Topband: coax change?

[Richard Detweiler]

I would not think you could really notice a difference in DB at HF.  
 
the LMR 400 is a good bet,  High velocity, low loss.
 
I've seen this surplus for much less than the going retail rate.
 
Another benifit of the 400 is that it is 100% sheild,  add a good Balun or RF isolator at the antenna and another before it goes into the house, and you'll pretty much block all sheild RF currents virtually eliminating the most commin source of RFI.Best WishesRichard,  K5SF> From: Gary at doctorgary.net> To: Topband at contesting.com> Date: Mon, 19 Jan 2009 08:20:19 -0500> Subject: Re: Topband: coax change?> > > > I need to put up an antenna at a 2nd QTH which will need at least> > > 150' of coax.> > > > > The question I am asking here is if using a lower loss coax like the> > > 400 or 500 would allow a significant difference that I would notice> > > with my K3? I will be using higher bands during the summer. Getting> > > more 213 would be the cheapest answer and I don't want to waste money> > > if the benefits would not be noticeable.> > > > You need to run the numbers for the highest band you expect to be using. You > > talking about using 20m or 10m?> > > > It's hard to make a case for LMR 500 on 160m at amateur power levels.> > > > 73, Guy. > > Well,> > The way the bands have been as of late, I don't hear much happening > on 20 or 10. I did mention using the higher bands as when the low > bands turn poorly during the summer I'll turn upwards for QSOs. My > transmitting antennae are an L for 160, an L for 80 and a butternut > HF9V for everything else. I have the HF9V's 80 meter coil shorted to > be resonant on 5M (turns out I have little interest on 5 as I've > heard more "CB" mentality there in a compressed space)> > But... I do have all the HF bands available and I use a common radial > plate/radials for all three antennae. I'll surely use whatever band I > need to to make a Q with a new one & do want that ability but if the > practical gains of LMR-400 or 500 over 213 are not significant, I'll > save my money. Specially after my just fully loading the K3 with all > the available Elecraft options & with a full filter compliment.> > The only time I had a 350' run of coax was with some larger Andrews > Heliax back in Illinois in the 90's & that became long gone when I > left the area. RG-213 isn't the best performance wise for long runs > and I have had zero experience A>B different coax with long runs.> > I'm hoping to have a 6M 5/8 wave to mount to the house and for that I > suspect I'll get a length of LMR-600 for that as I have no access to > surplus heliax now that I've relocated back to CT after nearly 30 > years of being elsewhere. But that will be a separate line to that > antenna.> > Gary> KA1J> _______________________________________________> Topband mailing list> Topband at contesting.com> http://lists.contesting.com/mailman/listinfo/topband