P3i Antenna performance

[Ian Melville]

I have had Enstone running for a  week now, and am very disapointed in the coverage given by the P3i antenna.

It's difficult to judge with low PAW traffic over the last week, but it seems that PWWilmcot has better coverage of Enstone area Traffic overflying Enstone is seen by this station but not PWEnstone.

Extension lead is 10m of RG8X and using the standared 869.5Mhz End fed dipole supplied with PAW Kit. I have tried two antenna, and even made up a second extension with exactly the same results. Cables check out for shorts and poor connections etc. Range seems to be no more than a few KM.

Swapped the end fed dipole for the 'Tuned Low Profile Antenna' and performance is slightly better, but still not good enough.(still on it now)

Am I doing something wrong? I could shorten the extension by a few meters, but this feels to be so far out of what was expected. What does PWWilmcot have that I don't 

Range for the FLARM is good, in fact very good to the South and South West. Both antenna seem to show a bias in this direction, which was a supprise to me.

[Keithvinning]

Hi Ian

All sites have a bias in one direction due to local terrain etc.
PW wilmcote is much better looking South. I use a 5dB co-linear antenna and RG8x
Give me a call or PM I will help out with better Coax etc and get it working

Keith

[Ian Melville]

Enstone now has a 5Bd Co-Linear and a short length of LM400 coax cable. Only been operating a few hous now, but already show a marked imporvement.

Cheers Keith

[Keithvinning]

Ian

Thanks for this. Yes I do believe that the 5dB antennas are very good when coupled with the higher grade C0-Ax and easier to make off the Type connectors. I have ordered another 10 of these 5dB antennas for some stuff we are doing. I had 10 metres of RG8x at PWWilmcote and have reduced this to 3 metres to get closer to 3dB at the stick which is the important bit.

For info for the techies the new station that Grant Shapps put up at PWBpark is giving great N/S/W coverage using this antenna and LM400 cable even using 10 metres and only about 4metres off the ground. Must cut down the Co-Ax.

Paul Ruskin gets enviable results from his installations so I will be using these from now on. Both PWWilmcote and PWEnstone are now concurrent with Turweston and PWUKEDG in the middle.

We are getting some good redundancy now.

Someone on the Flyer forum said that he had noticed that there were lots of OGN-R units down. Don't know who it is because they don't use their real names. However obviously reading the data wrong. Ho hum.

Edit Ian just had a look at PWEnstone WOW!!!!! Turbocharged compared with last week. Thame next!!!!



Keith

[Ian Melville]

Yup, Thame next. Now Enstone is up and running I can return the borrowed antenna and restart the station. Next job will be to make the installation a permanent  fix with roof mast and high grade antenna.

[Moffrestorer]

Hi Keith,

I wondered about a better P3i antenna as well, especially as my station is situated in a bit of a dip in the terrain. However will it be a pointless exercise considering Lee’s discussion in the thread “Station Transmission Constraints on Re-Broadcast”?

Regards,

Chris

[Admin]

Hi Keith,

I wondered about a better P3i antenna as well, especially as my station is situated in a bit of a dip in the terrain. However will it be a pointless exercise considering Lee’s discussion in the thread “Station Transmission Constraints on Re-Broadcast”?

Regards,

Chris

Hi Chris
I think that this is probably not an issue, as far as the overall link budget is concerned, there is going to be loss in the cable leading to the antenna, hence not a gross miscalculation
I was more concerned with using the 12db antenna that the OGN/FLARM connection uses.

Thx
Lee

[Moffrestorer]

Thanks for that Lee.

Also, comparing station coverage in my neck of the woods, I have thought for sometime that the P3i performance of Long Mynd ground station seems pretty constrained. Not sure if they are aware of this, especially considering their very elevated position. Is there some mechanism for drawing their attention to this, particularly coverage toward the South? I’m guessing higher ground to the North might pose a problem.

Thx,

Chris

[Keithvinning]

Yes the Myndd coverage is disappointing especially the their FLARM reception reaches the outskirts of Birmingham. Perhaps I should take a visit and have a look when i have time.

Keith

[Deker]

Edit Ian just had a look at PWEnstone WOW!!!!! Turbocharged compared with last week. Thame next!!!!
Keith

Wow indeed.
I think I'll see if I can get one of the colinears up at Turweston to improve the PAW range.
Flarm OGN reception maxes out at 100KM+ on 8m of RG8X, but the PAW rebroadcast is averaging 'only' 30 to 35KM as that is the standard dipole antenna on 10m of RG8x.
It would be nice to get these in closer balance.

Deker

[Keithvinning]

Derek
I have 10 on order arriving soon

[Deker]

Derek
I have 10 on order arriving soon

Hi Keith,

Put me on the list for one please.
Deker.

[Keithvinning]

Great stuff l'll make up the cable as well if you want. Ill give you a call.

Keith

[EricC]

The OGN PWPOULTON antenna has withstood a severe lashing for the last twenty four hours and suffered no damage.
WX Station on same mast recorded a max gust of 35kts
The design is obviously sound.

[Keithvinning]

I am just about to get some 7dB antennas rather than the 9dB antennas that we currently use Why?

Cheaper to post 1.7M is very expensive and the new ones are only about 80cm
There is an argument why do we need to see glider at 120Km anyway
The antennas are cheaper in themselves
Lees obtrusive

If anyone want install an OGN with these new antennas let me know
86 installed so far another 4 in the pipeline 10 to go to get over the 100 line

Also when we introduce Mode-s/3D to enable MLAT so that we can see Mode-s Targets as clear as others including ADSB then we will all want greater coverage. This will of course also help the Gliding community - Win Win

Keith