Airband Higher Gain Omni Recommendation?

MDScanFan

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I am looking for a vhf airband omni antenna to pair with my 780XLT for a dedicated setup. I am currently using a discone but would like to try something narrow band and with a bit more gain. I recently tried my hand at building a four element coaxial collinear but was not convinced it was working properly.

My ideal antenna would be a reasonably priced collinear with ~4-5 dBi of gain. A simple pole style antenna is a big plus as well for my installation, as opposed to say a multi-bay dipole array. Primary frequencies of interest are in the 118-125 range. Price range is under $200. Max height is around 10’.

I found the following for antennas that are in the general ballpark:
  • DPD airband antenna. 70”; 2.6 dBi claimed; $140. 1/2 wave dipole.
  • DPD OmniX. 44”; 3dBi claimed; $160. Dipole style at vhf air.
  • Antenna Products DPV 40. 120” - too tall for my attic; 4 dBi claimed; “call for price” means more than I want to spend. Collinear antenna.
  • BRC HP-50A. 65”; 4 dB claimed (no reference to units :)); $100. 1/2 wave.
  • And a couple different jpole options
Are there any other dedicated airband antennas I should consider? Aside from the dpv40 and some expensive options I could not find any collinears for airband. Thank you.
 

MDScanFan

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I have been eyeing that one as well. The price is right. I mistyped the type of antenna it is on my list above. They specify it as a “3/4 wave C loaded” antenna. A true 3/4 wave would be a strange choice for a typical base antenna since its peak gain is above the horizon around 45 deg. I am guessing it is physically a 5/8 antenna with a loading coil. From an impedance standpoint that would make it similar to a 3/4 wave antenna and from a radiation standpoint it would be more like a 5/8 with good horizon gain.

I am surprised by the impedance bandwidth they show in their measured plots. I would expect it to have narrow a relatively narrow bandwidth. I wonder how well the pattern holds up.

I've been curious about these but don't need one bad enough to try out. I think it should work better than a Discone and it seems to be fairly wide band looking at the charts. BRC HP-50-A 118-137Mhz Airband Band Base Antenna 4.2 dB , 200 Watts | eBay
 

Ubbe

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BRC have stopped producing that antenna so it's probably just a few to be had from Ebay until they are finally gone forever.

/Ubbe
 

MDScanFan

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It is still listed on the BRC website. How do you know it is discontinued?

BRC have stopped producing that antenna so it's probably just a few to be had from Ebay until they are finally gone forever.

/Ubbe
 

prcguy

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I have a BRC HP-500 2m/70cm antenna and its of good quality, not much different than a Comet or Diamond from what I can see. I was talking with Frank at eagle_antenna on Ebay and he mentioned BRC was a small Taiwanese company run by a couple of brothers who's father owned one of the larger well known antenna companies.

If someone (MDScannerFan?) were to get one and it gets a favorable review, I suspect they would sell out quickly.
 

iMONITOR

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Sirio Gp 108-136 LB/N. this antenna is not a collinear, has anyone tried one of these?
Yes I had one a couple years ago. Due to health reasons I never got it outside. While I had it I sat it on my home office floor and even at that I felt it performed well. It's built really nice, great fit and finish, very sturdy would probably withstand any storm your house would survive! The larger element has two screws in the top cap, then the tube slides off and there is a interesting and unusual brass element inside, possibly used for final tuning. I sold it to pcrguy, maybe he can add something. Sirio is a good company.


1599274975546.png

  • Type: 1/4λ ground plane large band Frequency range: VHF AIR. band: Rx 108-136 MHz; Tx 118-136 at V.S.W.R. ≤ 2:1 Impedance: 50Ω
  • Radiation (H-plane): 360° omnidirectional Radiation (E-plane): beamwidth @ -3 dB = 78° Radiation angle: 0° Polarization: linear vertical
  • Gain: 0 dBd - 2.15 dBi Max. Power (CW) @ 30°C: 1000 Watts
  • Grounding protection: All metal parts are DC-grounded, the inner conductor shows a DC short Connector: GP 160 LB-N: GP 160 LB-N: N-female
  • Materials: Anodized Aluminum, Stainless Steel, Nylon Wind load / resistance: GP 160 LB: 43 N @ 150 Km/h / 160 Km/h Wind surface: 0.06 m²
 

prcguy

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The Sirio is a very broad band 1/4 wave ground plane. No more gain than any other 1/4 wave but the fat element gives it a good match and consistent performance across the entire VHF air band. Thanks again iMONITOR!

I have collected several other Sirio antennas like the 380-470MHz ground plane and a couple of 6 element VHF Yagis and they are all of excellent quality and design.



Yes I had one a couple years ago. Due to health reasons I never got it outside. While I had it I sat it on my home office floor and even at that I felt it performed well. It's built really nice, great fit and finish, very sturdy would probably withstand any storm your house would survive! The larger element has two screws in the top cap, then the tube slides off and there is a interesting and unusual brass element inside, possibly used for final tuning. I sold it to pcrguy, maybe he can add something. Sirio is a good company.


View attachment 90894

  • Type: 1/4λ ground plane large band Frequency range: VHF AIR. band: Rx 108-136 MHz; Tx 118-136 at V.S.W.R. ≤ 2:1 Impedance: 50Ω
  • Radiation (H-plane): 360° omnidirectional Radiation (E-plane): beamwidth @ -3 dB = 78° Radiation angle: 0° Polarization: linear vertical
  • Gain: 0 dBd - 2.15 dBi Max. Power (CW) @ 30°C: 1000 Watts
  • Grounding protection: All metal parts are DC-grounded, the inner conductor shows a DC short Connector: GP 160 LB-N: GP 160 LB-N: N-female
  • Materials: Anodized Aluminum, Stainless Steel, Nylon Wind load / resistance: GP 160 LB: 43 N @ 150 Km/h / 160 Km/h Wind surface: 0.06 m²
 

dlwtrunked

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Sirio Gp 108-136 LB/N. this antenna is not a collinear, has anyone tried one of these?
I used one of these with an ICOM A5 radio instead of the whip, to do ground-to-air for work once as I had bought one earlier for personal use but never tried it. When the pilots first heard it, having expecting a much poorer signal, they were surprised and wanted to know what I had done. I donated it for all future work. The thick vertical gives it coverage over the entire VHF air band (a narrow vertical piece will not).
 

spanky15805

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MDscanFan, DPV-40 would be the "gold standard" of this group. Really is an awesome antenna if; someone else is buying; someone else is mounting; if someone else is transporting. It's an 11 foot pole, it does not flex. Even the one I found in the ground, only had scuffed paint. The mounting assembly didn't fare as well, bad welds. If you are close to a DoD installation, check DRMO for what they have lying around.
 

daddyjohn

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And it's Dual-Band!
I also have used the OMNI-X for the last year or so and I love it. It does well on all bands for me. The Website actually says it is tuned for 118-137, 148-175, and 225-900 MHz. Wouldn't this be tri-band?
 

iMONITOR

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I also have used the OMNI-X for the last year or so and I love it. It does well on all bands for me. The Website actually says it is tuned for 118-137, 148-175, and 225-900 MHz. Wouldn't this be tri-band?
I refer it to being a dual band for monitoring aircraft. VHF Commercial & UHF Military. Actually 225-900 MHz is much wider than what would be considered one band. So I guess the antenna is actually a wide-band with tuned segments targeted at where most scanning is done.
 

MDScanFan

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I like that quote about the DP-40 “ is an awesome antenna if; someone else is buying; someone else is mounting; if someone else is transporting” :)

MDscanFan, DPV-40 would be the "gold standard" of this group. Really is an awesome antenna if; someone else is buying; someone else is mounting; if someone else is transporting. It's an 11 foot pole, it does not flex. Even the one I found in the ground, only had scuffed paint. The mounting assembly didn't fare as well, bad welds. If you are close to a DoD installation, check DRMO for what they have lying around.
 

MDScanFan

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I appreciate all of the replies. I recently made the switch from a discone to a 5 dBi collinear for railband reception and noticed a significant improvement. That is the motivation for my airband setup. I plan to mimic that the installation and would like to shoot for the highest possible (within my constraints) omni gain to start.

A ground plane antenna, like the Sirio mentioned earlier, would be a step up from a discone.

I have heard good things about the OmniX but I would not take advantage of its bandwidth, only its vhf flared dipole element.

If the BRC is truly a 5/8 antenna then its horizon gain should be around 1-1.5 dB better than a dipole. Its height is manageable at 5.5’. Right now I am leaning towards trying that one.
 

Ubbe

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If the BRC is truly a 5/8 antenna then its horizon gain should be around 1-1.5 dB better than a dipole.
The hight of the antenna suggests two 5/8 stacked on top of each other and probably one tuned to 120Mhz and the other to 130MHz to make it wide banded and that might also explain the moderate gain that are claimed to be 4dBi.

/Ubbe
 

MDScanFan

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The height of it translates to only a single antenna. A 5/8 antenna designed for 120 MHz is around 55” long. Add some metal at the bottom for mounting it. They list a length of 65”, which seems about right.

Don’t quote me on this but I seem to recall seeing a spec for then BRC antenna that states full band coverage but optimized for something like 118-125.

The hight of the antenna suggests two 5/8 stacked on top of each other and probably one tuned to 120Mhz and the other to 130MHz to make it wide banded and that might also explain the moderate gain that are claimed to be 4dBi.

/Ubbe
 
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