Hitec Optima 2,4 signal stability

[freezer]

I'm using Spektrum DX7 and I had short signal losses when engine, ignition and/or battery had blocked signal to my recievers. I know one person which were using futaba 14 channel 2.4 reciever and have lost his model probably because signal was blocked by the engine. Many people knows, there might be issues with carbon fuses and carbon parts in model. As I presume that is only because 2,4 Ghz signal specifics.
And question is - if Hitec Optima recievers have only 1 short antena, isn't it possible that signal might be completely lost if will be shadowed by engine, ignition or any carbon parts ?
Any one had allready flown his gas model, composite or carbon fuse model with Optima recievers ?

[BubbaGump]

I have not had any problem with mine and I fky IMAC. I fly a really big box almost unlimited size box. I mount my antenna on one of the formers point out towards one of the wingtips. I have included a pic of how mine is mounted. Hope this helps.

[Mike Mayberry]

In an all/mostly carbon fuselage you should exit the the tag end of the antenna. In all other airframes we've flown, we can mount the antenna inside with no issues of shadowing.

FYI: We did a power down range test today using a motorcycle because we could not get to the limit in 90 seconds on foot. 1320' (1/4 mile!)

There was also another guy that reported doing the power down range check with the RX antenna disconnected to 100'... no antenna!

I knew this system was good, but I was blown away! A good range check on 72 was 100'-150'.

Mike.

[dirtybird]

On a 1/4 wave dipole antenna there will be null spots off the end, You can take care of that on the transmitter but the airplane will at some time point the antenna at you and if it lasts long enough you will lose lock.
What I would like to know is how long will it take to rebind after a fail safe. Especially at flying distance. I am not talking about the reboot time of the microprocessor.That is only a part of it.

[Mike Mayberry]

I've never been able to induce fail safe by pointing antenna to antenna.

Re-link time is almost instantaneous... Similar to start up.

Mike

[dirtybird]

Try this:
Set your fail safe to close the throttle.
Stand on one end of your runway and taxi to the other end.
Point your transmitter antenna antenna at the aircraft and see if you can open the throttle.
When I do this with my XPS system installed in my Multiplex Evo I cannot open the throttle.
It will open when I turn the antenna broadside.
Our runway is 700' long.
XPS says their ground range is 600' so my system exceeds spec. It makes an easy range check.
On the XPS system there is a noticeable difference between DSSS and FHSS on bind time at startup
Jim Drew says that is due to the fact that DSSS must look for a low noise channel prior to bind and FHSS just starts off without looking because its going to use all channels anyway.
I have noticed a few glitches when flying on DSSS. I switched to FHSS and I haven't noticed any glitches yet.