27 Mhz

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13 April 2010 at 22:37 #26395
glen stuart
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@glenstuart29237
I am new at this game so I hope someone can help me. I have just got 2boats and both say they are 27mhz. I wanted to sale them together or at least when other people are sailing.I know have been told that I won’t be able to do this. I thought that although they were classed as 27Mhz there were other channels eg Brown to Purple. Is there any thing I can do about this or will I have to just sail by myself and hope no one else comes along.

Glen
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13 April 2010 at 22:37 #5075
glen stuart
Participant
@glenstuart29237
14 April 2010 at 08:48 #26397
Charles Oates
Participant
@charlesoates31738
Hi Glen,

welcome to the world of model boats. You presume right, there are normally several spot frequencies in the 27 mhz band all identified by colours. The only exception used to be on some cheap or very old types of radio control which used most of the band. These were called superegenitive or non superhet radios, not expresions you hear these days.

To check you could try 2 things, switch both on together and see what happens. if the transmitter from one works the other you might have a problem, or they may both have the same spot frequency.

Alternativly, and much better, you could go to a decent model shop or boat club and get some help.

Can you tell us a bit more about the models? it might help us to be more precise with an answer.

Charlie
14 April 2010 at 17:17 #26401
Bob Abell 2
Participant
@bobabell2
I picked up a lovely bargain at the Bury Show last Sunday

A pretty speedboat going for a song!

Didn`t realise it was one of those fixed frequency jobbies…….Looks very nice though

How will I go on at the pond?……………..Bob
14 April 2010 at 17:23 #26402
glen stuart
Participant
@glenstuart29237
Hi Charlie

Thanks for your reply.If I switch both boats on and use either transmitters both boats work together.

The boats I have I got on Ebay one is a warship HT-2877 27Mhz and the other is a Severn Life boat Model 27Mhz. I don,t know any more details.I think one of the problems on any internet sites that shops either don’t tell you the freequencies or just say 27Mhz and don’t give you any more details ( I don’t think they know about anything else)

I don’t get much help from model shops as I didn’t get the boats from them .

Glen
14 April 2010 at 17:23 #26403
Pierre
Participant
@pierre
Hi Glen

Presuming you have one transmitter and two boats you can sail both boats with the same transmitter (not at the same time,though) You need to have the same crystal (frequency) in the transmitter as in the receiver in your boat. If you have different frequencies in the boats you could buy the missing transmitter crystal from a good model shop (you might have to buy a matched set, TX as well as RX). Then its a simple matter of changing your transmitter crystal to match the boat you want to sail.

As for sailing with other boats on the water you will need to check what frequencies other sailors are using. Two boats cant use the same frequency, due to interference. If you are with a sailing club they will have a “frequency board” showing what frequencies are in use.

Hope this helps

Pierre
14 April 2010 at 17:46 #26405
Bob Abell 2
Participant
@bobabell2
Pretty eh?……………Pity about the radio gear
14 April 2010 at 18:05 #26407
glen stuart
Participant
@glenstuart29237
Hi everyone

Just to try and make it clear.I have one boat 27Mhz and a transmitter, another boat 27 Mtz with transmitter. Both transmitters will operate both boats. There are no crystals that I can change.

Bob is this what you call fixed freequency

Glen
14 April 2010 at 18:13 #26408
Dave Milbourn
Participant
@davemilbourn48782
Glen

The frequency of each transmitter will be controlled by a component called a crystal. This will be about 10mm x 10mm x 3mm with radiused sides and mounted on its end; it’s usually a bright silver colour. If you can remove the back of the transmitter then see if you can locate it. It will be soldered in place but it should have the frequency marked on it (often just the figures after the decimal point eg 27.695 will be marked 695). Can you do that and get back to this forum with the answer?

If so then we can probably identify the appropriate “colour” of the channel and then you can avoid sailing when any other skipper is flying that particular 27MHz flag. You won’t be able to sail your models simultaneously, however.

Dave M
14 April 2010 at 18:38 #26409
glen stuart
Participant
@glenstuart29237
Bob

Done as you say and found they are both 145.

As I was hoping to sail with my grand daughter is there any way to chang the crystals in one of the boats.

If I bought another boat they just say 27Mtz and that might be a 145.

Glen
14 April 2010 at 19:02 #26410
Charles Oates
Participant
@charlesoates31738
Hi again Glen,

Dave has got it right, you have both boats on the same spot. If you can find the crystal in one of the boats, you can buy another pair for a few quid and swap then over. This will give you what you want. You will have to see what access you can get to the inards of the models and see if you can find the crystal and then see if you feel able to replace them. What area are you in? there may be a club or a forum member near you who can help.

Charlie.
14 April 2010 at 19:56 #26412
Dave Milbourn
Participant
@davemilbourn48782
27.145 is the YELLOW band. You should therefore fly a yellow flag from your Tx aerial if sailing in company, and don’t switch your Tx on if someone else is using yellow at the time.

Unfortunately it’s not as easy as just replacing them with a pair of crystals on another of the 27MHz “spots” as these crystals do vary in other respects. Not all types will work with all brands of radio, and there’s no easy way of knowing which “overtone” etc the ones you have are operating at.

The most elegant solution is to gut the radio from one of the models and fit a “proper” 27MHz set with a separate receiver, speed controller, servo and battery pack.

DM

Edited By Dave Milbourn on 14/04/2010 19:58:08
14 April 2010 at 20:12 #26413
glen stuart
Participant
@glenstuart29237
Hi Again

I have just searched in my garage and found a Acoms Techniplus AP202 transmitter which takes moveable crystals so I am half way there. Is it possible to get crystal sockets that I could fit in the boat and solder into the crystal place I take out of the receiver that is if I can find out how to get at the Severn Life boat receiver. Has anyone taken the top off such a boat. I know there is a club in Southport but I don’t want to join a club at this stage but if there is a forum member near by it would be ideal.

Glen
14 April 2010 at 20:17 #26414
glen stuart
Participant
@glenstuart29237
Hi Dave

I dont think my boats have servos. They have two props I think thats how you would discribe them.

Glen
14 April 2010 at 20:46 #26416
Colin Bishop
Moderator
@colinbishop34627
I’m afraid that when you buy these sort of boats then this is what you have to expect. They are probably Chinese in origin and don’t follow the usual ‘rules’ which we expect in the UK. I have a friend who bought a couple of R/C helicopters for his nephews and exactly the same thing happened., they were both on the same frequency and nothing could be done about it.

Colin
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