For purposes of a wingtip NAV antenna (or any of our other standard antennas), is there any reason to pay $5-$6/ft for RG400 from the usual suppliers, or would this RG400 RF Coax Cable M17/128 Double Shield Coaxial Cable work just as well?
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Low cost RG400
- Thread starter Ben Ellis
- Start date
I have bought cable and thermocouple wire on Amazon and ended up throwing it all out and buying from Stein. This description of that seller is not confidence inducing:
Shenzhen Eightwood Electronics Co.,Ltd was established in 2008, a professional company specialized in production ,Research and Development and operation of Radio frequency (RF) Cable Assemblies. Eightwood is the perfect combination of global E-commerce and China's low manufacturing costs, providing the high performance, low-cost product solutions for the global RF coaxial cable assemblies users.
About Seller
Shenzhen Eightwood Electronics Co.,Ltd was established in 2008, a professional company specialized in production ,Research and Development and operation of Radio frequency (RF) Cable Assemblies. Eightwood is the perfect combination of global E-commerce and China's low manufacturing costs, providing the high performance, low-cost product solutions for the global RF coaxial cable assemblies users.
For what it's worth, I know two people who have used this exact coax for all of their antennas. It's just anecdotal, but they said they've had no quality issues at all and would use it again, especially given the cost savings. I'm considering trying it out. My routing is such that if it turns out it's garbage when I'm flying, pulling the mil spec stuff through will be an easy change.
I normally use Stein as I really try to support our fellow pilots and people who keep Doug in business, but about 3 months ago, I needed some cable and had to order it on a Friday afternoon … I really wanted to finish my work over the weekend so I ordered that exact cable listed above. I didn’t see anything that would lead me to believe it’s inferior to what Stein sells. No issues since install.
I considered the Eightwood cable on Amazon and found the following review useful:
"Being unmarked and at a price of about 1/3 that of Mil-spec RG-400, I was skeptical but decided to give this a try for a non-critical application -- and I was pleasantly surprised. I measured the 40 foot length with a professional grade vector network analyzer (VNA) and compared it to a length of Mil-spec cable I'd previously purchased from a reliable source.
Velocity factor and characteristic impedance (Z0) of the two cables were virtually identical. Also, the Z0 of this cable was at least as constant along the 40 foot length as that of the Mil-spec cable, indicating that the physical construction is uniform with no anomalies. The shields appear to be as tightly wound as those of the Mil-spec cable.
The only difference I could detect was a slightly higher loss. I measured the loss only between 3 and 200 MHz which was the range where I'll be using it. The loss of this cable was about 6% greater at 3 MHz, and 1 to 2 percent greater at 10 - 200 MHz. These could indicate that the silver plating on this cable isn't as thick, or might be some other material. This small difference in loss itself would be insignificant in just about any application, but if due to a plating difference it might mean that the cable would deteriorate in a shorter period than the Mil-spec counterpart, if exposed to the environment for a long time.
At least as far as I'm able to determine, this cable will be useful for a lot of applications calling for RG-400/U, at greatly reduced expense."
The above being said, I bought the milspec stuff from ACS anyway...
"Being unmarked and at a price of about 1/3 that of Mil-spec RG-400, I was skeptical but decided to give this a try for a non-critical application -- and I was pleasantly surprised. I measured the 40 foot length with a professional grade vector network analyzer (VNA) and compared it to a length of Mil-spec cable I'd previously purchased from a reliable source.
Velocity factor and characteristic impedance (Z0) of the two cables were virtually identical. Also, the Z0 of this cable was at least as constant along the 40 foot length as that of the Mil-spec cable, indicating that the physical construction is uniform with no anomalies. The shields appear to be as tightly wound as those of the Mil-spec cable.
The only difference I could detect was a slightly higher loss. I measured the loss only between 3 and 200 MHz which was the range where I'll be using it. The loss of this cable was about 6% greater at 3 MHz, and 1 to 2 percent greater at 10 - 200 MHz. These could indicate that the silver plating on this cable isn't as thick, or might be some other material. This small difference in loss itself would be insignificant in just about any application, but if due to a plating difference it might mean that the cable would deteriorate in a shorter period than the Mil-spec counterpart, if exposed to the environment for a long time.
At least as far as I'm able to determine, this cable will be useful for a lot of applications calling for RG-400/U, at greatly reduced expense."
The above being said, I bought the milspec stuff from ACS anyway...
