---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Tue 07/26/05: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:24 AM - Re: First flight N214KS (Rowland Carson) 2. 01:28 AM - Loose muffler heat shield clamps (willie harrison) 3. 05:07 AM - testing (KARL HEINDL) 4. 03:17 PM - Re: Radio reception problems (Peter Rees) 5. 08:22 PM - Re: Radio reception problems (Fred Fillinger) 6. 08:50 PM - Re: Radio reception problems (Fred Fillinger) ________________________________ Message 1 _____________________________________ Time: 12:24:29 AM PST US From: Rowland Carson Subject: Re: Europa-List: First flight N214KS --> Europa-List message posted by: Rowland Carson At 2005-07-24 20:06 -0400 KandShill@aol.com wrote: >it was first flown by me (Ken Hill) on July 20, 2005 Ken - congratulations, and thanks for a comprehensive report! I have just one query - where did the first flight take place? regards Rowland -- | Rowland Carson Europa Club Membership Secretary (retiring) - email for info! | Europa 435 G-ROWI (750 hours building) PFA #16532 | e-mail website ________________________________ Message 2 _____________________________________ Time: 01:28:18 AM PST US From: "willie harrison" Subject: Europa-List: Loose muffler heat shield clamps --> Europa-List message posted by: "willie harrison" Beware! The new design of clamp for securing the muffler heat shield (which uses screwed fasteners instead of a crimped fasteners) has no thread locking and shakes itself loose due to engine vibration. In my case one of the two clamps fell right off after 8 hours flying and the other one was very loose - not nice if the remains of the clamp find their way back to snag the rudder cables. Also not nice if the heat shield falls off and the muffler cooks something which shouldn't be cooked. I will try lock nuts next time. Happy landings! Willie Harrison G-BZNY ________________________________ Message 3 _____________________________________ Time: 05:07:57 AM PST US From: "KARL HEINDL" Subject: Europa-List: testing --> Europa-List message posted by: "KARL HEINDL" do not archive ________________________________ Message 4 _____________________________________ Time: 03:17:55 PM PST US From: "Peter Rees" Subject: Re: Europa-List: Radio reception problems --> Europa-List message posted by: "Peter Rees" I've been following this with interest for a while as we have an Icom in HI and have almost exactly the same problems - sometimes we can hear / be heard from a good distance away but on occasions, we can't hear Rochester until we are within about 5 miles of them (122.25Mhz). As far as I can see, the problem must be one of three things: 1) the aerials gain isn't over the required range - this could easily be fixed by a more conventional aviation aerial 2) The squelch is either over enthusiastic or being triggered by noise from the engine, GPS etc (anyone found any links here - I believe it may be noise from the engine electrics as the radio 'deafness' seems less pronounced when the throttle is closed. 3) The design or manufacture of the radio isn't 'as it says on the box' - which I doubt from a name like Icom. My theory is number 2 above - anyone got any ideas on this? (my limited understanding of the Rotax history is that there are 2 types of ignition unit in use - could it help if those with the same problem told us what engine they have and what ignition units are installed - this problem seems to be very widespread (we thought we were just unlucky and needed a new aerial). Peter ----- Original Message ----- From: "Bryan Allsop" Subject: Re: Europa-List: Radio reception problems > --> Europa-List message posted by: "Bryan Allsop" > > > Thanks for your response Fred. > > I confess though that I am not sure that I understand all of it. Age is > beginning to effect the clarity of my thinking processes, perhaps in the > same way that my six year old Icom A 200 is not so clear in extreme > circumstances. > > I began to lose the thread with the 'wild geese' and 'turkeys', and > something to do with 'doorstops'. I must also confess that I am not > totally > up to speed with 'Genave Alpha 360's either, and I am even a little rusty > on > 'general azimuth'. Other than that, I think I am almost quite clear about > what you are saying. > > So, what can I do Fred? Can I chop a bit off somewhere, or do I need a new > radio? > > Incidentally, friends have noticed that the transmit performance drops off > when the European Safety Com frequency 135.475MHz is used. > > Regards.. Bryan > > ----- Original Message ----- > From: "Fred Fillinger" > To: > Subject: Re: Europa-List: Radio reception problems > > >> --> Europa-List message posted by: "Fred Fillinger" >> >>> --> Europa-List message posted by: "Bryan Allsop" >> >>> >>> They were receiving me strength five, but for much >>> of the transit I could not hear them at all. >>> >> Antennas work by the rule of reciprocity, and above indicates antenna >> is not the problem, at least in that azimuth of the 360-deg pattern. >> >>> In both cases I have been able to hear other >>> aircraft speaking to them strength five, >> >> If you can't hear a ground station, but other A/C yes, and they're not >> in the same general azimuth, the radiating pattern of the antenna is >> suspect -- an installation location problem. A/C to A/C doesn't have >> the line-of-sight problem like A/C to ground over terrain. But the >> ground station can achieve a near perfect antenna, canceling out the >> line-of-sight issue. >> >>> I can now see that I have a common problem at the lower frequencies, >> >> Receive problems on the extremes of the bands indicate alignment >> problems, but radios just don't go out of alignment to any significant >> degree, if at all. The degree of problem you report suggests a >> component might be way off spec. Low odds, but people hit lotteries. >> Also, radiating pattern problems can be frequency dependent to some >> degree. >> >> Hope this helps rather than chases wild geese! >> >> BTW, we can't deduce strength five or strength anything from what is >> heard, unless rather weak. Leveling circuitry in modern radios + >> other factors. Our old control tower was even handing "strength >> three" or "four" to people. Must have an S-meter I figure. But first >> visit to the tower, I alarmingly saw they used a Genave Alpha 360, a >> "doorstop" in alternative use. No S-meter, but that turkey of a radio >> could actually hint at strength reasonably well. >> >> Reg, >> Fred F. >> >> >> > > > ________________________________ Message 5 _____________________________________ Time: 08:22:17 PM PST US From: "Fred Fillinger" Subject: Re: Europa-List: Radio reception problems --> Europa-List message posted by: "Fred Fillinger" > --> Europa-List message posted by: "Peter Rees": > ...sometimes we can hear / be heard > from a good distance away > but on occasions, we can't hear Rochester until we > are within about 5 miles of them (122.25Mhz). If at all times off the nose, or same azimuth point elsewhere, it could be a simple matter of which of their transmitters they're using. They need not have the same xmit power, but if an installation is performing poorly, above can happen. When you have squares and logs in the math, seemingly small matters can then cause extreme results! Like get this. At only 100AGL over really flat terrain, theory says at 5 miles you should hear ATC if they were using a 100milliwatt transmitter! Something's not working well at all. > 1) the aerials gain isn't over the required range - It's the loss, not the gain. Only a directional antenna can have gain of practical use. There is a small, omnidirectional gain of 2.2db due to pure physics. If there's greater than 2.2 in some directions, other points around the circle _must_ have a loss. But if a loss in one direction, there may not be a gain anywhere else, depending upon what a nearby metal element is doing (like changing the signal's polarization). > this could easily be fixed by > a more conventional aviation aerial The radiating pattern of a whip antenna pointed down is somewhat better than a dipole. However, more significant is where it's located within a fuselage. External to the fuselage, and any problems go away. > 2) The squelch is either over enthusiastic or being > triggered by noise...from the engine, GPS etc GPS can't do anything to VHF, but engine or strobe etc. noise is nothing but audio carrier modulation which makes no sense as spoken words. Same as ATC with talent as a voice comic mimicing an alternator whine into the mic. So squelch may break, and we hear noise. It won't decrease ability to receive carrier, but rather as a combined signal makes carrier stronger -- in a cheap circuit, squelch can be broken. So Narco in its 810 uses a fancy circuit which attempts to determine if words are being received. They call it "squelch comparator and carrier override." IOW, ain't voice, so let's ignore the stronger, noisy carrier and nothing is heard in the audio. Works great! Reg, Fred F. ________________________________ Message 6 _____________________________________ Time: 08:50:19 PM PST US From: "Fred Fillinger" Subject: Re: Europa-List: Radio reception problems --> Europa-List message posted by: "Fred Fillinger" > --> Europa-List message posted by: "Bryan Allsop" Bryan, My slang references to turkeys, geese, and doorstops do have meaning, "...but that's not important right now." [from our classic comedy movie "Airplane!"] :-) > I am even a little rusty on 'general azimuth'. Azimuth references points around a circle when viewed from above. > So, what can I do Fred? Can I chop a bit off, > somewhere or do I need a new radio? First an airborne check, listening to a continuous broadcast, or a real chatty Approach freq, at a distance that is very weak at best while doing the test. Fly big, lazy 360-deg circles, and listen for where there's loss of signal. If necessary fly further away and try again. If significant voids around the circle, that says antenna installation problem (location with the A/C). It's helpful for me to know about distance from an ATC facility and your AGL altitude, and flatness of the terrain. For example, 2,500 AGL, 40 nm from a smaller field with a control tower who uses a 10W transmitter. Actually, their actual xmit power doesn't matter too much. 2,500 may enough above line-of-sight to allow for rolling terrain. You're nominally receiving 90 microvolts, and you should hear them if a decent antenna and up-to-spec comm radio. Reg, Fred F.