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Hi Guys.
Ive just had the RF looked at on the car decoder.

a)The antenna should be as vertical as possible with a slight kink in the middle.

This will mean it needs to pass up and into the cockpit in most cases.

b)The antenna length remains the same at 28mm. Somehow some escaped into the wild at 34-39mm! Just trim to 28mm.

c)No need to pass antenna to outside of car. This is not recommended and also to retain car aesthetics.

d)The antenna tip should not be near the motor. and clear (on top of) any other wiring.

Rick
 

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Before I start trimming my antenna, I just wanted to make sure about the length. Should the length of 28mm be measured from the top surface of the chip to the tip of the antenna, or should the 28mm length also include the antenna wire that is soldered into the chip?
 

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In cars having no issues, i have followed the rules like pointed out in the beginning: straight as possible, away from the decoder in a straight angle, away from the motor, no wires (metal) on top of the antenna.

With cars having lap counting issues, I have experienced better reception (that is to say, no more missed laps) after repositioning the car decoder antenna.
In most cars, i managed to position the antenna (sort of) to shape D: straight up, then a slight bend into the cockpit.
In this way, the antenna tip would be higher than any metal part or wire in the car.

It seems like some cars are very forgiving when it comes to antenna positioning, others very demanding.
My Ninco Mosler kept having issues until i positioned the antenna straight up, into the cockpit. My SCX Bugatti however, is on the inside crowded with wires and stuff, the antenna lies suboptimal in the car but it has not missed a single lap - and it has made quite some laps the past weeks.

I have three questions:
1. How come this new advice - out of testing, empiric / experience, or some other source?

2. it try to understand why the antenna length is so critical for good reception - will a too long antenna have distorted reception / broadcasting? I'm not into R/F tech knowledge, but i'd like to understand it.

3. My english fails me at times: what exactly is a kink in the middle? shape A (straight up, then somewhere 90 degrees bend), B (small S or Z shape), C (big S or Z) or D (like i have in most cases)?



Merc
 

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Discussion Starter · #4 ·
QUOTE (h00ch @ 4 Feb 2012, 03:29) <{POST_SNAPBACK}>Before I start trimming my antenna, I just wanted to make sure about the length. Should the length of 28mm be measured from the top surface of the chip to the tip of the antenna, or should the 28mm length also include the antenna wire that is soldered into the chip?
Good question, 28 mm from surface of PCB.

QUOTE (Merc_A @ 4 Feb 2012, 05:56) <{POST_SNAPBACK}>In cars having no issues, i have followed the rules like pointed out in the beginning: straight as possible, away from the decoder in a straight angle, away from the motor, no wires (metal) on top of the antenna.

With cars having lap counting issues, I have experienced better reception (that is to say, no more missed laps) after repositioning the car decoder antenna.
In most cars, i managed to position the antenna (sort of) to shape D: straight up, then a slight bend into the cockpit.
In this way, the antenna tip would be higher than any metal part or wire in the car.

It seems like some cars are very forgiving when it comes to antenna positioning, others very demanding.
My Ninco Mosler kept having issues until i positioned the antenna straight up, into the cockpit. My SCX Bugatti however, is on the inside crowded with wires and stuff, the antenna lies suboptimal in the car but it has not missed a single lap - and it has made quite some laps the past weeks.

I have three questions:
1. How come this new advice - out of testing, empiric / experience, or some other source?

2. it try to understand why the antenna length is so critical for good reception - will a too long antenna have distorted reception / broadcasting? I'm not into R/F tech knowledge, but i'd like to understand it.

3. My english fails me at times: what exactly is a kink in the middle? shape A (straight up, then somewhere 90 degrees bend), B (small S or Z shape), C (big S or Z) or D (like i have in most cases)?



Merc

Hi Merc,
1. I had Seppo take another look to be sure thats things are optimised.
2. 28 mm is simply the optimum length, but will work on other lengths to a lesser quality
3. D is the one youre after.

Cheers
Rick
 

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In classic FM-RF technology for any radio reception the lenght of the antenna should correspond to the emissions wavelenght (or an exact part of that lenght, e.g. half or quarter) for optimum réception. So the lenght of the antennawire is important.
 

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Hi Rick,

I finally fixed my missing lap problem. After rewiring my power feed to the track just before the S/F line. Removed cross over wires from lane 1 to 2
Then wired power to lane 1 and lane 2 directly from PS.
Then trimed all antenas on chips to 28mm. I still had problems counting laps.
My problem was the placement of one magnet.
I race mostly Scalextric NASCARS going back to my analog days and then digitall Scalextric days. I would place a shim and a magnet on the underside of the chasie behind the rear axle to get as much down force as possible. Then put a piece of black electrcal tape to cut down on the shorts to the track rails.
I removed the magnet on the bottom of the car This fixed my lap counting problem.

Dean
 

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Discussion Starter · #7 ·
Hi Guys,
Any demand for an insulated car decoder? ie cannot short out anywhere? I can now clear gel coat car decoders with a non corrosive material. Iy looks neat too.

Rick
 

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Discussion Starter · #8 ·
Hi Guys,
Any demand for an insulated car decoder? ie cannot short out anywhere? I can now clear gel coat car decoders with a non corrosive material. Iy looks neat too.

Rick
 

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Discussion Starter · #9 ·
Hi Guys,
Any demand for an insulated car decoder? ie cannot short out anywhere? I can now clear gel coat car decoders with a non corrosive material. Iy looks neat too.

Rick
 

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David Taylor
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Rick,

Goind solely off having the Ninco digital system....as my order is in production run #2...and not having the scorpius chips, but yeah...I would be interested. I used to wrap the ninco digital in electrical tape but looked pretty scrappy.

Dave
 

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Discussion Starter · #15 ·
....or do it yourself
Manufacturer: Dow Corning
Description: "3140 RTV Coating'" " Non Corrosive silicone rubber flowable".
Part No: 5 948 920 010

My advice just try one and test for a while before going over all your chips.

Rick
 
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