How far with VHF?
- Gemini4
- Radio Addict
- Posts: 942
- Joined: 02 Jan 2010, 21:26
- Location: Derbyshire
How far with VHF?
Might be a bit of a thick question..but I was wondering how far you could get on vhf using repeaters?.
- ch25
- Top Poster
- Posts: 1679
- Joined: 03 Dec 2016, 11:07
- Call Sign: Lemmy
- Location: Poland
Re: How far with VHF?
Worldwide.
Chris
Chris
WE ARE MOTÖRHEAD, AND WE PLAY ROCK N' ROLL
You can't have too many antennas...
You can't have too many antennas...
- thedeerhunter270
- Top Poster
- Posts: 1248
- Joined: 13 Nov 2009, 18:47
- Location: Nr Consett County Durham
Re: How far with VHF?
I always thought it was line-of-sight plus a third. But like Chris says, in the right conditions much further.
Operating in South Northumberland and Weardale.
- Metradio
- Radio Addict
- Posts: 605
- Joined: 28 Apr 2016, 19:10
- Call Sign: G7HID
- Location: Box 500, Slough UK
Re: How far with VHF?
As has been said worldwide - but through networked repeaters..
Through a single repeater, your distance to the repeater plus line of sight + 1/3rd from the repeater...
Through multiple radio repeaters, ISTR the maximum being 12 hops before the signal becomes unusable..
Search "Backbone"...
http://www.subbrit.org.uk/rsg/features/ ... ndex.shtml
Mike
Through a single repeater, your distance to the repeater plus line of sight + 1/3rd from the repeater...
Through multiple radio repeaters, ISTR the maximum being 12 hops before the signal becomes unusable..
Search "Backbone"...
http://www.subbrit.org.uk/rsg/features/ ... ndex.shtml
Mike
Last edited by Metradio on 09 Mar 2018, 13:09, edited 1 time in total.
Connect Systems CS750 and CS800, Hytera PD-365, Motorola DP4600.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
- Gemini4
- Radio Addict
- Posts: 942
- Joined: 02 Jan 2010, 21:26
- Location: Derbyshire
Re: How far with VHF?
Will it also depend on antenna and power?.
- Metradio
- Radio Addict
- Posts: 605
- Joined: 28 Apr 2016, 19:10
- Call Sign: G7HID
- Location: Box 500, Slough UK
Re: How far with VHF?
Yes, plus frequency...
The international Space Station can be worked on a 2M 2 Watt handheld on it's own antennta when the ISS is within range (LOS+1/3)...
Mike
The international Space Station can be worked on a 2M 2 Watt handheld on it's own antennta when the ISS is within range (LOS+1/3)...
Mike
Connect Systems CS750 and CS800, Hytera PD-365, Motorola DP4600.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
- Gemini4
- Radio Addict
- Posts: 942
- Joined: 02 Jan 2010, 21:26
- Location: Derbyshire
Re: How far with VHF?
Well thanks for the replies.
-
- Top Poster
- Posts: 1098
- Joined: 10 Jun 2007, 22:41
- Call Sign: G4RMT
- Location: North East Suffolk
- Contact:
Re: How far with VHF?
where on earth has this magic 1/3rd figure come from? Coverage from any location is dependent on topography. The idea of a set figure doesn't work.
Unless all my education is totally wrong, it's simply signal strength at the antenna - and that's a function of the path loss, which can be predicted with software that has topographical data in it.distance to the repeater plus line of sight + 1/3rd from the repeater...
- Metradio
- Radio Addict
- Posts: 605
- Joined: 28 Apr 2016, 19:10
- Call Sign: G7HID
- Location: Box 500, Slough UK
Re: How far with VHF?
Line of sight + a third is something I picked up about 50 years ago, do you know what ? As a rule of thumb it does work, on top of a mountain or on a flat plain.. If there is stuff in the way - well common sense comes into play..
Mike
Mike
Connect Systems CS750 and CS800, Hytera PD-365, Motorola DP4600.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
- Tigersaw
- Radio Addict
- Posts: 895
- Joined: 19 Oct 2013, 15:48
- Call Sign: GW6RRL
- Location: Llanwrtyd Wells Powys
- Contact:
Re: How far with VHF?
I did some (AM) VHF trials for a new ATIS at Southampton airport, with 25w from ground station the aircraft could still pick it up at 6000ft around Manchester
- Metradio
- Radio Addict
- Posts: 605
- Joined: 28 Apr 2016, 19:10
- Call Sign: G7HID
- Location: Box 500, Slough UK
Re: How far with VHF?
Connect Systems CS750 and CS800, Hytera PD-365, Motorola DP4600.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
-
- Top Poster
- Posts: 1098
- Joined: 10 Jun 2007, 22:41
- Call Sign: G4RMT
- Location: North East Suffolk
- Contact:
Re: How far with VHF?
metroradio - I still don't understand? what is 'line of sight' in this context - As tigersaw says, from the ATIS to an aircraft is line of site, and ground to the space station is line of sight, but is there a line of site at all to a repeater that makes sense? Maybe if it's on a high block of flats - but line of sight at ground level fails very quickly - line of sight for a repeater could be hundreds of yards in some cases, so this 'rule' fails in any urban location because there isn't one! Not even with binoculars.
- Metradio
- Radio Addict
- Posts: 605
- Joined: 28 Apr 2016, 19:10
- Call Sign: G7HID
- Location: Box 500, Slough UK
Re: How far with VHF?
It was something I learned in the army when setting up temporary VHF links, where vehicle location was a mixture of good radio location and natural camouflage, plus the question of where the enemy would expect you to be. So the LOS +1/3 was used as a rule of thumb together with a common sense appreciation of intervening terrain and ground clutter.. Sometimes you did not have the luxury of setting up links in advance and had to work off of maps - no computers to work it out for you.. The LOS +1/3 expectation was under optimum conditions, everthing in between became a variable, this is where common sense and experience are heavily relied upon..
Mike
Mike
Connect Systems CS750 and CS800, Hytera PD-365, Motorola DP4600.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD V1.
Whistler WS1088 / TRX-1 / Whistler Q / UBCD3600XLT / WTR Browser.
-
- Super Member
- Posts: 188
- Joined: 27 Jul 2013, 17:53
- Call Sign: 26TM516
- Location: Surrey
Re: How far with VHF?
When talking "Line of sight", it means the ground. The signal will be degraded by the presence of buildings, but it does rattle around them somewhat, depending how close those buildings are to you. If you live in a bungalow next to a tower block, you will have more of a problem than if the tower block half way between you and the other station.paulears wrote: ↑10 Mar 2018, 08:50 metroradio - I still don't understand? what is 'line of sight' in this context - As tigersaw says, from the ATIS to an aircraft is line of site, and ground to the space station is line of sight, but is there a line of site at all to a repeater that makes sense? Maybe if it's on a high block of flats - but line of sight at ground level fails very quickly - line of sight for a repeater could be hundreds of yards in some cases, so this 'rule' fails in any urban location because there isn't one! Not even with binoculars.
Malcolm
-
- Top Poster
- Posts: 1098
- Joined: 10 Jun 2007, 22:41
- Call Sign: G4RMT
- Location: North East Suffolk
- Contact:
Re: How far with VHF?
exactly - so what is line of sight, when you can't see it? A mile? 10 Miles? You can't have a formula to work to with an unknown variable?