---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 12/12/10: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:27 AM - Noise from Garmin 496 (Marty) 2. 08:13 AM - Re: Noise from Garmin 496 (Dave Saylor) 3. 10:39 AM - Teflon Wire - 7 strands vs. 19 stands (dave.gribble@mchsi.com) 4. 01:07 PM - Re: Teflon Wire - 7 strands vs. 19 stands (Peter Pengilly) 5. 01:36 PM - Re: Teflon Wire - 7 strands vs. 19 stands (Robert L. Nuckolls, III) 6. 01:49 PM - Re: Teflon Wire - 7 strands vs. 19 stands (Bob McCallum) 7. 02:04 PM - Re: Teflon Wire - 7 strands vs. 19 stands (dave.gribble@mchsi.com) 8. 02:16 PM - Re: Noise from Garmin 496 (Kevin Klinefelter) 9. 03:44 PM - Re: Teflon Wire - 7 strands vs. 19 stands (Robert L. Nuckolls, III) 10. 06:04 PM - Computing a Resistor Value (AlRice) 11. 08:44 PM - Re: Computing a Resistor Value (Richard E. Tasker) ________________________________ Message 1 _____________________________________ Time: 07:27:04 AM PST US Subject: AeroElectric-List: Noise from Garmin 496 From: Marty I posted a message a few days ago and haven't seen one response. Question is, has anyone else found that their Garmin handheld with 30A weather antenna produces a periodic type "hiss" noise in their radios? Marty ________________________________ Message 2 _____________________________________ Time: 08:13:52 AM PST US From: Dave Saylor Subject: Re: AeroElectric-List: Noise from Garmin 496 I get kind of a da-da-da-shhhh (repeat endlessly) from my 696. If I disable the DC-IN it goes away. It's a pretty low level background noise that I can live with. I've tried all kinds of filters and alternate grounds with some relief but it's still noticeable. The noise is there whenever the 696 is plugged in, whether its powered on or not. I assume it has something to do with the battery being charged/monitored. Dave Saylor AirCrafters 140 Aviation Way Watsonville, CA 95076 831-722-9141 Shop 831-750-0284 Cell On Sun, Dec 12, 2010 at 7:21 AM, Marty wrote: > I posted a message a few days ago and haven't seen one response. Question > is, has anyone else found that their Garmin handheld with 30A weather > antenna produces a periodic type "hiss" noise in their radios? > Marty > > ________________________________ Message 3 _____________________________________ Time: 10:39:00 AM PST US From: dave.gribble@mchsi.com Subject: AeroElectric-List: Teflon Wire - 7 strands vs. 19 stands I found some surplus M16878/4BGB1 wire. I think it is 20 AWG wire with teflon insulation and coated copper conductors. It is made of 7 strands of wire. I know that newer wire is made of up 19 strands. Will the 7 strand wire "work" with crimp connections such as AMP FastOn and crimped D-sub pins? Thanks for any info, dave gribble ________________________________ Message 4 _____________________________________ Time: 01:07:38 PM PST US From: Peter Pengilly Subject: Re: AeroElectric-List: Teflon Wire - 7 strands vs. 19 stands It will be very much less flexible than 19 strand wire, and so may break in service. Peter On 12/12/2010 18:35, dave.gribble@mchsi.com wrote: > --> AeroElectric-List message posted by: dave.gribble@mchsi.com > > I found some surplus M16878/4BGB1 wire. I think it is 20 AWG wire with teflon insulation and coated copper conductors. It is made of 7 strands of wire. I know that newer wire is made of up 19 strands. Will the 7 strand wire "work" with crimp connections such as AMP FastOn and crimped D-sub pins? > > Thanks for any info, > > dave gribble > > ________________________________ Message 5 _____________________________________ Time: 01:36:51 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Teflon Wire - 7 strands vs. 19 stands At 12:35 PM 12/12/2010, you wrote: > >I found some surplus M16878/4BGB1 wire. I think it is 20 AWG wire >with teflon insulation and coated copper conductors. It is made of >7 strands of wire. I know that newer wire is made of up 19 >strands. Will the 7 strand wire "work" with crimp connections such >as AMP FastOn and crimped D-sub pins? See attached file for description of M16878 wires. Yes, you have a Type E (600v thin teflon) wire that will be 20AWG silver coated 7 strand copper. Teflon was never real popular as an airframe wire. It's not very tough although the temperature ratings are great. 7-strand wire is not a really big deal. A quintrillion vehicles including airplanes have be wired with 7-strand wire . . . and we don't seem to be hearing about the lack of vibration resistant stranding. If you got this wire cheap and you're thinking about using a lot of it (it could probably substitute for 22AWG in most applications, then it's probably a cost effective thing to do with no significant increase in risks. Bob . . . ________________________________ Message 6 _____________________________________ Time: 01:49:55 PM PST US From: Bob McCallum Subject: RE: AeroElectric-List: Teflon Wire - 7 strands vs. 19 stands Dave; Yes, it will "work" with respect to being properly secured by the various terminals/connectors etc. However, 19 strand is considerably more flexible and consequently more vibration resistant than 7 strand. Both may perform satisfactorily in your application but if there is flexing involved (vibration?) the finer stranding will last longer and will impart lower loads on the devices to which it is attached. Gauge for gauge its fatigue resistance will be greater and mechanical forces transmitted less. This is the reason Bob recommends "welding cable" for fat wires due to its extremely fine stranding and hence greater flexibility. (Having said all that the fatigue resistance of the 7 strand may exceed the life of the airframe, but regardless the 19 strand will outlast it from an apples to apples fatigue standpoint) Bob McC > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list- > server@matronics.com] On Behalf Of dave.gribble@mchsi.com > Sent: Sunday, December 12, 2010 1:36 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Teflon Wire - 7 strands vs. 19 stands > > > I found some surplus M16878/4BGB1 wire. I think it is 20 AWG wire with teflon > insulation and coated copper conductors. It is made of 7 strands of wire. I know that > newer wire is made of up 19 strands. Will the 7 strand wire "work" with crimp > connections such as AMP FastOn and crimped D-sub pins? > > Thanks for any info, > > dave gribble > > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > > ________________________________ Message 7 _____________________________________ Time: 02:04:00 PM PST US From: dave.gribble@mchsi.com Subject: Re: AeroElectric-List: Teflon Wire - 7 strands vs. 19 stands Thanks Bob - great reply.. but I'm confused about why the 20AWG Teflon wire "could substitute for 22AWG in most applications" dave ----- Original Message ----- From: "Robert L. Nuckolls, III" Sent: Sunday, December 12, 2010 3:30:21 PM GMT -06:00 US/Canada Central Subject: Re: AeroElectric-List: Teflon Wire - 7 strands vs. 19 stands At 12:35 PM 12/12/2010, you wrote: > >I found some surplus M16878/4BGB1 wire. I think it is 20 AWG wire >with teflon insulation and coated copper conductors. It is made of >7 strands of wire. I know that newer wire is made of up 19 >strands. Will the 7 strand wire "work" with crimp connections such >as AMP FastOn and crimped D-sub pins? See attached file for description of M16878 wires. Yes, you have a Type E (600v thin teflon) wire that will be 20AWG silver coated 7 strand copper. Teflon was never real popular as an airframe wire. It's not very tough although the temperature ratings are great. 7-strand wire is not a really big deal. A quintrillion vehicles including airplanes have be wired with 7-strand wire . . . and we don't seem to be hearing about the lack of vibration resistant stranding. If you got this wire cheap and you're thinking about using a lot of it (it could probably substitute for 22AWG in most applications, then it's probably a cost effective thing to do with no significant increase in risks. Bob . . . ________________________________ Message 8 _____________________________________ Time: 02:16:04 PM PST US From: "Kevin Klinefelter" Subject: Re: AeroElectric-List: Noise from Garmin 496 I have a 496 with weather, mounted just above the comm radio. No hiss. Power is through the external cable to the main bus. Kevin ----- Original Message ----- From: Marty To: Aeroelectric-List Sent: Sunday, December 12, 2010 7:21 AM Subject: AeroElectric-List: Noise from Garmin 496 I posted a message a few days ago and haven't seen one response. Question is, has anyone else found that their Garmin handheld with 30A weather antenna produces a periodic type "hiss" noise in their radios? Marty ________________________________ Message 9 _____________________________________ Time: 03:44:01 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Teflon Wire - 7 strands vs. 19 stands At 03:58 PM 12/12/2010, you wrote: > >Thanks Bob - great reply.. but I'm confused about why the 20AWG >Teflon wire "could substitute for 22AWG in most applications" If you have a drawing that calls out 22AWG, then you either go out and buy some 22AWG or you consider substituting 20AWG assuming you don't mind taking the hit on weight (very small) and the wire will fit into all the crimped pins. In terms of footage, 22AWG wire is the most popular size in most airplanes. We did try 24AWG in the Premier . . . I think the techs on the line are used to it now but there was a lot of fuss at the beginning. It's more difficult to work with. I think I suggested to this List many years ago that builders buy full spools of 20AWG wire (1000'). It's cheaper in large quantities and can be used wherever the drawings call for 22 or 20AWG. This one size MIGHT account for 90% of all your wiring footage in a small airplane and ease your procurement task. Bob . . . ________________________________ Message 10 ____________________________________ Time: 06:04:23 PM PST US Subject: AeroElectric-List: Computing a Resistor Value From: "AlRice" I want to install my AV80R GPS in my panel and wire the power lead to the bus without installing a clunky cigarette power socket on my panel. The GPS input voltage is 5V and it draws 1.5A (at least that's what the cigarette power lead says on it). My buss voltage is 13.5V, so how do I compute the resistor ohm's and watts needed for my power lead? I know enough about Ohm's law to be dangerous. Thanks. -------- Al Rice Skybolt 260 RV-9A Helping with my grandson's Piet Read this topic online here: http://forums.matronics.com/viewtopic.php?p=323122#323122 ________________________________ Message 11 ____________________________________ Time: 08:44:36 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Computing a Resistor Value Just adding a resistor is probably not a good idea. A resistor drops a variable amount of voltage depending on the actual current consumption. Additionally, your bus voltage will vary from 12V or less when the alternator is off to as much as 14.2V when it is on. Unless the AV80R draws a constant current (unlikely) and can handle a relatively wide voltage input, you really do need to use the power cord or some other source of 5V. I couldn't find a manual to see what voltage it can handle, but given they sell adapters for 12/24VDC and for 110/220VAC, it is likely that it can use only a limited voltage (5V). The markings on the adapter almost surely refer to the adapter capacity, not the exact consumption of the AV80R. For educational purposes, assuming that the AV80R actually did take exactly 1.5A at 5V and your buss voltage was a constant 13.5V, you would calculate the resistor value as follows: The resistor would have to drop 13.5V minus 5V or 8.5V at 1.5A. Since V=I*R or R=V/I, then R = 8.5V/1.5A or 5.666 ohms which is close to a standard 5.6 ohm resistor. If we used that resistor we would actually get 8.4V drop which gives us 5.1V for the AV80R which would probably be close enough. The power dissipated in the resistor would be P=V*I or 8.4V*1.5A = 12.6W which would mean it would have to be a pretty large wirewound ceramic resistor that would get mighty hot. Of course, all this is based on the paragraph above this one, which is highly unlikely. You can either find a 12V to 5V power converter to include behind the panel or just use the optional cigarette lighter adapter provided by Honeywell. Dick Tasker AlRice wrote: > --> AeroElectric-List message posted by: "AlRice" > > I want to install my AV80R GPS in my panel and wire the power lead to the bus without installing a clunky cigarette power socket on my panel. The GPS input voltage is 5V and it draws 1.5A (at least that's what the cigarette power lead says on it). My buss voltage is 13.5V, so how do I compute the resistor ohm's and watts needed for my power lead? I know enough about Ohm's law to be dangerous. > Thanks. > > -------- > Al Rice > Skybolt 260 > RV-9A > Helping with my grandson's Piet > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=323122#323122 > > > -- Please Note: No trees were destroyed in the sending of this message. 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