I'm so stupid- maybe chicken. Need some confidence.

Hardware help and support for the FrSky Taranis
Post Reply
c131frdave
Posts: 30
Joined: Tue Feb 04, 2014 11:21 pm
Country: -

I'm so stupid- maybe chicken. Need some confidence.

Post by c131frdave »

I am the first to shout the praises of the Taranis radio to my friends. I explain how it is superior to my old radio, a JR11X DSM2, how I happily sold my JR for twice what I paid for my Taranis and wouldn't look back. etc., etc. But I'm staring at my 3D gasser here in my workshop- the most expensive airplane in my stable, and I'm nervous.

Currently the airplane has a JR 1221 12-channel receiver with three satellites. Before this I had a 9 channel RX with two satellites and I had brown out problems when the airplane was at certain angles away from me. I lost control of it twice and almost crashed, so I invested in the 12 ch RX with three satellites and oriented them every which way you can. I had no issues after that.

But here I am again, with a FrSky D8R-XP receiver in my hand. I'm about to tear out the JR RX with all three of its satellites and install the D8R. Then I see those two flimsy antennas. Two. Flimsy. Two.....

I need some reassurance that I won't regret changing the RX to FrSky please. I know it is stupid because my buddy flies Futaba in an airplane worth twice what mine is, and it only has two flimsy wire antennas and he flies his darn near to the moon and back, he gets so high. I need a pat on the back and some courage. Thanks...

User avatar
dvogonen
Posts: 453
Joined: Tue Jan 31, 2012 9:38 pm
Country: Sweden
Location: Stockholm

Re: Sv: I'm so stupid- maybe chicken. Need some confidence.

Post by dvogonen »

My part of the confidence boost:
I have used Futaba 2.4, FrSky 2.4, FlySky 2.4 and DSM2 2.4.
Never any problems with neither Futaba nor FrSky. Both seem rock solid. Would gladly use either system for anything.
Lots of problems with FlySky and a few with DSM2. I would not trust either of these systems for anything expensive.
c131frdave
Posts: 30
Joined: Tue Feb 04, 2014 11:21 pm
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by c131frdave »

Thanks. It's funny because I've lost two airplanes to DSM2, and nearly lost others several times, yet for whatever reason, all those antennas everywhere makes it hard for me to replace them with just two. In actuality, the fact that DSM requires all those antennas should tell me that DSM2 is c**p and I should swap in the FrSky with haste... lol
User avatar
gohsthb
Posts: 1412
Joined: Wed Dec 28, 2011 2:32 pm
Country: -
Location: Naperville, IL

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by gohsthb »

The really nice thing about Frsky that you don't get with the other systems is telemetry. Note: you can get telemetry but it is $$$! And so it will warn you possibly before you have problems. I've mounted my' flimsy' antennas in plastic antenna tubes. Now they are not so flimsy. And helps keep proper 90 degree orientation. The last piece of advice, do good ground testing. Orient the plane in different directions while you range check.
-Gohst

Sent from my LG-D801 using Tapatalk
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Flaps 30 »

I haven't seen the aerial/antennas of the D8R-XP. Assuming they are the same as the D8R with it's 33mm 'whiskers', then I can say that I have got up to 1500 feet with minor blips on the telemetry. My first change was to reduce the whisker from what will be around 33mm to 29mm, which improved the signal by a reasonable amount. Do not cover the whisker with heatshrink as that will detune the antenna. You can put it in a plastic tube (I use plastic drinking straws) without any problem.

A further improvement over the whisker is something like a sleeve dipole, which from my tests gives something like a 6dB (double range) improvement over the whisker. Field tests backed that up with no beeps from the transmitter at all at the same altitude, which is at my limit before I loose orientation. . :)

I have yet to have any problems with the Frsky setup and any signal issues, even if you leave things as supplied. :)

User avatar
jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by jhsa »

Flaps 30 wrote:
A further improvement over the whisker is something like a sleeve dipole, which from my tests gives something like a 6dB (double range) improvement over the whisker.
Do you make them or do you buy them?

Sorry, I mean, can they be easily made from the stock antennas?

Thanks,

João
My er9x/Ersky9x/eepskye Video Tutorials
https://www.youtube.com/playlist?list=PL5uJhoD7sAKidZmkhMpYpp_qcuIqJXhb9

Donate to Er9x/Ersky9x:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=YHX43JR3J7XGW
User avatar
Bill
Posts: 195
Joined: Thu Jul 04, 2013 5:54 pm
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Bill »

from what will be around 33mm to 29mm
Is the length of the sleeve the same as the whisker? Is 29mm a 1/4 wavelength?
What tube diameter did you use? :ugeek:
“A good politician is quite as unthinkable as an honest banker”
They used to say "if you don’t want to work at McDonald’s, go to college." Now they say "if you want to work at McDonald’s, go to college.”
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Flaps 30 »

I make them. Yes they are easy to make using the stock antenna.

Bill - The 29mm worked fairly well and it did look better than the 28 odd millimetres that I have for most of my aerials. Hence why I suggested it.

All that I have made have been measured/adjusted using an SWR meter along with doing a rough measurement of the signal strength compared to a standard dipole. The centre frequency was set at 2440 Mhz (which is the centre of our band in the UK) rather than 2400 Mhz where many antennas seem to be cut for.

Below is a picture of three different ones. The first one (top) has a 3mm nickel plated brass sleeve. The second uses a 4mm brass sleeve/tube. The bottom one is another way you can do things and it gives the same result as the sleeve versions. The extra bit of wire that makes the ground plane is made out of a paper clip. :) Overall the bottom one (ground plane dipole) along with the 4mm sleeve, gave the most consistent results and they were more tolerant of small errors in dimensions.

The sleeve versions have the coax outer soldered to the sleeve at the top where the whisker is. The inner won't melt if you use a reasonable heat iron and you are fairly quick. The coax where it comes out of the sleeve is kept central by a few wraps of PTFE (plumbers) tape that is pushed into the sleeve, no need to fill the sleeve with it. I made a thin string out of the PTFE tape which I wound around the coax until it reached the diameter of the sleeve before pushing it in to make a tight fit. Silicone glue works as well if you so wish. :)
Dipoles.JPG
PNaz
Posts: 142
Joined: Tue Dec 27, 2011 5:28 pm
Country: -
Location: Kaleden (Twin Lake), British Columbia

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by PNaz »

Flaps 30, have you tested these: http://www.alofthobbies.com/40cm-receiver-antenna.html. Also available in 25cm and 60cm lengths. They appear to be sleeve dipole. I have a set but haven't installed them yet.
The pcb antennas that come with the Taranis X series receivers are supposed to be better than the whiskers and should work with the D series receivers. They are bulky and inconvenient to use in small diameter glider fuselages.

Paul
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Flaps 30 »

PNaz wrote:Flaps 30, have you tested these: http://www.alofthobbies.com/40cm-receiver-antenna.html. Also available in 25cm and 60cm lengths. They appear to be sleeve dipole. I have a set but haven't installed them yet.
No I haven't tested them. It looks like it is the sleeve dipole as you say or what Hitec love to call a BODA. Don't be tempted to remove the heatshrink, as it will detune the antenna. I have made a few that I have covered with heatshrink, with dimensions altered slightly compensate for the covering. The results were not as good as the uncovered ones placed inside a drinking straw or left in the open. Having said all of that. With or without heatshrink without altering the dimensions shown in my last post the results are far superior than the original whiskers.

What I found to be of some interest regarding the comments left on the link you gave was the one concerning how it reduced servo jitter and reduced interference for fpv. It should be remembered that the telemetry receivers have a transmitter inside them, and you should try to keep the antennas away from other electronics. The sleeve dipole does help a lot (if built correctly) in stopping unwanted RF appearing on the outside of the coax which helps in preventing interactions with other things.
PNaz wrote:The pcb antennas that come with the Taranis X series receivers are supposed to be better than the whiskers and should work with the D series receivers. They are bulky and inconvenient to use in small diameter glider fuselages.
Well yes. The whiskers as they stand are not that brilliant, even when they are cut down the 33mm whisker showed an SWR of around 4:1 (RL 4dB) and the 29mm was 2.3:1 (RL 8dB) which isn't tall that good but the 29mm one is an improvement all the same. Of course SWR is not the great God when it comes to how good an antenna is with respect to gain, hence why the field strength measurements that showed the whiskers to be not that good, even when they are cut back. I got something like a 2dB improvement at 29mm over the 33mm one that was far out of resonance.

For a glider with limited space I would go for either the 3mm sleeve dipole or the ground plane.

I would love to see a picture of what is under the wraps of the PCB antennas. IMO whatever it may be it will more than likely be no better than a sleeve dipole. Laws of physics come into play here. :)

Sorry about the thread hijack c131frdave. I hope this information is of some use.
davx
Posts: 210
Joined: Sun Sep 15, 2013 7:01 am
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by davx »

Flaps 30 wrote: I would love to see a picture of what is under the wraps of the PCB antennas. IMO whatever it may be it will more than likely be no better than a sleeve dipole. Laws of physics come into play here. :)
Here you go :
http://fpvlab.com/forums/showthread.php ... post319091
User avatar
Bill
Posts: 195
Joined: Thu Jul 04, 2013 5:54 pm
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Bill »

I have made a few that I have covered with heatshrink, with dimensions altered slightly compensate for the covering.
Is the heatshrink conductive at RF frequencies or is it carbon loaded, does clear heatshrink do the same?
“A good politician is quite as unthinkable as an honest banker”
They used to say "if you don’t want to work at McDonald’s, go to college." Now they say "if you want to work at McDonald’s, go to college.”
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Flaps 30 »

The heatshrink isn't conductive as such with regards to the RF. The dielectric properties of the heatshrink is what is playing the part here. It has the effect of detuning the aerial slightly to a lower frequency. I have checked out the effect with black and clear heatshrink and they both give the same result. The plastic drinking straw with a bit of Blu-tack stuffed in to stop the aerial from falling out doesn't affect the aerial at all.

Having said all of that. Even if you insist on putting heatshrink over the assembly, you will find that the SWR still remains below 1.7:1 which is fairly respectable and a darn sight better than the original whisker.

I have noticed on Giantshark that they are selling Frsky receiver aerials that look like they are of the sleeve dipole type. Maybe Frsky have decided to go that route, and phase out the whisker only receivers. Does anyone know?
User avatar
MikeB
9x Developer
Posts: 17990
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset, UK

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by MikeB »

They seem to be the 40cm and 60cm types, perhaps they are compensating for losses in that length of coax.

Mike.
erskyTx/er9x developer
The difficult we do immediately,
The impossible takes a little longer!
pixturethis
Posts: 25
Joined: Sun Mar 02, 2014 3:26 am
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by pixturethis »

I've been out past 5 miles with a stock antenna on a DR8-ll receiver. I would like to try the dipoles to see how they do.
This was done with a FPV radian. I could never get past 1.5 mile with a A9 or 1.0 with a DSM2.


Sent from my iPad using Tapatalk
Using Tapatalk
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Flaps 30 »

MikeB wrote:They seem to be the 40cm and 60cm types, perhaps they are compensating for losses in that length of coax.
You could be right Mike. The loss of the mini coax is about 1dB per foot with the wind in the right direction.
pixturethis wrote:I would like to try the dipoles to see how they do.
Please post your results. :)

Someone suggested stripping the coax shield back and using that instead of the tube as the other element of the dipole. The problem with that, is that it puts you back to a position not far removed from the original if you push it against the coax. So you do not get much in the way of an improvement if any.

If you want to avoid using the tube or having a bit sticking out from the side at right angles. You could do something along the lines of the following. You will need a paper clip or some stiff wire to make the other element. The spacing between the coax and the paper clip earthed element needs to be no less than 3mm, it can be more if you so wish. Contact adhesive was used as the standard hot glue has a detrimental effect on the performance at the frequencies we are using. I was watching the SWR slowly improving as the solvent evaporated from the contact adhesive until it finally dried out giving an SWR you would expect in open air. :)

No field strength measurements have been made with this one, but I have no doubt that it will be pretty close to the sleeve dipole. The SWR was very good at 1.15:1 (RL 23dB) centred at 2440 Mhz
100_0272 Dipole.JPG
IMO this isn't the best of the bunch as there is some interaction between the coax and the dipole which has some effect on the performance, but that is me being picky. Again this baby is a better bet than the standard whisker.
User avatar
jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by jhsa »

could we use hot glue instead of the contact adhesive? Flaps30, thank you for the pics and the explanation. Very good info.. It deserves WIKI ;)
I know Rob, I know :D

João
My er9x/Ersky9x/eepskye Video Tutorials
https://www.youtube.com/playlist?list=PL5uJhoD7sAKidZmkhMpYpp_qcuIqJXhb9

Donate to Er9x/Ersky9x:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=YHX43JR3J7XGW
User avatar
Bill
Posts: 195
Joined: Thu Jul 04, 2013 5:54 pm
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Bill »

could we use hot glue instead of the contact adhesive?
No...
Contact adhesive was used as the standard hot glue has a detrimental effect on the performance at the frequencies we are using.
“A good politician is quite as unthinkable as an honest banker”
They used to say "if you don’t want to work at McDonald’s, go to college." Now they say "if you want to work at McDonald’s, go to college.”
User avatar
jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by jhsa »

ahh, thanks.. missed that. Sorry..

João
My er9x/Ersky9x/eepskye Video Tutorials
https://www.youtube.com/playlist?list=PL5uJhoD7sAKidZmkhMpYpp_qcuIqJXhb9

Donate to Er9x/Ersky9x:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=YHX43JR3J7XGW
pixturethis
Posts: 25
Joined: Sun Mar 02, 2014 3:26 am
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by pixturethis »

I will be glad to try different types of antennas. If you could you could send me some to try, if you want, I'll be glad to send them back after I try them and I could send back stock one if you want to modify them. I like the dipole with the paper clip glued to the coax. I might try that one first.
Marc


Sent from my iPad using Tapatalk
Using Tapatalk
User avatar
Flaps 30
Posts: 1490
Joined: Tue Dec 27, 2011 6:04 pm
Country: -
Location: Wokingham Berkshire

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by Flaps 30 »

Marc - You are a bit far away and the costs of sending aerials to you is prohibitive.

It is easy to build the paper clip one. You can do that without having to tear things apart from your receiver. Just use what is there now. Take off a small section of the outer covering off, which will expose some braid and solder the paper clip section to that. Then cut the paper clip and the 'whisker' to the dimensions shown. It took me less than ten minutes to build test and trim the one shown. The most difficult part will be stripping off the coax outer covering without damaging the inner conductor, so some care is required there.

João - Hot glue and most resins that we use are have loses that are pretty high at 2.4Ghz which screws things up. You could use a small dab of clear silicone glue/compound instead of the contact adhesive as that seems to be fine in small quantities.
User avatar
jhsa
Posts: 19480
Joined: Tue Dec 27, 2011 5:13 pm
Country: Germany

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by jhsa »

I have an antenna that I've damaged (if I didn't throw it away already) that I can use to practice. I would like to make 2 of these to put on my glider with a D4R-II receiver. I had an "telemetry lost" alarm the other day and I wasn't even at 100 meters high. A few days before the RSSI logging was much higher and I was even higher. :o will have to investigate it. But the D4R-II has less range than the other frsky receivers in my opinion, even if they class it as a full range receiver. It might not be suitable for a glider..

Thank you.

João
My er9x/Ersky9x/eepskye Video Tutorials
https://www.youtube.com/playlist?list=PL5uJhoD7sAKidZmkhMpYpp_qcuIqJXhb9

Donate to Er9x/Ersky9x:
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=YHX43JR3J7XGW
pixturethis
Posts: 25
Joined: Sun Mar 02, 2014 3:26 am
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by pixturethis »

I use the DR-XP as I need ppm out. It has been a great receiver. I do take it out of its case, as it is much smaller.
Thanks Flap, I did not know you where so far away. I'll make some my self.
Marc


Sent from my iPad using Tapatalk
Using Tapatalk
ReSt
Posts: 1581
Joined: Tue Dec 27, 2011 11:34 pm
Country: -

Re: I'm so stupid- maybe chicken. Need some confidence.

Post by ReSt »

@ Flaps 30
Hi Flaps, what do you think of these antennas, scrapped from a laptop (probably bluetooth and wifi) ?

Reinhard
ANT2.JPG
ANT1.JPG

Post Reply

Return to “FrSky Taranis radio”