The worst they did was to compare range, with antennas removed from the RX,
what they actually measure is ONLY how well is the bare pcb shielded,
the better it is shielded, the less range you get that way,
so less range measured that way is actually better
does that matter ? not a darn thing, since what you want is to run the RX with antenna,
and that one pick up millions time more signal compared to what the board can pick up
unshielded, so no need to add nice tight and heawy shielding,
so that result is, even to put it nice, compleetly useless
To measure HARMONICS, you dont use a video receiver..
you use a SPECTRUM ANALYZER !!
you need to find out exactly how many db the 3rd is under the main carrier..
it is called dbc for db under carrier.
By using a video receiver, you dont reveal a darn thing, since all systems hop
at a little bit different bands and a bit different timings, so how well this hit the video rx
is just pure random result, and dont tell a thing at all..
Correct video (system frequency band planning) is always a mandetory task to perform.
and you will NEWER EVER be able to use a video band at EXACTLY the 3rd
of any other TX frequency in a system.
Any user simply change the video channel to the one, with as little as possible
conflict with his LRS
problem solved..
As a side note, we also did see some video RX systems not to contain a very effective band pass filter,
this way they got overdriven with the LRS main carrier
that is a bummer, if a user thinks it is the harmonics that is causing him problems,
while it is simply bad video rx design.
again real measurement equipment will reveal the truth, and not just random numbers.
How well a system handle jamming from another systems,
is also very funny made, that other system hops again on some frequencies
and timings, so this means by simple luck or unluck, it may jamm one other system from nothing at all to very easy.. this test again dont tell a thing about how well or how imune the system is to random noise, or narrow band noise or wide band noise in general..
or even a very strong inband carrier from a tetra base station tower near by..
the result based on that filmed methode, could have been what ever system.
it is like if you want to see how good and immune a system is:
Zigbee, BlueTooth, Zwave, and use a microoven as strong jammer, and a random wireless hotspot too,
what you get of compare results are useless.
if you want to compare radio stuff..
use MEASUREMENT equipment,
and signal generators.
It is hard to measure the receivers weak signal handeling,
since the TX will emit air borne signals stronger than the signal thru the antenna connectors when attenuated down to sensitivity level.
the trick is to modify the TX and to shield the tx and its wires extra,
else you will not be able to feed the RX pure -110 to -120dBm signals
to verify real range capabilities..
oh, you forgot to test the latest LR600 receivers,
it got like 2-3 times the range over the previous versions ...
also a funny thing is, price may be important to some people,
but we did not want to design things to win on low price, sorry,
actually we wanted to be allowed to use the most expensive and excotic parts
we can get our hands on, if they perform better, and then just accept what it cost.
our main customer group is not hobby people,
but prof use for film making, music video making, space, and millitary,
offcourse we are happy some hobby people dont care so much what parts cost,
as long as they feel it works as good as possible for them,
the plane and all other parts they use, cost many times more,
so the total % radio cost on a compleete system, is not that much.
many other factors also apply, how about receiver supply quality handeling,
drop outs, peaks, different frequencies, different spikes.
I performed quite alot of tests on exactly this topic in the old days we used 35MHz FM equipment,
Before this, no one understood why some equipment worked good for some users,
while completely useless for other users.
RC RX mlinger, kompelt listen
I stopped updating that page in 2008 when we stopped using those kind of receivers
and turned into other things, like home made radio links
but the supply voltage handeling issue is not to be underestimated,
we even revealed some very well known and respected servo brands to have design errors,
they shorted the supply rail in the motor bridge for a few micro sec at every motor drive pulse,
so the supply rail jumps several volts, even with good and strong BEC systems
rated many times what all servoes would ever need.
oh did I forget to say:
the TSLRS did perform over the speed of sound.
and did fly model planes over 100km out and back home..
. Ik had helaas geen spectrum analyzer