hmm... looks like bacon is the way to go, if you can't use glass or ABS On Sat, Feb 20, 2016 at 5:33 PM, Chuck McCown <[email protected]> wrote:
> Well, glass, silicon dioxide is a good dielectric. And dielectric > materials can make RF lenses. So if it is flat, it will not refract the > signal and should faithfully transmit it with low loss. > > The amount of loss, assuming you are out of the reactive near field range, > is related to a factor called the loss tangent or dissipation factor. It > is dependent on frequency. > > Air =0 (depends on weather and atmospheric parameters) > > Glass = .02 (decreases with higher frequency) > ABS plastic I use for radomes = .01 > > Wood = as much as .4 Commonly in the .02 range @ 3 GHz if dry. > Walnut wood = 1.4 @ 10 MHz > Water = .157 > > Bacon (smoked) = .05 > > > > *From:* Christopher Gray <[email protected]> > *Sent:* Saturday, February 20, 2016 4:00 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] Antennas Behind Wood or Glass in Old Building? > > The building is 200+ years old, so most of the glass is old enough. I've > requested to replace some panes with acrylic sheets, but I don't think they > will let me. > > Thanks for the feedback. It sounds like mounting behind glass is much > preferred over wood. I have not found good loss estimates yet, but I > haven't dug into it too far. > > > On Sat, Feb 20, 2016 at 4:59 PM, Eric Kuhnke <[email protected]> > wrote: > >> Old windows are not so bad RF transparency wise. It's even possible to >> use 80 GHz through glass in high rise office buildings that predate 1982 or >> so, when metallic coatings and special IR/UV coatings on windows started to >> become possible. >> >> It's the *new* windows you have to worry about. >> >> >> >> On Fri, Feb 19, 2016 at 7:37 PM, Christopher Gray < >> [email protected]> wrote: >> >>> I may have an opportunity to install some radios inside a steeple with >>> some very specific requirements. I'm currently considering 5 GHz and 3.65 >>> GHz radios for this location. I'd like to do some PTP and PMP links, but I >>> cannot afford to lose too much. >>> >>> I have the option between mounting behind 1" thick solid boards, 2x 1" >>> thick solid boards, or behind original windows. Are locations with such >>> barriers even worth entertaining? If so, would it be best to ask for >>> locations behind wood or glass? >>> >>> Thanks you, Chris >>> >>> >> >> > >
