RTL-SDR Antennas

[cybersec]

Hello!

I'm a bit of a newbie here and with SDR in general, but I had a question about RTL-SDR dongles.

From what I've heard and read so far, RTL-SDR dongles are the cheapest way of getting into SDR while still having a fairly quality product. I impulse-bought a dongle a few months ago when I saw it for $3 with free shipping on Amazon, it was this one:

Utilizing the RTL2832U chipset.

When playing around with it recently, I quickly realized that the stock antenna is terrible, and that I was going to have to upgrade.

My question: Should I buy a new adapter with a normal (I don't know the proper terminology, so forgive me) coax jack on it, or do they sell adapters that can go from this much smaller size to your normal antenna-sized coax?

Again, excuse my noobishness, sorry!

Thanks for anyone that can help, I've been looking around on here and on the Wiki and stuff, but was unable to find any info on it (I think its just because I don't know the right words to search)

 

[slicerwizard]

$3? You should've picked up a few more...

That pic looks like the typical MCX connection, so you probably need something like this to connect to a better antenna.

Amazon.com: RF coaxial coax cable assembly BNC female to MCX male right angle 6'': Computers & Accessories

Get yourself an antenna designed for the frequency bands you want to monitor.

 

[cybersec]

$3? You should've picked up a few more...

That pic looks like the typical MCX connection, so you probably need something like this to connect to a better antenna.

Amazon.com: RF coaxial coax cable assembly BNC female to MCX male right angle 6'': Computers & Accessories

Get yourself an antenna designed for the frequency bands you want to monitor.

Oh okay sweet, so I can just get MCX to whatever adapter I need, that makes it easier.

Also lets say I wanted to use a 14dbi 900mhz antenna with an N Connector, like this one:

YA90014 Wireless 900MHz Directional Yagi Antenna with 14dBi Gain | eBay

From what you said, I'd just need an N Connector to MCX adapter and I'd be fine?

I'm a bit of a noob when it comes to radios, but I know with things like headphones you have to have an amplifier when you have more powerful headphones. Does the same type of thing apply to radios? Will this little dongle not be able to power a large/high dbi antenna?

Thanks!

 

[slicerwizard]

Oh okay sweet, so I can just get MCX to whatever adapter I need, that makes it easier.

Also lets say I wanted to use a 14dbi 900mhz antenna with an N Connector, like this one:

YA90014 Wireless 900MHz Directional Yagi Antenna with 14dBi Gain | eBay

From what you said, I'd just need an N Connector to MCX adapter and I'd be fine?

Normally, I'd just say yup, but you will not be directly connecting the dongle to that antenna's six inch coax, will you? I assume you'll have a cable run of some sort. BTW, nice price on that antenna.

I'm a bit of a noob when it comes to radios, but I know with things like headphones you have to have an amplifier when you have more powerful headphones. Does the same type of thing apply to radios? Will this little dongle not be able to power a large/high dbi antenna?

That antenna, like most, doesn't need any power. There is no power being sent over the connecting cable.

 

[cybersec]

Normally, I'd just say yup, but you will not be directly connecting the dongle to that antenna's six inch coax, will you? I assume you'll have a cable run of some sort. BTW, nice price on that antenna.


That antenna, like most, doesn't need any power. There is no power being sent over the connecting cable.

Yeah, I was thinking about getting some sort of extension to go between the antenna's coax and the MCX adapter. When getting extensions, does one have to worry about anything other than the cable having the right connectors?

And thanks for the info about the power, that clears up the other half of my question.

 

[slicerwizard]

For a short (6-10 foot) coax run, not really. For a long (50-100 foot) run, cheap coax will attenuate higher frequencies, so some loss at 450 MHz, more at 850, 935. Not much of an issue at 150 MHz.

 

[SpectrumAnalyzer]

N To MCX Jumper Cable

I'm not sure but the eighth image down on your left might what you require.

Radio RF Microwave Communication Coaxial Cables

That's just the first page of "Off the shelf" jumpers, if you don't see exactly what works for you, I'm sure they can configure something to meet your requirements, good luck.

 

[cybersec]

For a short (6-10 foot) coax run, not really. For a long (50-100 foot) run, cheap coax will attenuate higher frequencies, so some loss at 450 MHz, more at 850, 935. Not much of an issue at 150 MHz.

Oh okay, thanks for all of the info! You've been a huge help

I'm not sure but the eighth image down on your left might what you require.

Radio RF Microwave Communication Coaxial Cables

That's just the first page of "Off the shelf" jumpers, if you don't see exactly what works for you, I'm sure they can configure something to meet your requirements, good luck.

Yeah that looks really close to what I need, thanks. I'll check out that website a bit more as well, it seems useful

 

[Superdinosaur]

When DIY a coaxial cable, shall we consider it a 50 Ohms or a 75 Ohms?

 

[Voyager]

What type of cable? A DIY cable could be 50 ohm or it could be 75 ohm.

 

[Superdinosaur]

For connection between sdr and antenna.

 

[slicerwizard]

If you're making your own cable, use 50 ohm coax.

Mind you, a more complete answer would be that 50 vs 75 isn't that critical in RX-only applications; I've used high quality 75 ohm cable TV cable because it had less attenuation than whatever else I had easy access to.

 

[Superdinosaur]

If you're making your own cable, use 50 ohm coax.

Mind you, a more complete answer would be that 50 vs 75 isn't that critical in RX-only applications; I've used high quality 75 ohm cable TV cable because it had less attenuation than whatever else I had easy access to.

Noted and thanks very much!