Base Antenna

[MesaAZGuy]

I'm sure this may have been talked about before but I can't find the source. Does anyone have a pole mounted in their yard with antennas connected to the remote? If I could get the remote antennas up at roof height or better, I know I can achieve longer flights over the 1/2 mile I am getting now. Perhaps the Tactical case may have antenna outputs for such use? Hint Hint!

 

[JOE CHRONIC]

I'm sure this may have been talked about before but I can't find the source. Does anyone have a pole mounted in their yard with antennas connected to the remote? If I could get the remote antennas up at roof height or better, I know I can achieve longer flights over the 1/2 mile I am getting now. Perhaps the Tactical case may have antenna outputs for such use? Hint Hint!

Dragging this back from the dead...

I too am curious to know who is using some form of base antenna connected to the remote antenna for
long distance flights?

Anyone???

 

[Thomas B]

Nope. My RC is good for 1-2 miles just like it is.

not sure how you’d power one of those and be mobile.

 

[JOE CHRONIC]

Nope. My RC is good for 1-2 miles just like it is.

not sure how you’d power one of those and be mobile.

Not looking to be mobile, just wondering if anyone has a connected base antenna to their remote, maybe like a CB Radio base antenna kinda deal ?

 

[Rich QR]

I'm an amateur radio operator, and though I don't have direct experience with remote antennas for drone controllers, I may be able to shed some light on why you don't hear much about them.

Antennas are normally connected to radios via coaxial cable. The cable always has some loss. The loss gets worse as the frequency gets higher. It also gets worse as the cable gets longer.

RG-58 is a popular coax cable for general purposes. As an example, assume we need 30 feet of it between our radio and rooftop antenna. At CB frequencies of 27 MHz, that results in a loss of about 0.6dB, meaning that 4 watts of transmitter power at the radio results in 3.5 watts of power reaching the antenna, not a bad situation.

But that same 30 feet of RG-58 at 5.8 GHz (common frequency for our remote controls) results in over 17dB of loss, meaning that the same 4 watts of transmitter power would result in 0.076 watts of power delivered to the antenna, with the rest of the power lost in the coax.

At the frequencies our remote controls use, for reasonable lengths of reasonable coax, almost none of the power reaches the antenna. The situation is similar for reception: almost none of the received signal makes it from the antenna to the receiver.

The problem can be mitigated by amplifiers at the antenna, but since the receiving amplifier is amplifying in the opposite direction from the transmitting amplifier, there needs to be some coordination to switch one on and the other off at the right time. It would be very difficult to get this to work unless the RC were designed with a remote antenna in mind.

Here's a calculator to run other scenarios. Coax Calculator

 

[JOE CHRONIC]

I'm an amateur radio operator, and though I don't have direct experience with remote antennas for drone controllers, I may be able to shed some light on why you don't hear much about them.

Antennas are normally connected to radios via coaxial cable. The cable always has some loss. The loss gets worse as the frequency gets higher. It also gets worse as the cable gets longer.

RG-58 is a popular coax cable for general purposes. As an example, assume we need 30 feet of it between our radio and rooftop antenna. At CB frequencies of 27 MHz, that results in a loss of about 0.6dB, meaning that 4 watts of transmitter power at the radio results in 3.5 watts of power reaching the antenna, not a bad situation.

But that same 30 feet of RG-58 at 5.8 GHz (common frequency for our remote controls) results in over 17dB of loss, meaning that the same 4 watts of transmitter power would result in 0.076 watts of power delivered to the antenna, with the rest of the power lost in the coax.

At the frequencies our remote controls use, for reasonable lengths of reasonable coax, almost none of the power reaches the antenna. The situation is similar for reception: almost none of the received signal makes it from the antenna to the receiver.

The problem can be mitigated by amplifiers at the antenna, but since the receiving amplifier is amplifying in the opposite direction from the transmitting amplifier, there needs to be some coordination to switch one on and the other off at the right time. It would be very difficult to get this to work unless the RC were designed with a remote antenna in mind.

Here's a calculator to run other scenarios. Coax Calculator

Wow!
More complicated than I thought, thanks for all the info, much appreciated...

 

[Aerial Edge]

Not looking to be mobile, just wondering if anyone has a connected base antenna to their remote, maybe like a CB Radio base antenna kinda deal ?

The problem is feed line loss. At 2.4ghz and 5.8 ghz the loss even in a short piece of coax is astronomical. You would need a hardline and a lot of antenna gain. Even then I bet the ERP or effective radiated power would be less then the antenna on the remote. You would have to run an amplifier at the antenna, then a separate antenna with a preamplifier for each band. Not to mention any of the modifications affect FCC type certifications since they all work under part 15.

The only real solution is on remote amp with fractal patch antennas. There is a reason why those are available. I will not get into the legalities of that on here. I am a radio guy and bounce radio signals off the moon. I run 26,000 watts erp on 432mhz.

My 23cm (1.2ghz) station is 10 watts at the transmitter with a 40 foot of 1-1/4 inch hard like coax. Only like 2 watts makes it to the antenna. I run 2 56 element loop yagis in a phased array. My amp is on the bench being built that will give me 140 watts output.

The Mavic remotes are probobly like 30 milliwatts output.

Dave

 

[Aerial Edge]

The problem is feed line loss. At 2.4ghz and 5.8 ghz the loss even in a short piece of coax is astronomical. You would need a hardline and a lot of antenna gain. Even then I bet the ERP or effective radiated power would be less then the antenna on the remote. You would have to run an amplifier at the antenna, then a separate antenna with a preamplifier for each band. Not to mention any of the modifications affect FCC type certifications since they all work under part 15.

The only real solution is on remote amp with fractal patch antennas. There is a reason why those are available. I will not get into the legalities of that on here. I am a radio guy and bounce radio signals off the moon. I run 26,000 watts erp on 432mhz.

My 23cm (1.2ghz) station is 10 watts at the transmitter with a 40 foot of 1-1/4 inch hard like coax. Only like 2 watts makes it to the antenna. I run 2 56 element loop yagis in a phased array. My amp is on the bench being built that will give me 140 watts output.

The Mavic remotes are probobly like 30 milliwatts output.

Dave

Another ham beat me to it lol. I did not read far enough down. But you get the idea that it is indeed more complicated. Hence the reasoning of why radio guys are licensed. Especially whe. running Legal limit peak Envelope power of 1500 watts.

 

[Gygax]

Wow!
More complicated than I thought, thanks for all the info, much appreciated...

Solution.. sit on your roof and fly from there

 

[Conservative Nihilist]

This concept has indeed been implemented by the legendary Jeremiah Nelson, with astonishing results.

The discussion thread runs a whopping 121 pages, but there are some nuggets of profound wisdom therein. Pay particular attention to the use of SUNHANS in-line amplifiers.

Bob's yer uncle.

Flying from inside house or car anyone?