Even with the extra antenna height i am not sure as long as it’s not used for passing trees etc.
Long range you would need much more height to have an impact.
I checked this a couple of times on heywhatsthat.com with different antenna heights.
But if you can pass a single tree with that, it will have a significant impact.
I thought about the height factor, but the only real obstructions are a few houses, slightly higher than mine to the north and two colossal non-deciduous trees to the north west.
If you look at my tar1090 middle screenshot, most of the light aircraft are to the south.
Maybe there was something getting in the way further away to south I hadn’t realised.
This is one of the reasons I was so surprised at the difference and put it down to the antenna.
Maybe it was my pesky discone antenna getting in the way 
Anyhow, whatever it is, the difference is night and day and not subtle at all 
A pTracks screenshot of the before and after could be helpful … identifying which directions you gained something.
Though that can also be related to traffic patterns.
Can’t see your FA stats but you could check for directional changes in there.
Not wishing to be a party pooper but don’t underestimate the effect of the better weather in the UK over last couple of days though.
Lots of light aircraft taking advantage. I’m on the south coast and my numbers have increased a lot over the last couple of days with no changes to my setup.
It’s not only about the trees around you, but those further away. Or buildings. At 1000 meters from you, and low horizon angles, the houses there are densest of the obstacles. That inclination is where your farthest away planes will be “seen”.
A bit more of height on the antenna does a lot for that max range, more than just the theoretical model that doesn’t have obstacles.
Same here, especially today. Most of them are visible via MLAT only.
On a normal day i have a 80-20 ratio, today it is almost 80-50 (ADS-B vs. MLAT)
Just be aware that conditions are very good today, the best I’ve seen for some months so you might also be benefitting from that a little bit.
Yes, I didn’t think of the weather etc and I’ve only been doing this since February, so I’ve not seen a summer yet and also Covid restrictions easing. That could be coincidental to when I upgraded the antenna system making it appear a lot better. Although I’m definitely seeing more aircraft, as at night when the light aircraft are no longer around, I’m getting a lot more, unless they’ve suddenly increased commercial and cargo flights too.
I’m definitely getting better range too, mostly to the NW, N and NE where I have local obstacles - I’m not getting much further range southwards, where I have a good view to the horizon, so yes, the height increase will not effect this area much.
I didn’t have any unusual traffic here. in 2019 (where i started) until now the range is the same, only the # of aircraft and reported positions changed for a well known reason
Different cable? Connectivity issues? Different settings?
You offended the main antenna at some point, so she hates you now.
You’ve swapped the setups connected to them, as in swapped the coax coming from each antenna to the other system each?
I already swapped the setups (cavity filter, rtl-sdr lna, airspy mini, Pi4) and that reverses the results, both feeders are identical with same Airspy settings including gain level. One thing I haven’t done is swapping the cables, it takes a lot of time and it’s quite dangerous with my shaky knees on top of the roof only holding a metal pole! 
Are you sure about which is which?
And what’s that 3rd antenna?
I’d expect to clearly see the other antenna in pTracks on the backup antenna creating a dead direction.
If you look at the pTracks for both, do you see that?
There’s no confusion because the coaxial cables have different sizes (10 & 13mm) and both Pi’s have unique DNS names like pi1.lan & pi2.lan to avoid mix-ups.
The third antenna is a 2m/70cm ground plane.
Both A3’s are about 2m apart so the ‘dead direction’ is less than half of a degree wide, this will be barely perceptible due to the mitigating effects of polarisation skew, atmospheric refraction and the very short obscuration interval.
I mean obscuration by the mast the backup A3 is attached to.
Maybe that obscuration is shielding you from the mobile tower 
You have extra filters you can put in front of the LNA to check if you still have issues with your super strong interference?
I suppose you could chain both cavity filters … or add one of the FA barrel filters if you have one lying around.
Now, that it is a mystery 
Nice build.
Proud of you for using a decent connector instead of an SO-PoS.
