Had a lovely afternoon on Scout Rd on the side of Winter Hill with the Bolton Wireless Club operating G0BWC/P for the Practical Wireless 2m QRP Contest. Weather was hot and sunny a great day for a field day contest, just like the old days!
I read about the the uBITX tranceiver kit a while ago and thought that it looked good and would make a nice project for the future. I was put off because the main board has many SMD components and I thought at the time that they would need assembling and soldering to the board. Then a couple a weeks ago I came across the uBITX website with more information about the transceiver kit. I then realised that the kit board is actually assembled and tested, you just need to add on the extras to build it into an all band HF Tranceiver with an output of 10w. It also includes the Arduino digital controller and display. The specs on this device are impressive!
So, for my next project I am going to build one of these uBITX and try it out. The price is $103 and is shipped from India. I decided to order one from http://www.hfsignals.com/index.php/ubitx/ and a matching case from https://amateurradiokits.in/store/
Expecting a wait of about 6-8 weeks, I was amazed when the uBITX turned up only 8 days after ordering!
I look forward to building the project!
Received some nice SSTV pictures from the International Space Station today. Very strong signals on 145.800Mhz!
Just bought myself an oscilloscope for my shack. After months of searching on e-bay and looking at prices of oscilloscopes, I finally decided on a scope that I used for many years when I was mending televisions and radios. I know the Telequipment D1011 like the back of my hand, I had one of these on my bench while working at TAM Techserve and Visionhire back in the 1980’s. In those days if I needed a scope for anything I was building I could borrow one from work. Now that I am building my own equipment again I have realised how useful it would be to have a scope again. I built a small Chinese scope, which works fine, but is fiddly to use. At first I considered buying a digital scope like the Rigol, but really I can’t justify spending that much money for something that has more features than I would ever use. So I looked at some older second hand oscilloscopes, but again, some of these are more complex than I really need. Then last week I came across the Telequipment D1011, just what I need…cheap, reliable and easy to use, works up to 10Mhz and I know how to use it…so here it is! I look forward to using it with my future projects.
After thinking about my next construction project, I decided to have a go at building from scratch the old P.W. Dart Double Sideband Topband Transmitter, which came from Practical Wireless in Nov / Dec 1983. The components were all easy to find and I already had most of the small components. This will make a nice complement to the RAT5 Receiver and Multi-Rock II VFO.
I used the PCB designs in the magazine and set about making my own boards. There would be three boards…audio board, mixer board and PA board. Later I decided to build an extra board with an ‘RF sniffer’ connected to an LED so that I could monitor the output. The circuit uses a diode mixer SBL-1x which is similar to the MD108 that I used when I built a transceiver using SL600 chips many years ago.
With the boards now completed, I bought a matching case to the RAT5 and Multi-Rock VFO II to mount the boards and build up the wiring and controls. I took the PA tuning capacitor from an old ATU that was given to me. I bought a CB microphone from Maplin to use with the transmitter.
The completed P.W. Dart
When I tested the transmitter I had some RF feedback, but managed to cure this by adding more decoupling capacitors on the audio and mixer boards as well as making sure that everything was properly earthed including the screened cables. I have been getting good reports locally even though the output of the transmitter is just 2w. I can also see my transmissions on G4HYG’s on-line SDR Receiver. I have found this very useful to monitor my transmissions and set up the audio and PA output.
This is the first project for many years that I have built from scratch, which included making the printed circuit boards.
Although I have used FT8 a lot on HF, I would like to try it on 2m and 70cms. Trouble is that there has been some confusion about what frequency to use. In this month’s Practical Wireless there is a short article about FT8 on 144Mhz and shows the actual frequency used (144.174Mhz) I have given it a try, at first I heard nothing, then after an hour or so a couple of stations appeared and I worked them. Later it became even more active and I managed to work 15 stations, one in Scotland, a couple on the South coast and two French stations. This is a wonderful mode for working DX on VHF when the rest of the band is dead. In the olden days predicting openings and lifts became an art. Nowadays high pressure over Europe and all the tell tale signs of a lift leaves me dissapointed because there is not the activity that we had in the past. I think FT8 gives a bit of a boost towards working more distant stations.
Another thing that I have noticed over the last couple of days is the occasional ‘ping’ of Meteor Scatter reflecting FT8 signals from distant stations.
PSK Reporter showing the many spots picked up over the last 24 hours.
The Multi-Rock II is an addition to the RAT5 receiver. It is a programmable DDS frequency generator designed to use as a VFO with the RAT5 receiver and FAT5 transmitter. It can also be used as a signal generator to test equipment. It used PIC processsor chip and already assembled DDS generator. With the success of my RAT5 receiver, I decided to have a go at building this kit and build it so that it matches the RAT5. The kit is fairly straightforward to build, if you follow the instructions, but you have to be careful with the soldering as the tracks are very small. There are two separate boards to build and they are fixed together using solder-in pins.
This is a nice project to build, I have not built anything like this before. When I first switched on to try the MR2 I followed the set up instructions, these are a little complicated as it means pressing the control buttons in sequence. I had a bit of a hicup at first as the frequency control didn’t change frequency! After spending a while checking and measuring I discovered a microscopic short between two tracks. I managed to clear the short with a craft knife. Once cleared, I realised that there was a fault in the PIC chip, it was stuck on channel 2. With some help from Eric GW8LJJ he kindly sent me another PIC chip. This solved the problem!
Now all I need is a case. I looked at the supplier that I used for the RAT5 receiver and they make one which is a perfect fit for the MR2. It needs modifying slightly to ensure that nothing touches the case.
The RAT5 receiver needed modifying to accept the input from the MR2, which was easy enough to do. I also added a switch so that I could change from the external MR2 VFO to the internal VFO.
The MR2 works great with the RAT5 receiver, I have programmed a few channels so that I can just switch to a fixed frequency on Topband or use the VFO to tune the whole band.