---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 03/18/16: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:12 AM - Re: BNC connectors and SWR (user9253) 2. 07:27 AM - Re: Re: BNC connectors and SWR (John Cox) 3. 09:28 AM - Re: Re: BNC connectors and SWR (Charlie England) 4. 09:57 AM - Re: Re: BNC connectors and SWR (Kelly McMullen) 5. 10:39 AM - Re: Re: BNC connectors and SWR (Charlie England) ________________________________ Message 1 _____________________________________ Time: 06:12:15 AM PST US Subject: AeroElectric-List: Re: BNC connectors and SWR From: "user9253" Since nobody else has replied, I will give my opinion which is only based reading these forums. No, the BNC connector splice will not affect SWR. No, RF will not leak from this BNC spice. Should a new cable be run: maybe. Anytime wires are spliced, a potential trouble spot is created. If the spice is readily and easily accessible for future inspection and troubleshooting, then OK, splice on additional cable. On the other hand, if you want peace of mind and less chance of future problems, replace the cable. RG400 or RG142 is better than RG58. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=453905#453905 ________________________________ Message 2 _____________________________________ Time: 07:27:52 AM PST US Subject: Re: AeroElectric-List: Re: BNC connectors and SWR From: John Cox Affirmative to each of the above points. However each connector introduces additional db loss which will degrade transmission and to a lesser extent reception. Don't cut the corner. Run a new cable run. We have fits with four cable runs to upper TCAS antenna and especially lower runs. 8 cables are a bitch and the central failure point in the absence of lighning strikes directly with the Antenna. John Cox Avionics Tech On Fri, Mar 18, 2016 at 6:09 AM, user9253 wrote: > > Since nobody else has replied, I will give my opinion which is only based > reading these forums. > No, the BNC connector splice will not affect SWR. > No, RF will not leak from this BNC spice. > Should a new cable be run: maybe. Anytime wires are spliced, a potential > trouble spot is created. If the spice is readily and easily accessible for > future inspection and troubleshooting, then OK, splice on additional > cable. On the other hand, if you want peace of mind and less chance of > future problems, replace the cable. RG400 or RG142 is better than RG58. > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=453905#453905 > > ________________________________ Message 3 _____________________________________ Time: 09:28:12 AM PST US Subject: Re: AeroElectric-List: Re: BNC connectors and SWR From: Charlie England You're technically correct. But run the numbers to see if the degradation is enough to justify the hassle of re-running an existing cable. The original post didn't make it into this post, but if he's talking SWR, he's probably talking about a comm; not a gigahertz range radio. How much range loss is there for 0.2 dB insertion loss when a typical max *needed* range is maybe 30 miles? 1/2 mile? 1/10 mile? 50 feet? The reliability issue remains, but in my experience, cutting into wire bundles all over the plane to extract the old cable and run a new one introduces many more and greater risks. Another perspective... On Fri, Mar 18, 2016 at 9:26 AM, John Cox wrote: > Affirmative to each of the above points. However each connector > introduces additional db loss which will degrade transmission and to a > lesser extent reception. Don't cut the corner. Run a new cable run. We > have fits with four cable runs to upper TCAS antenna and especially lower > runs. 8 cables are a bitch and the central failure point in the absence of > lighning strikes directly with the Antenna. > > John Cox > Avionics Tech > > On Fri, Mar 18, 2016 at 6:09 AM, user9253 wrote: > >> >> Since nobody else has replied, I will give my opinion which is only based >> reading these forums. >> No, the BNC connector splice will not affect SWR. >> No, RF will not leak from this BNC spice. >> Should a new cable be run: maybe. Anytime wires are spliced, a potential >> trouble spot is created. If the spice is readily and easily accessible for >> future inspection and troubleshooting, then OK, splice on additional >> cable. On the other hand, if you want peace of mind and less chance of >> future problems, replace the cable. RG400 or RG142 is better than RG58. >> >> -------- >> Joe Gores >> >> ________________________________ Message 4 _____________________________________ Time: 09:57:00 AM PST US Subject: Re: AeroElectric-List: Re: BNC connectors and SWR From: Kelly McMullen That is one of the great trade-offs, difficulty vs quality communications. A good com(6-8 watts), with good cable and good antenna/ground plane can communicate over at least 50 nm or more. Very important in some parts of the West, especially IFR. On 3/18/2016 9:25 AM, Charlie England wrote: > You're technically correct. > > But run the numbers to see if the degradation is enough to justify the > hassle of re-running an existing cable. The original post didn't make it > into this post, but if he's talking SWR, he's probably talking about a > comm; not a gigahertz range radio. How much range loss is there for 0.2 > dB insertion loss when a typical max *needed* range is maybe 30 miles? > 1/2 mile? 1/10 mile? 50 feet? > > The reliability issue remains, but in my experience, cutting into wire > bundles all over the plane to extract the old cable and run a new one > introduces many more and greater risks. > > Another perspective... > > On Fri, Mar 18, 2016 at 9:26 AM, John Cox > wrote: > > Affirmative to each of the above points. However each connector > introduces additional db loss which will degrade transmission and to > a lesser extent reception. Don't cut the corner. Run a new cable > run. We have fits with four cable runs to upper TCAS antenna and > especially lower runs. 8 cables are a bitch and the central failure > point in the absence of lighning strikes directly with the Antenna. > > John Cox > Avionics Tech > > On Fri, Mar 18, 2016 at 6:09 AM, user9253 > wrote: > > > > > Since nobody else has replied, I will give my opinion which is > only based reading these forums. > No, the BNC connector splice will not affect SWR. > No, RF will not leak from this BNC spice. > Should a new cable be run: maybe. Anytime wires are spliced, a > potential trouble spot is created. If the spice is readily and > easily accessible for future inspection and troubleshooting, > then OK, splice on additional cable. On the other hand, if you > want peace of mind and less chance of future problems, replace > the cable. RG400 or RG142 is better than RG58. > > -------- > Joe Gores > ________________________________ Message 5 _____________________________________ Time: 10:39:12 AM PST US Subject: Re: AeroElectric-List: Re: BNC connectors and SWR From: Charlie England Fine; call it 70 miles. Run the numbers. On 3/18/2016 11:54 AM, Kelly McMullen wrote: > > > That is one of the great trade-offs, difficulty vs quality > communications. A good com(6-8 watts), with good cable and good > antenna/ground plane can communicate over at least 50 nm or more. Very > important in some parts of the West, especially IFR. > > On 3/18/2016 9:25 AM, Charlie England wrote: >> You're technically correct. >> >> But run the numbers to see if the degradation is enough to justify the >> hassle of re-running an existing cable. The original post didn't make it >> into this post, but if he's talking SWR, he's probably talking about a >> comm; not a gigahertz range radio. How much range loss is there for 0.2 >> dB insertion loss when a typical max *needed* range is maybe 30 miles? >> 1/2 mile? 1/10 mile? 50 feet? >> >> The reliability issue remains, but in my experience, cutting into wire >> bundles all over the plane to extract the old cable and run a new one >> introduces many more and greater risks. >> >> Another perspective... >> >> On Fri, Mar 18, 2016 at 9:26 AM, John Cox > > wrote: >> >> Affirmative to each of the above points. However each connector >> introduces additional db loss which will degrade transmission and to >> a lesser extent reception. Don't cut the corner. Run a new cable >> run. We have fits with four cable runs to upper TCAS antenna and >> especially lower runs. 8 cables are a bitch and the central failure >> point in the absence of lighning strikes directly with the Antenna. >> >> John Cox >> Avionics Tech >> >> On Fri, Mar 18, 2016 at 6:09 AM, user9253 > > wrote: >> >> > >> >> Since nobody else has replied, I will give my opinion which is >> only based reading these forums. >> No, the BNC connector splice will not affect SWR. >> No, RF will not leak from this BNC spice. >> Should a new cable be run: maybe. Anytime wires are spliced, a >> potential trouble spot is created. If the spice is readily and >> easily accessible for future inspection and troubleshooting, >> then OK, splice on additional cable. On the other hand, if you >> want peace of mind and less chance of future problems, replace >> the cable. RG400 or RG142 is better than RG58. >> >> -------- >> Joe Gores >> > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.