Radarspotting

I have trawled through the similar posts but they are 4 years or so ago. I am "experimenting" with antennas and would like to connect 2 antennas. I have seen SMA type splitters but think I need more than this, and probably a preamp?
If anyone has done similar perhaps you could share your experiences.

I've never combined two antennae but have shared one with multiple receivers.

From my understanding you need a suitable splitter/combiner.  The RF Systems SP-3 could do either job and I have one for splitting the antenna feed.  But this is now discontinued.

https://www.universal-radio.com/catalog/preamps/0973.html

When I needed another splitter, I bought a suitable Mini-Circuits device off ebay.

https://www.minicircuits.com/WebStore/Splitters_tab2.html

New, these are expensive and one has to choose the correct frequency range and connectors.  Mine was a Mini-Circuits ZB4PD1-2000 Power Splitter/Combiner, 2000 MHz and cost US$40 incl. shipping.

If you do an ebay search for "Mini-Circuits" you should find one with the correct connectors and frequecny range (to include 1090 Mhz).

It's still in use today and I don't use a preamp.

Hope that helps?

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Thank you very much for the information and links. Very comprehensive,

At least now, I have a starting point for my search.

I am generally happy with my reception apart from the west where I am limited by big hills. I live below one of the airways and hoping to see if I can increase the reception using a yagi orientated to the Brecon beacon. I do realise propagation is line of sight - but who knows.

Thanks again.

One suggestion is to try an antenna on its own placed where you would intend to add a second.  You may not get better reception especially if there are hills in the way.

I had a window mounted antenna on the north side of the house and it was picking up aircraft to the south at about the same range as my chimney mounted antenna.  But neither could get "over" the high ground to the west.

Using two antennae with independent dongles and combining the output via software may be an an alternative (and cheaper?) option.

That situation is fairly common in your situation. The FlightAware forum for ADSB flight tracking has threads about this. I would post links if I were not in the middle of a PC rebuild and Win10 upgrade - not everything is working yet!