Response

Re: Any Advice On 40MHZ!

Hi Pete, "I am using 40MHz for my submarine. It is very good for sending a signal under water. 2.4GHz is not. This would suggest a fairly strong signal." The water penetration has very little to do with power. The main factor is the wavelength of the signal. Low frequencies, = longer wavelength, travel well through water, that's how whales can 'chat' over hundreds of miles 😉 Higher frequencies, = shorter wavelength, are mostly reflected from the surface back into the sky. What little penetrates the surface quickly dissipates it's energy by warming the water. Just like your oven which also works in the 2.4GHz frequency band. Ed; if you have a half decent 40Meg set the range will exceed how far we can properly see and control the model! My 40Meg set reaches the other side of the Ostpark Lake here in Munich, a good 200 meters, no problem at all. At that range I can just about see which way I'm steering😉 You do have to pull the telescopic antenna fully out though due to the longer wavelength of the signal. Also; DO NOT POINT THE ANTENNA AT THE MODEL!! The least part of the signal comes out of the end of the antenna. The strongest signal is radiated sideways (at a right angle) from the antenna. So hold the TX so that the antenna is vertical for the best range. Also fit the RX antenna in the boat so that as much as possible is vertical. I usually use the mast. Any antenna wire left over below deck can be coiled around a wooden dowel. This maintains the effective length to match the signal wavelength. DO NOT CUT THE ANTENNA WIRE!! If you can only fit the the RX antenna horizontally then hold the TX so that it's antenna is also horizontal. It's known as matching the Polarisation of the signal for the best received signal strength. Happy building😊 Cheers, Doug 😎

4 years ago by RNinMunich

Forum

Night Watch

The woodburners great and it does all the hot water central heating and the cooking, I couldnt imagine life without it, I was the same with the , tried cooking with it but all the food tasted like warm cardboard lol, but just discovered you can do poached eggs in it and they are marvellous

4 years ago by GSNMeyer

Forum

Night Watch

I'd love a woodfired rayburn or even a solid fuel one or aga, but I doubt if I'd ever become converted to a . I admit you can heat things in them, but I don't do that sort of cooking. Nerys

4 years ago by Nerys

Forum

Night Watch

Old fashioned gas cooker. LOL, I cook on a woodfired rayburn, I use my for making porridge, and heating things up, its great, wouldnt dream of cooking with it

4 years ago by GSNMeyer

Forum

Night Watch

Never try making porridge in the it explodes everywhere and takes a lifetime to clean 😂,even bought one of these cups with the lid on and the porridge managed to get fired through the vent hole and pebble dashed the inside of the . Doug,you need that extra we dram as the alcohol gets burnt off 😂😂when its heated.

4 years ago by marky

Forum

Workshop

"access to everything" .... even the coffee machine and just round the corner behind the bookcase!😋 And a TV/Monitor attached via HDMI cable to my PC in the other room - so I can hear the "Honks" and keep track of what U Lot are up to😉 😎

5 years ago by RNinMunich

Forum

46'' RAF Crash Tender

Hi Red, Just found this on the net. There are two approaches you can try for fixing warps in plastic. The first is to simply clamp the parts and adhere them with adhesive. I prefer the liquid styrene cement, which actually fuses or welds the parts as opposed to adding an adhesive to create the bond. Once so fused, they're nearly impossible to separate. Most of your alignment issues can be addressed this way. Most warping issues for these models come when you cut it to allow access for your RC components. These are usually long cuts along the mid-line of the boat. It is common for the cut parts to see warping along the length, creating gaps in the seam that are unsightly and hard to address via the first method. For these, the solution is to mechanically force the part straight, then heat the plastic up to its Glass Transition temperature for a short time, then cool it off. Polystyrene begins GT between 175-195° F (79-91 C) depending on its molecular weight, plasticizers, pigments and fillers. In order to straighten warped polystyrene parts, you need to get the plastic up to that temperature, allow it to settle in the proper shape, and then cool it back down again. There are a number of ways to accomplish this. The safest one for small parts is to use hot water. Simply heat up a bowl of water in the to something around 200F, allow it to cool slightly and then dunk your part. Once the plastic has heated up, it should become more malleable and retain whatever shape it's put into. Dunk the part in cool water to lock in the new form and you're done! You can also use your oven, which allows for precise control of temperature in a larger format. Most sub hulls are going to be much larger than your bowls or oven, so you're going to need to use something like a hair blow dryer or, ideally, a heat gun. This takes some practice, as it's easy to overheat the parts and get warping and distortion, or even burning if you're not careful. Never focus the heat gun on one section for too long. Keep it moving at all times and use broad strokes so that you're heating up a large area. You'll see the part relax into the proper shape. Once it does, let it cool thoroughly before releasing your clamps and checking alignment. Repeat as often as necessary for a great fit. Martin.

5 years ago by Martin555

Response

Re: Steampunk Pike.

Hi Martin, if they were food containers I very much doubt that they were ABS! Cos the three constituents are; Acrylonitrile (possibly carcinogenic to humans), Butadiene (carcinogenic to humans), and Styrene (suspected of being carcinogenic to humans.😮 Most food containers appear to be made of one of these- high / low density polyethylene (HDPE/LDPE), polyethylene terephthalate (PET/PETE), polypropylene (PP). PET/PETE you may also recognise from 3D printing. Depends a lot on which food is going into them. Main thing is that they won't react with the food and/or leach their binders etc into the food 😝 Especially if they get hot; e.g. in the oven! Bon appétit Gents 😉

5 years ago by RNinMunich

Forum

Help and advice please

Hi JB, At 2.4Gig some is reflected and some refracted into the water but is then rapidly absorbed through heating the water molecules. Just like your oven which works in the same frequency band. So don't take your down to the lake with you to warm up your lunch!!😂 The absorption rate (and hence depth penetration) is a function of the wavelength and salinity of the water. The shorter the wavelength (= higher frequency) the higher the absorption and inverse. That's why real naval subs use the VLF (Very Low Frequency) band to receive their orders when at depth. Frequencies used are around 8kHz or less so they can only receive very low data rate signals, more seconds or even minutes per byte rather than the MBytes/sec we are used to!! They can't transmit an acknowledgement as the TX antennas used are kilometres long at these frequencies! At the depths model subs (intentionally!) reach, ca 1 to 2meters, 40MHz is OK, 27MHz gives a slightly stronger signal at the same depth. The modulation itself also having an effect; due to the fact that FM signals have a constant amplitude (peak to peak voltage) whereas AM has an amplitude which goes up and down with the modulating signal (pulse train) as the name implies. Thus the FM receiver has more signal voltage to work with. Here endeth today's lecture 😉 Anyone still awake?💤💤 Cheers, Doug 😎

5 years ago by RNinMunich