I did this repair many years ago after the mounting failed on the X-300 (original single bold stub mast) which allowed the antenna to sway. It gave a few more years of service after the repair and mounting modification and was only taken down to be replaced with a new X-510 which has the same mounting modification.
The X-510 has been up for many years with no issues despite being battered by the winds and salt coming off the North Sea.
Continue reading “Diamond X-300 repair”
I love a good T2FD antenna and have built a good few. There’s a few variations but they all work well and are easy to construct. I’ve been asked a few time about the length and spacing so I made a small Excel sheet to work it all out and provide data for the 3 most popular variations.
Free free to download and use. The sheet is protected to prevent the formulas from getting messed up but if you would like to experiment with alternative formulas then please just contact me for the password. All I require is for my original credit to remain on any derivative works.
M0LMK T2FD Calculator
A cheap but very useful item of test equipment that would be an asset to any experimenter’s tool box. I picked up a BG7TBL Noise Source from ebay and built it into an enclosure.
There are reports that the PCB gets very hot during operation so mounted the entire PCB onto a piece of copper clad PCB which I also used to secure inside the enclosure. Continue reading “Wideband Noise Source”
I’ve been wanting to built a good 4:1 BalUn as part of the never ending project that is my HF antenna system for some time and today, I finally got around to the job. This is a “true” 4:1 Current BalUn that is wound as two separate 1:1 current baluns and then placed together to create the 4:1 ration. Any 4:1 built on a single core that claims to be a current BalUn is lying and is actually a Voltage BalUn! Continue reading “4:1 BalUn”
I usually get static build up on my HF doublet due to sand particles (I live above the beach) in the air so have been thinking about a way to bleed off the static and provide some protection to my TS-590SG. After a little research, I came up with this, a lightning arrestor/static bleed device that provides a permanent path to earth for DC whilst allowing RF to pass and providing protection from nearby lightning strikes. Continue reading “Ladder Line Surge Suppressor”
A common fault on the SGC range of antenna tuners is a reduction in receive performance as they get on in years. This can be attributed to contamination on the relay contacts since SGC stoped using fully sealed relays. Any small condensation inside the tuner makes it’s way into the relays and causes contamination on the contacts as they are hot switched. The best thing to do is to replace all 26 relays with new units…
Continue reading “SGC-230 relay replacement”
I purchased my trusty SGC-230 Smartuner around 8 years ago as a faulty unit and soon got it back up and running with a new binary counter IC. It’s worked great since then but has always had a cracked ceramic post on the output terminal. It was one of the jobs I wanted to do but I never got around to finding a new post so when I had time to replace it, I never had the part handy. Continue reading “SGC-230 Ceramic post replacment”
Just a quick mod to the CN-901 SWR and Power meter. This mod allows the SWR needle to work when the meter is set to PEP measurement mode. Not very practical but it looks nice!
Continue reading “Swing that needle!”
This is a simple modification that takes around 5 minutes but makes a big improvement to the already great TM-V71. The fan on this radio is very loud and runs at full speed from the moment you press the PTT then stays on for a few minutes after you release the PTT. This isn’t a problem in a mobile setting where there is usually more background noise but it is very loud when using the TM-V71 in a quiet home shack.
Continue reading “TM-V71 fan upgrade”
I’m lucky enough to have been given to opportunity to become the next keeper of the GB3EK repeater, an iconic 70cm repeater on the South East coast with 40 years of history and service to the local Amateur Radio community.
Continue reading “GB3EK Repeater”