Cables for FlightAware antenna in UK/Switzerland


#1

Hi all,

I recently purchased the FlightAware ADS-B antenna and want to mount it outdoors on a mast. All well and good. I also purchased a set of pigtail adapters that will allow me to connect more or less any type of connector to my NooElec SDR dongle. Based on the location of the mast and where I can place the Pi (even with a USB extension cable for the dongle), I’ll probably need 5-10m of cable from the antenna to the SDR dongle.

The problem is that I live in Bern, Switzerland, and I’ve had some difficulty finding shops (either local or online) that sell weatherproof cables with N type connectors. Local consumer electronics shops stock a bunch of short (~1-5m) RG58 cables with F-type adapters, such as one would use to connect to the TV, but that’s not really useful. There’s not really any RadioShack (for US reders) or Maplin (for UK readers)-type shops that stock various electronic components, cables, etc. for hobbyists. If there’s anyone in Switzerland that can recommend any particular shop, I’d be happy to buy you a beer.

Next week I’m traveling to the UK (London, in particular). Does anyone have any particular recommendations for good places to get the necessary cables and connectors? Ideally, I would like to get a 6-10m reasonably low-loss cable with pre-fitted N-type connectors, though N-to-F or N-to-SMA is fine. Alternatively, I can get cable by-the-meter and connectors separately and attach them myself.

It looks like Maplin sells a variety of cable by-the-meter, including RG58, RG6, and RG213, as well as clamp-on type N plugs that can handle cables with either 5mm or 10mm outer diameters.

What would be a suitable cable to use? To my admittedly-inexperienced eye, RG213 looks pretty ideal: 10mm OD, reasonably priced, 50 ohm impedance, and low loss. The SDR dongle has an impedance of 75 ohms, but the loss due to a single mismatch should be quite small.

How about connectors? Would the clamp-on connectors be suitable for use in an outdoor environment? If not, where else might I look for suitable ones?

At present I don’t have an in-line amplifier. Would this be a problem with 6-10m of cables and the FlightAware antenna? If so, what amplifier should I use? If it’s to be mounted to the antenna, it’d need to have N connectors and be weatherproof.

While not critical, time is somewhat of a factor: I’ll only be in the UK for a few days so I won’t be able to order anything to be shipped once I’m there. Ideally I’d like to order things in advance for delivery to a local shop (or perhaps to the hotel where I’ll be staying) so I can see it in person first.

Many thanks!

P.S. If there’s any London or Swiss-based readers here who’d like to meet up and get a pint somewhere, that’d be outstanding.


#2

Can I suggest Martin Lynch hamradio.co.uk/ who are situated near Heathrow airport? They would be able to give you advice if you contact them before your trip. I am located in Wales so would be unable to meet up. Good luck.


#3

I got my antenna and cables here:
shop.jetvision.de/epages/6480790 … ucts/70400

This may be suitable for you.


#4

Perfect! Thanks! That’s exactly what I’m looking for. One less thing to haul back from the UK (my wife and I do a lot of shopping there since it’s relatively cheap).

The one downside of buying stuff online outside of Switzerland is that since Switzerland is not part of the EU customs area items occasionally get caught by customs, who then demand outrageous fees. I think I’ll be ok with this one.


#5

Do a search on ebay.co.uk for LMR400

This is a thick low loss cable everyone recommends, you should be able to find someone who will supply the cable you need and maybe also fit the connectors. It is expensive and awkward to work with.

An alternative available here (UK) is WF100 or CT100 cable (also on E-Bay), this is low-loss and is usually used to connect satellite dish LNBs to the satellite receiver using F-Connectors. This is 75 ohm cable so there is a little loss at the antenna (a fraction of a db), bit you would have had that loss at the dongle anyway since that is 75 ohms.

Waterproof F connectors by wrapping with self amalgamating tape.

RG6 cable will also work.


#6

Good suggestions, thanks!

On a related note, are typical inexpensive in-line satellite amplifiers like this or this normally weatherproof?

Some satellite TV installation instructions I’ve seen state that the amplifier should be located outside, as close to the dish as possible to minimize pre-amplification cable losses, while others put the amp inside the house. It’s unclear if this is simply because it’s easier to install them inside, or if they’d be damaged by being outside and exposed to sun, rain, and snow.

The location for my new station will be more or less ideal (FlightAware antenna, clear view of sky, 10m of coax running to the SDR dongle), but I’d like to get all the details for an amp/filter setup just in case it becomes necessary.


#7

More tape! Self-amalgamating tape is your friend. I don’t know if my inline amp that’s outside is weatherproof or not because it’s completely covered in tape :slight_smile:


#8

laughs That’s one way to do it. :slight_smile:

Any issues with heat/cold/sun with the tape? Does it degrade over time?


#9

Self amalgamating tape by design is resistant to degradation when exposed to nature’s elements.

en.wikipedia.org/wiki/Self-amalgamating_tape


#10

Outstanding. I’ll pick up a roll or two. That sounds like great stuff.


#11

Good question - some people say they are, but I pulled the covers off one … they tight fitting aluminium covers popped onto a moulded aluminium box - there’s no sealing stuff, so I doubt it - perhaps they let the water out the bottom as fast as it comes in the top.

Mine is wrapped is self amalgamating tape too.