new to all this some advice please

[David Knowles 1Participant @davidknowles1]

Ihave just joined a model boat club and bought a club 500 and a yacht from one of the members. I have a old type 40.695 mhz transmiter that needs a reciever when im looking for this online im searching for 2 crystals and a 40.695 reciever . is that right ?

is there anything else i need to take into consideration.

then what type of esc do i need I belive the battery size is 7.2

could I buy two of the same recievers but different crystals and use the same transmiter for the yacht also.The members of the club are very helpfull but i thought someone could let me know before the next club meeting as i am eagser to get on the lake

thanks

[David Knowles 1Participant @davidknowles1]

[Dave MilbournParticipant @davemilbourn48782]

David

It's the crystals which dictate the frequency. They come in pairs; one each for the receiver and transmitter. This means that you don't have to specify a frequency when you buy the receiver. If you have two receiver crystals on the same frequency as the transmitter then you can use the transmitter with either model without changing the Tx crystal.

Now comes the more technical stuff; there are TWO different types of 40mHZ radios; AM (Amplitude Modulation) and FM (Frequency Modulation). They are NOT mutually compatible. You have to have FM transmitter, FM receiver and FM crystals (or all AM). You can't, for example, use an AM crystal in the receiver and an FM one in the transmitter.

It's also far safer to buy branded crystals to suit your make of radio e.g. if your radio is a Futaba then buy Futaba crystals. In general most types are interchangeable but there are exceptions.

Ref the speed controller, I'd suggest that you find out what type was originally fitted and see if you can buy one the same. I would say it needs to be at least 15A continuous current capacity and fitted with Battery Eliminator Circuitry. MTroniks' Viper15A is a popular unit.

You will find out a lot more by reading the article here **LINK**

Dave M

[ashley needhamParticipant @ashleyneedham69188]

Hi David and welcome to the MB forum.

ESC first, the easy bit…. an MTronics 20A one will probably do, or 25A.

Your "old" transmitter. It may be best, as you are starting up, to get a cheap 2.4Ghz set. A Planet T5 set is not expensive, comes with one reciever and does not need any crystals. The recievers for this are also cheap. It is as simple a set as you could want.There is no need to fiddle about with hiding the Rx aerial wire, as the 2.4 Rx one is about 40mm long.

By the time you have bought several pairs of crystals (as one pair is not usually enough) plus a couple of compatible recievers (assuming you can get them), you may as well go to 2.4Ghz.

Ashley. You know it makes sense!

[David Knowles 1Participant @davidknowles1]

Hi I have a brand new 2 channel AM transmitter I i have found a new viper speed controller the crystall i have is a 40 mhz on a am transmitter

So have i got this right i can use any crystal AM reciever then get two crystal one for the boat and one for the transmitter and then im away.?

I understand about the newer 2.4 digitl units being a better buy but on a limited budget i thought this would be a cost effective way of getting afloat and i could always swap systems later when i have more knowledge.

the club members have been great and said they have this and that that they will bring in for me to use.

[Dave MilbournParticipant @davemilbourn48782]

So have i got this right i can use any crystal AM reciever then get two crystal one for the boat and one for the transmitter and then im away.?

Read this slowly and carefully. I will write it only once.

You need two 2-channel receivers which match your transmitter i.e. made by the same manufacturer (Futaba, Hitec, ACOMS etc) and of 40mHZ AM type. You don't have to specify a frequency for them.
You need a 40mHZ AM crystal for your transmitter.
You need two identical 40mHZ AM crystals for the receivers, both of which crystals are matched to the same frequency as the transmitter crystal.
You can now operate either boat with the same transmitter without having to change any crystals.

There is no more to it than that. If it were any more complicated I'd have taken up cloud-spotting instead a long time ago.

DM

[ashley needhamParticipant @ashleyneedham69188]

DM. I didnt know you were french ! Do you wear a beret as well??

David. Where abouts are you ??? a plea for redundant 27m or 40m sets may be the way to go. A lot of people have gone over to 2.4 now and all those old sets are laying around unloved in the corner.

2.4 may be cheaper in the long run even so,it is ever so convenient simply switching on the transmitter, then the boat, and sailing away without worrying about crystals…as a bonus the Planet sets only use 4x AA batts!

Ashley

[Dave MilbournParticipant @davemilbourn48782]

DM. I didnt know you were french ! Do you wear a beret as well??

You stupid boy……………..

DM

[Malcolm FraryParticipant @malcolmfrary95515]

As Dave says, if buying extra crystals, stick to the same manufacturer to ensure that it will all work. You can have as many receivers as you like with the same crystal, the transmitter knows no better. The downside is that they are usually supplied as a transmitter and receiver pair. The transmitter one is invariably labelled with the frequency it will cause to be transmitted to air. The receiver one, because of the way radios work will have been cut to work at an offset frequency. It might be labelled with either that frequency, or the frequency that it receives from air, usually with an "R" involved to avoid (?) confusion. There is the "normal" offset, then some manufacturers like to be a bit different, then there is a different one for FM, then, to put a top hat on it, there is something called a "double conversion" receiver, which is different again.

As Ashley says, brand new 2.4 GHz outfits are relatively cheap. What was not mentioned was that if you get lucky and pick the right one, compatible extra receivers are actually cheaper to buy than a pair of 40MHz crystals. Just the minor minefield of finding a good, but low cost transmitter that has cheap compatible receivers available.

While I can picture DM in a beret and trench coat, I'm not sure about the high heels and stockings…….

[Dave MilbournParticipant @davemilbourn48782]

I'm not sure about the high heels and stockings…….

It's the sizes that are the problem, Malcolm – as you should well know.

David
It might help if we knew exactly which transmitter you have e.g. Futaba, Hitec, ACOMS. Also please could you tell us what figures are printed on the crystal (it might say something like 40.675 or just have a two-digit number like 53).
DM

[Paul TParticipant @pault84577]

DM

For high heels and stockings to fit your manly girth there is a place in Sheffield or if you prefer French Sheffeeled

[Dave MilbournParticipant @davemilbourn48782]

Paul

Does it have your personal recommendation? You know how fussy a boy can be……………..

DM

[Charles OatesParticipant @charlesoates31738]

Enough,enough, I’m feeling queezy.

[David Knowles 1Participant @davidknowles1]

Hi guys sorry for the late reply my computors playing up kep getting messages from a transexual dress up site and althought the stocking are nice they dont have my size.

My transmitter is a two channel futaba the number on the crystal are 40.695 mhz on the box there is a large number 53 with 40.695 aound the outside I think 53 is the crystal number . I have the servo the on off switch and the battery compartment but no reciever I have found one online is this what i need as well as these crystals

http://www.ebay.co.uk/itm/331041264997?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

this is 40.685 not 40.695

i need two of these with a matching crystal for each boat ? excuse me for my poor lack of understanding .

Thanks for your replys

but i cant get the image of a bloke in stocking out of my head

[ashley needhamParticipant @ashleyneedham69188]

David. The crystal thing is simple. Please do not take offence at this easy explanation.

The set operates at 40Mhz. In order to focus the Hertz`s into channels (within the broad 40Hz spectrum), tuning crystals are used; they come in various frequencies (giving the channels) as marked on the things, You have to have one in the Tx and one in the Rx, obviously they need to match..ie be the same frequency) in order that the tx and rx operate as one. I hope thats explained it. Sometimes we take these things for granted.

For instance 40.685 is one channel, 40.695 is another and so on.

If you have two boats, you only need the pair of crystals, the tx marked one stays in the Transmitter and the Rx one can be moved to the reciever units in either boat….OR you get two pairs (of the same frequency)…and use one each Rx crystal in each boat (to save swapping about) and the one Tx crystal in the Tx unit.

Assuming yours is an FM set then the crystals spotted will be ok BUT the Tx one is in a little holder and the holder needs to fit your handset of you is in trouble. I have two makes of 27M sets and they had holders (long gone now) but the crystals simply plug straight in the little hole.

The 2.4Ghz sets do away with the crystals by using different technology, and all you need then is a transmitter and the corresponding manufacturers reciever, the pair are "bonded" electronically. This is what makes it easy, there is no need to have loads of crystals, any new recievers you buy are simply bonded to your personal transmitter and thats that.

Please be aware the only correct use for stockings is to cover boat hulls in prior to applying fibreglass/epoxy resin.. Wellies are the recommended footwear at the pond, at least, our pond..but customs vary, and we are down south…..

Ashley

[Paul TParticipant @pault84577]

and we are down south…..

Where all the southern softies are, up ear int north we have steel toecaps on us ballet pumps and lard in us Jo.kstraps.

These have been easy explanations? I am really confused what is all this talk about bonding 40mg with fiberglass resin and spotted crystals on your wellingtons…..and I thought Hertz rented cars.

Is there nobody on this forum that can give a simple answer to a simple question.

[Dave MilbournParticipant @davemilbourn48782]

Is there nobody on this forum that can give a simple answer to a simple question.

Just for a fleeting second back there I actually believed that I had……………………but it appears not.

(Back to the Cumulo-Nimbus and Alto-Stratus for me, then.)

DM

[ashley needhamParticipant @ashleyneedham69188]

An explanation from absolute basics does no one any harm. If you know nowt about a subject then a "back to basics " is whats required.

The relationship between crystals and 40M tx/rx units I thought had not been explained in the simplest of terms. David will, in due course tell us if he is suitably enlightened

I know where the only lard is, oop north, and it has to do wi` flat `ats !!

Ashley ; Disclaimer, usual.

[shipwrightParticipant @shipwright]

David,

You can purchase the appropriate receiver crystal here. If you have two 40 MHz AM Futaba receivers you will need two receiver crystals (one for each receiver) – otherwise buy one crystal and swap the crystal between the receivers.

**LINK**

Ian

[Paul TParticipant @pault84577]

DM

You should be careful with those Cumulo-Nimbus and Alto-Stratus……did you see the Watchdog report on how much sugar is in them apparently they are worse than Frosties.

Sorry I tried to read your explanation but couldn't get the image of your manly figure encased in fishnets out of my mind. btw Mac fisheries want them back.

I always found 27m the easiest RC sets to use but after reading all these technical explanations I will be going back to a long piece of string and a brick.

Paul

[Dave MilbournParticipant @davemilbourn48782]

So……………

David
Two new Futaba 40mHZ AM receivers at £18 each and two receiver crystals at £10 each comes to £56 (Hobby Store).

New Planet T5 Tx and Rx £45.50 plus spare receiver £15 = £60.50 (Howes). That's for a FIVE channel radio and no frequency worries. For an extra four quid. That's just enough to buy a pint of lager south of Potter's Bar. Do they drink bitter south of Potter's Bar anyway?

I know which choice I'd go for (and it ain't the lager, dude).

Paul
You are indeed a very strange man. My advice would be to avoid tight clothing and eating cheese before bed-time, and to put more whisky in your water.

Dave M

[David Knowles 1Participant @davidknowles1]

That sounds like a better idea than messing with the crystals I have been pronised loads of bits by club members but i was hoping to speed things up.

I do have A birthday coming up soon so maybe i will be lucky

as a northernener living daaawn sath I cannot get away from my

Dunt spend owt mindset but maybe digital is the way to go

Thanks for your replys and help I have no doubt That I will be asking again

Dave

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