HI all, today I range checked my Kingcat and got different reading ( JR 940S ) dual conversion receiver and Jetcat 160 with Verson 4.9
Check1, Kingcat on a table ,No antenna, walked more than 300ft, no failsafe
" 2, Kingcat on the ground, 225ft and then went into failsafe
" 3 ,Kingcat on the ground, turbine running , no antenna 80 ft ,went into failsafe


" 4, Bobcat on the ground with JR R950S receiver, tubine not running, walked 400ft
and still did not go into failsafe

Another flyer had a 33% extra that he flys all the time , we tested his and got 80ft with no antenna, plane on the ground, engine not running and had a JR 940S receiver.

Any comments would be appreciated
Thanks Rcpete

how is your RX antenna routed ?? its stuff like this that has me using the long whip antennas .. on sport jets, i dont mind the antennal all that much ... but some people do not like them ...

If you have the antenna route in the wing as per the KingCat design, i do not see there being a problem with that ... is your RX by any chance right next to any fuel pump ? ECU ? solenoids (yea, i have see n issues with this) .... also, try to not run any servo extensions or leads around where the RX antenna wire is ...



Wojtek

Pete:

I am also flying a KC with P-160/4.9.......I do have a ham license and operate on 53 Mhz.....with a 955S RX amd 10X.....I use one of the German whips about 20.5 inches long, mounted about 2" behind the centerline of the canopy with 18.5" of antenna remaining on the RX end running horizontally inside the fuse.....everything is mounted per BV specs with the fuel pump and ECU on the right side of the plate and RX on the aft-left side of the plate with solenoids near the aft-middle of the plate....I use a 5 cell/2800maH RX pack with no regulator, and a Duralite pack in the 10X and on the ECU......

Range checks in excess of 300 ft in all four quadrants, TX antenna off, with engine running and plane sitting on the ground...

So far, 15 perfect flights.....

Tom

On the ground range checks are a waste of time... You will get different results with different locations and surface types. Anyone who does a range check with the receiver antenna within 8 to 10 inches of the ground, is I'll say it again wasting his time! Keep in mind you will never fly with no transmitter antenna, right... So given your poorest range check results.... with your transmitter antenna where it's supposed to be and fully extended... your on the ground range at worst will be 700 feet. Normally that distance should be plenty of distance before you become airborne where the effective range multiplies exponentially.

So learn to do a good range check, and make corrections before flying:
1. Find your ECU unplugged (NO Turbine components functioning base line range) the receiver antenna needs to be 3 to 4 feet above the surface! This means fail-safe free operation all transmitter orientations, (360, up & down). With a well matched receiver & transmitter, assuming a JR10X system that distance should be no less than 225 feet, and more normal with good matched alignments near 300 feet.
2. My suggestion is not to fly if the ultimate range with turbine running @ full power is less than 225 feet. So if your starting with a base line of 225 feet your more than likely going to have to do some installation magic as suggested by wojtek.. You will probably have to do a little of both, installation corrections and Trans. / Rec. tweaking.

The most reliable range checks are done with the transmitter antenna fully extended, just like your going to do when flying. They are a pain in the butt to accomplish, but after doing a Real Range check you'll know for sure your ready to fly safely. Base line distances should be between 2100 & 2630 feet. The very poorest trans. ant. fully extended range check, turbine @ full power should not result in a fail-safe distance of less than 1800 feet.
Please don't assume your 940s receiver is any better than any other... shoot I've got plenty of old 910 Z types that are as good as any dual conversion. The only way to know is to check them. One of the best ways to do that is to have several same type receivers and compare them all. You will find out very quickly no two receivers are the same, no two installations give the same results. My experiences have shown me that about 50% of all rec. / trans. combinations can be tuned & aligned better than they come out of the box!
Lee H. DeMary
AMA 36099

Tom, I sent you an e-mail looking for some help with where I can buy one of the German antennas for my Kingcat also...Thanks, Gary

Gary,

call Don at Planes Plus .. he has them ..


Wojtek

Yup....Don Kanak has them as well as Tad at Golden West Models....

T....

Lee:

One reason most guys check the 10X with the antenna off is that's the way Horizon described range checking in one of their catalogs/hints and tips mags a year or two ago.....

Practicality becomes an issue with the 2500 + ft checks.......

Never had a problem with hundreds of giant scale vibrator flights with electronic ignitions, as well as turbines, even the old noisy 2.0 JetCat ECU software, over the last 5-6 years using a 10X and the simple 300 ft, antenna-off method, holding the TX at arms length like Horizon suggests, plane on the ground or on a non-metallic structure(I often use a PVC mount about 3 feet off the ground).......check all 4 quadrants if antenna is mounted inside the plane.....probably less critical to do a 360 check with a vertical...

As far as tweaking the RX and TX, good idea, but once again, most guys don't have the gear to do it at home, and are often hesistant to send their TX/RX back to Horizon or Radio South unless something really is wrong, like a totally dead RX, or after a crash.....


Tom

quote]ORIGINAL: Tom Antlfinger

Lee:

One reason most guys check the 10X with the antenna off is that's the way Horizon described range checking in one of their catalogs/hints and tips mags a year or two ago.....

Hi Tom, I have no problem with antenna removed range tests, the problem I have is with the rec. antenna on or near the surface of the ground.

Practicality becomes an issue with the 2500 + ft checks.......

Never had a problem with hundreds of giant scale vibrators with electronic ignitions, as well as turbines, even the old noisy 2.0 JetCat ECU software, over the last 5-6 years using a 10X and the simple 300 ft, antenna-off method, holding the TX at arms length like Horizon suggests, plane on the ground or on a non-metallic structure(I often use a PVC mount about 3 feet off the ground).......check all 4 quadrants if antenna is mounted inside the plane.....probably less critical to do a 360 check with a vertical...
You might not of had a problem with checks on or near the ground... I have found the results are not consistent!

As far as tweaking the RX and TX, good idea, but once again, most guys don't have the gear to do it at home, and are often hesistant to send their TX/RX back to Horizon or Radio South unless something really is wrong, like a totally dead RX, or after a crash.....
I would never suggest anyone do there own tweaking, I am saying about 50% of what comes out of the box will benefit from a good tuning and alignment. Anyone that spends thousands of dollars on a model aircraft project should find a way to know for sure if they have one of the lessor 50% RF links, and if so send it to a knowledgeable repair facility before the crash.
Lee


Tom
[/quote]

Why is it a bad idea to leave the plane on the ground? What creates the inconsistent results by simply leaving the plane on the ground? Just curious. [8D] Thanks, Gary

Well radio waves are to one extent or another effected by anything near them.. the surface of the ground is a major something.. I say something cause you don't even know for sure the consistency of the soil or what might be in it. Radio waves are less disturbed by air than by solid objects, like the ground. The inconsistencies are measurable, just do enough range checks with the same radio and aircraft setup on the ground and you'll discover what I have observed.
Lee