---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 01/26/17: 15 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:01 AM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Werner Schneider) 2. 05:06 AM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Alec Myers) 3. 08:40 AM - Re: Com radio coax (Robert L. Nuckolls, III) 4. 09:30 AM - Re: Com radio coax (Ken Ryan) 5. 09:38 AM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Robert L. Nuckolls, III) 6. 09:48 AM - Re: iCom Antenna Switchbox effect on Com Radio (speedy11@aol.com) 7. 10:03 AM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Alec Myers) 8. 12:07 PM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Robert L. Nuckolls, III) 9. 12:24 PM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Robert L. Nuckolls, III) 10. 12:32 PM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Alec Myers) 11. 01:36 PM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Earl Gmail) 12. 02:02 PM - Re: Re: iCom Antenna Switchbox effect on Com Radio (Bill Maxwell) 13. 05:25 PM - Double Check Antenna Placement (Art Zemon) 14. 06:00 PM - Re: Double Check Antenna Placement (Sebastien) 15. 06:57 PM - Re: Double Check Antenna Placement (Kelly McMullen) ________________________________ Message 1 _____________________________________ Time: 02:01:18 AM PST US Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio From: Werner Schneider Bob being in Europe things are a bit more difficult to find, I found in Amazon: Gam3Gear Surecom SW-102 Digital-VHF UHF 125-525 MHz Power & SWR-Meter This would be a bit at the edge of our band, but a review of a user stated (translated from German): If a resitor of 50 ohm is used (reflection > 30 dB) and connected to the antenna connector a VSWR of 1.02 is shown open antenna connector shows 19.99 (full reflection), so far so good. He then tests with different resistors (non inductive precision resistors) he tells with 25 ohm or 200 ohm he should see a VSWR of 2, 75 ohm should show 1.. But this unit always did show 1.02 when trying to calibrate with 1W and even with other power settings he never did see a VSWR which was to expect and tells the unit is useless for measuring VSWR. So I probably should go better with a standard box like DAIWA CN-102 L? Cheers Werner On 25.01.2017 20:41, Robert L. Nuckolls, III wrote: > > An SWR check at the radio end of the feed > line would be equally useful. These things > are coming down in price . . . and this offering > even ships from US. > > http://tinyurl.com/j7muztq > > You'll need a pair of BNC(F)->N(M) adapters > > http://tinyurl.com/h3666vz > > > Bob . . . > ________________________________ Message 2 _____________________________________ Time: 05:06:02 AM PST US From: Alec Myers Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio Is there any significant benefit of a digital meter over an analogue one? Iv e never trusted the fake precision of cheap digital meters. On Jan 25, 2017, at 14:41, Robert L. Nuckolls, III wrote: At 11:37 AM 1/25/2017, you wrote: > Bob, > > Thanks for discussing this subject. > I'm having trouble with my SL30 not receiving and transmitting and had ass umed the problem to be with the radio. After your discussion I remembered I wired in one of the iCom boxes and it well could be the problem. It certainly warrants investigation. Do you have a BNC barrel adapter . . . or perhaps a BNC-Tee? You can pull the coaxes off the back of the Icom-Box and bypass it with the connectors. Let us know what you discover. An SWR check at the radio end of the feed line would be equally useful. These things are coming down in price . . . and this offering even ships from US. http://tinyurl.com/j7muztq You'll need a pair of BNC(F)->N(M) adapters http://tinyurl.com/h3666vz Bob . . . ________________________________ Message 3 _____________________________________ Time: 08:40:08 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Com radio coax At 07:40 PM 1/25/2017, you wrote: >Is it okay to run my com radio coax (RG-400) in the same conduit as >the positive and negative fuel pump wires (16AWG, twisted pair, >@3amps)? The conduit is about 3 feet long. Absolutely . . . Bob . . . ________________________________ Message 4 _____________________________________ Time: 09:30:50 AM PST US From: Ken Ryan Subject: Re: AeroElectric-List: Com radio coax Thanks! On Thu, Jan 26, 2017 at 7:33 AM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 07:40 PM 1/25/2017, you wrote: > > Is it okay to run my com radio coax (RG-400) in the same conduit as the > positive and negative fuel pump wires (16AWG, twisted pair, @3amps)? The > conduit is about 3 feet long. > > > Absolutely . . . > > Bob . . . > ________________________________ Message 5 _____________________________________ Time: 09:38:54 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio At 06:56 AM 1/26/2017, you wrote: >Is there any significant benefit of a digital meter over an analogue >one? Ive never trusted the fake precision of cheap digital meters. > Interesting perception. In actuality, achieving digital precision has become jelly-bean technology. There are 80-cent micro-controllers in my drawers with 8-bit, a/d converters with less than 1% error for all effects combined. On the flip side, precision translation of feed line characteristics from the realm of radio frequencies to DC voltages proportional to amplitude and phase has become the longest pole in the tent. Whether you display results digitally on LCD/computer screen or analog on meters, the dominant error sources are quality of directional couplers (if used) and linearity of detectors at the frequency of interest. Here are but two of many exemplar articles on SWR measurement techniques. http://tinyurl.com/jojys8k I own one of the Red-Dot SWR meters. The extra ordinary compactness of this product speaks to a natural compression of physical size as one climbs the spectrum of radio frequencies. It agrees most favorably with my BIRD 43 watt meter. At $50, it 'seems' cheep but in this case, the thing performs well and is a useful tool for resolving antenna/ feed line performance in the state frequency range. I'm waiting for those guys to offer another version on the transponder/TCAS range. The short response is that analog to digital conversion and display has become a rudimentary process. I've had occasion to compare a number of the least expensive Harbor Freight multimeters against precision bench instruments. In every case I've found the DC accuracy of these instruments to be on the order of 1%. Bob . . . ________________________________ Message 6 _____________________________________ Time: 09:48:43 AM PST US From: speedy11@aol.com Subject: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio I have to rummage through my electronics box but I'm sure I have a BNC tee. Good idea to bypass it to test. I will followup. Stan >Bob, > >Thanks for discussing this subject. >I'm having trouble with my SL30 not receiving and transmitting and >had assumed the problem to be with the radio. After your discussion >I remembered I wired in one of the iCom boxes and it well could be the problem. It certainly warrants investigation. Do you have a BNC barrel adapter . . . or perhaps a BNC-Tee? You can pull the coaxes off the back of the Icom-Box and bypass it with the connectors. Let us know what you discover. An SWR check at the radio end of the feed line would be equally useful. These things are coming down in price . . . and this offering even ships from US. http://tinyurl.com/j7muztq You'll need a pair of BNC(F)->N(M) adapters http://tinyurl.com/h3666vz Bob . . . ________________________________ Message 7 _____________________________________ Time: 10:03:25 AM PST US Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio From: Alec Myers A transponder SWR meter would be great, but how are you going to get the output stage to transmit a carrier for long enough to measure anything with basic equipment? On 26Jan2017, at 6:32 PM, Robert L. Nuckolls, III wrote: At 06:56 AM 1/26/2017, you wrote: > Is there any significant benefit of a digital meter over an analogue one? Ive never trusted the fake precision of cheap digital meters. > Interesting perception. In actuality, achieving digital precision has become jelly-bean technology. There are 80-cent micro-controllers in my drawers with 8-bit, a/d converters with less than 1% error for all effects combined. On the flip side, precision translation of feed line characteristics from the realm of radio frequencies to DC voltages proportional to amplitude and phase has become the longest pole in the tent. Whether you display results digitally on LCD/computer screen or analog on meters, the dominant error sources are quality of directional couplers (if used) and linearity of detectors at the frequency of interest. Here are but two of many exemplar articles on SWR measurement techniques. http://tinyurl.com/jojys8k I own one of the Red-Dot SWR meters. The extra ordinary compactness of this product speaks to a natural compression of physical size as one climbs the spectrum of radio frequencies. It agrees most favorably with my BIRD 43 watt meter. At $50, it 'seems' cheep but in this case, the thing performs well and is a useful tool for resolving antenna/ feed line performance in the state frequency range. I'm waiting for those guys to offer another version on the transponder/TCAS range. The short response is that analog to digital conversion and display has become a rudimentary process. I've had occasion to compare a number of the least expensive Harbor Freight multimeters against precision bench instruments. In every case I've found the DC accuracy of these instruments to be on the order of 1%. Bob . . . ________________________________ Message 8 _____________________________________ Time: 12:07:27 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio > But this unit always did show 1.02 when trying to calibrate with > 1W and even with other power settings he never did see a VSWR which > was to expect and tells the unit is useless for measuring VSWR. I'm surprised at this . . . I'm wondering if the device under test was broke. I'm ensnarled in some house-projects right now . . . I'll dig out my red-dot and run the same tests on it in the next day or so. >So I probably should go better with a standard box like DAIWA CN-102 L? Without digging into the internals and/or doing bench testing, I can offer no additional insight. The red-dot series has been out there for several years. I searched a bit for technical reviews but couldn't come up with anything in the time I had to look. If anyone out there can find a published narrative on a technical bench test of the red-dot (or any similar instrument) it would be a useful addition to the archives. Bob . . . ________________________________ Message 9 _____________________________________ Time: 12:24:19 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio At 11:54 AM 1/26/2017, you wrote: > >A transponder SWR meter would be great, but how are you going to get >the output stage to transmit a carrier for long enough to measure >anything with basic equipment? Excellent point . . . I should have amplified my wish with the phrase "self excited". Such a device is not so much an SWR meter as it is an antenna analyzer . . . the next step up in RF measurement. I have an MFJ-259 that's getting rather long in the tooth. Got mine back when they were $170! [] This critter, and it's relatives have built in variable frequency excitation sources. Of course, the ship's transponder would not be a useful energy source for analyzing the antenna's performance. Bob . . . ________________________________ Message 10 ____________________________________ Time: 12:32:51 PM PST US Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio From: Alec Myers I bought a lovely Agilent 8664A 100Mhz-3GHz signal generator on eBay a while back for about $800 - that would do the trick. Unfortunately it weighs 50lbs and getting down the stairs from the attic and out to the airport ramp would just about kill me. On 26Jan2017, at 9:19 PM, Robert L. Nuckolls, III wrote: At 11:54 AM 1/26/2017, you wrote: > > A transponder SWR meter would be great, but how are you going to get the output stage to transmit a carrier for long enough to measure anything with basic equipment? Excellent point . . . I should have amplified my wish with the phrase "self excited". Such a device is not so much an SWR meter as it is an antenna analyzer . . . the next step up in RF measurement. I have an MFJ-259 that's getting rather long in the tooth. Got mine back when they were $170! This critter, and it's relatives have built in variable frequency excitation sources. Of course, the ship's transponder would not be a useful energy source for analyzing the antenna's performance. Bob . . . ________________________________ Message 11 ____________________________________ Time: 01:36:47 PM PST US From: Earl Gmail Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio Some time ago when the MFJ-259 was mentioned in a post, I was wishing you ha d made a 'comic book' about it's proper use associated with aircraft testing . You were otherwise occupied at the time but thought it was a good idea to put on your to-do list. I would still appreciate your guidance since the in cluded manual mentions several things NOT to do. Knowing how to do nondestr uctive testing would help. Thanks. > On Jan 26, 2017, at 14:19, Robert L. Nuckolls, III wrote: > > At 11:54 AM 1/26/2017, you wrote: >> >> A transponder SWR meter would be great, but how are you going to get the o utput stage to transmit a carrier for long enough to measure anything with b asic equipment? > > Excellent point . . . I should have amplified > my wish with the phrase "self excited". > > Such a device is not so much an SWR meter as > it is an antenna analyzer . . . the next > step up in RF measurement. > > I have an MFJ-259 that's getting rather > long in the tooth. Got mine back when they > were $170! > > > > > This critter, and it's relatives have built in > variable frequency excitation sources. Of > course, the ship's transponder would not be > a useful energy source for analyzing the > antenna's performance. > > > > > Bob . . . ________________________________ Message 12 ____________________________________ Time: 02:02:48 PM PST US Subject: Re: AeroElectric-List: Re: iCom Antenna Switchbox effect on Com Radio From: Bill Maxwell I would imagine the MFJ-259 would be of limited application when testing at the transponder frequency, given it's normal application doesn't extend above VHF? I have the later MFJ-269, that does reach up into the lower part of UHF but only gives SWR results at that frequency. On 27/01/2017 8:32 AM, Earl Gmail wrote: > Some time ago when the MFJ-259 was mentioned in a post, I was wishing > you had made a 'comic book' about it's proper use associated with > aircraft testing. You were otherwise occupied at the time but thought > it was a good idea to put on your to-do list. I would still appreciate > your guidance since the included manual mentions several things NOT to > do. Knowing how to do nondestructive testing would help. Thanks. > > On Jan 26, 2017, at 14:19, Robert L. Nuckolls, III > > > wrote: > >> At 11:54 AM 1/26/2017, you wrote: >>> > >>> >>> A transponder SWR meter would be great, but how are you going to get >>> the output stage to transmit a carrier for long enough to measure >>> anything with basic equipment? >> >> Excellent point . . . I should have amplified >> my wish with the phrase "self excited". >> >> Such a device is not so much an SWR meter as >> it is an antenna analyzer . . . the next >> step up in RF measurement. >> >> I have an MFJ-259 that's getting rather >> long in the tooth. Got mine back when they >> were $170! >> >> [] >> >> >> This critter, and it's relatives have built in >> variable frequency excitation sources. Of >> course, the ship's transponder would not be >> a useful energy source for analyzing the >> antenna's performance. >> >> >> >> >> Bob . . . >> ________________________________ Message 13 ____________________________________ Time: 05:25:07 PM PST US From: Art Zemon Subject: AeroElectric-List: Double Check Antenna Placement Folks, Would you double-check my antenna placement? Do I have anything in the wrong place? Did I forget anything? I am building a glass panel with 2 comm radios, and a VOR/ILS receiver. I think I'll skip the ADF and the LORAN. :-P So here is what I have in the way of devices, antennas, and locations. Devices and Antennas - The VOR/ILS/Glideslope receiver, probably a GNS 430, needs a VOR+ILS antenna and a GS antenna. I believe that all three functions can be combined into a single antenna with a splitter to the two receivers, with some loss of sensitivity. - Marker beacon receiver with its own antenna. Can this be relegated to the dust bin next to the ADF? - Transponder with its own antenna - ADS-B UAT with its own antenna - Comm 1 with its own antenna - Comm 2 with its own antenna - EFIS GPS with its own antenna - ADS-B UAT GPS with its own antenna Locations - VOR/ILS/GS antenna on the bottom of the fuselage, about 8 feet aft of the transponder and UAT antennas. It would be a pain to put it up on the vertical stabilizer so I want to skip that if it is reasonable. The splitter will be behind the panel, near the GNS 430, not near the antenna. - Marker beacon, transponder, and ADS-B UAT antennas on the bottom of the fuselage, near the front. - Comm antennas on the root, about 3 feet apart. - GPS antennas on the roof. Wiring - RG 400 for the GPS antennas - RG 58C/U for everything else Are there standard connectors for these devices, so I can order them at the same time that I order the coax? Or should I wait until I purchase each antenna and each radio to determine the right connector? Thank you, -- Art Z. -- https://CheerfulCurmudgeon.com/ *"If I am not for myself, who is for me? And if I am only for myself, what am I? And if not now, when?" Hillel* ________________________________ Message 14 ____________________________________ Time: 06:00:34 PM PST US From: Sebastien Subject: Re: AeroElectric-List: Double Check Antenna Placement Hello Art 1. Binning the marker beacon would be a great idea. 2. I have both GPS antennas on the front of the glareshield under the windshield. Always sees plenty of satellites and adds no drag. 3. The VOR/LOC/GS antenna placement depends on whether you are getting a V antenna or a blade. I've never seen a blade one that could be mounted on the belly, but have seen some V dipole ones that work well. Keep in mind that any antennas on the tail will get oil on them, and a big complicated antenna like the V dipole is a pain to clean around and will be broken off if you ever have someone help you wash your plane. Before deciding on a final placement of any of your antennas walk around your fuselage and imagine the idea there and think "Is someone going to walk into this antenna and poke an eye out, use it as a handle and break it off, kick it by accident while wandering around the aircraft...?" I would use RG400 for all wiring. Easier to work with. On Thu, Jan 26, 2017 at 5:20 PM, Art Zemon wrote: > Folks, > > Would you double-check my antenna placement? Do I have anything in the > wrong place? Did I forget anything? > > I am building a glass panel with 2 comm radios, and a VOR/ILS receiver. I > think I'll skip the ADF and the LORAN. :-P So here is what I have in the > way of devices, antennas, and locations. > > Devices and Antennas > > - The VOR/ILS/Glideslope receiver, probably a GNS 430, needs a VOR+ILS > antenna and a GS antenna. I believe that all three functions can be > combined into a single antenna with a splitter to the two receivers, with > some loss of sensitivity. > - Marker beacon receiver with its own antenna. Can this be relegated > to the dust bin next to the ADF? > - Transponder with its own antenna > - ADS-B UAT with its own antenna > - Comm 1 with its own antenna > - Comm 2 with its own antenna > - EFIS GPS with its own antenna > - ADS-B UAT GPS with its own antenna > > Locations > > - VOR/ILS/GS antenna on the bottom of the fuselage, about 8 feet aft > of the transponder and UAT antennas. It would be a pain to put it up on the > vertical stabilizer so I want to skip that if it is reasonable. The > splitter will be behind the panel, near the GNS 430, not near the antenna. > - Marker beacon, transponder, and ADS-B UAT antennas on the bottom of > the fuselage, near the front. > - Comm antennas on the root, about 3 feet apart. > - GPS antennas on the roof. > > Wiring > > - RG 400 for the GPS antennas > - RG 58C/U for everything else > > Are there standard connectors for these devices, so I can order them at > the same time that I order the coax? Or should I wait until I purchase each > antenna and each radio to determine the right connector? > > Thank you, > -- Art Z. > > -- > https://CheerfulCurmudgeon.com/ > > *"If I am not for myself, who is for me? And if I am only for myself, what > am I? And if not now, when?" Hillel* > ________________________________ Message 15 ____________________________________ Time: 06:57:24 PM PST US Subject: Re: AeroElectric-List: Double Check Antenna Placement From: Kelly McMullen I have similar equipment...GTN-650, SL30, Dynon Skyview with Dynon 1090ES for transponder and Dynon UAT receiver for in. I have a Bob Archer VOR antenna in each wingtip...each feeding one navcom/GS. Two com antennas on belly under rear seats. ADSB-out antenna right behind firewall. ADSB-In antenna behind baggage compartment on belly GTN-650 GPS antenna on cabin roof. Dynon GPS antenna in front of firewall under fiberglass cowling. No marker, no ADF, no Loran (I have both units, uninstalled from earlier aircraft). So 8 antennas, 3 under glass, 5 external. All are performing well so far. All on RV-10 4 place mostly metal airframe. I cannot see installing a mode A/C transponder and UAT out unit in a new installation to meet ADSB requirements. It means you need two boxes that talk to each other, that both have to be tested and certified and maintained. Why get separate GPS for ADSB when you plan on a certified GPS that can provide the data to the ADSB box? The difference in cost is negligible if you eliminate the extra GPS. On 1/26/2017 6:20 PM, Art Zemon wrote: > Folks, > > Would you double-check my antenna placement? Do I have anything in the > wrong place? Did I forget anything? > > I am building a glass panel with 2 comm radios, and a VOR/ILS receiver. > I think I'll skip the ADF and the LORAN. :-P So here is what I have in > the way of devices, antennas, and locations. > > Devices and Antennas > > * The VOR/ILS/Glideslope receiver, probably a GNS 430, needs a VOR+ILS > antenna and a GS antenna. I believe that all three functions can be > combined into a single antenna with a splitter to the two receivers, > with some loss of sensitivity. > * Marker beacon receiver with its own antenna. Can this be relegated > to the dust bin next to the ADF? > * Transponder with its own antenna > * ADS-B UAT with its own antenna > * Comm 1 with its own antenna > * Comm 2 with its own antenna > * EFIS GPS with its own antenna > * ADS-B UAT GPS with its own antenna > > Locations > > * VOR/ILS/GS antenna on the bottom of the fuselage, about 8 feet aft > of the transponder and UAT antennas. It would be a pain to put it up > on the vertical stabilizer so I want to skip that if it is > reasonable. The splitter will be behind the panel, near the GNS 430, > not near the antenna. > * Marker beacon, transponder, and ADS-B UAT antennas on the bottom of > the fuselage, near the front. > * Comm antennas on the root, about 3 feet apart. > * GPS antennas on the roof. > > Wiring > > * RG 400 for the GPS antennas > * RG 58C/U for everything else > > Are there standard connectors for these devices, so I can order them at > the same time that I order the coax? Or should I wait until I purchase > each antenna and each radio to determine the right connector? > > Thank you, > -- Art Z. > > -- > https://CheerfulCurmudgeon.com/ > > /"If I am not for myself, who is for me? And if I am only for myself, > what am I? And if not now, when?" 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