Yagi or J pole?

[AngWay]

So i am new to this and completely in the dark somewhat, i am looking at antennas and i need one to pick up a specific band as good as i can, right now i'm using a discone on my roof and i have a freqs on 453.6625 that i can pull in well enough for dsdplus fastlane to tell me what it is and the nac and i can hear a voice every now and then the signal is just to low.

Now would a yagi be better for me to receive that signal and if so would i be ok getting This 2 meter/70cm yagi antenna or would i be better off getting This which is only 70cm?

I have alot of stuff i listen to in the 150mhz range but if i go for the first yagi i might be shooting myself in the foot because i'm wanting to hear that specific freqs but if the first antenna would pick up 150 and 450mhz better than the tram discone i have then i could just get that and get the best of both worlds so what do you think?

Would a yagi pick up a freqs in the 450s better than a J pole Because i already have a J pole mounted on my roof and to be honest the discone picks up better than the J pole, crazy i know why is this?

I read to that a 2meter/70cm yagi is just two yagi's put together, if that is true then the first link i attached would work on 450mhz just as good as the second link right? or am i wrong on that?


Thanks for any reply's oh and please keep your answers simple really i'm new to the antenna lingo and everything.

 

[dave3825]

Discone is omni directional. It will pick up from all directions.

Yagi, directional. Has to point towards what your looking to receive. If its facing East, you will not get much from North, South or West. You have to aim it. So unless you have an antenna rotor on your roof, you would have to climb up every time you want to change direction.

 

[prcguy]

An amateur band antenna like your first example is not the thing to use on a commercial UHF frequency. The second antenna will work but will limit you to UHF only. How high is your Discone? Height is a big deal and raising the antenna can sometimes improve things without buying a new antenna. Otherwise I would look into a dual band antenna with some gain that covers commercial/public service frequencies.

 

[AngWay]

An amateur band antenna like your first example is not the thing to use on a commercial UHF frequency. The second antenna will work but will limit you to UHF only. How high is your Discone? Height is a big deal and raising the antenna can sometimes improve things without buying a new antenna. Otherwise I would look into a dual band antenna with some gain that covers commercial/public service frequencies.

My discone is on the roof of my house attached to a 10 foot pole so i would say 40 feet maybe. what dual band antenna are u talking about, do you have a link?

 

[R0am3r]

@AngWay - As an alternative to swapping your discone, have you considered replacing your splitter with a multicoupler? You will have a better signal from your discone antenna if you stop using a splitter. Check out an Electroline multicoupler as a good option. You can find the Electroline EDA2800 on ebay, but make sure you get one with the power supply.

 

[AngWay]

@AngWay - As an alternative to swapping your discone, have you considered replacing your splitter with a multicoupler? You will have a better signal from your discone antenna if you stop using a splitter. Check out an Electroline multicoupler as a good option. You can find the Electroline EDA2800 on ebay, but make sure you get one with the power supply.

I'm already using a LNA isn't that enough?

 

[R0am3r]

I spotted your setup in another thread, but didn't realize you had an LNA in-line. Good luck with that.

 

[prcguy]

I'm already using a LNA isn't that enough?

An LNA is not a replacement for a good antenna. If your feeding a splitter to multiple receivers ok, or if the LNA is at the antenna and a high level unit to resist overload and IMD then ok. Otherwise they can raise your noise floor, create ghost signals (IMD) and make reception worse.

 

[AngWay]

An LNA is not a replacement for a good antenna. If your feeding a splitter to multiple receivers ok, or if the LNA is at the antenna and a high level unit to resist overload and IMD then ok. Otherwise they can raise your noise floor, create ghost signals (IMD) and make reception worse.

Well i am hearing music behind the police and ems traffic. it's really weird but it happens on every freqs that pops up and this is all in the 150mhz range i don't understand how i'm hearing what sounds like country music in the background. could my local radio station which is country music be that strong? if so then dang!

Video

 

[prcguy]

Well i am hearing music behind the police and ems traffic. it's really weird but it happens on every freqs that pops up and this is all in the 150mhz range i don't understand how i'm hearing what sounds like country music in the background. could my local radio station which is country music be that strong? if so then dang!

Video

LNA getting overloaded causing strong FM stations to mix with other signals and that's what you get. Try bypassing the LNA when you hear music where it doesn't belong, see if that clears up reception.

 

[AngWay]

LNA getting overloaded causing strong FM stations to mix with other signals and that's what you get. Try bypassing the LNA when you hear music where it doesn't belong, see if that clears up reception.

I'm not using a LNA in that video at all. and it's the antenna hooked straight to the radio

 

[spongella]

Depends on the signal strength of that station. A J-pole's a lot less work to erect but hasn't the gain of a Yagi, generally.

 

[bearcatrp]

If you’re hearing music in the background, you need a FM trap filter. I bought a mini circuit version. Works very well.

Connectorized Band Stop Filter, 88-105 MHz | ZBSF-95-N+ | Mini-Circuits

Mini-Circuits is a global leader in the design and manufacturing of RF, IF, and microwave components from DC to 86GHz.

www.minicircuits.com

 

[dave3825]

As an alternative to swapping your discone, have you considered replacing your splitter with a multicoupler? You will have a better signal from your discone antenna if you stop using a splitter.

Check out an Electroline multicoupler as a good option.

I'm already using a LNA isn't that enough?

I told you a while ago when you asked, that for near by strong signals, a tv splitter would be fine to split between sdr and scanner.

Also told you that for far/weak/distant signals, a tv splitter is not good. If your trying to receive a weak signal, a splitter is splitting the signal which sends even less signal to your sdr and scanner. That results in more decoding errors.

Many of your pics and videos show that your noise floor is pretty high and still reflect weak signals.






I use the poor-mans multicoupler and for my needs it works fine with my discone. I also use attenuators on select ports if needed when I have my LNA hooked up at the antenna.

 

[AngWay]

An amateur band antenna like your first example is not the thing to use on a commercial UHF frequency. The second antenna will work but will limit you to UHF only. How high is your Discone? Height is a big deal and raising the antenna can sometimes improve things without buying a new antenna. Otherwise I would look into a dual band antenna with some gain that covers commercial/public service frequencies.

I have a discone and a j pole doesn't that have enough gain? what other type of antenna would there be besides a yagi?

 

[mmckenna]

I have a discone and a j pole doesn't that have enough gain? what other type of antenna would there be besides a yagi?

A discone antenna has zero gain. It also has radiation patterns that are less than ideal when used on higher frequencies.
A J-Pole is a type of half wave antenna. Without a ground plane under it, the J pole has zero gain. Adding a ground plane gives it about 2.1dB of gain (not a lot).

So, two low performing antennas, and not surprising you are seeing poor performance.

To get more performance out of your antenna system, you only have a few options:

Band specific antennas with gain. Omni directional (works the same in all directions).

Yagi antenna. Usually single band, but there are some amateur radio versions that will cover multiple amateur radio bands. Since you are listening to Land Mobile Radio frequencies, the ham antennas are not a good choice. Other drawback/benefit of the Yagi, depending on how you look at it is that it's directional, and only receives well in one direction. This can be a benefit or a hindrance.

Log Periodic Antenna. Wider bandwidth, can be multiple bands. Directional, so works well in one direction. Expensive and large, will require proper support structure.

Multiband omni directional antenna with gain. Finding a good one that covers the LMR bands will be expensive if you want good performance.


There is no one antenna that does everything well. You need to decide what attributes fill your specific needs. You may need multiple antennas to get what you want. It won't be cheap.

You also need to look at the -entire- antenna system, that includes your coaxial cable. High gain antennas can suffer from performance issues if you are using the incorrect coaxial cable for the job. There is no one coax cable that is correct for every installation. Good coaxial cable is not cheap.

We've had other posters with similar situations and they'll try desperately to do everything with one single antenna, and then get frustrated when it does not work. You may need multiple antennas, multiple coaxial runs and an antenna switch to make this work well.

 

[AngWay]

I told you a while ago when you asked, that for near by strong signals, a tv splitter would be fine to split between sdr and scanner.

Also told you that for far/weak/distant signals, a tv splitter is not good. If your trying to receive a weak signal, a splitter is splitting the signal which sends even less signal to your sdr and scanner. That results in more decoding errors.

Many of your pics and videos show that your noise floor is pretty high and still reflect weak signals.

View attachment 173287

View attachment 173288


I use the poor-mans multicoupler and for my needs it works fine with my discone. I also use attenuators on select ports if needed when I have my LNA hooked up at the antenna.

I tried removing everything and connecting the antenna straight to the sdr and it didn't help the mountain view signal at all.

 

[dave3825]

Your in the middle of, basically nowhere, right? You in a valley or surrounded by mountains?

 

[AngWay]

Your in the middle of, basically nowhere, right? You in a valley or surrounded by mountains?

surrounded by mountains.

 

[dave3825]

You most likely going to have issues pulling in signals from the other sides of the mountains. Anything transmitting from on top of the mountains (the two you are in between) should come in good.