Have you ever been bothered by such harmonics when working with the FT8? If you don't have the correct settings, you may be transmitting harmonics too.
Harmonic generation can be prevented by software settings.
Read more how:
Thanks to JP1LRT Yoshiharu
We had a storm earlier this week. But since I leave home when it is still dark and come back when it is already dark I didn't notice my vertical antenna was gone...
Found the broken parts in the neighbouring garden, they didn't notice as well I guess....time to analyze the damage.
For a while I noticed the antenna was not straight up anymore, it did bend even without wind. So this all came not as a surprise. You can see the wire the is originally inside but was not used anymore and the wire I attached at one side. I saw the tube went flat and not round anymore, I guess it was already a weak point that eventually cracked. I was unable to see the cracks because the antenna was covered with plastic tape.
I cut the center tube to have a view inside You can see the small wire inside. A common fault with these antennas is a broken wire which is difficult to repair. Since an Imax2000 is 7,5m long they bend a lot in the wind, with such a tin and solid wire it's no wonder it snaps.
After I replaced the A99 (with alutape cover) with the Imax2000 (with coppertape cover) years ago I have been thinking many times to threw this one in the garbage. But luckely I didn't....and yes, this one also suffers from the broken inner wire...
The A99 is 4,75m long. And not 5,5m like many think. Many 11m operators do use these antennas but I think originally it is a 10m band antenna. The formula to calculate a wire antenna with insulation is: 300/28,5(MHz)=10,52m/2=5,26m-5%=4,74m
I found one part suspicious. The center part is glued into a steel bushing. But I could turn it around. So I made some kind of splint to be shure it will no break at that place and stays into the bushing.
I wouldn't be a experimenter if I wouldn't try something new. This time I tape 5 1/4 wave wires onto the A99 for 20 till 10m. I want to see how this works.
When the antenna was ready it occured to me that I probabely used the mast mounting U-bolts for other projects......but how lucky I was, I still had this mast mounting system from my Diamond CP-6 which fits exactly around the bottom tube from the A99. A lucky miracle!
I was so lucky the weather was great. After some cutting, grinding, connecting and insulating the new 5 band 1/4 wave vertical is up again. The configuration is as follows:
TRX > Coax > Galvanic Isolator at botom of tower > Coax > Air choke > CG3000 autotuner > High quality 1:1 balun > 5x 1/4 wave wire for 14,18,21,24 and 28 MHz.
Results: Most important, does it tune. Yes, the tuner had a problem with 12m at first but after tuning 10m 12m was fine. Compared to the inverted-V the vertical does not win on 20m, receive is about 1-2 signal point weaker and sometimes it is the same...On 17m it clearly wins from the inverted-V. I don't know for 15, 12 and 10m since there is no propagation present. Hope to find out tomorrow.
I tried to make some SSB contacts with the vertical but I could hear only a few stations which were not really strong. Have been calling for 10 minutes but no one answers. So I switched to FT8.
Did some calls with 100W to see results. This was after about 20 minutes. Despite my signal was heard in Africa and USA I didn't make any DX QSO. Only a few European stations that responded. I'm shure it is not my signal that is the problem but the amount of stations that are transmitting in multiple signal layers on just 3000Hz. I couldn't simply find a clear spot on the waterfall to get my signal out the the DX stations I wanted to work. 20m FT8 is not really my piece of cake...
Well, I hope this antenna will survive any other storm this year. Hopefully it will help me getting my signal out on 17, 15 and 12m.
A while ago I saw a topic on a dutch hamradio forum about the failing clock back-up battery in the IC-7300. When this battery is broken and completely empty you have to set the time every time you switch on the radio. That could be very annoying. Of course you can replace the internal battery, which is a little tricky...But there is another way, you can easily set your time through the USB connection with your computer. I'm not the first one that published about this, there are other ways, there are multiple solutions. Although my internal battery is still working I just had to see if this works I had to test this. It might help some other HAMs as well...
Some powershell scripts were made by Martin PA2MP. At first he made one that only set the time and date but not exactly on the second. The IC-7300 doesn't know a command that set the time on seconds. But Martin wrote another script that waited till the clock hits "zero" before it send the commands to the IC-7300. It works very well. And since most of us have a small program in use that sets the time right to work with WSJT/JTDX or other software the time will be exactly right on the IC-7300, wonderfull...
This whole thing can be automated at the startup of your computer. It goes too far to completely explain how. I can give one hint: task scheduler. Martin wrote me a complete explanation about how to make a task in task scheduler that will automate running the powershell script. It is in PDF format, but it has been written in dutch. I have found it quite complicated but it works. So, anyone that likes to have that PDF send me an e-mail and I'll send it to you. If anyone can make a english version that would be highly appreciated!
In the mean time, Martin continued to update his powershell script till it evolved in one that not only will set the time but also switch on the IC-7300 if it is not on yet. That way it is excellent for remote control via the internet as well. So I wrote Martin if he could write a script to switch the set off as well with the computer. Since I do a lot of remote this really is excellent since I can now remotely switch off the whole station.
If you like you can try them yourself, PA2MP Martin has given permission to use the scripts for anyone that needs them. Download them here:
(You don't have to log in with a dropbox or google account, just click the message away. You'll find a download button in the right upper corner)
I have packed the files into a .rar file. I included the original script that set the date and time only on the minute, the second script that waits for a new minute to begin to set the time exact at the second and the third script that switches your IC-7300 on and then sets the date and time. As a bonus I added the script to switch off your IC-7300.
Thanks Martin PA2MP, really appreciate your effort to make these scripts and make them available to others.
