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[dickyp]

I have had my refurbished speedboat on the water for the first time today and whilst it responded to my Acoms transmitter for the first 20 metres or so it had a mind of its own after that.

The aerial wire from the receiver goes around the inside of the boat and then connected to an external aerial.

I was wondering if I was having interfearance from the motor/battery as the boat is so small all the RC gear is compact

Is it OK to to shorten the aerial wire or is it tuned into the receiver.

The aerial wire was 1 metre long but I have cut it off by a length equal to the height of the aerial outside the boat

Any advise welcome

[Patrick Henry]

I never worry about my aerials in my subs, they just get scrunched up and shoved out of the way where they will fit.

I'd check all your connections, especially the batteries, and it wouldn't hurt to check out the aerial wire where it leaves the rx either, they can break off.



You'll see in the pic below how tight the radio installation is in my Deep Quest, the aerial wire will be run out of the r/c box and just rolled up and get shoved in the free space in front of the box and in the flooding area of the sub.


Rich

[Netleyned]

The length should be ok as overall you have the original length
Sometimes the lead to the circuit board does come adrift as Rich says
The batteries should be fully charged and the motor suppressed
A range check at home away from other transmitters should eliminate some
possibilities easy these days with mobile phones just to walk away from base
for a hundred yards or so with the transmitter in your hand ignoring the passers by
that look for the item you are controlling!
I just gaze into the sky!

Ned

[DickyD]

Hi dicky all my antenna run round the inside of my boats with no problem.

Is your motor suppressed ?

[scoop]

I have had my refurbished speedboat on the water for the first time today and whilst it responded to my Acoms transmitter for the first 20 metres or so it had a mind of its own after that.

The aerial wire from the receiver goes around the inside of the boat and then connected to an external aerial.

I was wondering if I was having interfearance from the motor/battery as the boat is so small all the RC gear is compact

Is it OK to to shorten the aerial wire or is it tuned into the receiver.

The aerial wire was 1 metre long but I have cut it off by a length equal to the height of the aerial outside the boat

Any advise welcome

Hi Dicky P, Is it a new radio set or a used one, if used it may have 'blackwire' corrosion on the Rx aerial lead, did you notice any blackwire corrosion when you cut the lead shorter to join to the external aerial ? I have seen blackwire work its way all the way back to the receiver, it normally happens when the tip of the aerial wire gets wet or the receiver has been left inside a boat in a damp shed all winter ! Easiest way round that one is to put a blob of silicon sealant on the end of the aerial lead when it's new.
This might not be the cause in your case but its worth a look   Also running in sea water does untold damage to radio gear if it is allowed to get wet.

Regards
Scoop

[dickyp]

Hi Guys

The Acoms transmitter/receiver is probably about 20 years old. The battery meter is about half way up the green band. Not sure what you mean about "blackwire ?"

I have fitted suppressors to the Mabuchi motor but I have not put insulation on the capacitor legs

[cuppa]

Hi Dicky P

The other posters on this thread have given you sound advice: do a range check and see what happens.

If you are handy with a soldering iron or know somebody who is then it would probably be worthwhile replacing the receiver aerial wire. It could possibly either be suffering from corrosion or perhaps have been suffered an internal break at some point in its life. Another thing to check is that you do not have a faulty crystal in either the transmitter or receiver.

Radio control sets can now be had so cheaply that it may be worth thinking about buying a cheap 2.4GHZ set.

Cheers
          Jon

[dickyp]

John

Can you please advise where I can buy aerial wire

Is it ok to open the receiver box ?

[Netleyned]

Do a range check away from the lake before taking more drastic action
If everything is ok then the Rx is probably taking interference from another TX
If this is the case spend 25 hard earned pounds and get a 2.4 GHz set up
BTW Any thin multi strand wire with insulation will be ok at 27 or 40 MHz

Ned

[dickyp]

Ned

Was only one at lake so I don't think it will be interference

[tr7v8]

Try a range check with the motor not running & see if it is OK. It could be motor noise swamping the rx. Do the motor wires run near the rx?

[scoop]

Hi Guys

The Acoms transmitter/receiver is probably about 20 years old. The battery meter is about half way up the green band. Not sure what you mean about "blackwire ?"

I have fitted suppressors to the Mabuchi motor but I have not put insulation on the capacitor legs

Hi Dicky P, Blackwire is the name given to wire that has corroded, if you strip back the insulation and the wire is not shiny copper or steel but it looks black and may even crumble in your fingers then you have a bad case of black wire. There is no repair for this apart from cut the aerial wire off at the receiver and replace it with a new piece.
You don't say whether the radio gear is 27 or 40mhz, in the ' old ' days some of the 27 mhz radio sets were affected by CB radio transmissions.

[dickyp]

Thanks for the responses

Radio is 27mh

When I cut the wire it was indeed black

If I replace the aerial wire, do I need to open up the receiver or join it as near to the receiver as possible

[mikearace]

You may as well replace the receiver if it has blackwire for the £12 or so it will cost.

[RaaArtyGunner]

You may as well replace the receiver if it has blackwire for the £12 or so it will cost.

I think it has been mentioned before, but am I correct, in that there is no remedy for blackwire, other than replacement of wire/component and also it is not 100% preventable.

[barriew]

If I replace the aerial wire, do I need to open up the receiver or join it as near to the receiver as possible

You would need to open up and remove the old wire from the circuit board and solder on a new length. It is very difficult to clean the 'black wire' well enough to solder to, and the new wire would soon become contaminated.

Barrie

[dickyp]

Any comments on the standard length of the aerial wire.
I have been told that the receiver is tuned to the length of the wire ?

[dickyp]

Should I have insulated the capacitor legs

Would this help

[cuppa]

Hi Dicky

I believe the original aerial length was 1 metre.

Cheers
          Jon

[malcolmfrary]

The blackwire problem is where the strands of copper wire are now strands of copper oxide wire.  Since there is no actual copper there any more, it is impossible to get it clean enough to solder to.  As said before, any thin stranded insulated wire of the right length will do the job.  Length is fairly critical for range.
The receiver case will split easily, just needing the clips prying gently.  You can then see where the aerial wire is connected - just a simple matter of unsoldering the old, cleaning the hole, poking the tinned end of the new in, soldering down and clipping the box back together.  A small tipped, but very hot iron is best - get in and out quick, before the heat gets to where it can do harm.
Insulating the capacitor legs will only help prevent unexpected short circuits due to other bits of metal hitting them.  It does nothing to improve interference performance.
It might be a good idea to check out the power wiring at the same time.  All sorts of strange things happen when that gets infected, and the only guaranteed cure is replacement.

[Netleyned]

electrical current of any frequency (or no frequency in the case of DC) travels along the outer circumference of the wire (skin effect)
Even if the wire is still shiny inside the black surface says 'Bin Me'
As Malcolm says check every wire in the model. After 20 years it will all need replacing.
Better finding out now than in the middle of the lake.

Ned

[dickyp]

Thanks for your help chaps

Been on the internet and can only find one supplier whos wires are nearly 3 ft long

AS Cuppa has said I think the original Acoms wires were 1 metre; are the lengths critical

[Colin Bishop]

My Futaba 27 meg sets had aerials 30 inches long. I remember that the Acoms sets of the time were a bit unreliable and short ranged though - I had one of those too!

Colin