Archive for the ‘qrp’ Category

One More Winter For The Tri-Tet-Ten?


I originally built what I called the "Tri-Tet-Ten" to  test out a long-held idea of actually working Europe on 10m, using just a single-tube tri-tet oscillator and a 40m crystal. I had no idea what amount of power might be obtained on 28MHz from a single 6L6 crystal-controlled oscillator, quadrupling from 40m to Ten. After building several configurations as well as trying five different tube types, I was pleasantly surprised to end up with almost five 'clean' watts of 10m RF on my 40m crystal's 4th harmonic! I suspected that the tone would be unusable but the tri-tet proved to be surprisingly good at isolating the oscillator from the output stage. Although chirpy, the signal is indeed usable and somewhat reminiscent of what so many 10m CW signals must have sounded like at one time.

Having completed the transmitter just in time for Cycle 24's hoped-for great 10m conditions, it turned out that only a couple of one-week periods over the past three winters where good enough to reach Europe. During the two "double-peaks" I worked many dozens of Europeans, all of them in response to my crystal-controlled CQ's, mostly on 28.042kHz.


Courtesy: http://www.noaa.gov/

Nobody was more excited than I, the first time I heard a reply from Europe....it was from G4RRA who, as fate would have it, recorded my signal on that early October morning.


There were a few mornings when I had long pileups and worked Europe for several hours, most of the time shaking my head in disbelief that such a simple transmitter could provide so much DX pleasure...but really of course, it was mostly the great performance of Ten....the "other magic band".





I really doubt that 10m will once again support European conditions good enough for my one-tuber but it's still fun to work the U.S. With Cycle 24 on the decline I was happy to see that F2 has returned to Ten once again and this week I sparked-up the tri-tet to enjoy the propagation.

My chirpy return to the band produced many enjoyable QSO's..... NG2T (NY), KD8IFJ (MI), K9DP (IN), KA2MLH (NY), W4NA (VA), N4OW (FL), K8NS (FL), N5AF (TX), WA5AFD (OK), K5TIA (TX), K9DX (IL) and VE3IKV/m, boldly travelling along the freeway at 120kph!

So....if you hear a chirpy CQ just a smidgen below 28.042, please.... give me a call!

Will I be lucky enough to squeeze out one last winter of tri-tet fun before having to move down to 15 or 20m? Time will tell....but somehow it won't be quite the same as riding that delicate 10m ether over the pole to Europe, on just one tube.

Keep trying and you will finally get it!

My first PSK31 contact
For some time now I have been trying to get my feet wet with the digital modes and have had no luck. This morning I gave it another go with the setup, in the past I have tried Fldigi, Digipan, Digital Master 780 and WinPSK and the list goes on. These are all great programs as many use them and have great success but as for me I just was not able to make them tick with my set up. I became frustrated and it was do to me just not figuring out the setup. As I said this morning I tried it again but from another angle, there are two programs I use to control my rig from my PC the first being N4PY's program and the other program is DXlab. The DXlab program has many modules  from rig control, logbook, propagation, DX cluster and a digital program that's called Winwarbler! DXlab already controls my
Screen shot 
radio and does a fine job of it so I added the Winwarbler module and with a few configuration tweaks I had radio control and was able to read signals from the waterfall. It was now time for the moment of truth to see if I am transmitting a PSK signal. On 20m I pressed the "call CQ" macro button and low and behold my power meter showed 5 watts making it's way to the antenna!!! Next was to find someone calling CQ and make my first contact with PSK31. I saw W1AW/5 calling CQ and I gave him a call and W1AW/5 came back to me with a 599 report. I now can say that I am PSK active but there was not much time left to make any other contacts as things around the house had to be done. I was thrilled to get things up and running and the waterfall was very busy. One of the drawbacks to Winwabler is it's limited to PSK and RTTY but for now I'm ok with that.
The K3 all ready to go
This is the setup that I am running….
Rig is the Elecraft K3 in DATA A mode set at 5 watts
The sound card interface is the Signalink USB
Software is DXlab's  Winwabler
Antenna is the MFJ 1788
Some of the items on the "to do list" are
1. Set the macro's up as they are generic ones right now.
2. Learn more about the Winwabler  program.

Making your radio time interesting is what counts!

I spent some time on 20m in the CW portion of the band and as always I wanted to make contacts with the lowest power possible. I came across 9A2G who was calling CQ and at the time he was not to busy with takers. This is a great opportunity for me to drop my call to someone who is listening. I started out at 500mW's and moved all the way up to 5 watts and nothing no contact. He did have some stations answer his CQ  and some where very weak so  he had good ears but not for VE3WDM. I then came across EG7MAL and I worked my way up to 5 watts and he came back to me with VE3?. He decided to move on as I was just not making the trip. At this point I was wondering how my low power signal was doing so I decided to call CQ at the QRP watering hole on 20m. I was checking with the Reverse Beacon Network to see how I was doing.  My 500mW signal was heard by AA4VV in North Carolina which was just over 1,000 miles per watt. I then bumped my power up to 1 watt and was very happy to see F4DXW was hearing me which meant my 1 watt of power made it 3461 miles. I did not make any contacts but I did find a way to make the radio evening a bit exciting even without making a two way contact.

Take time to listen it pays off.

W1ZU's home setup.
I had some spare time just before dinner time and thought it would be a nice idea to sit down and relax at the radio. The rig was set to the QRP watering hole of 14.060 and very soon after I heard W1ZU calling CQ. Now having said that I just read the other evening in my CQ magazine of how important it is to listen, so I thought I would give the ears a workout and the key could sit idle. By listening I found out that W1ZU was operating from a summit in Maine, that he was activating SOTA (summits on the air) summit W1/DI 006. Not being an active SOTA chaser I did some more listening and was very surprised how fast the pileup developed to contact him. It would seem you can obtain points for contacting summits and this one was worth one point. Once the pileup settled down I threw my call out and Scott came back to me with a decent report. If I did not spend the time to listen and just tossed my call in and make the contact and move on I would never had learned the detailed info about this contact.

So you want to play with a Pixie?

My own surface mount version of the Pixie2

This page provides a guide to Pixie and related kits in a table format. These are simplistic single-band transceivers which are fun to build, yet they perform well enough to be used, although with some effort, for real contacts.

The idea of using the power amplifier transistor as a mixer seems to come from George Burt – GM3OXX – whose five transistor FOXX was described in 1983 in SPRAT. The basic design of the oscillator, PA/mixer and the simple keying has been more or less unchanged since RV3GM – Oleg Borodin – described the four transistor Micro-80 in 1992 in SPRAT. Later the Pixie 2 by WA6BOY replaced two of those transistors with the LM386 audio amplifier (QRPp 1995). Most later versions are variants of these designs.

Foxx


Foxx-3 kit from Kanga, £29.95
Incorporates a sidetone oscillator, changeover relay and low-pass filter. Different versions for the 80, 40, 30 or 20 m bands

Micro-80


Kit from QRPme, $35.00
Micro80D.
Updated version with choice of  high or low impedance headphone, polyvaricon tuning cap and board mounted connectors, 80 m.

Pixie2


Kit from HSC Electronic Supply, $14.95
For 80 and 40 m.
Eham review

Kit from Kenneke, $29.95
Includes 80 m crystal

Kit from QRPme, $40.00
Lil Squall Transceiver ][.
Several components and the output low pass filter are on sockets. Comes with a crystal for 40 m.

Ali Express Ham QRP DIY Kit Shack 40 m, $15.07
40 m version. Tuning pot for VXO.

Radi0kit, £22.00
Enhanced Pixie2 which comes in 80, 40 and 20 m versions. Judging from the PCB layout it has an improved pin 7 muting circuit.


What can we say to characterize these designs? One the one hand they are very simple to build and get to work. One the other hand they are also simple in the sense that they do not always perform very well. Therefore I don’t think I would recommend them to any novice ham. It takes some understanding of frequency offsets and sidebands in order to make real contacts. But many have had great fun with this minimalist transceiver which in its basic version puts out some 2-300 mW. And it encourages experimentation and modifications. Also, it should be remembered that it isn’t really necessary to get a kit, as the Pixie 2 is quite simple to build from scratch also. I did that myself.

The original designs and many variants and modifications are documented in the Pixie file document of SPRAT. There are many, many more clever modifications out there and I have my share on this blog also. To sort out and link to all the other pages is too daunting a task, so therefore I have focused on kits here. Finally I wouldn’t be surprised if the table is incomplete so I would appreciate comments if you think that something is missing.

The list of projects is huge!

I have been having serious radio withdrawal – I am really itching to get on the air and operate!  Unfortunately, life is happening and I have had zero time to operate.

When this happens I usually watch a lot of videos and read blogs.  This then leads a big list of “I wanna do that” type projects.

So I thought I would list the top 3 or 4 here and set a goal of getting them done by Christmas:

1.  Get a long wire inverted L 9:1 UNUN antenna installed at the house.  I have the UNUN built and I have the small gauge “stealthy” wire from the Wire Man – just need to get it up in the trees!

2.  Rockmite 40 – I have had this kit along with the Mitybox for several years – just need to get it built.

3. DIY Powerpole Distribution Block – There are some great plans for this here: http://www.qsl.net/wd4bis/connect.htm

4. Magnetic loop antenna with automatic controller.  I have the board, just need some components to get the board built up and working – I really want to get this going early this fall!

The list is much longer – but this is the top four I want to get done right now.

What is on your project list?

The list of projects is huge!

I have been having serious radio withdrawal – I am really itching to get on the air and operate!  Unfortunately, life is happening and I have had zero time to operate.

When this happens I usually watch a lot of videos and read blogs.  This then leads a big list of “I wanna do that” type projects.

So I thought I would list the top 3 or 4 here and set a goal of getting them done by Christmas:

1.  Get a long wire inverted L 9:1 UNUN antenna installed at the house.  I have the UNUN built and I have the small gauge “stealthy” wire from the Wire Man – just need to get it up in the trees!

2.  Rockmite 40 – I have had this kit along with the Mitybox for several years – just need to get it built.

3. DIY Powerpole Distribution Block – There are some great plans for this here: http://www.qsl.net/wd4bis/connect.htm

4. Magnetic loop antenna with automatic controller.  I have the board, just need some components to get the board built up and working – I really want to get this going early this fall!

The list is much longer – but this is the top four I want to get done right now.

What is on your project list?


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  • Matt W1MST, Managing Editor