Between your antenna and the preamp is where you want your best coax at, cause every bit of loss you have there, is lost.
Once it's past the preamp, it will give you good gain, so then it's just how paranoid you are, as to how much loss you are willing to give up, to get it into your shack.
If your preamp has a noise level of like 1db, you should be able to safely loose 1db in coax from your preamp to your shack, and at 40feet, your talking about rg8, maybe mini8 (1.2db I believe).
I'm one of the paranoid people, and normally keep my losses <1db, and most of them are <.5 db
Quoting Michael Tondee mat_62@netcommander.com:
I need to rework my 70cm antenna system and was thinking about going with LMR 400. I have about a 40 foot run. Is there any real advantage to using the ultra flex for the entire run or can I get by with a short section of the UF between the preamp and antenna to accomodate the rotor turning? How about just using a short section of RG8U there instead of the LMR400UF? I'm trying to do this on a budget. Tnx and 73, Michael, W4HIJ _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb