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Feb 22, 2016, 03:35 PM
Can you fly bobby?
MK1G4V's Avatar
Quote:
Originally Posted by Daemon View Post
I've tested the stock Rlink Tx whip to a range of 105km.
Planning to need more than that?

One thing rarely noticed is that most 3rd party antennas including SRH-771 have a male SMA
connector that lacks the normal barrel surrounding the center pin. Per SMA spec that barrel actually
is supposed to make the ground connection, but even if it's just a block of Teflon (as is sometimes the case)
it stops the connector from screwing in too far. Lacking that barrel, when you screw this non-standard
male connector into to any female connector it will keep going down until it buries the center pin at the bottom
of the female receptacle. That can damage the female connector. On some systems
that receptacle is supported only by a small center core of a coax wire, and it'll eventually
just snap it off with repeated insertions. Anyway, no point in taking this risk, because Rlink works fine with
stock Tx antenna. I do replace the Rx whip antennas with dipoles though.
That distance. No not yet at least..

I could do with swapping out the whips to be honest to something with a small length of extension maybe 15cm to get the antennas right at the rear of the plane..

What sort of orientation are you mounting the dipoles?
1 horizontal 1 vertical?
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Feb 22, 2016, 05:38 PM
Registered User
Daemon's Avatar
I only use one, and it's vertical.
Feb 23, 2016, 07:58 PM
Opt
Opt
Registered User
I'm a little dissapointed - I had a fail and crash with my RLink. I wasnt expecting it as I still had 5.8 video, although the vrx antenna was at head height and the rctx was at my waist. It happened at what might have been slightly over the horizon from where I was at about 500m distance, so could be a multipathing and slight bvlos issue.

I'm not sure if it was onboard noise (I flew 1.5km at higher altitude away on the same flight), or maybe the stock whips - my first time using them.

My plan is to add ground wires to the whips to convert them to dipoles and try out the micromode to see if there is any apparent onboard noise. Any other suggestions?

Can see the failsafe in the last few seconds of this video
Skyfun FPV maiden and chase flight (4 min 14 sec)
Feb 23, 2016, 08:47 PM
Registered User
Daemon's Avatar
While I've done some great long range ground tests with the stock whips on the Rx, I've
been less impressed when I tried using them on a plane. Pretty much the only time
I've ever experienced a failsafe, was while using the stock whips. I make my own dipoles
and only use one. (never felt I needed more than one).
A buddy of mine did what you're thinking of, adding a ground to his stock whip, and it
seems to work fine.

As for flying NLOS. Assuming no other factors are hurting the signal, I can say almost unequivocally
that that is not the issue. I've flown it completely out of LoS miles away and still retained
full control. I've done many ground tests where I put good sized hills and parts of mountains
between Tx and Rx, without losing control. I've never had any issues when violating
the Fresnel zone, other than a small decrease in RSSI. No other UHF system comes
close to Rlink's NLOS performance.

The only problem with the micro mode is that it's still good for several hundred meters,
so setting the baseline range (outside the aircraft) can be somewhat of a pain.
If you can, I suggest adding an attentuator to the Tx, so you can cut the micro power
range down to less than 100m.
Mar 01, 2016, 03:22 PM
Registered User
Need help!

When connect TX to PC just got 2 files (tx.txt and tx.cfn) with 0 size.
Can't open it for editing.

Tried copy 1.1.4 firmware but without luck.

How to copy correct tx.txt config file to TX ?
Mar 01, 2016, 04:46 PM
Registered User
Daemon's Avatar
There should only be one file there. Judging by the dates, one of them you copied there yourself.
You haven't said whether you have an older Rlink unit or newer, so I can't say which format of config file it's expecting.
Why are you messing with the firmware?
Mar 02, 2016, 12:10 AM
Opt
Opt
Registered User
Quote:
Originally Posted by Daemon View Post
While I've done some great long range ground tests with the stock whips on the Rx, I've
been less impressed when I tried using them on a plane. Pretty much the only time
I've ever experienced a failsafe, was while using the stock whips. I make my own dipoles
and only use one. (never felt I needed more than one).
A buddy of mine did what you're thinking of, adding a ground to his stock whip, and it
seems to work fine.

As for flying NLOS. Assuming no other factors are hurting the signal, I can say almost unequivocally
that that is not the issue. I've flown it completely out of LoS miles away and still retained
full control. I've done many ground tests where I put good sized hills and parts of mountains
between Tx and Rx, without losing control. I've never had any issues when violating
the Fresnel zone, other than a small decrease in RSSI. No other UHF system comes
close to Rlink's NLOS performance.

The only problem with the micro mode is that it's still good for several hundred meters,
so setting the baseline range (outside the aircraft) can be somewhat of a pain.
If you can, I suggest adding an attentuator to the Tx, so you can cut the micro power
range down to less than 100m.
Appreciate the input Daemon. Ive converted the monopoles to dipoles and will be out to test soon.
Also have an attenuator and will check up on that noise floor
Mar 02, 2016, 03:43 AM
Registered User
Quote:
Originally Posted by Daemon View Post
You haven't said whether you have an older Rlink unit or newer, so I can't say which format of config file it's expecting.
Why are you messing with the firmware?
I don't know which version I have, but my rx have blue color sticker (a new one?)

Tried copy 1.1.4 firmware with switch on low. Firmware file didn't disappear after reconnect and config are 0 size always.

Can't find any other firmware on Internet.
Mar 02, 2016, 04:17 AM
Registered User
Daemon's Avatar
So basically you just randomly started copying old stuff you found on the internet to the new
Rx, without actually seeing if the Rx already works?
Delete the rx.cf file (it's for the older version of the Rx). Stop trying to destroy it with old firmware.
Change your windows Explorer settings to show the extensions of known file types.
It'll show you that the config file that's already there is called rx.txt and should be editable with Notepad.
Same on the Tx (tx.txt) . Just need to make sure max channel count, and min/max
frequency are the same, and then bind Rx to Tx using instructions in the manual.
Mar 02, 2016, 04:59 AM
Hobbyzone.Au's Avatar
Here is a 4.2 hour Flight with the MTD, achieved using our FPV-Power Ion battery packs.

Range : 184km total.
Furthest distance : 90km with full video and control.

Yes its a long flight! Will upload the video of the DVR down link soon for those interested.

This is a 4s12p Lithium Ion pack. 42,000mah 16.8v fully charged, and weighs only 2.4kg
noting that each cell can go safely down to 2.5v ! yes 2.5v

Notice the Lowest Voltage we hit was 10.4v ( try that with a lipo)
The AUW on this MTD was approx 4.7kg, battery fit perfectly with the pack push right at the front. which produced a perfect COG.

More than ample room to move the pack backwards towards the tail if you wish to put a gimbal at the front etc..

This flight was aimed for efficiency, so No unnecessary drag such as gimbal was used.

A combination of the following product was the key to this successfully flight.

Fpv-Power ion packs
MTD Plane
MFD Auto pilot
MFD Link

And Yagi antennas.

253 mins in the air !! over 4 hours!
Latest blog entry: Custom Tuned Yagi Antennas
Mar 02, 2016, 05:23 AM
Hobbyzone.Au's Avatar
BTW, Rlink was on Low power for the duration of the flight. with out any issues at all.
Latest blog entry: Custom Tuned Yagi Antennas
Mar 02, 2016, 11:03 AM
Registered User
_Milo_'s Avatar
Very impressive,

Congrats on your successful flight!
Mar 02, 2016, 11:19 AM
Registered User
Daemon's Avatar
Quote:
Originally Posted by Hobbyzone.Au View Post
BTW, Rlink was on Low power for the duration of the flight. with out any issues at all.
What antenna did you use on the Rlink Tx?
Mar 02, 2016, 03:54 PM
Registered User
Quote:
Originally Posted by Daemon View Post
Delete the rx.cf file (it's for the older version of the Rx).
I'm trying to remove both tx.txt and tx.cf but they reappear in themselves instantly.

Quote:
Originally Posted by Daemon View Post
Change your windows Explorer settings to show the extensions of known file types.
It'll show you that the config file that's already there is called rx.txt and should be editable with Notepad.
Same on the Tx (tx.txt) . Just need to make sure max channel count, and min/max
frequency are the same, and then bind Rx to Tx using instructions in the manual.
I can't open this files in notepad because of error message "The file or directory is corrupted and unreadable".

What other options might I try to solve this problem?
Mar 02, 2016, 04:05 PM
Registered User
Daemon's Avatar
Other than trying it from a different computer, I got nothing.


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