I've been looking into the MikroTik mAnt sectors they just released, it seems they are one of the most simple / shallow sectors that could be flush mounted (disguised / less noticeable). Any ideas for other sectors / panels with relatively flat front surfaces? I've discussed replacing building components with custom pieces, and they are not interested.
Thanks for the help, I'll my testing and see what I can actually do within the proposed constraints. On Tue, Mar 15, 2016 at 9:36 AM, Chuck McCown <ch...@wbmfg.com> wrote: > Try to get a minimum of 2 wavelengths away and better up to 10. Past 10 > you will have pattern distortion but the impedance and gain will be > unaffected. Or, get as far as you can. If under 2 wavelengths expect > weird behavior. > > *From:* Christopher Gray <cg...@graytechsoftware.com> > *Sent:* Monday, March 14, 2016 10:43 PM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] Antennas Behind Wood or Glass in Old Building? > > Chuck, > > How far back should an antenna be from an obstruction (if the obstruction > is mandatory and space is limited)? > > I found a nice paper with information about empirical RF loss testing > through various materials. The main drawback is the tests are for 0.5-2 GHz > and 3-8 GHz (skipping 2-3 GHz). Found here: > http://fire.nist.gov/bfrlpubs/build97/art123.html > > Glass test results starting page 141, and wood on page 147. Based on the > published results, it seems I might expect signal loss in the 3 dB range > when moving from behind glass to behind 1" boards, but I'm not sure I can > be as far back as in their testing (1 m from the horn to the specimen). > > -Chris > > On Sat, Feb 20, 2016 at 6:38 PM, Mathew Howard <mhoward...@gmail.com> > wrote: > >> 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 <ch...@wbmfg.com> 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 <cg...@graytechsoftware.com> >>> *Sent:* Saturday, February 20, 2016 4:00 PM >>> *To:* af@afmug.com >>> *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 <eric.kuh...@gmail.com> >>> 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 < >>>> cg...@graytechsoftware.com> 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 >>>>> >>>>> >>>> >>>> >>> >>> >> >> > >
