THE crip cap (in tha car) mod....

ph2t · #1 05-10-2003, 01:05 PM

I’ve been doing this method on a few cars now and settled on this being my standard for all my cars when increasing the range. With the method outlined below I can achieve 10 meters (approx 30 feet) indoors.

First of all, here’s my stock MS 49Mhz with a Skyline shell and crapola antenna, it will be the guinea pig for today’s little exercise…..

Now let’s remove the shell and carefully prize the plastic pcb cover off. For all you Aussie Compact Char-G owners the pcb cover is actually glued so be extra careful. The M’Sizers don’t suffer from this, dunno about Bit Char-G.

Next, let’s locate the nasty 'lil bugger, you will see it outlined in red below. NOTE: This is in every car I have seen to date. Unlike the crip cap in the TX which varies at the best of times. Upon closer inspection you will notice that the solder work done on this surface mount capacitor is messy and not as clean a job as the rest of the circuit board. There are theories going around that TOMY added this cap after production due to the range being too good…..go figure…..

Prize open the pcb from the chassis CAREFULLY, you don’t want to break anything, especially little steering wires... This is done from the side OPPOSITE to all the solder pads that say L R B F V+.

Once you have opened the chassis up sufficiently, flip it over and secure it to your bench top using some plastic putty stuff, I’m using Bluetac in this example. You will need the pcb to be secure to give you the leverage you will need to continue…

Now, here’s the trickiest bit of the whole procedure. Make sure you have the capacitor in the grip of some needle-nose pliers, using a soldering iron heat of the solder pads on each side of the capacitor and slowly work it loose. Be careful to not damage other components close by.

Ahhhh, now isn’t that better? See below…. No more @#$%^ cap!

ph2t · #2 05-10-2003, 01:06 PM

Look how bloody small the thing is, shown here next to a steering knuckle.

Now that the hard parts done, let’s add a new antenna. For those people paying attention I had removed it earlier. Shown below is some enameled wire (0.25mm dia) I’m using for an antenna, it works well for its purpose…..

Remember to always TIN your wire first to allow for an easier solder job when connecting it back onto the pcb. I cannot stress this enough.

And you’re done……

With the cripple capacitor removed and a new antenna added, we’re ready to hit the town.

Not without our crew though!

TypeZer0 · #3 05-10-2003, 01:49 PM

nice tutorial ph2t! just wanted to add a thought:

the crip cap could also be removed by using copper braid to suck off (now now, no nasty thoughts

) the solder on the cap's either ends

New_B · #4 05-10-2003, 02:48 PM

Do the ends of the crip cap NEED to be soldered?

ph2t · #5 05-10-2003, 06:26 PM

New_B, it's hard to remove the cap without using a soldering iron. If you were to try just pulling it out with pliers you will probably ruin to copper tracks surrounding the cap. This could kill to RX all together.......

ph2t · #6 05-10-2003, 06:29 PM

TZ, not a bad idea. Just remember that the pads the crip cap is connected to are acutally used by the electrolytic capacitor ( the big black can shaped thing sticking out the other side of the pcb). Make sure there is enough solder left over to be able connect this cap back into the circuit.

bloodyroots · #7 05-10-2003, 11:50 PM

I found the cap on the sport MS, but I don't think the Pro MS has it. If it does, I think they moved it or the apperance of it changed.

RobotGT · #8 05-11-2003, 12:04 AM

I wanna try that, but i wont concidering ill wreck my car. LOL!

ph2t · #9 05-11-2003, 01:53 AM

It ain't the easiest of mods, but it sure does help!

bloodyroots · #10 05-12-2003, 06:46 PM

I did this Cap mod on one of my Sport MS yesterday, except for the replacing of the antenna part and I don't see a difference. I still get the same 15-20 feet out doors. I think your increase in range come from replacing the antenna and not from removing the cap.

ph2t · #11 05-12-2003, 07:02 PM

I've done this mod and have gotten extra range. I've then upgraded the antenna and gotten further range after someone asked me about it just the pther day. You need to prolly re-tune the inductor on the board for maximum reception.

ph2t.

#12 05-13-2003, 02:59 PM

Does anyone know what "the big black can shaped thing sticking out the other side of the pcb" is for? It really gets in the way, and I would like to just cut it off. Has anyone tried this? If you try it, the worst thing that could happen is that you gotta put it back, right?

btw, nice cars ph2t!

ph2t · #13 05-13-2003, 04:16 PM

Thaks BillyP

.

The "big black can thingy" is a capacitor, yeah another one. It is used most probably used as a line/noise filter for the circuit to be able to operate smoothly. The motor would generate a bit of noise which in turn could interrupt the circuit, especially when we are talking about an AM radio reciever on the pcb. If you were to remove it you would probably get a crappy response from your car irrespective of its distance from the controller.

ph2t.

#14 05-13-2003, 05:56 PM

Okay, I guess I should keep it there.

How do the motors generate noise? The magnetic field? I don't have a car to experiment with right now, but I HATE CAPACITORS! (Especially the ones that were on the AP Physics test I had to take yesterday.

) "Capacitors are evil" should be my new sig!

ph2t · #15 05-13-2003, 07:26 PM

When the motor spins around the brushes that allow current to travel to the rotor mechanism have their contact with the rotor start and stop very quickly thousands of times per second.

This causes the voltage potential across these contacts to vary wildly and combine this with the EMF (Electro Magnetic Field) and reverse EMF that is generated (when the coils lose power they spit back some current in the opposite direction), it can make for a serious amount of noise.

This is why in a lot of older cars (1:1 ones

) there is a bypass capacitor (AKA auto capacitor) across the auto transformer. This eliminates a lot of noise in the 12V supply line in the car so you can actually hear the stations on your AM radio and not just the pop/hiss/crackle that is EMF noise.

FM radios aren't effected by this only AM radios are. The transmission scheme used by these Bit Char-G is AM, hence why I believe that big black electrolytic capacitor is there.

For anyone not knowing what BillyP and I are talking about it's the black POS here:

ph2t.