Poor Airband Reception in North London (UBC125XLT & Slim Jim) - Need Advice

[FoxGolf]

Hello everyone,

I hope I’m posting in the right section. I'm looking for some advice on troubleshooting my airband setup.

As a kid back in the 2000s, I used to have a GRE radio. I live in North London in a relatively low altitude area (around 20m above sea level). Back then, I really struggled to hear London Heathrow controllers, and I eventually gave up on the hobby. Recently, the bug bit me again, and I decided to get back into it.

I started off with a Radtel RT-470X. With the stock rubber duck antenna, I could hear some pilots, but anyone further than about 10 miles away was incredibly faint and plagued with interference.

Thinking it was an antenna issue, I started upgrading:

1. I tried a telescopic 118-136 MHz antenna, but noticed no real improvement.
2. I then purchased a custom built Airband (118-137 MHz) Slim Jim antenna paired with RG174 coax cable. After looking at all the good reviews also I've tried this both indoors and outdoors, and it still didn't fix the issue.
3. Blaming the radio next, I upgraded to a Uniden UBC125XLT. Unfortunately, I am getting the exact same results whether trying to monitor Heathrow, Stansted, or London City.

I fully understand that picking up ground/tower controllers is highly unlikely due to my distance, terrain, and low elevation. However, I am baffled as to why I can only clearly pick up aircraft within a 10mile radius. Anything further than that becomes unreadable.

Am I dealing with a line of sight issue due to my low altitude, or is there a weak link in my equipment? (I have my suspicions about the RG174 coax cable).

I would really appreciate it if someone could point me in the right direction regarding what tools, filters, or cabling I might need to fix this.

Thank you in advance

 

[hill]

On the US version of this scanner the BC125AT it does hear a5rcraft at good distances with just using the stock antenna.

 

[FoxGolf]

On the US version of this scanner the BC125AT it does hear a5rcraft at good distances with just using the stock antenna.

Thanks That’s exactly what’s driving me crazy. No matter what radio or antenna I use, the result is identical: decent pilot comms within 10 miles, then a total drop off.

What's frustrating is a friend of mine lives nearby in Edgware Area in London and he can hear both pilots and ATC controllers crisp clear without issues. I want that better reception so I can hear controllers too. If I drop my squelch down to 0 or 1, I can just about hear the controller, but it's buried in a lot of interference sound and isn't clear at all.

Since the radios clearly work, how do I break past this 10mile brick wall? Could local London interference be deafening my scanner?

 

[prcguy]

Are you listening with the antenna indoors or is it outside?

 

[FoxGolf]

Are you listening with the antenna indoors or is it outside?

I normally use it indoors since my roof isn't much higher than my bedroom ceiling anyway. However, I’ve tested it outdoors several times I even mounted it on a pole to get it completely above the roofline..and there was absolutely no difference in the audio quality.

 

[wtp]

are you using any coax all the time trying this ?

 

[FoxGolf]

are you using any coax all the time trying this ?

I do even tried other standard antennas maybe with the coax I get slightly better reception. I've attached some pictures of the custom antenna for reference, along with an elevation map of my area.

Looking at the map, I think the terrain is indeed the main culprit. Being at such a low elevation means the higher ground surrounding me is likely blocking the line-of-sight signals from the airports.

Thanks
Adam.

https://adam-332.tumblr.com%2Fpost%2F818806955000922112

 

[wtp]

too many things can go wrong with coax to list.
try it without any coax if you can and try it outside as there can be many problems with walls, windows and roofs.

 

[FoxGolf]

too many things can go wrong with coax to list.
try it without any coax if you can and try it outside as there can be many problems with walls, windows and roofs.

I've tried both a telescopic 118-136 MHz antenna and the standard rubber duck antennas that came with my two radios, but haven't seen much improvement. Looking at the terrain maps I posted above, I'm starting to think my low elevation is the real issue. There’s a higher ridge between me and the airport that seems to be completely blocking the direct line of sight signals...

Adam.

 

[VK3RX]

Google Earth has a terrain profile feature that's proved useful to me.

1. Center Google Earth on your area;
2. create a Path (Add > Path) by clicking on two points on the topographical display i.e. one being your location and the other the site you are trying to receive;
3. then right click on the created line, and one option is "Show elevation profile".

When the profile is displayed at the bottom of the screen you can then move the arrow cursor along the profile and see on the topo. display where the various elevations are.