DPD Productions ADS-B Vertical Outdoor Model Antenna

[nzradar]

Ordering and Delivery

My original installation included a locally (New Zealand) made variant of a 800-900 MHz colinear.  This, together with an SBS-1er provided me a maximum consistent range of around 160nm with very occasional hits out to 180nm.  Thinking that this could be improved upon by using an antenna actually designed and manufactured for the ADS-B consumer I decided to buy the one on offer from DPD Productions because of the good reviews I found on various forums and on the internet.  With no one else to blame on my lack of financial guidance I ordered one in early Feb from Dave in Los Angeles and was duly dispatched on the 15th.

I had read and was advised that some additional charges might be incurred by the recipient mainly based on the arrival country's postal service.  I love living in New Zealand!  There were no delays and no charges and the antenna arrived on my doorstep on the 27th Feb.  Less than two weeks, I'm pretty happy with that!

Anyway, the package arrived wrapped in two joined together triangular cartons and with good quality bubble wrap encasing the antenna.  It appeared to have been handled well on it's journey across the Pacific with no dings, dents, or breakages.

I have posted some photo's I took while unwrapping it and they are available on my website here http://nzradar.com/gallery/default.aspx?aid=3

Installation

I did advise Dave that my mast was only 25cm in diameter where the recommendation is 1.5 inches so before the antenna arrived I cut 7 inches of 25cm aluminium tube and bashed it flat and then curved it around the mast in preparation to provide some additional width for the jubilee clips.

As I was attaching the antenna to the mast I was a bit concerned that the plastic radome material might crack as I tightened up the clips so was not too forceful.  With high winds due this weekend I'll see if I was forceful enough!

As my original antenna also had a short tail terminated with an N-Type female connector it was an easy job to reconnect my main LMR-400 cable to the tail, waterproof it with amalgamating tape and re-erect the mast.

Findings

Back in the 'Radar Room' I rubbed my hands in glee as I cranked up Basestation.  With not a lot of traffic in New Zealand anyway I also opened up Flight Radar 24 to see where my first aircraft was going to appear from.  I had also loaded the latest plot outline from SBS Plotter so I could gauge any range improvement.

The first ADS-B aircraft appeared on the Christchurch-Auckland track and showed up a good 15-20nm before the plot outline, encouraging!  This was the theme for most of the aircraft that evening, all showing a good increase in range over my original antenna, but my main interest was the trans-Tasman flights which would arrive in Wellington late that night, but like most mortals I also have to sleep. 

Up first thing and checked SBS Plotter for max range overnight - 207nm WOW, never got that far before.

Since then, and it's only been a couple of days I am consistently getting 180/190nm where as before it was consistently 140/160nm.

Conclusion

I have to reiterate that I am surrounded by trees to the south, mountains to the east and my outlook west to where most aircraft track is impinged slightly by some higher ground so I think I'm doing well. 

It was interesting to use PlanePlotter and MySky for a while earlier this year to see where the aircraft appear in relation to the horizon, I was amazed to find that all my aircraft tracks are below 7 degrees above the horizon!  This was one reason why I decided on a high gain antenna.

I know that if I were to move to the other side of town away from the trees and over that hill.............!  Happy Days!

One thing is for sure now though, I have the best set up possible for my hobby and things can't be any better.

[BigRed]

Hi Mike,

Great review!!!

I recently upgraded too to the Moonraker..... curious if the DP suffers any 'donut' effect? I hear allot of good things about your antenna.

This weekend and like you I suffer greatly from mountain and forrest so Im going to improve upon my current pole setup by gaining I hope an additional ten plus feet by placing everything up on the roof rather then currently having everything attached to the side.

Its a great hobby this but my gosh once you get the improvement bug it doesnt stop!!! 

Take care

CAM
TVL1 (MMS2)
v5 (PP)

[Anmer]

Thanks for the Review MIke.

Was your previous antenna in the exact same location?  I appears to have been.

[nzradar]

..... curious if the DP suffers any 'donut' effect? I hear allot of good things about your antenna.

Hi Cam,

Cheers mate, yes it does, but do'nut care!! 

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[nzradar]

Thanks for the Review MIke.

Was your previous antenna in the exact same location?  I appears to have been.

Yes Mike, on top of the same mast attached to the same chimney.

[Truetrack]

Hi Mike (nz)

thank you for posting this interesting review of your setup

May I comment on the mast diameter
mast length vs. OD of only 25mm seems very slim to me
and your area is surely not deadcalm no matter how secluded your location is.
The DPD and the downleading coax bring some greater windload than just a small magmounted.
I would not hesitate to exchange the mast for some larger dia, say 46-52mm (1 3/4 , 2 inch)
especially when you consider to attach sidearms for other antenna to it.

Tolerate/accept dough-nut effect or not ?
Sure enough it depends on ones individual situation.
For those looking for range there is something positive in it.
There is some 200 NM to reach out horizontally but about only 7-8 NM vertically to receive !
It may even be of advantage if a high closeby strong signal is somewhat subdued.
Well for those interested more into close quarters but then down to Ground would choose
some other type of antenna anyway.


tks too for pointing to your photo gallery.

regards
Klaus

[nzradar]

Thanks Klaus, yes I am a bit concerned but I have had two antennas on this mast for a while now and have replaced both with just the DPD, so I've saved at least a 5m of cable weight but probably not a lot else as both the old antennas weigh about as much as the DPD or maybe a little less.

We have a weather warning for tomorrow so I will shimmy up the chimney tonight and make sure the bolts are secure and keep an eye on it tomorrow, I don't want to break the antenna! 

I have no great concerns about the loss of signal within short range so the donut effect is a non-issue for me.

[nzradar]

Just a quick graphical comparison between the new and the old. 

Two pictures below:

Before.jpg is a nine day snapshot of ADS-B tracks using my Hi-Tech CX800 and SBS-1er.

After.jpg is a three day snapshot using the DPD and SBS-1er.

The significant points for me are the increase in hits out to the west of the top of the South Island and the increase in range north and south.

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[BigRed]

OK... I see what you mean Mike.

Im going to elevate mine by ten feet this sunday as my aim is to improve my north (so I can see Cairns) and my East to get more of the Trans-tasman routes which Im just getting the tail end of at 200NM with the Moonraker. My south is doom because of the mountain range and west the only traffic is the mines.

I love the comment about the Don-nut effect!!!  Im similar Im wanting range. My 1105 with PP will be used for more local stuff. If I could just get one or two more gound stations for Mlat then we could have some fun up here!!! 

I will have some new pics Monday of the improved setup (third for the four weeks).

CAM
Townsville

[nzradar]

I thought I'd provide an update on the DPD antenna.  The attached graphic shows the old coaxial 1/2 wave 8dbi antenna profile in yellow and the blue the 9dbi DPD Productions antenna.  I'm very happy with it so far although I still lie awake at night when the winds blowing and hope the jubilee clips and mast keep it up until daybreak!  The range rings are 50nm apart.

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[BigRed]

They sound like a great antenna Mike, I went and sourced one from the Company but the import duty and other taxes made it cost prohibitive!!! Your one lucky man!! 

CAM

[birdie]

Thanks for the Review MIke.

Was your previous antenna in the exact same location?  I appears to have been.

Yes Mike, on top of the same mast attached to the same chimney.

Use the 1.5 m long co-linear from Andy. The Best antenna I ever use. See the range i am having from WSSS - > 300 nM.

It is on a temporary location - mounted on the side of my window - I cant imagine how much improvements in range when i finally mount it on the roof top.



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[gcopter1]

Got mine 2 days ago but wasn't able to put up until yesterday. Previously, I had a home brewed antenna about 30 feet off the ground. I was getting at most 78 nm. Now, so far, over 210 nm, without pre amping. Definitely, a great antenna and recommend it without reservation.

[Radio2.0]

My Antenne worked great BUT find some other sharer "in your area" bring more efford. Maybe put some money together for an antenna on an mountain or an parking lot next to an airport helps more.