5Dbi Antenna Help

[SKYBORNE]

Hi All,

I would like to seek the knowledge of the group.
I bought a 5Dbi Antenna from Adafruit, along with the u.fl Connector. When I removed the original antenna I accidentally removed the signal pad from the module's PCB board. Luckily, I was able to expose a little bit of trace, and I soldered a very thin little piece of coper wire from the u.fl connector's signal tab to the exposed signal trace. I used a multimeter and all looked good so I powered up. This, also looked good and there were no antenna warnings or anything from the Taranis.

I think it's working well, and when I turn on the Taranis (not bound to a Rx yet.) The SWR reads 1 and then creeps up to 4, if I cover the antenna with my hand the SWR goes up to about 29, but when I release my hand, it goes back down to 16 and no lower. Than, if I put the radio in the microwave the SWR goes up to 35 and if I close the door the SWR goes up to 47. When I remove the radio from the microwave the SWR goes back down, but no lower than 16. However, if I power sycle the radio the SWR starts back at 1, creeps up to 4 and all is good as long as I don't touch the antenna.
Don't worry, I never turn on the microwave, I just use it as a ferrite cage. (Thanks James Burrill)

This SWR reading not dropping lower than 14~16 might be due to being inside my place, but I just don't know.

Any advice would be GREAT.

Thanks.

[bob195558]

Hi SKYBORNE,
I believe when testing the telemetry RSSI and SWR readings, the Taranis needs to be bind to its receiver.
With the telemetry SWR readings, 0 is the strongest signal connection strength
and the higher number readings indicates a lower signal connection strength.
There should always be a proper antenna attached to your Taranis transmitter when
powering it up or damage could happen to the transmitter.

Bob B.

[bob195558]

Hi SKYBORNE,
The older or D-Series telemetry TSSI signal connection strength readings are more to what we would think they should be, as the higher number
(like 100) is the strongest signal connection strength reading and the lower number readings are the weaker TSSI signal connection strength.

SWR reading have larger data reading jumps between reading that are opposite value readings compared to the TSSI data reading reports
which show much more stable data reporting.

D-Series telemetry TSSI signal readings track closely next to the RSSI signal readings.
X-Series telemetry SWR signal readings jump up and down between reading a lot more, making it seen to be less trust worth
and so less importance then what the TSSI readings give you.

Bob B.

[Kilrah]

D-Series telemetry TSSI signal readings track closely next to the RSSI signal readings.
X-Series telemetry SWR signal readings jump up and down between reading a lot more, making it seen to be less trust worth
and so less importance then what the TSSI readings give you.

You're implying TSSI and SWR are somehow related/similar, they are not.

With the telemetry SWR readings, 0 is the strongest signal connection strength

SWR has NOTHING to do with "connection strength".

SWR is evaluating antenna performance but VERY roughly, as in "if it's higher than 52 you should check the antenna is not broken because it might well be", but there isn't much more to learn from it.
What you get seems perfectly normal.

DO NOT forget that this is absolutely not linked to the range you may get, so that still needs proper range testing to determine. And remember your higher gain antenna achieves that by sending LESS signal in some zones compared to others, which is why they're only a good thing in very specific applications, which incidentally don't include casual RC flying.

[bob195558]

Hi Kilrah,
Thank you for clarifying the differences between TSSI and SWR .
I think because RSSI is signal strength between transmitter and receiver / model controls and
TSSI is signal strength between transmitter and receiver / telemetry data, because the SWR takes the same screen location as TSSI data did/dose, and by replacing TSSI with SWR, caused me to think SWR did the same function as TSSI but reported the data from the opposite direction.

So then the SWR (telemetry data) purpose is for comparing (roughly) antenna performance do to its construction, position and to the FrSky receiver antenna(s) construction, position with a know amount of FrSky D-Series and X-Series Receivers and Radio XJT transmitter power outputs.
Is my description of SWR purpose correct ?

Bob B.

[Kilrah]

No. It's only meant for detecting if the cable/connection to the radio's antenna is broken, i.e. whether a decently working antenna is connected to the radio or not.

[SKYBORNE]

OK, Here's an update.

Bound Tx to Rx, SWR, about the same as before.
RSSI, when first bound is around 85 to 90, just a few feet away. When I place radio in microwave RSSI drops to about 35 to 45.
When I put the Tx in [Range] mode the RSSI drops down considerably (I forget which value now). When I place Tx in microwave, in [Range} mode RSSI value drops down to 0.
Then I placed Tx in [Range] again (inside my house) and walked away from Rx. When I got about 37 feet away the "RSSI Low" alarm came on, then I went outside (about) 40 feet and I got the "Lost Signal" alarm.

So I'm guessing it's pooched, Maybe the module or the antenna.
What do you guys think??

[jhsa]

I wouldn't use the radio to fly if I didn't have control well over 100ft in range test mode, and that with a normal antenna.

João

[bob195558]

You could try purchasing an external XJT module: (https://alofthobbies.com/frsky-xjt-jr-g ... odule.html).
I have found the external XJT module has better range readings (works better) then the internal XJT transmitter.
In my RC group we have two Taranis-x9d's and see this with both of them displaying the same behavior.
I believe FrSky upgraded or changed (fixed) the internal XJT transmitter after the Taranis's that we have now.
I have a 2.4 Clover antenna, but I need to do a lot more testing (when I have time) to see if it has any improvement.
Here is a good video that will help to understand a little more about frequency: (https://www.youtube.com/watch?v=xCVd3QGQhKU).
Also you may want this tool: (http://www.immersionrc.com/downloads/ma ... Manual.pdf),
(https://www.hobbyking.com/hobbyking/sto ... duct=51616).
And also the see this: (http://j3.rf-explorer.com/40-rfe/articl ... cification)
more info about spectrum analyzers: (https://www.youtube.com/watch?v=19JNDCVHaQQ) and (https://en.wikipedia.org/wiki/Radio_spectrum).

Edit: How do Antennas work ? : (https://www.youtube.com/watch?v=fSoXIqBlg9M).

Bob B.

[SKYBORNE]

Thank you guys.

I'll look into this.
I was planning on just buying a new backboard <http://www.helibatics.com/frsky-taranis ... jt-module/> with the module for Taranis Plus, I never thought of buying an external XJT.
Maybe I can find a seller here in Canada.

[bob195558]

A video of modifying a Taranis plus radio to a 5dbi antenna
and range testing it: (https://www.youtube.com/watch?v=WBRddJsTYb0).

Bob B.