---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 01/21/12: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:46 AM - Re: Headset microphone level reducer (Jay Hyde) 2. 05:05 AM - Weak and Static on Transmission () 3. 05:13 AM - Re: Grand rapids cs02 / cs01 amp sensor (bob noffs) 4. 05:55 AM - Re: Headset microphone level reducer (Etienne Phillips) 5. 11:02 AM - SWR Meter (ROGER & JEAN CURTIS) 6. 01:58 PM - Re: SWR Meter (Robert L. Nuckolls, III) 7. 02:44 PM - Re: SWR Meter OOPS (Robert L. Nuckolls, III) 8. 02:51 PM - Re: SWR Meter (Noel Loveys) 9. 02:52 PM - Re: SWR Meter (Noel Loveys) 10. 04:29 PM - Re: SWR Meter (Robert L. Nuckolls, III) 11. 06:45 PM - Re: SWR Meter (ROGER & JEAN CURTIS) ________________________________ Message 1 _____________________________________ Time: 12:46:38 AM PST US From: "Jay Hyde" Subject: RE: AeroElectric-List: Headset microphone level reducer Hi there Etienne, The MGL radio can have the microphone levels independently set- do you have the V10 or V6 radio? Jay -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Etienne Phillips Sent: 02 January 2012 08:29 PM Subject: AeroElectric-List: Headset microphone level reducer Hi All I have two dissimilar headsets that have very different microphone output levels. The one headset is an oldish basic Avcomm model, and the other is a new child-sized one. My MGL radio/intercom doesn't have the ability to reduce the volume of the new headset adequately. I've never worked with electret microphones before, so am not sure how to build a signal reducer. I have noticed that they are polarity sensitive, which leads me to expect some phantom power is required...? I need to reduce the volume by about 15dB (according to the MGL radio) to match the Avcomm. Ideally, I'd like to be able to build a passive circuit that I can squeeze into the headset itself, rather than an interface box or off-the-shelf device. This will allow me to use the new headset in other aircraft as the Avcomm's seem to play nicely with other major brands. If anyone has some insight, I'd be most appreciative! Thanks Etienne ________________________________ Message 2 _____________________________________ Time: 05:05:51 AM PST US From: Subject: AeroElectric-List: Weak and Static on Transmission 1/21/2012 Hello Bill Bradburry, You wrote: "These radio problems at a Class C airport have made me afraid to fly." I consider the following items to be mandatory equipment in my experimental amateur built airplane both during phase one testing and subsequently: 1) One of the readily available, portable, battery powered hand held VHF communications radios along with both its original rechargeable battery (recently recharged) and a spare fitted battery case filled with alkaline batteries. 2) An adapter that allows me to plug my headset into the portable radio. 3) A means to temporarily connect the antenna connection of the portable radio into one of the airplane's more capable antennae. Note that: a) Actually using this temporary antenna connection is optional at the time of intended use and initial attempts at communication may be made using the antenna mounted on the portable radio itself. b) Using this temporary antenna connection and the hand held radio for trouble shooting may aid in locating the source of your communication problem. Following the above philosophy may take you out of the "afraid to fly category". When you eventually solve this problem please let us know what the problem was -- thanks. 'OC' Baker Says: "The best investment we can make is the time and effort to gather and understand knowledge." PS: You also wrote: "I sent my radio back to have it checked out and nothing was found." A "ground checks OK" result does not guarantee that the connection between the radio and your airplane is also OK. Have you been able to borrow an identical radio and test it in your airplane? ========================================================== Time: 05:42:24 AM PST US From: "Bill Bradburry" Subject: RE: AeroElectric-List: Re: Weak and Static on Transmission Well, to further clarify this problem. I seem to be able to hear ok on the ground while taxiing around the airport, but after I leave the airport the reception gets really bad. At first I thought it was a problem with the approach frequency because that is where it would first start up. It was a loud hiss in the headphones so loud that I could not hear ATC. In fact, I have made two NORDO landings as a result on this loud hiss. I sent my radio back to have it checked out and nothing was found. All this trouble is at below 5000 ft and fine weather. I am flying off my 40 hours (22 so far) and am only flying in good weather. These radio problems at a Class C airport have made me afraid to fly. ATC could take some action against me if it continues. Lancair has an all carbon Legacy available but this one is all fiberglass with the exception of the horizontal stabilizer, which is carbon. The antenna is inside the fuselage about 4+feet forward of the stabilizer. The bottom and rear half of the plane is in primer. The rest of the plane is bare fiberglass. The primer ends just about at the location of the antenna on the fuselage. I don't know if this would have an effect on the static on the plane or not. I would have had to consider static wicks a long time earlier in the build in order to install bonding wire. It is too late now AFAIK. Bill B ________________________________ Message 3 _____________________________________ Time: 05:13:19 AM PST US Subject: Re: AeroElectric-List: Grand rapids cs02 / cs01 amp sensor From: bob noffs i put mine on the cable from the battery after the starter so it monitored supply to the panel. bob noffs On Fri, Jan 20, 2012 at 11:46 PM, chris Sinfield < chris_sinfield@yahoo.com.au> wrote: > chris_sinfield@yahoo.com.au> > > Hi all > > I am installing a Grand Rapids J6000 EIS in my aircraft. > > > Where have people wired the amp current sensor? and through whit size > > > wire was it? > > > There are 2 different current sensors and they are for different size > > > wires? > > > > > > you can use the CS-01 or CS-02 or amps. the most important difference > > > is the size wire that is allowed for each. > > > the CS-01 100amp can fit up to a #4 wire and the CS-02 50amp can only > > > fit up to #6 wire. so if you're using a big battery cable most > > > people require the #4 wire and the CS-01. > > > > > > So which one to use and where did you fit it in the elec circuit on a > > > Jab3300? > > > > > > Chris > > > Zodiac XL > > > Jab 3300 > > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=364425#364425 > > ________________________________ Message 4 _____________________________________ Time: 05:55:14 AM PST US Subject: Re: AeroElectric-List: Headset microphone level reducer From: Etienne Phillips Hi Jay I've got a V10 radio, and I've already maxed out the settings, turning the pax headset all the way down, and it still was too loud. I don't want to turn up the Pilot's mic, as it is set correctly, matching the incoming radio volume. I haven't gotten around to trying out Bob's suggestion yet, but I'm pretty sure it'll work. Thanks Etienne On 21 Jan 2012, at 10:43 AM, Jay Hyde wrote: > > Hi there Etienne, > > The MGL radio can have the microphone levels independently set- do you have > the V10 or V6 radio? > > Jay ________________________________ Message 5 _____________________________________ Time: 11:02:27 AM PST US From: "ROGER & JEAN CURTIS" Subject: AeroElectric-List: SWR Meter I have a Vintage Sears SWR / FS meter which appears to be the same as the Cal Com Model 9856. Can this be used to check the antenna on aircraft nav com radios? If so, how do I set it up for use? Roger ________________________________ Message 6 _____________________________________ Time: 01:58:45 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SWR Meter At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote: > I have a Vintage Sears SWR / FS meter which appears to be >the same as the Cal Com Model 9856. Can this be used to check the antenna >on aircraft nav com radios? If so, how do I set it up for use? > > Roger > This is no doubt an excellent example of a transmission line sampling reflectometer. Dozens of products of this genre' were manufactured and they are quite common. Bob . . . ________________________________ Message 7 _____________________________________ Time: 02:44:24 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SWR Meter OOPS Sorry, hit the 'send' function before finishing the reply. Ignore the previous posting . . . At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote: > I have a Vintage Sears SWR / FS meter which appears to be >the same as the Cal Com Model 9856. Can this be used to check the antenna >on aircraft nav com radios? If so, how do I set it up for use? > > Roger This is no doubt an excellent example of a directional coupler sampling reflectometer. Dozens of products of this genre' were manufactured and they are quite common. Emacs! A general description of this device can be secured at: http://en.wikipedia.org/wiki/SWR_meter They are quite effective over the range of 2 to perhaps 30 MHz. To be useful, the length of transmission line inside must be a small fraction of a wavelength at the frequency of interest. In this case, 126 Mhz. When you study the design of a Watt/SWR meter suited for VHF . . . Emacs! The sampling is in a single "slug" that can be rotated to present complimentary forward and reverse power samples. Emacs! The slug contains a miniaturized version of the directional coupler sampling sampling loops found in your SWR meter. Here's a photo of a miniaturized version of your SWR meter optimized for VHF/UHF service. The loops are about 1/2" long. Emacs! So the short answer is the instrument you have is useful at Citizen's band frequencies and below. You need something tailored to VHF to do any serious work with your ship's antennas. Something like this Emacs! which can be had for about $60 off eBay. It's optimized for VHF and will produce more useful readings. For an more in-dept explanation you can browse a compendium of publications at: http://www.aeroelectric.com/articles/RF_PWR_Meter/ and in particular an article at: http://www.aeroelectric.com/articles/RF_PWR_Meter/Directional%20Coupler%20pa0nhc.pdf which describes a modification of instruments like yours that extends their useful range into VHF/UHF regions. Bob . . . ________________________________ Message 8 _____________________________________ Time: 02:51:07 PM PST US From: "Noel Loveys" Subject: RE: AeroElectric-List: SWR Meter I wouldn't use this type of SWR meter on anything north of 50 mHz. Find a ham or telco tech who used to work on microwave equipment to test your antenna. Such a person might also advise you on things like ground planes and antenna location. For certified aircraft the work should be signed off by a certified avionics shop. Noel -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: January 21, 2012 6:24 PM Subject: Re: AeroElectric-List: SWR Meter At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote: > I have a Vintage Sears SWR / FS meter which appears to be >the same as the Cal Com Model 9856. Can this be used to check the antenna >on aircraft nav com radios? If so, how do I set it up for use? > > Roger > This is no doubt an excellent example of a transmission line sampling reflectometer. Dozens of products of this genre' were manufactured and they are quite common. Bob . . . ________________________________ Message 9 _____________________________________ Time: 02:52:35 PM PST US From: "Noel Loveys" Subject: RE: AeroElectric-List: SWR Meter I forgot to say there was at least one Heathkit VHF SWR/FS meter on E-Bay a few minutes ago. Not the highest quality meter but it will put you in the ball park. Noel -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: January 21, 2012 6:24 PM Subject: Re: AeroElectric-List: SWR Meter At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote: > I have a Vintage Sears SWR / FS meter which appears to be >the same as the Cal Com Model 9856. Can this be used to check the antenna >on aircraft nav com radios? If so, how do I set it up for use? > > Roger > This is no doubt an excellent example of a transmission line sampling reflectometer. Dozens of products of this genre' were manufactured and they are quite common. Bob . . . ________________________________ Message 10 ____________________________________ Time: 04:29:43 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SWR Meter At 03:54 PM 1/21/2012, you wrote: At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote: I have a Vintage Sears SWR / FS meter which appears to be the same as the Cal Com Model 9856. Can this be used to check the antenna on aircraft nav com radios? If so, how do I set it up for use? Roger This is no doubt an excellent example of a transmission line sampling reflectometer. Dozens of products of this genre' were manufactured and they are quite common. (insert OOPS here when I sent the response too soon). I fumbled the ball when I changed the subject line and my complete response didn't get tacked onto this thread. Be sure to get the whole 9-yard response under a similar subject line. Bob . . . ________________________________ Message 11 ____________________________________ Time: 06:45:50 PM PST US From: "ROGER & JEAN CURTIS" Subject: RE: AeroElectric-List: SWR Meter At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote: I have a Vintage Sears SWR / FS meter which appears to be the same as the Cal Com Model 9856. Can this be used to check the antenna on aircraft nav com radios? If so, how do I set it up for use? Roger This is no doubt an excellent example of a transmission line sampling reflectometer. Dozens of products of this genre' were manufactured and they are quite common. (insert OOPS here when I sent the response too soon). I fumbled the ball when I changed the subject line and my complete response didn't get tacked onto this thread. Be sure to get the whole 9-yard response under a similar subject line. Bob . . . Thanks Guys, It appears that I have a unit suitable for the CB band. Since they are reasonably priced I will purchase a new one in the correct frequency band. 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