Can one antenna be shared with several SDRs? If so what is the recommended connection? Appreciate the help and suggestions. Looks like I'm going to wind up with 3 or 4 SDRs to cover the necessary bandwidth. I found this on ebay: 6" SMA Female to Y type 2X SMA Male Splitter Combiner cable pigtail RG316 USA or 2 SMA Males to one BNC female would probably work better for me if it will work at all. Here is a picture of a diy home made 800MHz ground plane antenna that I made for a PRO-668/WS-1080 type scanner and believe it or not, works pretty good with the SDR. I also have the Tram antenna that I have wired to a female BNC.
Sharing one antenna with two SDRs or more?
- Thread starter humblegeo
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I see, I've got plenty of those around. So for TV coaxial connections. So I would need some coaxial to sma adapters or sma pigtails
G0NMY
Member
Remember each time you split the signal path you will lose 3db (approx) of signal strength, or half of the signal strength.
If you are going to have several splits then I recommend you buy a wideband amplified splitter to compensate for the losses you added.
Not so bad at HF frequencies but at VHF/UHF the losses are significant. So look for an amplified splitter.
The above does not take into consideration the losses of the coaxial run off each split.
Ok you can also turn the gain up of the SDR's to help. but it also amplifies the noise level so may make things worse.
Hope that helps
If you are going to have several splits then I recommend you buy a wideband amplified splitter to compensate for the losses you added.
Not so bad at HF frequencies but at VHF/UHF the losses are significant. So look for an amplified splitter.
The above does not take into consideration the losses of the coaxial run off each split.
Ok you can also turn the gain up of the SDR's to help. but it also amplifies the noise level so may make things worse.
Hope that helps
lwvmobile
DSD-FME
I've ordered and used RTL dongles with the MCX Y-Splitter to BNC bulkhead adapters in the past on eBay and the adapters have been of good quality and worked extremely well when paired with my two dongles. I do believe you lose some signal dB when using splitters and such though, so just depends on faint the signal is more than anything else. I believe if you look at those RG59 coax splitters or diplexers, they usually have a signal loss of 2.5 dB or 3.5 dB, and if they have more than two ports, subsequent ports may have additional signal loss
My current set up is 800Mhz RS antenna with BNC connector to BNC to F-Type connector to RG6 Coax to inside to F-Type to BNC adapter to BNC Y-Splitter bulkhead to a pair of RTL dongles. Works well for me, but I do suspect there is some signal loss due impedence mismatch and multiple adapters in play, but testing it versus having the dongles connected directly to the antenna outside don't seem to indicate any substantial signal loss for systems I wish to monitor.
Edit: Mispoke. Said SMA, meant to say MCX connector on the RTL Dongle.
My current set up is 800Mhz RS antenna with BNC connector to BNC to F-Type connector to RG6 Coax to inside to F-Type to BNC adapter to BNC Y-Splitter bulkhead to a pair of RTL dongles. Works well for me, but I do suspect there is some signal loss due impedence mismatch and multiple adapters in play, but testing it versus having the dongles connected directly to the antenna outside don't seem to indicate any substantial signal loss for systems I wish to monitor.
Edit: Mispoke. Said SMA, meant to say MCX connector on the RTL Dongle.
Before anyone writes / reads anything else in this thread, do some reading over here on RR -
Splitters, Filters and Multicouplers
Splitters, Filters and Multicouplers
mmckenna
I ♥ Ø
lwvmobile
DSD-FME
Or else somebody will toss their sucker in the dirt
I'm interested doing the same thing so I can have many live feeds coming from one location.
AB5ID
Member
Begin with a cost-effective approach. If the signals are strong enough for reliable decoding, utilize passive TV splitters. If not, consider moving towards a more suitable setup by investing accordingly.
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PLEASE as the above says, read the earlier thread rather have people tired of having to repost it (and may not chose to).
Thank you, I will surely look into your suggestions AB5ID and dlwtrunked.
I use the bingfu sma pigtails allot, couldn't tell me otherwise, lol, that was mostly with strong simulcast, I'm here to eat some crow, cheap splitting leaves you in lurch 😀 I was missing out on allot of sonde reception
Ubbe
Member
Maybe it's better and cheaper to build a couple of more of those DYI antennas. Nothing fancy just a 3,5 inch wire and a 7 inch diameter tin can metal sheet as ground. Drill a hole in the sheet metal and stick the coax thru it and peel off the braid 3,5 inch and solder to the metal. No connectors needed at that end of the coax. I believe my latest RTL-SDR came with a length of open end coax that where already stripped at the end to be used as an antenna.
Most standard amplified TV splitters have terrible noise figures that makes it worse than having an antenna directly coupled to a receiver. There are low noise ones but costs a lot more. It depends on how strong signals you have now, if you still have a noise free signal when attenuated 3dB-6dB by a passive splitter connected to one common antenna. If you can reduce the gain of the dongle by 10dB and check if all signals can still be used then a passive splitter will work.
/Ubbe
Most standard amplified TV splitters have terrible noise figures that makes it worse than having an antenna directly coupled to a receiver. There are low noise ones but costs a lot more. It depends on how strong signals you have now, if you still have a noise free signal when attenuated 3dB-6dB by a passive splitter connected to one common antenna. If you can reduce the gain of the dongle by 10dB and check if all signals can still be used then a passive splitter will work.
/Ubbe
JamesWest
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this is more professional. i have a few:
I'm using an Antronix powered cable splitter with my VHF tower and it works great. Antronix VRA901 or something similar...
RichM
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I also use a powered cable splitter, mine is an 8 port Electroline EDA-FT080100 that cost around $40 on eBay. I run 2 SDR’s and 2 hardware scanners off one wide band external antenna. Works perfectly, no signal loss or amplified noise. When shopping make sure and choose one that includes the power supply, many don’t.
I've used this one from Cross Country Wireless for years: Cross Country Wireless HF/VHF/UHF Multicoupler
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Mike
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