Keep losing signal at about 300 ft up

[jax]

Hey guys,

I'll try to not make this a typical "solo lost signal" thread, and my situation may be unique so please keep reading.

New Solo pilot here - I bought one used from a buddy of mine who only flew it a few times. I've flown various RC craft and strapped cheap cameras to many of them (and kites as well) but this is my first serious GPS controlled camera platform, and so far it is pretty cool, and very easy to fly, but I do have one issue.

When flying from my roof (I have a big flat roof deck at my house) I keep losing connection to the controller and the app at about ~300 feet. I am flying with stock antenna and I tend to not let it wander too far from the launch location, just straight up and maybe 10 of feet away from me in any direction, at least for now as I get comfortable with the aircraft.

The signal always looks relatively ok, but then seems to drop out very quickly as I ascend. On one more cautious follow up flight I noticed the signal dropping from 4 bar to 2 bar almost immediately as I passed 200 feet.

My antenna are configured correctly, pointing down and separated as the manual says. GoPro Wifi is off and I always have a clear LOS to the aircraft.

From what I have read it could be a number of things:

• It could be wifi interference, but I feel like that would get better as I ascend not worse. There aren't too many other wifi radios broadcasting up there, but there's definitely some competing wifi signals on the ground, but despite the wifi environment on the ground the copter flies great under 300 feet.
• It could be that the stock antenna sucks.
• It could be that the stock antenna doesn't work well when I am roughly straight up, and I should be flying away and up instead of just up. I'm sort of scared to test that because a recovery if something went wrong far away from me could be tricky. I saw something about the cone of best reception for the dipole antennas and straight up didn't look ideal.
• It could be that the nearby radio mast is causing interference at that height. There is one about 0.3 miles away and I don't have a lot of information on what it transmits (maybe FM). You can see it in the Google Earth image I am attaching.

I tried flying way out in the suburbs and it didn't lose signal out there, so maybe it has something to do with the environment here.

Anyway I am wondering what I should do about it.

• Just not fly above 300 feet when I launch from home?
• Buy a different antenna? Any recommendations? Do I Need to spend $130 to get a good Antenna? FPVLR may be overkill for me. I don't want one that will let me fly 2 km from home, only one that will let me fly more reliably in the 400 feet altitude range above my house. I love taking shots of the landscape here. Is there a cheaper antenna that will improve performance that somebody could recommend?
• Something else?

I've viewed the data flash logs in APM Planner but don't see any way to view signal strength. It would be interesting to plot that if possible. Any ideas on that?

One piece of good news is RTL has performed flawlessly every time this has happened, although my heart always skips a beat and I have to hope the Solo comes home like it's supposed to. Luckily I haven't had any GPS issues yet.

Any advice would be appreciated.

 

[DJMc]

I think the concensus will be that one of your suspicions is correct. It's likely the vertical climb - it doesn't really help reception

For a comprehensive description of performance, including stock antennas, this is a good thread;

Basic Guide to Solo Antennas (Stock, Alfa, FPVLR)

It gives you an idea of the pros and cons of each option, if you were thinking of modding antennas - not essential at all BTW, but 'horses for courses'.

I'd try and fly in open field with some lateral separation if you can. It should help confirm your issue is related to staying in the overhead.

 

[jimloss]

Your situation is only unique because of your exact location. This is not a unique problem and there are many posts about it.

Factors include interference near your transmitter, interference where your Solo is at the moment, and the location of your Solo in relation to your antenna position on your transmitter.

The best signal strength from stock transmitter antennas is located 90 degrees from the antenna length. The weakest signal is off the ends of the antenna.

Regardless of what antenna you use on your transmitter, you are going to need to change the angle of your antennas (or transmitter and antennas) when you are flying high overhead. Imagine a line extending 90 degrees from the surface of the antenna and keep it pointed toward your Solo. The stock omni-directional antennas are the most forgiving since their signal is a large donut shaped signal. Directional antennas will be less forgiving, but allow you to fly greater distances.

 

[jax]

Thanks. Is there any particular antenna that works best straight up, or any optimal way to orient the stock antennas for that type of flight?

 

[jimloss]

Thanks. Is there any particular antenna that works best straight up, or any optimal way to orient the stock antennas for that type of flight?

Given the fact that you were able to get to around 300' with stock antennas with the standard orientation, I don't think that you need different antennas to fly straight up. Try pointing your antennas straight out from the back of the transmitter.

 

[jax]

Given the fact that you were able to get to around 300' with stock antennas with the standard orientation, I don't think that you need different antennas to fly straight up. Try pointing your antennas straight out from the back of the transmitter.

I'll try pointing them straight out when flying up.

It seems the paddle antennas might be a reasonable option to try. With those I'd point the flat surface of the antenna to the drone, correct? I like the idea that they provide a wider "beam" than the other long range directional options like FPVLR.

 

[jax]

Is flying with one stock antenna and one paddle antenna a possibility? I'm looking at the Alfa. Seems like a cost effective option.

 

[DJMc]

Post #30 of the thread I mentioned above discusses testing just such an arrangement.

 

[jimloss]

Is flying with one stock antenna and one paddle antenna a possibility? I'm looking at the Alfa. Seems like a cost effective option.

I have Alfas and FPVLR. Depending on the location and type of flying that I'm doing I switch between them.

Why mix a directional and omni antenna? The two antennas are not used for separate functions. They work together. Either you want the added distance or strength of a directional antenna or you want to fly near and all around without the limitations the directional antenna.

Given the fact that your stock antennas got you to around 300' without being "aimed" toward your Solo, you'll almost certainly be able to get to the max of 400' when you orient the antennas for overhead flight. If you find that you don't get the height or distance you want when facing the antenna toward your Solo, then try the Alfas.

 

[jax]

I have Alfas and FPVLR. Depending on the location and type of flying that I'm doing I switch between them.

Why mix a directional and omni antenna? The two antennas are not used for separate functions. They work together. Either you want the added distance or strength of a directional antenna or you want to fly near and all around without the limitations the directional antenna.

Given the fact that your stock antennas got you to around 300' without being "aimed" toward your Solo, you'll almost certainly be able to get to the max of 400' when you orient the antennas for overhead flight. If you find that you don't get the height or distance you want when facing the antenna toward your Solo, then try the Alfas.

Thanks. I'm pretty sure when I first started flying and first had this issue, I had the antennas pointing relatively straight up. Then when I read the manual more closely, I tried pointing them down. Now I need to test it out again pointed up for vertical flight even though I did that once before -because now I am paying a lot more attention to whats going on with the antennas and signal strength. After a few more test flights I'll probably decide about the Alfas.

 

[jax]

One more question, is there a way to log signal strength? I'd like to be able to plot signal strength of various flights with different antenna orientations. Is that possible? The dada flash log did not seem to include rssi.

 

[jimloss]

Thanks. I'm pretty sure when I first started flying and first had this issue, I had the antennas pointing relatively straight up. Then when I read the manual more closely, I tried pointing them down. Now I need to test it out again pointed up for vertical flight even though I did that once before -because now I am paying a lot more attention to whats going on with the antennas and signal strength. After a few more test flights I'll probably decide about the Alfas.

No - never point them up. They should be down and slightly out for flying distances. If flying close by and/or above, position them so that your Solo is 90 degrees off the length of the antenna - never off the end of the antenna. If you are flying directly above, then you can try positioning the antennas to point straight out the back of the transmitter, not up.

 

[jax]

No - never point them up. They should be down and slightly out for flying distances. If flying close by and/or above, position them so that your Solo is 90 degrees off the length of the antenna - never off the end of the antenna. If you are flying directly above, then you can try positioning the antennas to point straight out the back of the transmitter, not up.

Ok, I see. That makes more sense. Thanks.

Any way to log RSSI?

 

[jimloss]

Any way to log RSSI?

Not sure where - at work now though so can't look up - maybe later

 

[jax]

I found the wifi log from the copter via SFTPing into it. Here's what I see during the event.

Feb 8 23:53:42 3dr_solo local3.info rssi_send: station sig=-58 txr=57.8 rxr=7.2 ret=331 err=84
Feb 8 23:53:43 3dr_solo local3.info rssi_send: station sig=-58 txr=39.0 rxr=7.2 ret=364 err=96
Feb 8 23:53:44 3dr_solo local3.info rssi_send: station sig=-59 txr=39.0 rxr=7.2 ret=112 err=96
Feb 8 23:53:45 3dr_solo local3.info rssi_send: station sig=0 txr=0.0 rxr=0.0 ret=0 err=0
Feb 8 23:53:46 3dr_solo local3.info rssi_send: station sig=0 txr=0.0 rxr=0.0 ret=0 err=0
Feb 8 23:53:47 3dr_solo local3.info rssi_send: station sig=0 txr=0.0 rxr=0.0 ret=0 err=0
...
Feb 8 23:54:08 3dr_solo local3.info rssi_send: station sig=0 txr=0.0 rxr=0.0 ret=0 err=0
Feb 8 23:54:09 3dr_solo local3.info rssi_send: station sig=-56 txr=1.0 rxr=6.5 ret=1 err=0
Feb 8 23:54:10 3dr_solo local3.info rssi_send: station sig=-54 txr=57.8 rxr=6.5 ret=102 err=0
Feb 8 23:54:11 3dr_solo local3.info rssi_send: station sig=-55 txr=65.0 rxr=6.5 ret=86 err=0

When I lose it my signal goes from -59 db to 0 in one second then when it recovers it's back at -56. Can anybody tell me if this seems normal? I need to brush up on my rx theory but is -59 a very poor signal? Is that poor enough for it to lose the connection?

 

[jax]

Any idea if -59 dB is low enough for it to normally lose signal or if this evidence supports the conclusion that I flew into the “dead ahead” transmitter dead zone?

 

[XterraGuy]

My experience is thast -59 is not low unless you're competing with stronger signals... and it seems you probably are. So it appears you need to get more signal there or fly elsewhere. Using the stock antennas oriented perpendicular to the Solo may do it... otherwise youll need to use a directional option.

 

[XterraGuy]

Perpendicular meaning to the radiation pattern as previously described. Of course, you'll always get less loss with a circular polarized antenna on the controller, as its easy to lose correct alignment with the stock antennas...

 

[carts123]

I think you need to fly away more i had thst exact thing happoen a few times and it was alwsys right above me. Its the signal tjing rigjt abive you. At least in most cases

 

[carts123]

Also looking at the pics i bet u csn get some good footage and shots from where u are . City shots