Ebay - Outdoor Antenna?


#1

Morning all,

Currently running an attic-mounted “spider” antenna - works well, but the next step is to get this on the roof outside.

Recent gales here have speeded my decision (I have a slate off)…

I know a few of us on here make and sell their own external antennas on ebay - could someone recommend one for about £20?

Have seen the same “spider” antennas, but housed in (pvc?) tubing?


#2

I bought one on eBay from a guy in Slovakia called stanislavpalo130. It has worked well for me and cost less than £20 including delivery, Note: it has now gone up to just over £20.

ebay.co.uk/sch/stanislavpalo … 7675.l2562


#3

I’ve been running one of these for about a year ebay.co.uk/itm/191595766728 - with a satalite amp fixed an adaptor at the bottom of the antenna.

I believe it’s a printed circuit collinear - but I have no proof


#4

I bought the same antenna with the same guy… I’ll put on the roof. I hope it works perfectly.

Do you have a graph that shows working of this antenna? … coverage, etc.

Thanks!


#5

The price for that one over here is $71.50 US with free shipping from Bulgaria (shocking) - although it may very well take it a month to get here.

I’m using a home-brew eight-element collinear in a PVC pipe on the roof that has served me very well. If I were to order one of those, I would just have to open it up to see what I paid for. PVC is easy enough to re-seal. :slight_smile:

Has anyone ever opened one of these Internet-purchase ADS-B antennas to see what they paid for?

Matt


#6

I have one without the ground plane and the guy is actually quite helpful, his English is a bit off but nevertheless he’s handy and I wouldn’t recommend taking it apart i broke one doing that haha. I did send him a request for it and he found a work-around for what I wanted.

@Mattbna the one above without a ground-plane is a J-Pole antenna which does have quite a good coverage when in clear sight of the sky. I’ve got atleast 150nm-200nm easy although my area doesn’t help. Can’t comment on the 5/8 antenna with ground plane but I am tempted to get one.


#7

I had the antenna open after a storm. :imp:

looks something like this, but the copper is coated with anything in silver color I do not know what it is.

http://home.arcor.de/papasven/bdant.jpg


#8

The image you linked is providing a 404 error. :slight_smile:

Matt


#9

It’s just you. I’m seeing it just fine.


#10

We’re both seeing it now…over two hours later. :slight_smile:

I copied the original photo link to another tab in two different browsers earlier and it 404’ed in both. Was originally dead.

Matt


#11

Thanks for the feedback!

Yes, that’s just the sort of thing Im looking for - will order shortly…

Whats the latest on lightning-arrest ; grounding the antenna in case of lightnig strike?

Have seen a couple of “connectors” that go inline on the Coax, with a connector presumably for a ground wire…

How do these work, where do I get them etc?

Ta


#12

Hmm… just read elsewhere that most people tend not to bother…

To quote another site “Do you have a TV Aerial - has it ever been a problem (with lightening)?”.

No.

So - unless anyone has any wild feelings to the contrary, dont think I’ll bother.


#13

I would definitely provide some earthing/grounding of the antenna - f only to deal with static build up. Without it your raspberry Pi Ethernet port will had a tendency to sacrifice itself to protect everything else.

(not uncommon!)


#14

If you are using a DC injector that should prevent any static build up from reaching the receiver.


#15

Yes - especially as the antenna is higher than the roof ridge, I’d prefer to err on the side of caution also…

So, what’s the best way to do this - what do you external antenna guys do?

Out of interest, the link I found suggesting “not to bother” …


I always ask have you ever had a problem with a TV antenna or FM stereo antenna?
If the answer is no then why would your adsb receiver be any more exposed?

… is here:

radarspotting.com/forum/index.php?topic=2543.0

That thread also warns about not grounding the antenna for fear of making it into a “lightening conductor”.

… All for academic interest only, ultimately I’ll go with advice from yourselves.

FYI, I got a radomed-Ground Plane from one of the links earlier in this thread.


#16

Good point Caius, I am using a DC injector!

Rather than killing the Pi (which admittedly isnt ideal), Im ultimately more concerned about burning down the house!

So, as I have the DC Injector, where do we stand on the lightening arrestor / static protection?


#17

Those who like to declare that safety items are useless, are fools. Or grounding increases the chance of a strike…no. At the energy levels of lightning (the lightning’s prospective), everything is grounded. It just an issue of how you would like to direct that energy (to prevent a fire). Would you like your walls and framing to conduct the strike to ground, or would you perfer a 4 ga solid copper wire to direct it. I personally don’t like my walls to be electrified (due to the inherent fire afterwards). The NEC is there to keep you safe.

Linked is a good article.

http://www.reeve.com/Documents/Articles%20Papers/AntennaSystemGroundingRequirements_Reeve.pdf


#18

well, it would block static from going down the core of the antenna coax, and to some extent the antenna might be grounded through what ever it’s mounted on - but with a home made antenna that’s insulated from it’s support, running off an insulated power source - the best ground could easily be the Ethernet port.

It’s no big deal grounding the coax shield.


#19

Thanks for all the input gents,

So, looks like we’re recommending something to arrest / divert a full on strike…

What cost are we looking at here, any links to products etc?

Re Grounding - my Pi, amp and network point are all mounted on to a roof joist in the attic.

THX


#20

Found this in another thread (knw i’d seen it somewhere…)
ebay.co.uk/itm/Lightning-Pro … 5affa91f9a

I believe I’d need enough copper wire to reach the ground, + 1.5m ground spike?

However, would something like this do any good?
ebay.co.uk/itm/Brennenstuhl- … 5af0099afd

Thinking - ground it to the house ground via Amp / Power inserter / Pi plug?