rangelink thread
http://www.rcgroups.com/forums/showthread.php?t=1518968

Originally Posted by stgdz

But why do people get the module based systems? Is it personal preference.

I run a module based Futaba 9C because it gives the option of having one radio and 2.4GHz Spektrum or Futaba, 72MHz and UHF, its just the flexibility of a module based radio is great. I guess you could say personal preference plays a huge part.

Yeah I figured that's what it was. I was out of the loop for a long time in RC and got back in last year. When I started doing my due diligence on fpv and UHF I noticed a lot were using 9c's and modules. I'm on spent rum and realize some issues it has with fpv so I looked around.


Again thanks guys for pointing out the range link. Is there any reason to get a UHF for a tricopter? I'm going to use it as my training device but I just don't see myself doing that far with it.

Originally Posted by stgdz

Again thanks guys for pointing out the range link. Is there any reason to get a UHF for a tricopter? I'm going to use it as my training device but I just don't see myself doing that far with it.

There are many reasons for UHF on a multirotor. 72MHz antennas are really long and there might not be a place to put it. 2.4 GHz is ok, but if you want to fly behind objects or use any frequency other than 5.8GHz for video, you can't use 2.4GHz for control. That leaves UHF as the only option.

-Alex

Originally Posted by gundamnitpete

His problem was a 1.5W TX (I cannot describe to you the utter amount of fail a 1.5w TX causes). Ditch the 1.5W TX, get a 200MW version.

The other problem is 2.4 radio. They just aren't great for FPV, although Futaba is probably the best to use if you want to stick to 2.4 control.

72Mhz with a good RX is easily capable of well over a mile. In many cases, 2 miles or more.


Please, do not let him get UHF yet. Get him a 200MW TX.

Pete hit the nail on the head. You know you are talking to a newbie when they mention TX power exceeding 1 Watt. I have seen Futaba go a mile repeatedly without issue with a 500mW 900MHz VTX onboard. Granted, this unit was from DPCAV and not HobbyKing which probably had something to do with it. He had plenty of video to go out even further with only an 8dbi patch on the ground. No tracker, no booster, nothing fancy.

-Alex

Originally Posted by iskess

Bump. Alex, what do you think? Do I need to cut off my sma so I can attach the adapter, or can I use two adapters, or will that shift the freq too far.
Thank you

I think your only solution is to fly it out of tune. It shouldn't hurt you too much.

Originally Posted by IBCrazy

I think your only solution is to fly it out of tune. It shouldn't hurt you too much.

Would you care to venture a guess as to what my loss would be in db?

Hi guys,

I had to balance out my plane by putting some weight in one wing. It is a very small metal nut, but I am concerned that it is only about a centimeter away from the end of my Dragonlink antenna. Is that going to be a problem or does metal not have any effect on antennas?

Thanks,
Jim

Lol you guys discriminate the 1.5W transmitter but I've had a lot of success with it!
I'm going to push it to the limits this weekend out in the country.

Originally Posted by iskess

Would you care to venture a guess as to what my loss would be in db?

I could only guess. Probably 2db or so. Nothing you are likely to notice.

-Alex

Originally Posted by iskess

Would you care to venture a guess as to what my loss would be in db?

I fly 1280 with 900mhz antennas all the time, and 900mhz with 1280 antennas on the time.

although that's only on the RX side, TX's always have an appropriate antenna.

This is because they do not know how to set up a plane properly.

A well set up plane can use 1.5 watt video tx no problem and do things lower watt video tx cannot.

Lower video tx like 200 mw works no problem but higher ones work better

If you fly small planes then smaller video tx is way to go to save weight as well as other factors

Originally Posted by Wettfeat

Lol you guys discriminate the 1.5W transmitter but I've had a lot of success with it!
I'm going to push it to the limits this weekend out in the country.

Try higher video tx for long range 3d

You will also be able to fly lower and longer with high video tx

Originally Posted by IBCrazy

Pete hit the nail on the head. You know you are talking to a newbie when they mention TX power exceeding 1 Watt. I have seen Futaba go a mile repeatedly without issue with a 500mW 900MHz VTX onboard. Granted, this unit was from DPCAV and not HobbyKing which probably had something to do with it. He had plenty of video to go out even further with only an 8dbi patch on the ground. No tracker, no booster, nothing fancy.

-Alex

With very small video tx antenna for speed and aerodynamic for plane go with high power video tx which is 2.4

I put video tx antenna inside plane or very very little exposed outside plane, about size of a servo cover, so actually no drag at all


Ground station antennas can be large but plane video tx antenna has to be smallest possible

Originally Posted by gundamnitpete

I fly 1280 with 900mhz antennas all the time, and 900mhz with 1280 antennas on the time.

although that's only on the RX side, TX's always have an appropriate antenna.

UHF antennas can be folded or shortened to 1/4 length so made very small and still go very far away

Been there done that



It's all about aerodynamics or in case of copter short antenna :

Originally Posted by IBCrazy

There are many reasons for UHF on a multirotor. 72MHz antennas are really long and there might not be a place to put it. 2.4 GHz is ok, but if you want to fly behind objects or use any frequency other than 5.8GHz for video, you can't use 2.4GHz for control. That leaves UHF as the only option.

-Alex