RCV 58 CD dead
On an earlier post, I mentioned a chirping noise. The noise went away completely so I felt there was no need to send the engine in for repair. I probably should have. I had my first dead stick landing with the engine. The engine acts as if the connecting rod is broken. I've only had the engine for 4 months and about a gallon of fuel run through it. I use sythetic 17% lubrication with 10% nitro. I would like to know what to do. Thanks.
Posted on: 6/1/2009 10:03 AM by Author "APMECH" in the forum "RCV Engines Support"
http://www.rcuniverse.com/forum/fb.asp?m=8816006

RE: First Warbird Suggestion?
I've got a VQ warbirds p-40. I am also looking at their p-51. Built solidly but easy to assemble and has all the hardware.
Posted on: 3/26/2009 11:34 PM by Author "APMECH" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=8620647

Chirping Noise during Idle RCV-58
Hello, I have purchased a RCV58CD and a RCV91CD the 58 for use in a Great Planes Escapade, and the 91 for a VQ P-40. I have only run the 58 so far. Doing the running in procedures. It seems to run really well... Just have one question after running at the prescribed 6000 rpm per the manual, I bring it back to idle and let it cool a bit during the idle maybe 60-120 seconds. During the idle the engine will have a "Chirping"sound that goes away if you bump the throttle up a little bit and bring it back down and it will slowly come back. Is this bad or is this just kind of normal run in sounds. Engine runs really good, seems to have alot of power. I am running rich like the manual said. I did adjust the low end needle after the first hour of running in, per the manual to lean out the mid range a little bit... Seems to have gotten much more powerful. But that quirky chirp happens around 2100-2350 rpm, it seems to vibrate much more when it makes this sound. Thank you- Erik
Posted on: 3/18/2009 10:06 PM by Author "APMECH" in the forum "RCV Engines Support"
http://www.rcuniverse.com/forum/fb.asp?m=8592547

RE: 2.4 GHz vs 72 MHz - Free space loss
I sit corrected ;), Thanks for that cool Info!!! When doing chamber testing in emc everything is done pretty much at 1M so the fresnel zone never really came into play. Maybe that's why all the standards call for almost everything at 1M?? But I did the calculations in excel and if I calculated them correctly (understood them correctly) the radius of the fresnel zone actually decreases (which is a good thing) with higher frequency Please correct me if I did this wrong. r = radius in feet D = total distance in miles (1 mile in this case) f = frequency transmitted in gigahertz. (2.4 for 2.4Ghz and .072 for 72MHZ) for 2.4 GHz ---- r=72.05*(1/(4*2.4))^.5 = 23ft for 72MHz --- r=72.05*(1/(4*.072))^.5 = 134ft here is the link to another interesting website http://www.zytrax.com/tech/wireless/calc.htm I checked my calculations above against this website and they came out good. Means 60% of the Radius of the 1st Fresnel zone must (Should) be unobstructed. The line of site plus a radius of 14 ft around the LoS at the 0.5 mile distance must be clear with 2.4GHz for a 1 mile distance The line of site plus a radius of 81 ft around the LoS must be clear with 72MHzfor 1 mile distance This should ease some apprehensions
Posted on: 3/7/2007 3:11 AM by Author "APMECH" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=5523523

RE: 2.4 GHz vs 72 MHz - Free space loss
This is an interesting suject to me. I used to be a electro-magnetic compatibility test technician for automotive components. And as a general observation, the higher the freq the lower power was needed to generate the same RF field (volts per Meter). But the signal strength decreases more over a distance than lower frequencies (Free Space Loss) The Fresnel Zone is independent of frequency and is determined by distance ( i.e. Curvature of the earth and line of site. So there should be no difference between the 72MHz and 2.4GHz frequencies. The main thing to remember is the noise floor at any given time for the two frequencies. The rule of thumb is the higher the frequency the lower the noise floor. When we did free range testing (open air - - outside of the Anechoic Chamber) the noise floor was greatly reduced at frequencies above 1.6GHz. The natural harmonics of lower fundamental frequencies lose lots of power the further they are away from the fundamental freqs. A good example of the noise floor is we have two rooms Room A and Room B Room A is 72MHz and Room B is 2.4GHz Two people are trying to have a conversation with each other accross in Room A and Two people are trying to have a conversation with each other accross in Room B. In room A there are 450 other people having idle chit chat, like at a wedding after the drinks have been flowing for a while. The two people have to yell and may not even hear each other. In Room B ther are 10 other people whispering and the two original people can talk with out yelling. The free space loss in 2.4GHz is there but you don't need the excess power that you do in 72MHz to overcome the noise floor. Not to mention the data transmission bandwidth increases by over 30 times (faster servo response times, possibly increased sensitivity in future servos). But all in all I think this will be good for the hobby.
Posted on: 3/6/2007 4:11 AM by Author "APMECH" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=5517951

RE: My receiver antenna wire is torn, is this ok or not.??
Best bet is to send it back to mfg to have them solder a new one on. They usually frequency check them afterwards to ensure proper tuning. Antenna length is fairly critical for range and making sure the center frequency sensitivity has not shifted.
Posted on: 3/5/2007 1:34 AM by Author "APMECH" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=5512364

Flap controlled remote glow?
I use "OptoGLoII" from [url]http://www.cliftech.com[/url] you can purchase the kit which you just need to drill the holes and install the components. Only $25. You will need a batt harness and a glow driver harness and a servo harness. It is an optically Isolated rc switch so there is no cuurent draw from your battery to power the glow plug. You can order a completely assembled on for $35 from Electronic Model System. [url]http://www.emsjomar.com/highly[/url] recommend the one you build yourself. You get to see exactly how the circuit works. You can set it to go on at the low end of the signal or the high end. I have mine set up to go on @0 throttle and go off after 1/3rd throttle to help prevent dead sticks with my inverted engine, I can reverse that if I need to reverse the channel for other reasons.
Posted on: 5/14/2003 4:11 AM by Author "APMECH" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=534007

Accessory Module
Have you looked into an rc switch that you can run in parallel with another channel? There is an optically isolated switch that you can run off a "Y" harness lets say off of your gear channel that will allow you to turn on a landing light when the gear comes down and off when the gear comes up. you can use these swithces to "close" or "open" anywhere during the channels movements. I use mine for landing light and also another for onboard glow driver at low throttle settings due to the fact my engine is mounted inverted. Makes starting and low speed flying easy and without the fear of dead sticking it.
Posted on: 5/7/2003 9:57 AM by Author "APMECH" in the forum "Tips & Techniques"
http://www.rcuniverse.com/forum/fb.asp?m=737010

Futaba 6xas- or JR 622
Actually the amount of circuitry integrated on a board and with the use of smds can greatly reduce the amount of internal interference the unit generates. Most radios made since the late 90's use smds because every wire with any kind of signal on it acts like a small antennae for that signal. Thats the advantage of smds.... You can get each component closer together and most of your traces on a circuit board can be ran right next to ground plane which helps reduce radiated emissions. Which is why all radio mfgs use as little wire as possible. It's also alot easier to manufacture and stuff circuit boards. The hard part is using wires to each panel. In fact most of your circuit boards are modular, ie. wires with quick disconnect conectors on both ends.
Posted on: 5/1/2003 10:10 AM by Author "APMECH" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=706042