Hi all,
just got my EZUHF in the post today, I've plugged it in & all "seems" to be well - so far. I've downloaded the UK firmware for it & have the 459 antennas too. Thank you Firstpersonview.co.uk!!
I've managed to get a baseline with the analyser & turned on all the plane's systems one by one to see if I get any noise, gopro, bec, rx, esc & motor (span-up), the only thing I found that increased the noise floor was my VTX which added about 6-10db of noise, from about -97 to roughly -86 is that ok? I placed the UHF RX halfway out on the wing of my ZII from the VTX which is halfway out on the opposite wing. I also tested the RX on the tip & got about -90, I was thinking of using 30-40cm pigtails to move the antennas tip-ward - would that be ok for respective signals?
Also how should orientate my diversity antennas? @ 45º fore & aft or left & right?
But what I'm thinking for buddy leads, could I say use a headphone switch to flick between x2 DX8 TX's with the exact same settings to use as a UHF buddy system? I'm guessing the EZUHF doesn't know what's plugged into it so long as it receives a valid PPM signal so could I just flick a switch from one PPM to another inflight?
Any thoughts or tips would be greatly appreciated here, I'm trialing the system on my battered old FPV trainer first, it cost me £30 so I ain't too fussed if it goes in.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18703 (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18703)
if you have 2 Transmitters
Quote from: hase2 on August 22, 2012, 02:09:35 AM
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18703 (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18703)
if you have 2 Transmitters
Nice one, I was looking at those, I was tempted but I just didn't fancy trying to shoe-horn that board, 24 servo leads & another rx into my ZII. I thought a quick flick of a switch on the ground & job done would be good, I didn't know if it would be possible with UHF, but I can't think of a reason why not.
Just thought, anyone know what sort of range I'll get on 459mhz with 100mw?
You could reasonably expect from 4 - 8km maybe more depending on location and noise floor
Quote from: Coyote on August 22, 2012, 11:22:31 PM
You could reasonably expect from 4 - 8km maybe more depending on location and noise floor
Cool, noise floor is looking like it'll be around -90 to -80, prob about -85.
Mate do you know if I can use cables to move the antennas out to the wingtip on for both the 5.8 vtx & uhf rx without having either all the way out there, am only thinking of about a 30-40cm run.
You can extend UHF coax without loosing much down the runs, the downside is getting hold of the Sma`s to make the antenna end and buying the crimp tool. But if you have them then yes you can
Quote from: Coyote on August 22, 2012, 11:30:23 PM
You can extend UHF coax without loosing much down the runs, the downside is getting hold of the Sma`s to make the antenna end and buying the crimp tool. But if you have them then yes you can
Sweet, got the cable & sma's in the post & have a crimp tool ;)
Click "wi-fi antennas" at the top.
http://www.allendale-stores.co.uk/ (http://www.allendale-stores.co.uk/)
Yeah that`s who I use :)
Quote from: Coyote on August 22, 2012, 11:33:44 PM
Yeah that`s who I use :)
They're a good lot, They sell eagle tree too!!
Today I tried a basic radio swap on my powered ezuhf. I had x2 dx8's with the same copied model active (love the sd card slot!!), I powered up with one then tested the controls, I then unplugged the 1st dx8 & plugged in the 2nd, & within a second I had full control on the second handset! I then switched back to the 1st dx8 & again full control within a second. This test was conducted on the ground with the ezuhf powered from a separate 3s lipo through the dc in socket & NOT spliced into the trainer/ppm cable.
Does anyone have any thoughts on this?
Also I have sander style antennas & have read in a few places that they need to be connected directly onto the UHF rx? Would this be correct thinking as it could effectively increase the overall antenna length if extensions are used thus decreasing sensitivity to the desired frequency?
Tested my ezuhf today, worked great. I range tested it on the 20mw super low power mode at 140m with full control!!
I couldn't believe it!! :o
It flew great, but as I taped my vtx on top of the wing it ruined the aerofoil & kept stalling the wing out, ended in a busted motor mount on landing after one circuit, doh!
Glad I put it on the apprentice! Shame I messed up the aerodynamics of flight, lesson learnt. Don't disturb the airflow over a wing.
Well, I got round to building my little UHF "buddy box" & I gotta say it works really nicely.
I have both TX's plugged in & the output is selectable to the EZUHF, as the same model is active on each DX8 TX the plane is instantly controllable from either TX with a flick of a switch.
Left mono 3.5mm jack is 2nd TX PPM input
Lower cable with mono 3.5mm plug is 1st TX PPM input
Lower mono 3.5mm jack is EZUHF PPM output
Right switch is a dual pole double throw switch (on/on)
The plugs & cables are set like this so I can just remove the "buddy box" completely & plug the EZUHF directly into the rear of the master TX without any additional plugs or adaptors.
(http://s16.postimage.org/fkvx1r8dd/photo_1.jpg) (http://postimage.org/image/fkvx1r8dd/)
(http://s16.postimage.org/seyk8ub6p/photo_2.jpg) (http://postimage.org/image/seyk8ub6p/)
I was told I should use "PPM in" on the TX to accomplish the same ends without this box, but as Spektrum only has a PPM out & ground wires in their TX's trainer sockets I don't think thats possible, unless Im missing something.
Probably doable on Futaba I guess.... :dunno: