FM Radio Station ANTENNA For FM Transmitter Set Up. How To Get It Right For Best Signal Quality.
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- čas přidán 6. 03. 2023
- Having the right antenna for your radio station can dramatically change your broadcast signal. I will show you the different types and one which I found to be absolutely amazing for low-power radio stations. Watch to the end and I will show this antenna and how it makes the maximum use out of your FM transmitter signal. Pirate radio stations and professional broadcast radio stations need quality antennas.
FM antennas come in a range of designs and configurations and not just the standard half-wave dipole. While the dipole is commonly used in FM broadcast many radio stations have found better results from some very unorthodox antenna designs.
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Antenna design is not just about gain or polarity. While these do matter, antennas can even affect the down tilt of the radiated signal. Both licensed broadcasters and pirate radio stations with pirate FM transmitters, need to have a good radio antenna setup. Hobby pirate radio stations often need to get the most out of their signal with a good antenna. Later in this video, I will show you that very special FM antenna that not only offers high gain but also tilts the radio Signal down to the horizon. This can turn a small signal into one that seems much stronger. This is because the signal is not lost out to the sky or down into the ground. All of the signal goes out to where you want it. That’s to your listener.
Let's first start with the standard half-wave dipole. This is the industry standard for low and high-power broadcasts. The reason is that this is the easiest antenna to match with additional antennas. Arras can be as little as two and as many as you can fit on a pool. This makes it very versatile and easy to adapt to any power level from low-power community radio stations to high-powered commercial stations. Once set up this antenna array can run for many years without being tested or adjusted. But like all stock standard things, the half-wave dipole offers nothing special. It provides a basic vertically polarised zero gain signal unless in an array of more than one. The additional downside to dipoles is that a lot of the signal is lost into the sky and down to the ground below the antenna.
There are antennas that can offer gain in a single antenna. The examples are a 5/8. or a J-pole. These offer a gain of 3 dB and more. That means a single 5/8 or J-pole can put out twice as much as a half-wave dipole. The 5/8 also lifts up some of the radio signal lost down to the ground because the ground radials tilt the signal upwards. The downside is that if you need even more gain it is extremely difficult if not impossible to match these antennas in an array. It's just not practical because of the ground plains. Also, it can only give vertical polarization like a half-wave dipole and there is still loss of signal into the sky.
The half-wave dipole also suffers from a partial directionality problem because it is side mounted. That means the pole it is mounted on acts like a reflector pointing a sizeable chunk of the radio signal in one direction. This is fine if your antenna is outside of your coverage area pointing in like on a mountain on the side of a city.
If you are broadcasting from the centre of your broadcast area then this is not good. You will want an antenna with an almost perfectly circular radio pattern.
There is another antenna that can do more than one polarity. This is called a circular polarized antenna. This antenna does not actually give all 180 degrees of signal but actually offers a combination of vertical and horizontal polarization.
This is often more than enough because radio receiver antennas are mostly vertical or horizontal or halfway in between like a car bee sting antenna.
This helps to fill in shadow areas, especially in urban broadcast footprints. So if you broadcast to a city then this can be a solution for you.
There, of course, is a downside which this that the antenna not only it does not offer any gain but in most cases has a minus gain meaning that it will radiate less on a plane than a dipole. In many cases, the circular polarized antennas need to be paired with at least one more antenna just to provide zero dB gain or put out the same signal strength as a dipole. You can also just turn up the power you put into a single antenna to compensate for the loss but most stations would opt for the matched pair. If these antenna arrays go out of tune and become slightly mismatched they can even create horrible ripple shadow areas that make moving within the signal footprint really unpleasant as the wave interference result in the signal doubling and halving giving a type of pulse RF signal which is really bad for listening on a car radio. They also suffer the same problem of the dipole that they are side-mounted giving a semi-directional radiation pattern. Pirate radio station transmitter antenna. - Věda a technologie
Weer een stukje wijzer geworden ! dank.
Thank you. I'm glad you enjoyed the video :)
Bedankt. Ik ben blij dat je genoten hebt van de video :)
Great video. There is one other thing that I would add that improves all antenna types. It worked for us and gives great results nearly 40 years on. I was technical director at KKFI in Kansas City. They are 100,00 watts ERP (25kw actually up the pipe).
We put in a very effective ground radial system. We have a 500 foot (152 mters) tower. The 4 ground radial (North, South, East, and West) go out that far. The 45 degree radials are that long as well. In betwwen the 45's (22.5 degrees) are radials that go out half way. There are circular cables that join all 16. From the air this looks like a bulls eye target. This gives us a low "departure angle".
Don't buy a cheap lightning arrester. A good one may cost you up front but save your ass week after week. We have frquent stoms (including thunder snow). What saved me is that at 500 feet we are the short tower on the hill. I was standing near our tower when a neighbor got hit. We were knocked off the air. Our arrestor worked and we were back on 5 minutes later.
KKFI is listener supported. We put their money to good use (EV RE20). Do a proper job and invest in good stuff as g michrophones, great consoles, good equipment and well maintained) Do a propper job and invest in good stuff.
Wow, awesome thanks for all the input. I think most of your info is very high-end...and probably over the heads of most newcomers to broadcasting lol. I say the lightning arrester was cheap but it was not so much cheap as cheaper than a new transmitter. It did cost a bit but I felt like it was cheap compared to the damage. We at one stage had a quarter-wave antenna mounted on the top of a pole on a hill. The highest thing for miles around and it got hit constantly with zero damage. So the little arrester was pretty good. I am quite chuffed that someone of your broadcasting level is checking out my little channel lol. Glad you enjoyed it :) Glad to have you watching.
@@inspiresoundpro My main problem was a Mains problem. We were fed 440 volts three phase at 60 Hertx. Our power company would drop a phase without warning. The input transformer would fry in a minute I built a circuit with some relays that opened all three phases if one dropped. Keeping good broadcasting on air is a challenge. Anything thaat can help new folks is of value.
@@crankshaft3612 Oh yeah been there. Had the same thing happen to our studio. I found op-amp chips exploded in the mixer and processing gear smoked from the same three-phase issue. Ridiculous that they can do that. A challenge for sure. Keeping a 24-hour station going with small budgets and volunteers is a challenge for real. I feel your pain lol.
We want to buy fm transmitter..
I love it good 👍
Thank you :) I'm glad you enjoyed it. Cheers.
Wonderful
Thank you! Cheers!
When is the radio presenter training coming up as you've promised
Hi. Check out my channel page. You Will see the training videos I have been adding.
olá,qual distancia entre 2 ou mais antenas agrupadas para transmissão de fm na torre.
Hi. I have to answer in English. The spacing between the two antennas is a very complicated situation. The reason is that it can vary depending on how much down tilt you want. Also it can involve using a balun. The theory on antenna arrays is quite complicated but some say that having a half wave measurement between the two antennas should work but others say that 3/4 wavelength gives more gain. It is something you would have to experiment with to get the best results.
Also with an lightning arrester, equipment will be damaged. The lightning just doesn't enter the building with full power.
No with a lightning arrestor all the electrical discharge goes straight into the ground if it is installed correctly. If you are still getting damage to equipment after stalling a lightning arrestor then you should check if the installation has been done correctly.
@@inspiresoundpro Arrestors only work when the voltage becomes above a certain threshold level, so that normal (wanted) operational signals do not trigger the arrestor. Equipment will therefore face a higher voltage, although for a very short period. If an electrical discharge from i.e. the center conductor goes straight into the ground, something is wrong. The path to earth for a center conductor has to be triggered first.
Im using GP :)
By GP do you mean a ground plane antenna? If so what type 1/4 wave or 5/8 etc?
Send a link for the dominator
Hi. I have had a look for where they are available. I am waiting for a response from the suppliers. As soon as I have an answer I will let you know. Cheers
Help with the link to buy arester
I'm not sure what you mean. What do you mean by arester?
I realized that you meant lightning arrester. I found these ones on Ebay: www.ebay.com/itm/232628601562?hash=item3629bec2da:g:yXEAAOSw6ShZRVHu&amdata=enc%3AAQAIAAAA8Nq4dm3mCDQm5igj2XWuMWqJQrxgcC8u0FQTRIjANfrEI9a2aMB4MpGZdML18KNNVn91LsURxYdHLza8tq9hT31MKPtEML%2FEDXegisxB6NSxdwWGLxwbSC%2BDzyqwpvPvwYVxKFchQAVJxNkdp2yWt7T8om8lf6Fub8yF5V4cWplBc4%2BXRr0sxe%2BbHBPvbPYp%2BKgHNS2mX%2BiQLEuCI0prrplGmZisWRh9A6unZvkxGuzzRxeGuxdrzR8KyFquBsNNnjUC1vjCMLV9MzXQQgtNCO1b6nLxktaoDL%2FpYYIzy%2F%2FBWuJD3xJTWMMtbsjX%2Fytj5Q%3D%3D%7Ctkp%3ABFBMyuC65p1i
or
www.ebay.com/itm/122360780152?hash=item1c7d455578:g:RooAAOSwr~lYqF1J&amdata=enc%3AAQAIAAAA8Gox6%2BHeavCbckCXfEmFMrKLuevdOBgCOSwgoPa02TzlU%2FlrwHQgAsK%2F1VQFEk25TK2sLVyZf88sq4FlKkmY2%2FN159u0BQHLxi75fAXhyC36ledQ14ZTUnj3vFaV91PGsmxXg7GatqT%2FE%2BJvWyIht8XS1FOzXS%2BTJVvwRG00S5YXoGax0AR%2FvjsukWsBrCgT1MFcArg0EAEw4BceN8b1X9ndbMoJdwzNqCt1DI%2FWRqBD64zbtUl0W06mpleEsiUVQuUAxQYgRve%2B2%2FKs%2BUW91pRgvXlcWG1TAtiXrldbk96wT%2B%2BZg1XQ1jBSQR9SfVq0oA%3D%3D%7Ctkp%3ABFBMyuC65p1i
or
www.ebay.com/itm/150798872656?hash=item231c503050:g:A-sAAOxyqUpQ8qcG&amdata=enc%3AAQAIAAAA8La1Ewuave0CksTdv1zJGZMQRaOR0wgtiNq56VyGS0NUFNs%2BhkAgSCtrzyFjNYepwdyOpKWabOJBAV%2Fm6rCYRaf9uHO9xWhooO2%2F1axARWdshmjdwVR2%2B%2ByS%2B529bcNlIYMok0hi7VHAY2coCsx%2FFhmbF5xJ4CsoXjrldu%2FRBmRF3WYzJv3qPkNqJVzAptDd9QEO8%2B1nAxK%2BRP74ugD3aSeDomI2c5Fr6ht61rAmZG8fSbDzvlhTIkxE7O%2B%2B2TDAdqP6WBoo1NZ5BVpHHLMQh75fBe6lPMW%2BNM3Wp0Gww9gW93TqDufp1EftF4uJVBoHrQ%3D%3D%7Ctkp%3ABk9SR8rguuadYg
or
www.ebay.com/itm/313798592306?hash=item490fda8732:g:9S8AAOSwvrxhTkqN&amdata=enc%3AAQAIAAAA4DF2Bp7dO1kWFiwnqC%2FWHWRYFCeuSoJwlUToi%2F90ZRSSkjPGVt2KRWZvVBKHDmoN68lk0HvfcHzdRflWWsKwZ5oPajGMnTw8F8Yvf%2BLLRD6Ovcchfi2KCbC9u6dk%2B69jvP39G%2FdGZPvoP0s%2F5Hn7%2FfNEOWBrKyqgNRewnuxOODkeoTn485x2n%2FW6tHjSZ1JZxN3dXMKm2UPGEbsmxrBrLH6%2F%2BhT3ejsFw9hzct6US%2FyUd4hY8pPNvkQS7aR5fUVMuxmIlWEn31bJ9B67UoVaFVGQCLOqMGF7SyJhHpUL0ljz%7Ctkp%3ABk9SR87guuadYg
1 watt can reach 7 miles ??
Yes 1 watt can reach 7 miles quite easily depending on the antenna, the terrain and most importantly the height of the antenna. The receiver is also very important. If you use an old analog tuner then no you will probably just get a mile or two but a good quality digital tuner in a car can have you receiving the signal for many miles. I have run a 1 watt station that had listeners in their cars listening quite happily within a 7 mile radius.
@@inspiresoundpro i used to have 500watts in my orginal country Lebanon . Now I been in the US for 10 years and I really want to go back to radio scene but license is almost impossible. But i think I low power don’t require a license so probably couple of watts will do me good especially in Providence RI very small city and over populated.
In USA it is possible le to get low power licenses but it is apparently quite difficult to get one. Unfortunately as far as I know the FM signal not requiring a license is less than 100 mw and even worse the regulations limit the range so you have to use a transmitter with a small built in antenna. Not good enough for a radio station. You will only get about 100 yards or meters from it.
Greqt video - but - Lots of inaccurate information in this video. Circular polarization "penetrator" design antennas produce the best quality coverage with the least amount of multi-path. In fact most commercial radio stations use them. The tuning thing is not a thing at all. I have never had to retune a properly designed cp antenna. This guy suggests vertical antennas which produce the most multi-path. Its not all about gain - its also about quality of the coverage. This from a broadcaast engineer with over 35 years of experience in the field and Broadcast antenna design. I dont have time to go into the minute details of why CP is better. But 95% of commercial FM broadcasters in the US use some form of a CP antenna. Dont ya think there is a reason for that?
In the video I do explain that CP are excellent for penetration so I'm not sure what you so upset about. For very low power stations often signal range can be more important and smaller stations often don't have the luxury of large CP stacks.. I have also worked with low power radio stations using CP where their antennas got damaged and suffered sever multi path interference. You say lots of inaccurate information but don't offer anything except that you can't be bothered to add to that. Either be helpful and add to other people's learning here or go play somewhere else. If you are such a big shot engineer why do you bother with small CZcams channel videos where you contribute nothing. Suffer ego much?
Call dan. I said it was a great video. Maybe I should watch it again all I got out of the CP portion was if they go out of tune which I've never had that happen. And I must have completely missed the Superior penetration. But then again I'm coming off of about 30 hours with no sleep after finishing the 2023 LPFM filing window with over 100 appliance. LPFM is a portion of what we provide we also have a full power radio and television licensing. As far as multipack it's just not that much of an issue with a cp. Now you are correct in your assessment that a multi-bay CP is the better option as it focuses more energy towards the horizon and not losing so much towards the skyward and downward ways. But it has much less multi path if installed properly. While vertical antennas are plagued with multipath the especially in an area that has lots of electrical lines and telephone poles things to bounce off of. That can be a critical situation for a 100-watt radio station. I'm not against you I liked your video the graphics are great and great voice over. Perhaps when I Wake from my slumber I will watch the video again and see it differently.
OK no problem. I just don't like it when people use the comments to vent but don't contribute anything. There are other engineers who comment on the videos too. Some with more than 35 years of experience and some with less but they try to add to the conversation and if they disagree with anything they explain in a way that helps the viewers. The comments can be just as important and valuable as the video for people who are new to radio. I don't say that I am perfect and get everything right. If there is other information that can help the viewers great but don't just say "lots of inaccuracies but can't get into it". That helps nobody. I welcome other people's views even if they completely disagree with me as long as it is done respectfully and in a way that helps the viewers.
Can I put tbe dominator in an attic?
Hi. No the dominator is a big antenna. It would not fit. The best antenna for an attic is a quarter wave antenna. It's probably the only antenna that will fit.