general radio frequecy question (non-r/c)?

[oracle_9]

Hello,

I was looking through the net at amateur radio, especially at the "foxhunt" radio hobby ...its a hobby where a bunch of guys with receivers try to find a hidden transmitter in the forest for example. Anyway, from what I gathered, there are two frequencies used mostly, or shall I say more popular in North America. These are 2 meter and 80 meter.

2 meter is 145 Mhz, and the 80 meter is 3.5 Ghz.

Can you see the problem at these numbers?
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If not, then here it is.

2 meter = 145 Mhz (correct)
80 meter = 3.5 Ghz (false)

3.5 Ghz is suppose to be 0.09 meter (9cm).
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I am not a radio amateur so I may be interpreting this wrong since a lot of radio websites show these numbers for 80m. I will now appalogise in advance, if I am wrong, but would someone please clarify this for me?

Why the 3.5 Ghz is implied for 80 meters???

Sidenote, 80 meter is 3.5 "M"hz but that seems too low concerning technical stuff desicrbed in the receivers and special antennas used.

I am confused :(

PS: a came to this confusing when I wanted to look for a foxhunt tx/rx to instead in my R/C plane as a RF beacon locator.

[Andy W]

λ = c / f = c × T f = c / λ
(for RF, c = 299792458 m/s)
..a

[Andy W]

so for 145MHZ,
λ = c / f
= 299792458 / 145000000
= 2.068 m

and for 3.5GHz
λ = c / f
= 299792458 / 3500000000
= 0.085654988 m

[Andy W]

.. and 80m would be
f = c / λ
= 299792458 / 80
= 3747405.725 Hz or 3.747405725 MHz

[Andy W]

.. so they meant 3.5MHz , not GHz.. :)

[Mr.RC-CAM]

The 80 meter ham band is roughly 3.5Mhz to 4.0Mhz, not GHZ.

3.500-3.750 MHz: CW, RTTY/Data
3.750-4.000 MHz: CW, Phone, Image

PS: a came to this confusing when I wanted to look for a foxhunt tx/rx to instead in my R/C plane as a RF beacon locator.For a convenient R/C beacon, look at using the UHF band area. The antennas are smaller and more directional, two things you will appreciate in fox hunting a lost model.

RC-CAM

[Andy W]

.. ah, but this sounds like it's not meant to be easy! :D

[oracle_9]

I agree, mostly likely some of those sites had typo's.

Yea, I was planning to use 2 meter band for this foxhunt setup for my plane. Though I have read somewhere that some people are getting into the 10 "G"hz range, ya...like radar quality. That would be neat.

[Mr.RC-CAM]

Microwave based lost model "fox hunting" would not be ideal. The RF in that region attenuates too easily in vegetation and watt for watt, is lower efficiency when it comes to practical range. I recommend the 70cm UHF band.

RC-CAM