RG-400, *MINIMUM* 14 feet to meet the db loss spec.WiseGuy said:Two questions:
1. Apparently Garmin 430W needs special coax for GPS antenna? Can I use RG400 or RG142? If so, which is better?
WiseGuy:WiseGuy said:Thanks William,
RG400 it will be then. Length will be less than 14 feet!![]()
Apparently, you also need a TNC connector, which are usually not easy to get locally...WiseGuy said:Thanks William,
RG400 it will be then. Length will be less than 14 feet!![]()
Regarding your other question about altimeters -- Here are a couple of links to 2-1/4" units with three needles:
Falcon Altimeter
Winter Altimeter
The Winter units have been used in the sailplane community for a long time -- they're good quality, and therefore relatively expensive. I don't have any experiences, good or bad, with the 2-1/4" Falcon unit.
Good luck!
You need to install NO LESS than 14 feet of RG400 coax. This is because the 430W requires between 3dB and 7dB of attenuation. 3dB occurs at about 13 feet of cable length.
There is a shielding issue - some cable loss is needed, and less "pick-up" through the co-ax shielding.johnp said:kind of begs the question -- if the loss is the determining factor, why can't i use a 3-4 foot section of rg-58? i don't know what the comparative losses are at 1.2G, but at 120MHz, the 58 is about 2db/100 foot lossier than 400.
(i have about 1000 feet of 58 lyin' around, sure would like to use it. i probably will use it for everything except the gps.)
az_gila said:There is a shielding issue - some cable loss is needed, and less "pick-up" through the co-ax shielding.
RG-400 has much better shielding than the RG-58, and the TNC connector ensures the shielding is continued through the connector more efficiently...
gil in Tucson