The best DIY antenna for AM broadcasting is the inverted L antenna. As with all of my videos, I do not condone breaking any laws in your jurisdiction with info you obtain from this video.
Pretty cool! My setup was a simple 25 ft copper pipe vertical radiator with a small 4ft capacity hat on top. and three 120ft. aluminum wire ground radials and a single 8ft ground rod at the base of the antenna. I used a tuning capacitor in a box at the base of the antenna to fine tune it and had a big hom,e made 200 turn center loading coil (with taps ) in the middle of the vertical radiating element. I was not trying to go "1000 miles". Final output transistor was a small 2N2222 NPN and transformer modulated from a PC sound card. (sound blaster with small speaker amplifier built in) It worked great!!! very loud and pro sounding for around 5-6 miles. And could just barely hear it/tell it was there at 30 miles from the transmitter in a car. Calculated ERP was around maybe only 6mW! after all losses were factored in. I have pictures of the antenna on Facebook. One of the most fun projects I haver did and it was wildly successful. Antenna was installed in the back yard in a residential neighborhood. It was on the air for a couple of years and all of my friends tuned it in when they were on the road.
Tuning was touchy but it worked and was very stable for months once tuned. Antenna 2.5 SWR bandwidth was only ~10KHz whcih was good in my case. touchy to tune but it was resonant and performed well past my expectations I had before putting it up.
Some things I forgot in the vid: 1. The spiderbeam needed extra hose clamps and a few wraps of tape on the bottom sections to prevent collapsing. It collapsed about a month after I put it up, but after installing the tape, it's been up for about 8 months. 2. The length of the field I gave was a little too high. It's more like 100 ft wide and 60 ft from ladder to pole (ground plane goes into woods). 3. The inductor is only 10uh i think. You don't need a big one even for 1kW. Might be a better Q with a bigger though. 4. The antenna works almost the same as a pro-AM station. The coverage is as good :)
Spectraman, you did a great job with the video and fully explained AM antennas. How many kilometers can you radiate your signal and what is the RF power you are sending to the antenna
Hey man. Love your vids!!!! I have an antenna question for you. What are your thoughts on an ocf dipole for 160 to 10 meters? On another note, I was getting several km's years ago with my broadcast warehouse 1 watt transmitter through a homebrew slim jim 🤯 The antenna is definitely a huge part of any rig!! Your setup looks awesome!!
Sorry, I wish I could answer, but I never looked into ocf dipoles. One of my neighbors had a 1W no brand Chinese FM that he was using just to play music around his farm. Turns out it was going 4-5 miles up the road to my place. It wasn't intentional and I left him a message saying I heard it. Told him I was fine with it, but was just curious what he was using. He got scared and never used it again.
@@spectra-man eh!! Thanks for your reply!! Lol....that's too bad that yer neighbour got scared 🤯 you're so right though about antennas.....it is one if the most "important" parts of the system.
It could be decent. First try it by making it full length 1/4 wave with a large horizontal portion. If that's no good, you could add a loading coil later. I don't know for sure how good it will be. It also depends on your location and ground conductivity, so...
Is the a list of all the part we need to do this type of antenna. We are building a community radio station on Am. We are located in Ontario Canada. If not could you do a part list included everything that you used for this built? Thank you
interesting I won't ever have anything like this but what range do you go day and night? MW is good to rebroadcast stuff with talking on like a podcast or youtube video.
It depends on the weather conditions and sunspots. During daytime, it never goes very far - maybe like 100 miles (with a doughnut hole). At night it can go 1000 miles. I think that's what I remember. It's been a long time since I used it. And yes, it is good for podcasts and youtube. If you do it, I recommend playing alternative media to compete with corporate media. It's VERY important during these times.
@@spectra-man yeah, I had mine under a meter and i noticed it made the audio a little quieter and less power was coming out according to my field strength meter. I have it up 2 meters or so and it is doing better. I will do a range test today, but the signal became twice as strong on the online SDRs after I brought it up from 0.5 meters to 2 meters above ground. My mast is a wooden pole thats only maybe a little under 20 meters tall. I wish i could get it higher but I live in an HOA lot.
You just need to look up spiderbeam. Then buy an adjustable coil on ebay and something to contain it. 580 Kc is going to be a serious challenge. You'd definitely need to get the tallest spiderbeam and need a big loading coil. The efficiency will be low, so you may also need to push a lot more power than expected. I wouldn't recommend doing anything lower than 1400 Kc. This comes from experience. I originally wanted to broadcast on 1000 (1 MHz) and I could never get it to work efficiently and have more than just a few miles range.
But it does also depend on ground conductivity, so if you're on very fertile soil or near salt water/swamp and you have a huge ground plane, then you might be impressed.
