DPD Productions Omni-X Antenna Performance Report-WOW!

[rbritton1201]

I erected the new DPD Productions Omni-X antenna in my attic, used the same cable I had connected to the Comet Discone antenna, RG8/U coax. I used a barrel connector to convert the N-style connector supplied with the antenna to a standard SO-239 connection, so I could simply connect the existing PL-259 on the end of the RG8/U coax to the antenna lead without having to change the connector provided with the antenna from N-style to a SO-239 connection. There are virtually no connection line losses. The N-style connector is preferable if erecting the antenna outside because they do seal better, etc...But, since the antenna is in my attic, I didn't see any reason to complicate things by changing out the N-Style connector to an SO-239. The connection is inside the attic, and doesn't need the weather resistance that an outside connection might need.

Previously, via the Comet Discone antenna, I was getting about one bar of signal, maximum, when receiving P25 simulcast signals off of the system located about 35 miles to the North from my QTH. Now, using the DPD Productions Omni-X antenna, IN MY ATTIC, it consistently yields the maximum signal indicator performance on the scanner's readout. There is a slight fluctuation of signal as the scanner scans over strategically located tower sites throughout that County to the North, some tower sites closer to me, and some further away. The furthest tower sites yield three or four bars of signal, and the closer tower sites yield a full five bars of signal reception on the readout. It doesn't really matter which towers the scanner receives, as they are Simulcast transmissions, so if you receive five bars of signal from even one of the towers, that's all you need with respect to excellent reception quality. The signals it receives on VHF/UHF are excellent as well. What I notice is that it's pulling in signals on VHF/UHF from further out than the Comet Discone Antenna from agencies I could not receive before.

Below is a photo of the Omni-X antenna in my attic. I mounted the antenna in a Christmas Tree Stand, and have the axis of the antenna's array oriented toward the North/South, where the County whose signals I'm trying to improve upon is located. I did test the directional characteristics of the antenna, orienting the array in various positions, and moving it around the attic in various locations. Some areas of the attic have more of what I suspected might interfere with reception, and those area were avoided, such as areas with electrical wiring, other antennas, etc...The axis of the antenna located toward the North was the most effective at improving the signal indicators on the scanner readout. With the axis of the antenna oriented to the East/West still yielded three to four bars of signal on the readout but North/South was the best performance.




Had the performance of the Omni-X not been as stellar as it is, I was considering moving the antenna outside onto a mast extension I have on my HF rotatable dipole. But now, getting five bars of signal strength, why expose the antenna to undue wear and tear from the weather? I see no reason whatsoever to move it.

 

[ems55]

I erected the new DPD Productions Omni-X antenna in my attic, used the same cable I had connected to the Comet Discone antenna, RG8U coax. I used a barrel connector to convert the N-style connector supplied with the antenna to a standard SO-239 connection, so I could simply connect the existing PL-259 on the end of the RG8/U coax to the antenna lead without having to change the connector provided with antenna from N-style to a SO-239 connection. There are virtually no connection line losses. The N-style connector is preferable if erecting the antenna outside because they do seal better, etc...But, since the antenna is in my attic, I didn't see any reason to complicate things by changing out the N-Style connector to an SO-239. The connection is inside the attic, and doesn't need the weather resistance that an outside connection might need.

Previously, via the Comet Discone antenna, I was getting about one bar of signal, maximum, when receiving P25 simulcast signals off of the system located about 35 miles to the North from my QTH. Now, using the DPD Productions Omni-X antenna, IN MY ATTIC, consistently yields the maximum signal indicator performance on the scanner's readout. There is a slight fluctuation of signal as the scanner scans over strategically located tower sites throughout that County to the North, some tower sites closer to me, and some further away. The furthest tower sites yield three or four bars of signal, and the closer tower sites yield a full five bars of signal reception on the readout. It doesn't really matter which towers the scanner receives, as they are Simulcast transmissions, so if you receive five bars of signal from even one of the towers, that's all you need with respect to perfection with respect to reception quality. The signals it receives on VHF/UHF are excellent as well. What I notice is that it's pulling in signals on VHF/UHF from further out than the Comet Discone Antenna from agencies I could not receive before.

Below is a photo of the Omni-X antenna in my attic. I mounted the antenna in a Christmas Tree Stand, and have the axis of the antenna's array oriented toward the North/South, where the County whose signals I'm trying to improve upon is located. I did test the directional characteristics of the antenna, orienting the array in various positions, and moving it around the attic in various locations. Some areas of the attic have more of what I suspected might interfere with reception, and those area were avoided, such as areas with electrical wiring, other antennas, etc...The axis of the antenna located toward the North was the most effective at improving the signal indicators on the scanner readout. With the axis of the antenna oriented to the East/West still yielded three to four bars of signal on the readout but North/South was the best performance.

View attachment 117022

Good report, thanks !!

 

[vagrant]

Your different results make sense for frequencies over 500 MHz where a discone is a poor performer for distant and or weak signal stations. Enjoy your new and improved antenna.

 

[Bmacs]

I have had the exact same experience - can't say enough about the Omni-X line!

What people don't realize about discones, is that the radiation ANGLE changes the higher you go in frequency. Low band signals (50 MHz or so) are received very well because the radiation angle is close to horizontal. The closer you get to 1 GHz, the LOWER the radiation angle. So, by 700-8oo MHz, the antenna is actually almost pointing down to the ground at a 30 degree angle.

Bmacs

 

[rbritton1201]

Thanks Vagrant...What impressed me as well was the ability of the Omni-X to pull in signals on VHF/UHF that were virtually not there before. So, it's working really great on all fronts.

Your different results make sense for frequencies over 500 MHz where a discone is a poor performer for distant and or weak signal stations. Enjoy your new and improved antenna.

 

[vagrant]

Interesting. Are you using an FM broadcast filter? How close are your nearby FM broadcast stations?

 

[rbritton1201]

I live in a rural area, I think the closest FM broadcast station might be 40 miles away. We have one AM broadcast station here, and it's probably about 5 or 6 miles away as the crow flies. I don't experience any interference from their transmissions, or any other commercial broadcast stations for that matter.

 

[Ubbe]

The closer you get to 1 GHz, the LOWER the radiation angle.

That's right. And at that low angle you usually have your house with all it electronics which it will pick up interferencies from. Then in the angle at the horizon there will be a 10dB loss, at frequenies above 500MHz, and then the radiation pattern gain comes back when pointing up in the sky. A standard size discone has a low SWR over its whole frequency range but are a real bad choice for signals above 500MHz.

A stubby antenna connected directly to the scanner might actually work better than a higher positioned discone in the 700-900MHz band.

The OmniX are a multi dipole antenna that hasn't got that problematic direction pattern and works much better at higher frequencies.

/Ubbe

 

[rbritton1201]

Yeah, it makes perfect sense why my Discone antenna only produced one bar of signal reception at 25' off the ground, in the attic. If the Discone was up around 40 feet would that make any difference? I assume not so much, since eventually the radiation angle would still be hitting the ground a little further out, but not far enough out to make any difference with respect to reception if the target agency you want to listen to is 30 miles away.

I have had the exact same experience - can't say enough about the Omni-X line!

What people don't realize about discones, is that the radiation ANGLE changes the higher you go in frequency. Low band signals (50 MHz or so) are received very well because the radiation angle is close to horizontal. The closer you get to 1 GHz, the LOWER the radiation angle. So, by 700-8oo MHz, the antenna is actually almost pointing down to the ground at a 30 degree angle.

Bmacs

 

[foster_006]

@rbritton1201 purchased an Omni X based on your very helpful review! I think you could be a spokesperson for their company.

It is apparently backordered so it'll be a bit before I can actually put hands on it. I live inside the city limits of Springfield... I'm looking to just increase signal strength on what I can already receive... I monitor several VHF digital frequencies that will break the squelch.. but not decode. How does it perform in UHF? That seems to be where I struggle the most. I'm also hoping to bring in a couple more MOSWIN sites. I do fine with 800. Currently have a tram discone with (50') LMR 400.

 

[rbritton1201]

I forecast that you'll see little difference between using the Omni-X verses the Discone if trying to improve digital VHF or UHF reception. The improvement that's most noticeable with respect to the Omni-X is in the 800 Mhz. range. That having been said, perhaps if you are able to experiment with aiming the Omni-X in the most efficient direction, you might be able to improve the digital UHF reception of those UHF digital stations that are in question, since the Omni-X has a directional wave pattern, versus the omnidirectional shape of the Discone's wave pattern. A dilemma may result from aiming the Omni-X wave pattern away from the other towers that your receiving well. You might be improving signal reception on the weak UHF digital signals at the cost of reducing the efficiency of reception you're currently getting off the towers you're receiving well with the Discone.

@rbritton1201 ...I monitor several VHF digital frequencies that will break the squelch.. but not decode. How does it perform in UHF? That seems to be where I struggle the most. I'm also hoping to bring in a couple more MOSWIN sites. I do fine with 800. Currently have a tram discone with (50') LMR 400.