RVG8tor

RVG8tor

Well Known Member
I am shopping around for RG400 and vender's list RG400 and some list RG400/U are these the same, i.e. shielded cable? Just trying to save some bucks and there is a big difference between what is charged for the stuff.
 
Call SteinAir

They will have what you need and also answer your questions.

Good luck,
David
 
The big differences between the RG400's from different places are the quality of the shield, quality of the dielectric (insulator), and # of strands in the center conductor (I think). You'll see everything from better than mil-spec to imported junk.

Stein's prices are competitive if not better than the supply houses I tend to use for work, and his reputation is second to none. I don't usually buy bulk coax at work since it is cheaper for us to buy it with the connectors attached in our lengths, but if I had to place an order, I'd go to Stein.
 
If it doesn't have...

Loboflyer said:
The big differences between the RG400's from different places are the quality of the shield, quality of the dielectric (insulator), and # of strands in the center conductor (I think). You'll see everything from better than mil-spec to imported junk.
......
Click to expand...

...a center conductor with 19 strands of 0.008 wire, then it's not RG-400....:)

The /U at the end seems to be an older specification replaced by the RG-400.

It might also be labelled M17/175-00001 - same cable. All of the copper - both center conductor and the double shield - should be silver plated copper, not tinned or bare.

The outer diameter should 0.195 inches.

Anything else is not really RG-400....:(
 
Helpful

Thanks for the inputs. I saw some stuff on Ebay, there was a spec sheet from some Swiss company, it sure seems like the same stuff. It is appealing in that it would be nearly a buck cheaper than Stein or Spruce which is a lot considering how much will go into the plane.
 
The Stuff on ebay may very well be acceptable wire - I went and looked at it and indeed it's a bit cheaper. The one thing you don't know is how old the wire is. Surplus stuff sometimes can be many years or decades old by the time it ends up being surplus.

It'll probably be ok - but you just don't know. Indeed my price is about $1/ft higher than that surplus cable, but I'm already about a $1/ft cheaper than spruce. I get my cable brand new almost every month direct from US mfgrs so I know the history of the cable and I know the specs on it.

In the grand scheme of things, you're likely going to have at least $50K into your plane. The audio/comm/nav cables are one of the most important things in the plane....so the extra $100 to ensure the cables are good equates to something like .2% (one fifth of one percent) of the airplane. I know pennies count, but don't pinch 'em where it counts the most.

My 2 cents as usual.

Cheers,
Stein
 
OK Stein, I'll bite....

SteinAir said:
The Stuff on ebay may very well be acceptable wire - I went and looked at it and indeed it's a bit cheaper. The one thing you don't know is how old the wire is. Surplus stuff sometimes can be many years or decades old by the time it ends up being surplus.
.....
My 2 cents as usual.

Cheers,
Stein
Click to expand...

...If it really is RG-400 or the newer MIL-C-17/128-RG400 designation, how can old stock be "bad"?

The cable has an operating temperature of at least 150 C and a minimum bend radius of 1 inch. The MIL- Spec has no storage time limits.

If it looks good visually, how can old stock be bad in this case?
 
Hi Gil,

Those are your words not mine. No where did I say it was bad, nor did I was it was good. I said you couldn't tell because you don't know anything about these kinds of things. Surplus stuff is just that - surplus. Sometimes it's very good...sometimes it's not. Believe me I've seen my share of surplus wire - I get calls all the time from people trying to sell me surplus wire. I prefer to buy it new because it's a known quantity. I know it's new and I know what it is. While the mil-spec may not have a shelf life, it can still be "old", or beat up, or dirty, or previously used, etc...

Not at all saying this is the case because I don't know, just saying it's surplus and you don't know anything about it other than the spec some guy posted a link to on his Ebay auction. I don't know if that's the spec for the wire he's selling or not, because there is no pic of the tag from the spool. Maybe it is, I just don't know and that was my point - it's hard to tell with stuff like that. My point was it's rarely worth the time spent searching for something surplus to save almost nothing in the end. Take into account the time spent searching and most builders will have lost money on the entire process to find something that is a relative unknown.

In the end it may be fine, it may not - you just don't know.

Cheers,
Stein
 
rg-142

I choose RG-142, best strenght and quality

my friend has a stock unused ... from helicopter manufacturer

ps: rvg8tor have you read your private message about july, 15 ?
 
The source does seem important...

SteinAir said:
Hi Gil,

Those are your words not mine. No where did I say it was bad, nor did I was it was good. I said you couldn't tell because you don't know anything about these kinds of things. Surplus stuff is just that - surplus. Sometimes it's very good...sometimes it's not. Believe me I've seen my share of surplus wire - I get calls all the time from people trying to sell me surplus wire. I prefer to buy it new because it's a known quantity. I know it's new and I know what it is. While the mil-spec may not have a shelf life, it can still be "old", or beat up, or dirty, or previously used, etc...

Not at all saying this is the case because I don't know, just saying it's surplus and you don't know anything about it other than the spec some guy posted a link to on his Ebay auction. I don't know if that's the spec for the wire he's selling or not, because there is no pic of the tag from the spool. Maybe it is, I just don't know and that was my point - it's hard to tell with stuff like that. My point was it's rarely worth the time spent searching for something surplus to save almost nothing in the end. Take into account the time spent searching and most builders will have lost money on the entire process to find something that is a relative unknown.

In the end it may be fine, it may not - you just don't know.

Cheers,
Stein
Click to expand...

...but post #3 seems to say that you can't even trust the new stuff.

"The big differences between the RG400's from different places are the quality of the shield, quality of the dielectric (insulator), and # of strands in the center conductor (I think). You'll see everything from better than mil-spec to imported junk."

Personally, I would prefer a marked, surplus MIL-Spec product in good physical condition to an unknown product made in China (or pick your own poor production world spot).

If it's not marked, or referenced, then you do take a risk, and E-Bay is probably a bigger risk than others.

Buying from reputable dealers is the best... but not all surplus is bad...

Sorry about trying to put words into your posting....:)
 
az_gila said:
...but post #3 seems to say that you can't even trust the new stuff.

"The big differences between the RG400's from different places are the quality of the shield, quality of the dielectric (insulator), and # of strands in the center conductor (I think). You'll see everything from better than mil-spec to imported junk."

Personally, I would prefer a marked, surplus MIL-Spec product in good physical condition to an unknown product made in China (or pick your own poor production world spot).

If it's not marked, or referenced, then you do take a risk, and E-Bay is probably a bigger risk than others.

Buying from reputable dealers is the best... but not all surplus is bad...

Sorry about trying to put words into your posting....:)
Click to expand...

Again...not my words and not my post...

Cheers,
Stein
 
Yes

lucaperazzolli said:
I choose RG-142, best strenght and quality

my friend has a stock unused ... from helicopter manufacturer

ps: rvg8tor have you read your private message about july, 15 ?
Click to expand...

Sorry I have not gotten back to you, I still need to check the train schedule, but I definitely want to make a visit. I will PM when I know the train times.

Ciao
 
Ok - next question - is RG400 or 400/U the cable used for both nav and comm? I am thinking of wingtip antennae for my secondary nav/comm, and I'm ready to close the wings now, so I need to run all my wires first. I'd like to pre-place the coax to the wingtips for this. Primary nav/comm will likely be a belly-mount antenna from my 430W, and a top mount GPS antenna.
 
Yep...

airguy said:
Ok - next question - is RG400 or 400/U the cable used for both nav and comm? I am thinking of wingtip antennae for my secondary nav/comm, and I'm ready to close the wings now, so I need to run all my wires first. I'd like to pre-place the coax to the wingtips for this. Primary nav/comm will likely be a belly-mount antenna from my 430W, and a top mount GPS antenna.
Click to expand...


...it's FAA fire rated good 50 ohm co-ax.

Only limits would be for a long transponder antenna run - check your transponder installation manual for limits.
 
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