I looked up RG-400 and found it's a very well designed cable, silver plated and all, easy to solder to, but very expensive $1.80 a foot. It's great for some uses but aircraft RF is ok but not it's forte'. It's loss at 100 mhz is 4.5 db and at 1000 Mhz 18.8 db. If it were given to me, I would use (nav/com only) it since we only use 10 feet or so but I wouldn't spend the money. RG-58 the mil spec stuff, not the junk, is 4.5 db at 100 Mhz and 17.0 db at 1000 Mhz. I would not use it. RG-8X is 3.1db at 100 and 11.2 db at 1000 Mhz at 1/5th the cost. I guess I'm just splitting hairs since we use short runs of it but a tenth of a db could make the difference in long range communication. Using any of this stuff for transponder or DME is a crime. Lose 3db and you've lost half your power and in bad WX it will mean the difference between being seen and not. I always try to squeeze every db I can out of a system. They do add up. The manufacturers used to specify RG-8 style low loss cables (RG-213 7.6 db/100ft at 1000 Mhz) for their 1 Ghz units because of rf losses in the coax, now they just leave it to the shops.
Perhaps I should have posted to make sure the new coax has the highest percent of shield to keep stray signals and noise out of the radio.
Thanks for your question. I hadn't heard or worked with RG-400 so I learned something today. LMR-400 yes (Good stuff), but not RG-400.
So many cables, so little time. ;)
John
On Sep 5, 2006, at 8:44 AM, A DeMarzo wrote:
----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
<x-tad-smaller>John;</x-tad-smaller>
<x-tad-smaller>Great text! I've been using RG400 for any new install or replacement. Comments, please?</x-tad-smaller>
<x-tad-smaller>Thanks</x-tad-smaller>
<x-tad-smaller>Al</x-tad-smaller>
