RC Model Reviews

Will this device also prevent blue screening? . even when the strongest signal is weak...

I think (that means I could be wrong) the device only switches to the strongest received signal and if it is too weak to avoid a bluescreen then you will still get one.

Thurmond

it won't prevent blue-screening but because you get such a consistently good video signal, you just don't see the blue screen unless you're really on the edge of reception.

The other weekend I flew out to 2.5Kms using the helical with solid video all the way and I flew a circuit of about 1Km radius around the ground-station with not a single drop-out.

That's using just the 5-turn helical and a SP through the diversity controller.

RCModelReviews wrote:it won't prevent blue-screening but because you get such a consistently good video signal, you just don't see the blue screen unless you're really on the edge of reception.

The other weekend I flew out to 2.5Kms using the helical with solid video all the way and I flew a circuit of about 1Km radius around the ground-station with not a single drop-out.

That's using just the 5-turn helical and a SP through the diversity controller.

I think I speak for many when I say coooool!

Bruce, how far are you from releasing circuit schematic of your controller? I'm trying to recreate dual diversity controller around arduino and 4066, but I cannot get nice picture out of that CMOS gate. I connect video output from RX straight through 4066 and decoupling 470uF capacitor to LCD. The picture is very dark, fuzzy and colors are messed up . It is definitely that 4066 stage, picture is perfect if I jumper the gate with wire or tweezers or screwdriver... I'm apparently missing something, impedance matching resistors or video buffer or something that you might have on the underside of your board that you do not show in youtube video .

Any advice highly appreciated.

Hallmark wrote:
I think I speak for many when I say coooool!

Yeah... interesting how the SP worked so well out to 1Km for as much of the real estate as the controller saw fit to use it.


Gimme

Rixx wrote:Bruce, how far are you from releasing circuit schematic of your controller? I'm trying to recreate dual diversity controller around arduino and 4066, but I cannot get nice picture out of that CMOS gate. I connect video output from RX straight through 4066 and decoupling 470uF capacitor to LCD. The picture is very dark, fuzzy and colors are messed up . It is definitely that 4066 stage, picture is perfect if I jumper the gate with wire or tweezers or screwdriver... I'm apparently missing something, impedance matching resistors or video buffer or something that you might have on the underside of your board that you do not show in youtube video .

Any advice highly appreciated.

Yes, impedance matching is important, as is signal routing (to avoid ringing and other nasties).

The 4066 isn't the "best" device for the job but it's the one I had plenty of and they're cheap, available in an easy-to-use DIL package and do a good enough job.

I don't get any loss of color and only a very, very slight loss of video bandwidth with the 4066 but it's very hard to notice any difference between the direct feed and a gated one.

Are you running your 4066 at 5V?

AltechMYOB wrote:

Hallmark wrote:
I think I speak for many when I say coooool!

Yeah... interesting how the SP worked so well out to 1Km for as much of the real estate as the controller saw fit to use it.


Gimme

A well-made SP works pretty well -- but today we got 3.5Kms out of the helical with no problems at all -- the SP gets pretty grainy at 2Kms.

RC failsafe starts kicking in occasionally at 3.5Kms -- that's when we're sitting in a camping chair. If you were to stand up and hold the transmitter at head-height you'd probably get to 4Kms or so for the RC.

I've ordered a 5dBi antenna for my transmitter to see what difference (if any) that makes. If it gets us to the limit of the video link then there's no need to go directional or raise the power of the RC system.

RCModelReviews wrote:Yes, impedance matching is important, as is signal routing (to avoid ringing and other nasties).

I don't get any loss of color and only a very, very slight loss of video bandwidth with the 4066 but it's very hard to notice any difference between the direct feed and a gated one.

Are you running your 4066 at 5V?

Yes, I run it at 5V. I tried if 12V wouldn't work better for switching analog signals, but then arduino couldn't switch it with 5V. I might try to switch it through transistors with higher volts if that could help. But I have no idea about that impedance thing

I checked today with old 5MHz scope, video signal on the output of cmos gate has about 1/3 or 1/4 aplitude of "good" signal. It is that weak even on input of 4066.

Are you using 74HC high speed Cmos logic (or equivalent) or the older type?
If you are using the older type it's an order of magnitude slower that may be your problem.