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Doesn't 440Mhz penetrate objects in the environment better than the 2-meter band?

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by KC0BUS, Jul 27, 2017.

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  1. KC0BUS

    KC0BUS Ham Member QRZ Page

    I've been away from ham radio for a long time and have forgotten a lot of things. Now that I'm back, I'm trying to recall some things I learned previously.
    My question is this:
    Doesn't 440Mhz band radio RF energy penetrate through physical objects in the environment (such as buildings and trees) easier and better than the 2-meter radio band RF signal?
    Thank you
     
  2. K8ERV

    K8ERV Ham Member QRZ Page

    I think there are too many variables to give a general answer. Material? Thickness? Configuration?

    Try it, see what works.

    TOM K8ERV Montrose Colo
     
  3. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    Where foliage (leaves on trees including pine needles, etc.) are concerned, just the opposite is true. There is almost always considerably more attenuation on the 70 cm band than on the 2-meter band.

    As for other things, "it depends"!

    Glen, K9STH
     
    K2EDM and N0TZU like this.
  4. N8EKT

    N8EKT Ham Member QRZ Page

    YES

    440 works much better inside buildings but suffers more attenuation through trees a than 2 meters
     
    K2EDM likes this.
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I can't verify 440 MHz works better "inside buildings," at all. The lower the frequency, the less attenuation from almost anything.

    However, the higher frequency will work better in buildings with windows, since apertures (openings in walls) are related to square wavelength and higher frequencies will find smaller apertures to be "big openings" as compared with lower frequencies, where the same apertures are "small openings." If there's no windows anywhere, the lower frequency should generally be better.
     
    KC0BIN, N0TZU, AG6QR and 1 other person like this.
  6. KJ4YEV

    KJ4YEV Premium Subscriber QRZ Page

    A lot of contractor radios for construction sites are in the 400mHz range. They work where 2M radios don't. Reflected signals aid propagation.
     
    N0TZU likes this.
  7. N0NB

    N0NB Subscriber QRZ Page

    My experience matches those of others where reflections tend to play a large role in allowing 440 MHz use where line of sight theory says it shouldn't. Such is also the reason I think "picket fencing" is more pronounced on 70cm than 2m.
     
    KC0BIN and N0TZU like this.
  8. G3YRO

    G3YRO Ham Member QRZ Page

    In terms of getting through obstructions, in my experience, the lower you go, the better . . .

    This is particularly noticeable when working Mobile stations, as their antenna is pretty near the ground, so there are often lots of things in the way.

    So 2m works better than 70cm . . .

    4m works better than 2m . . .

    6m works better than 4m.

    Of course, for local mobile working, 160m works better than ANY of the VHF bands !

    Roger G3YRO
     
    KC0BIN likes this.
  9. K3XR

    K3XR Ham Member QRZ Page

    Very true ...not much of a repeater user but do have a 440 wide area coverage input about 8 miles from the house also use it mobile and living in a rural and in some cases very heavily wooded area notice quite a difference between summer and winter conditions when the foliage is on the hardwood trees when it comes to making it into the repeater input also on 900 Mhz there is a repeater just can not access when the trees are in full foliage would guess on a straight line distance about 20-25 miles away.
     
    KC0BIN likes this.
  10. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    Pine trees and cypress trees are especially detrimental to operation above 400 MHz.

    Glen, K9STH
     
    KC0BIN likes this.

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