Dual band yagi?

[ih784]

Good evening everybody,

I’m looking for an antenna. Ideally one for marine frequencies 156-174 centered around 165 would be perfect for marine and the majority of DMR in my area. I’d also like a 450-470 that would help with some NXDN local to me as well. Is there a dual band yagi that would cover these two bands? Should I try and make one? eBay? I’ve got an Omni-X and a Laird for 800mhz. Really think I need something specifically for these two bands.

 

[Ubbe]

One TV band are 175-250MHz and another 470-700MHz and there are dualband TV antennas that might work. They are cheap enough anyhow to try and see what kind of reception you get. There are both yagi's and logperiodic type of TV antennas. At my local sat dish dealer the logperiodic types are $20 and I used a single band UHF type for several years and worked really well, at least many times better than a dipole.

When dealing with antennas that are used outside of their designed frequency band there are great benefits using an antenna amplifier that isolates the antennas bad SWR from the coax and gives a good constant load to the coax and the antenna that keeps its direction pattern more under control. An amplifier are not just for overcoming coax loss and the bad noise figure in scanners, it also makes the antenn perform better for scanner use.

/Ubbe

 

[ih784]

Awesome idea. I’ve got a band gilts for the 156-174. I’ll definitely check out the tv antennas. Amazon has been so slow, I’ll return the favor and give them some returns for my trouble. I’ll see about an amplifier as well.

 

[K4EET]

Hi @ih784,

Are you connecting the Omni-X, 800 MHz Laird, and this new VHF/UHF Yagi antenna to the same scanner? If so, what device(s) are you using to combine them? Or will the antennas be connected to different scanners?

Dave

 

[ih784]

I’m running the laird to two sdr(s) and the Omni-X to an Airspy SDR and BCT125AT. I’ve got an sds100 and bcd436hp I can run as well. Both with dmr/nxdn.

 

[K4EET]

I’m running the laird to two sdr(s) and the Omni-X to an Airspy SDR and BCT125AT. I’ve got an sds100 and bcd436hp I can run as well. Both with dmr/nxdn.

Sounds like a nice listening station. Hope you get a dual band Yagi antenna for the mix like you want.

 

[dave3825]

Ideally one for marine frequencies 156-174 centered around 165 would be perfect for marine and the majority of DMR in my area. I’d also like a 450-470 that would help with some NXDN local to me as well. Is there a dual band yagi that would cover these two bands?

There are dual band Yagi out there but Yagi are directional so one could work if all your looking to receive is coming from the same direction. It is not an omni directional like the Omni X, which is essentially a tri-bad omni directional antenna.

 

[mmckenna]

Is there a dual band yagi that would cover these two bands?

As mentioned above, there are dual band amateur radio band Yagi's. I've never seen one that would cover the commercial LMR bands. There's really not a market for such a thing in the commercial/public safety market.

Usually when someone needs a directional antenna that covers that much spectrum, they use a Log Periodic antenna. It sort of looks like a Yagi, but can cover large swaths of spectrum. They are not cheap.

CREATE CLP-5130-2N

105 - 1300 MHz 20 Element Log Periodic Antenna 10 - 12 dBi 54 Inches Long n Connector

www.hamradio.com

Should I try and make one?

Yagi's are not hard to make. There are a lot of good online tools that will give you the measurements. Where they will likely come up short is the 'dual band' part. Just combining two Yagi's probably comes with some challenges with interaction between the elements, and would take some maths to figure out.
Log Periodics are not super difficult to make, either. That's probably the path I'd take.

eBay? I’ve got an Omni-X and a Laird for 800mhz. Really think I need something specifically for these two bands.

The TV antenna solution might be a good approach, although the US market ones might be tuned far enough outside the bands you want to really be effective.
Two separate antennas, one for each band, might be a better solution if you want to purchase something. That way you can get one tuned in the center of the band and then use a diplexer to combine them into one feed. You can also point them separately to benefit your reception.

 

[prcguy]

I don't think anyone makes a dual band Yagi outside of the amateur bands and a Log Periodic will have moderate gain at best. I would look for separate Yagis for each band and you can combine them onto one coax with a diplexer. I have a Sirio VHF Yagi like this one but slightly lower frequency. Its really great quality and broad band.

Sirio WY155-6N 155-175 MHz 6 Elements Yagi Antenna | eBay

Frequency: 155-175 MHz @ SWR ≤1.5 No tuning required. Base station antenna, Directional. Stacked and bayed array for more gain. Wind load / resistance: 184 N @ 150 Km/h / 120 Km/h. Wind surface: 0.15 m².

www.ebay.com

A 450-470MHz Yagi is really common and you can sometimes get good used ones off ebay from major commercial mfrs in the $30-$40 range. Look for something with at least 7 elements for 10dBd gain.

 

[ih784]

I don't think anyone makes a dual band Yagi outside of the amateur bands and a Log Periodic will have moderate gain at best. I would look for separate Yagis for each band and you can combine them onto one coax with a diplexer. I have a Sirio VHF Yagi like this one but slightly lower frequency. Its really great quality and broad band.

Sirio WY155-6N 155-175 MHz 6 Elements Yagi Antenna | eBay

Frequency: 155-175 MHz @ SWR ≤1.5 No tuning required. Base station antenna, Directional. Stacked and bayed array for more gain. Wind load / resistance: 184 N @ 150 Km/h / 120 Km/h. Wind surface: 0.15 m².

www.ebay.com

A 450-470MHz Yagi is really common and you can sometimes get good used ones off ebay from major commercial mfrs in the $30-$40 range. Look for something with at least 7 elements for 10dBd gain.

I think this may be my best bet. The 450 NXDN is for a prison that I can pick up with my mobile antenna about 300 yards from the house but nothing on my Omni 24’ high. Off to fleBay I go.