable enclosure.

The little jiffy box, with a central piece of wood for screwing the keys to.

I chose to mount my kit in a plastic jiffy box, to which I cut a few slots in the front panel for the keys to protrude through. I chose real keys as I thought that would be a rather neat thing to do.

All I had to do next was to insert the completed PCB, and begin operating.

Fitting the PCB and wooden panel with the keys attached.

Even though this little assembly is very small and light, because there is absolutely no movement in the paddles, the assembly doesn’t move about on the bench when sending code. It’s amazing, even though it isn’t weighted down. And it performs fantastically, too. Perfect code every time.

The completed Model P3K Touch Paddles.

Simple Ham Radio Antennas--an easy to build 2 Meter Ground Plane Antenna, post #265

Reblogged from KH6JRM's Amateur Radio Blog:

AN EASY TO BUILD 2 METER GROUND PLANE ANTENNA

Most of the standard "ducky" antennas that come as standard equipment on HTs leave much to be desired.  How would you like to build a simple 2 meter ground plane antenna that will give you good local coverage  and will serve as an easily storable antenna for portable or emegency use?

Read more… 751 more words

Want to get a little more distance out of your trusty 2m hand held and its rubber ducky antenna? Here is one way that's easy to achieve.