Can you measure your HF Antenna Performance? Is it something you can do in your back garden?
Вставка
- Опубліковано 27 лют 2023
- How to measure your HF Antenna performance is a regular question. The answer is not easy and Peter G3OJV explains what you and cannot do in order to assess your HF Antenna performance.
Here is How to measure the loss in your coax feeder
kv5r.com/ham-radio/coax-loss-... - Наука та технологія
Am with you 100% right about Coax I couldn't tell the difference 3 different Coax at 25 meters on HF.
Seeking the perfect antenna and feedline became an obsession and prevented me from getting on the air for a long time. Like someone once said, Perfection is the Enemy of Progress.
Frustrated with the lack of progress, one afternoon I threw together an EFHW, attached a 200 mW WSPR transmitter, and contacted Melbourne, Australia on 10 M on the very first transmit cycle. :o
Ham radio has forced me to confront and suppress my OCD.
Thank you for the reassuring video regarding Antenna Performance
& coaxial cable length .
- also wishing you a safe journey to Scotland 73
Brilliant as always, Peter. We had much the same problem modelling Radars in the RAF. With the old Analog systems it was tuning everything to its best and then an aircraft (in the latter years a Hawk from 100 Sqn) would fly in and around the Station whilst the controllers would ‘Plot’ the results in what was called ‘Spotted Dog’. This was a one off snapshot. When Digital Radars came in, we were able to also hook up a pc and record a longer view based on regular aircraft traffic passing by. This gave more of a ‘Mean’ view but importantly confidence that all was ok .
With the introduction of WSPR and FT8/ FT4, I get the same ‘Mean’ view of my Amateur Radio Station, as such.. and a good ‘feel’ of what is happening when I alter just the one variables (ie the antenna). For me, digital modes are a great technical tool to help understand your antenna performance and layout, but it does have to be averaged out.
Keep up the great work. de Andy G0NKK
excellent advice Peter... I like the clingfilm idea... I may give this a go ...
Spot on Peter
Without having really good RF test kit around, or the ability to do proper field measurements, I think the RBN is the best method to determine how, in the present environmental conditions, the antenna is performing. It's measured, and you can even run RBN a few times for *each* setup to see the variations in the environment. As you say, conditions can change rapidly. So, whatever equipment parameters need to be changed (orientation, height etc.), should be ready to go to be changed quickly. I would keep a written log of what was done, and then after all the variations are run through, check the RBN results (which are time stamped). If you check RBN in-between, you're open to more environmental variation as the day (or night) passes. I ran RBN when on the gray line once, and 20m only performed well on the daylight side, and 40m only worked well on the dark side (within 5 minutes of each other). That was fun.
Excellent Peter
antenna performance can sometimes be gauged for improvements if you have regular sked with a group of stations, as everyone knows what to to expect from a particular station ( normally a poor signal or a good signal etc. )so any improvement or degradation can be spotted more easily.
Remember that improved conditions can still be the reason for better signals even in a group but regular contacts with the group may well be an indicator
very informative video!!!!
Web SDR's are handy to see if you can hear what they do and hear you as well. DX is hard in a small garden is without a 20 metre tower or two and beams, but fun. Getting good solid dependable performance on daily nets in the first skip zone is much easier to do.
It's not that any one change or improvement will make or break your HF antenna performance, but attention to the many small details that are known to affect performance can add up to a significant difference in the effectiveness of your antenna.
I use my internal SWR meter on the the radio however I do have a question about my analog meter on my radio. I have the IC-7300. This IC-7300 has an analog meter. When I set my IC-7300 to 100 watts and key up my mic the forward power is suppose to show 100 watts of forward power being put out however my analog meter shows only 35 watts of forward power being put out. What do you think could be causing such a huge discrepancy between the 100 watts the IC-7300 is set to and and the actual amount of forward power (35watts) that is being put out?
Good morning de KE8EC
WSPR
Forget all this; the best way, to measure antenna performance, is to buy a helicopter and an expensive calibrated wideband receiver and antenna, and train a friend to fly it whenever you come on the air..... 😂