Hi Bryan

Try one of Dave Milbourns from the Component Shop.

Bryan
If you have only a 2-channel transmitter then I'm afraid you're somewhat snookered, in as much as you need both of those for rudder and motor speed control. As Chas says, a budget 4 or even 6 channel set on 2.4GHz costs probably less than your existing 2-channel one did when new. As for a radio-controlled switch I can recommend this one – it's the one shown on the P29 instructions **LINK**
BTW you'll also ned a speaker – CompShop sell these, too.

Dave M

The old fashioned down and dirty way to fire off a sound unit on a 2 channel set (as mentioned above) is to use the trim overthrow on the rudder channel to operate a microswitch. Stop the motor, slide the trim over, give it a dab of full rudder, reset everything to normal before re-applying the throttle. Only works with sound units that need a dab to start, not the ones that need a continuous condition to run.

The second bit of the question – do they sound realistic? That depends on the amplifier, the speaker used, and how well it is mounted. Sound effect units fall into two broad categories – those that synthesise sounds, and those that use sample recordings of the real thing.

With the right speaker, the recorded ones sound better since they start with a huge advantage. Commercial ones are usually extremely versatile, but for a single sound, pricey. It is easily possible at ridiculously low cost possible to get recordable greeting card sound modules. They can store any sound effect that you can find, and play it back on demand, either the Heath Robinson way or via a switcher on a spare channel, both work, both need the amplifier and speaker.

OK Bryan, here is the simple dirty way of doing it. It's cheap and clumsy but it works just fine. I've used it when models are on display and once whilst sailing, I nearly lost control.

I bought a cheap Bluetooth speaker, one of the drum shaped ones for 10 quid from our market, which I installed in the model . I then downloaded the ships siren sound and a couple of other effects from the internet on my mobile phone and put a shortcut on the home screen so I just had to touch them to get the sounds from the model.

It works, but doesn't compare with the ease of use of properly designed systems, and the range of the Bluetooth is limited but sufficient. For a tenner, you can do a lot, including pre set sounds on a micro SD card, just don't blame me if you lose control whilst looking for the right button on your phone.

Chas

Edited By Charles Oates on 07/01/2019 00:13:26

There are devices that offer wireless remote control over short range like this – https://www.ebay.co.uk/p/Relay-Module-1-Channel-Remote-Control-Switch-Wireless-IR-12v-DC-F8l6-J1j5/1784162176?_trkparms=aid%3D666006%26algo%3DPRP.MBE%26ao%3D1%26asc%3D20151029144032%26meid%3Ddcf12a317412444c9f47a92edc05935a%26pid%3D100534%26rk%3D2%26rkt%3D15%26&_trksid=p2349526.c100534.m4207 – but I see a couple of problems.

One is there is zero indication what band it works in, and whether it would interfere with other model control systems, or vice-versa. Thats in a crowded situation at short range. The Bluetooth option should get round that at te expense of carrying around the unit with the stored sounds on.

The other is the short range. One of the main reasons why I had a siren on my Snowberry was finding it at the end of a cruise. After the walk round the lake, I had to "park" it while passing behind some trees. It would usually take the opportunity to drift off, and finding a camoflaged boat 50 or so yards away isn' always easy, but letting the siren off helped a lot.

DM. good spot, planet returns. Wonder if the new receivers will work with the T5 sets…??? Silly money, almost rude not to buy one…Ashley

If a bare speaker is left that way, when the sound signal is connected, the coil and cone assembly will do its thing and wobble back and forth, moving air to produce sound. Unfortunately, the moving air off the back will almost exactly counteract the moving air off the front, so when the result gets to your ears you just get the difference, which is next to nothing.

If the speaker is mounted into a hole in a panel with a long air path from front to back, this cancelling doesn't happen, so you get to hear what you hoped for. A flat panel became known as a "baffle board". If the speaker is mounted though one side of a sealed box, it becomes a known as an "infinite baffle", because there isn't a path.

Various tricks are done to arrange for the sound off the back to get to the front with a change of phase so that it doesn't cancel, but helps at low frequencies,. In a boat, the space inside the hull behind the speaker plate is the "speaker box". The longest dimension of this space will effectively determine the bass responce of the setup. 50-odd years ago I could have quoted the formula.

So, in short, a flat panel with a suitable hole for the speaker to shout through.

Edited By Malcolm Frary on 19/01/2019 10:23:33