Skyview SV-NET Cable

[andresmith76]

I want to build my own custom length SV-NET cables to connect my Skyview components. Does anyone know the Belden equivalent for the 9 conductor Tefzel wire cable Dynon uses for their prebuilt SV-NET cables? I would like to keep the same wire color codes and gauge sizes Dynon uses.
Andre'

 

[Bill Putney]

I think Dynon will sell you SV-Net wire by the foot. Call them and ask.

 

[andresmith76]

Thank you Bill - I did call Dynon and they don't sell the bulk cable. However, they do sell a 10' SV-NET cable with only 1 end terminated with crimped pins and connector, so that is what I ordered. A bit pricey at $60!

Andre'

 

[Bill Putney]

OK... Well, that's disappointing. It would be nice to be able to buy it directly from Dynon in the length you want but it's probably really hard for them to stock it that way. They may even have their cables made up by a vendor that keeps the cable reel and only ships the packaged cable kits to Dynon to keep in their stock. I'm sure they had that cable made to their specification and you're not likely to find that cable on the market.

Dynon does sell a 30' cable for $80. So, that last 20' is only $1 per foot. What a deal! Belden makes general purpose individually shielded cables and 3 pair Belden cable is about $2.60/ft. That cable doesn't have the same color code as Dynon uses, doesn't have the aviation grade insulation and you'd be missing the "EMS Auxiliary Voltage" wire unless you went to a 4 pair cable. At $80 for 30' you're only paying about a $0.06/ft premium for buying it from Dynon.

 

[jnmeade]

You could call SteinAir. I didn't see the cables you want in bulk, but it was my impression (I could be wrong) that they make up Dynon compatible cables. If my assumption is wrong I've sent you on a wild goose chase, but little harm in asking.

 

[andresmith76]

I did check SteinAir's website before posting on this forum but didn't find anything close. As Dynon uses this cable to transmit/receive data over 2 pair of wires, they twist the 9 wires for noise/interference reduction. Aircraft Spruce doesn't even sell this cable by the foot but they will custom make & sell SV-NET cables!

I only need about 6', so the Dynon 10 footer I purchased should be enough for me to complete my project. I just find it odd that this cable is so cryptic and difficult to find in bulk. Thanks guys!

Andre'

 

[jnmeade]

I didn't see it on Stein's site, either, which is why I suggested you call them. Sounds like you have it resolved anyway.

 

[airguy]

I did check SteinAir's website before posting on this forum but didn't find anything close. As Dynon uses this cable to transmit/receive data over 2 pair of wires, they twist the 9 wires for noise/interference reduction. Aircraft Spruce doesn't even sell this cable by the foot but they will custom make & sell SV-NET cables!

I only need about 6', so the Dynon 10 footer I purchased should be enough for me to complete my project. I just find it odd that this cable is so cryptic and difficult to find in bulk. Thanks guys!

Andre'

Actually you only have some of the wires twisted - you wouldn't get proper function with all nine twisted up. There are 4 sets of "twisted pairs" used in the cables, and then there is one straight wire with them - the data and power carriers are the twisted pairs. Twisted pair wire is available from Stein as well as the straight wire, and the pins and connectors and backshells. Make your own cables, I wired my entire airplane without any purchased premade cables. It's not that difficult.

See Appendix C of the installation manual for more details - but data pairs 1 and 2 must be twisted. Power/ground 1 and 2 don't technically need to be twisted, but it's good practice and avoids any interference from stray signals - and you're buying a bunch of twisted pair wire anyway, so why not? The 9th wire is EMS aux voltage.

 

[Raymo]

I cut several of the 18" cables in half and re-terminated. You can build them from scratch using 20-22g Tefzel. You can also purchase flexible wire sleeve from Aircraft Spruce. Use heat shrink at each end to keep it from fraying.

 

[Bill Putney]

I cut several of the 18" cables in half and re-terminated. You can build them from scratch using 20-22g Tefzel. You can also purchase flexible wire sleeve from Aircraft Spruce. Use heat shrink at each end to keep it from fraying.

I thought there were individually shielded pairs in that cable.

 

[airguy]

I thought there were individually shielded pairs in that cable.

Unless Dynon has recently changed the spec and construction, there are no shielded conductors in the network cables - only unshielded twisted pairs. I'm referencing HDX installation manual 15.4.7 revision AG, Appendix C pages 23-2 and 23-3, which I believe is the most current.

 

[Raymo]

Correct, @airguy, no shielding.

 

[andresmith76]

To follow up, I called SteinAir and talked to Nick in the shop. He said they do not sell or have access to unterminated SV-NET cable by the foot - they buy the partially constructed cables (10', 20', 30') from Dynon and cut to length as needed. He also said they sometimes make their own. Each SV-NET cable has 2 ea. unshielded twisted pairs and the rest are individual, non-twisted, non-shielded wires. They then wrap flexible wire sleeve around the wire group as Raymo stated. Every wire in the bundle is Tefzel insulated. Nick wasn't sure if the outer jacket was Tefzel. Dynon must have this cable custom-made!

 

[Raymo]

I don't think Dynon's wire is Tefzel. There is other aircraft appropriate wire.

 

[andresmith76]

Dynon's states their SV-NET wiring is Tefzel Grade:

Dynon Avionics Online Store

Purchase builder support items or components to complete your SkyView system. For Experimental Aircraft Only.

dynonstore.com

 

[RVDan]

The cable is SAE AS or M-27500 series. I doubt Belden makes it. Different than plenum cable. If you google the spec you can find the type and conductor number you need. Dynon also tells you in the install manual how to make your own, but it will be missing the outer jacket. I can look up what you need later if you need. Use the TH wire type with no shield. You can use shield but it is not necessary due to the twisted wires. They use AWG 22 conductors to be compatible with the connector pins. If you buy the connectors get the machined pins for best reliability. I think you will be surprised how much the wire and decent connectors cost.

 

[Raymo]

The DB-9 pins can accept up to 20g wire but 22g is likely sufficient.