While I have time on my hands I thought I'd discuss antenna gain too as it's a much misunderstood subject.
The theory ---------- The first thing to make clear is whoever coined the word "gain" in regard to antenna performance was an idiot. Antennas do not and cannot add energy to a radio signal. This is an immutable law of physics. However we're stuck with the damn word now.
An antenna converts the electrical signals produced by a radio transmitter into a form of non ionising radiation which we commonly call a radio wave. You are, of course, well familiar with radio waves; every time you are unfortunate enough to hear Jon Faine on 774 Melbourne he is annoying you via radio waves. Likewise radio waves are the basis for your GPS, mobile phone and television and when you see lightning and hear the radio crackle simultaneously that is also a radio wave generated by the lightning. Radio waves travel at the speed of light.
Your UHF CB radio produces around five watts (5W) maximum power, this is not very much. If the electric kettle in your kitchen used only 5W it would take around 28 hours to boil one litre of water. When this 5W is transmitted through your radio and via the antenna it spreads out in the shape of an invisible giant doughnut and any particular direction sees only a tiny proportion of that 5W energy. This is one reason why UHF CB has limited range.
The shape in which radio waves are produced by the antenna (our giant doughnut) is called the antenna "pattern" and is critical to the real world performance of antennas.
A UHF CB antenna which produces a giant doughnut is wasting a lot of energy. Why? Well... it is very unlikely we will want to talk to anyone directly above or below us so all the energy we are transmitting in those directions is wasted and it would be much more efficient if we could design an antenna which focused its energy into a cylinder shape or a deep circle around us. In that way people to the front, rear and sides would be able to hear us but aeroplanes and coffins would not and that is, generally, what we want from a CB.
That is exactly what antenna gain is - an antenna which is able to focus its energy in the desired direction. The ratio or amount by which it is able to redirect radiated energy from one direction to another is the antenna gain and is measured in decibels (dB).
Note: Decibels are used to measure ratios and have no native unit so antenna gain is usually referenced to either an isotropic antenna (dBi) or a dipole antenna (dBd). In general it will be dBi because that produces a bigger number and manufacturers like that.
You can think of antenna gain exactly like a torch with a focusing ability; the tighter you make the focus the further you will be able to see BUT you will only see a smaller area because you have made the beam more narrow. If you open the focus up you'll be able to see a much wider area but you won't see as far into the distance. As always with energy you cannot get something for nothing.
The real world -------------- You will see advertisements for UHF CB antennas which give a gain figure, 4dB, 6dB and 8dB are common and their prices usually follow the same rising pattern.
Vehicle antennas are almost always vertical and single element which means any gain they have must come by redirecting vertical energy to horizontal energy. Such an antenna cannot redirect energy in the horizontal plane (corrections welcome). In other words it will produce a circular pattern and is therefore pretty limited in how much gain it can generate and I doubt if many commercial UHF CB antennas could actually meet their specification.
The next problem we have is that a vertical antenna is only half of the antenna system (we'll ignore so called ground independent antennas for the moment) with the vehicle comprising the other half and this is where the real world takes over.
The antenna manufacturer has no control over how or where the antenna is mounted and, especially at UHF frequencies, this make a huge difference to antenna performance and can easily negate all that extra gain you thought you were buying. Each installation will be different but it may well be that 70% of your CB's energy is being transmitted south and west and only 30% north and east - these variations are called "antenna lobes" and there is no simple way to determine your particular antenna installation's pattern.
And, after all that, even if the You Beaut antenna works really well and is a 4dB improvement over your old one it will only make the smallest of difference to the signal actually received by another CB user. ie. It will make an unreadable signal slightly less unreadable it will not turn it into a fully readable one.
My suggestions: Buy the most popular, and probably amongst the cheapest, antenna from one of the major antenna manufacturers and mount it in the middle of the roof - this will give excellent performance. If you don't wish to cut a hole in the roof a magnetic mount works well at UHF otherwise a wing mount is probably the next best.
Comments and corrections most welcome.
MH
Peter_n_Margaret said
07:29 PM Mar 5, 2017
I use the little rubber zero or small gain antennas on the OKA.
They are cheap and almost indestructible and are ground independent.
They also produce the clearest transmission and reception over short (10km?) distances in variable terrain. Frankly, I don't want to hear anybody further away than that anyway, they just become "noise" that gets in the way.
For the odd occasion that we might need longer transmission/reception, we carry a high gain, ground independent antennae. I have never had occasion to fit it.
Mounting position is much more important for performance than how much you spend on some fancy antennae.
Cheers,
Peter
OutbackMK said
07:51 PM Mar 5, 2017
Most people with bull bars mount their antennas on same as it looks "right" however most trucks will mount them on their mirrors to get them up higher and out of the shadow of the truck. I run a 6db gain GME on the bull bar around town but would prefer a 8ft stainless steel whip if it didn't trash the lights and sprinklers in underground car parks.
Probably a good option is a spring loaded mount threaded to accept a number of different length antennas unfortunately the SWR goes out the window if they are not well matched.
Thanks Mike for the good explanation of antenna lobes never thought about it much as on the old 27meg super panther ssbs we used to get a bit of skip and found we could talk long distances at times. Guess in those days 27meg's were a bit off with the powers that be so the magnetic base on the roof was a quick way do a "now you see me now you don't"!
Bagmaker said
08:33 AM Mar 6, 2017
very informative Mike, thanks!
where would I mount an antenna on my bus?
Its too high (max legal) to mount anything on top, I could do the bullbar thing I guess.
But I am not sure on the mirror mount thing, maybe illegal? I thought mirrors were the only thing able to be mounted outside the 2.5m wide dimension......
patrol03 said
11:56 AM Mar 6, 2017
Great post Mike. Took me back to the 27mhz days when we played with land planes and SWR meters in pursuit of bettering the signal.I remember a conversation I had with a fellow c-ber one evening. I was on the Mid North Coast NSW and he was in Swan Hill Vic. I think that it was called signal skip whereby the signal was bounced from somewhere in the atmosphere, but this phenomenum was not a regular occurrence.I still have my SWR meter somewhere.
Phil C said
01:11 PM Mar 6, 2017
OMG! 27Meg, now thats going back to the good old days before Childrens Band Radio... Remember RB14 in the 70s?
I went through the exercise of 6db vs 9db antenna, found the uni and omni directional BS too hard and got a hand held.
I guess the trick is what do you want it for?
We/I decided I only wanted CB (UHF) for truck/caravan comms. Frankly I prefer 27MHz as the skip gives far better distance (bounced off the ionosphere). None the less the Hams love their 27Meg. However UHF works a treat for us, safe chat with passing trucks and other vanners.
Cheers
Mike Harding said
05:14 PM Mar 6, 2017
Bagmaker >where would I mount an antenna on my bus?
As mentioned; the middle of the roof is ideal but if that is not possible then somewhere with the maximum surface area of metal beneath is good. A mirror is a bad idea and the bullbar is not much better. Often it's a case of just doing the best you can.
Also, keep in mind that antennas are reciprocal ie. an antenna which receives well will also transmit well so you may be able to try the antenna in different locations whilst listening to a distant repeater to see which location produces the best reception - that location will also produce the best Tx.
patrol03 >I think that it was called signal skip whereby the signal was bounced from somewhere in the atmosphere, but this phenomenum was not a regular occurrence.
Radio signals below around 30MHz will bounce off the ionosphere under the right conditions (UHF CB is much higher at 477MHz and won't) and may be heard around the world. However the ionosphere is a fickle mistress and not properly understood by science. The lower frequencies (7MHz and 14MHz especially) work well in this regard and it is usually easy to make an overseas contact from Australia on these bands. I regularly use my Amateur radio from deep in the bush to chat with friends both across Australia and the world. A radio, a 12V battery and a bit of wire in the trees is all it takes.
There are "tricks" one can do with VHF and UHF frequencies; occasionally a phenomenon called "ducting" occurs (again we don't properly understand it) where VHF and UHF signals are literally ducted by the ionosphere for hundreds of kilometres so it is possible that very occasionally (very) you may hear someone from Adelaide on your Sydney UHF CB, make sure you say "Hi" :)
Another really neat trick for VHF and UHF signals is aircraft or meteor "enhancement". A transmitter with a highly directional antenna (say an eight or more element yagi) is required. The antenna is pointed at a high flying commercial jet aircraft and a short, usually digital, transmission made. A small part of the transmission will bounce off the aircraft and may be received by a station which is well beyond the line of sight of the transmitter.
Meteor enhancement is very similar except a known shower of meteors (of which there are many) is used to bounce the signal. This technique is used for military purposes and can create unbreakable codes which are well beyond my understanding :)
I am surprised more Grey Nomads and bush travellers do not pursue Amateur Radio, it is no longer difficult to obtain a licence - Morse Code is not required - and the basic licence exam for the Foundation Licence can be passed by anyone who is capable of operating a computer, additionally, most of the Amateur Radio clubs run courses to train people for it at little or no cost:
http://www.wia.org.au/licenses/foundation/about/
MH
-- Edited by Mike Harding on Monday 6th of March 2017 06:36:29 PM
Cupie said
06:37 PM Mar 6, 2017
Thanks Mike for the explanation.
As a trainee, I think that I slept through the lectures on Antennas. I have always treated them as a 'black art'.
This didn't stop me lecturing CMF Field Artillery Sigs on the subject. Just a matter of reading the book & parroting it off to them. Undoubtedly at the end they remained just as ignorant on the subject as me. (perhaps I just concentrated on voice procedure rather than the techo stuff). But then I also lectured the Drivers on cooking despite being a non cook in those days. Probably a factor in the terrible meals that they produced & I winged about. Our radio comms were always a bit iffy too but we blamed the old WW2? vintage sets.
I have a (free)second hand 40ch 5w set on the Patrol. It was given to me because the pressel switch was cactus so I replaced it with a $2.50 non locking toggle. Not pretty but it works. The aerial is a cheapie mounted on the bracket on the RHS mudguard that was previously used on the old 27meg set that I inherited from my son's junk pile. I put it there because of the ease of installation ... but I was aware of the benefit of a flat metal surface under the aerial.
Works well as do the two hand helds that sit on the dash.
Might have a look at an 80ch set one of these days.
macka17 said
07:35 PM Mar 6, 2017
A good thing to put UNDER the Antenna.
Is an Omnidirectional base.
Some arials are fairly directional.
If signal fades and returns when driving round corners in town.
You have a directional one.
Omni. Signal stays same strength.
Best one is 6 ft GME on a 5 mtr tinnie on the water.
Best ground plane you can get. chuckle.
Or a 30 ft insulated section of your yachts Backstay for HF.
IF you buy a 5w H\Held.
Do yourself a favour and buy one that takes External Antenna.
and 12v power.
Easy to boost when out bush then.
Vince said
11:45 AM Mar 7, 2017
Thanks Mike
Very informative article and explanation on antennas
Personally I use a small rubber whip 2dB mounted on the front bar and on the opposite side a fiberglass 1.2m 6dB
Both are switchable from in cab, I find with the small 2dB when travelling it has a small range which is good for
picking up traffic close by and keeps the crazies afar away.
Main use of my CB is for talking to trucks on route, hence the 2dB is perfect for that and the 6dB if I want a better range
I also have a Yaesu FT8900r Quad band and a TYT TH9800 Quad band for amateur use using Diamond NR 770HB one for each radio
Also fitted is a Byonics micro trak RTG FA -- For your info to find me -- VK2MIB-10
Cheers
Vince
Cupie said
12:37 PM Mar 7, 2017
Mike ...
This brings to mind a situation that confuses me.
I have a winegard TV antena on my Van.
I purchased a Wingman UHF enhancer adapter that was supposed to improve the reception for digital & the combination seems to work well.
But ... When installing it I noticed that there was no metalic contact between the existing aerial & the Wingman array. The mechanical connection is via some plastic studs and both antenna sections are coated with insulating medium
How does this work?
Mike Harding said
01:16 PM Mar 7, 2017
Hi Cupie
>When installing it I noticed that there was no metalic contact >between the existing aerial & the Wingman array. The mechanical >connection is via some plastic studs and both antenna sections are >coated with insulating medium >How does this work?
You know the deal! If I told you I'd have to shoot you! :)
The Wingman acts as a "passive repeater".
Their original antenna was not very effective at UHF because most TV in the USA was in the VHF region but once digital TV came along most (all?) of the channels were at UHF and rather than force their customers to buy a new antenna they came up with this solution - and quite a clever one it is too.
There is a, not very helpful, on YouTube: https://www.youtube.com/watch?v=N5sP7kRoljc
The Wingman is actually two antennas; one for receive (Rx) and one for transmit (Tx). The Rx antenna will be a capable UHF unit which receives the TV signals, it is coupled to the Tx antenna which will be a low gain simple unit.
When a signal is received by the Rx antenna it is passed to the Tx antenna which is located close to the original UHF/VHF antenna. The Tx antenna retransmits the signal and it is received by the UHF section of the original VHF/UHF antenna.
Passive repeaters have been around for a long time but are not often used as there is usually a more efficient way to do the job however they do have their place. Imagine a farmhouse at the bottom of a valley; they can't receive TV because the transmitter is on the other side of the hill and it's too far to run a cable to put an antenna on top of the hill. However a passive repeater made from two decent TV antennas located at the top of the hill with one pointing at the transmitter and the other pointing at the farmhouse may well work.
MH
Cupie said
03:39 PM Mar 7, 2017
Mike Harding wrote:
Hi Cupie
>When installing it I noticed that there was no metalic contact >between the existing aerial & the Wingman array. The mechanical >connection is via some plastic studs and both antenna sections are >coated with insulating medium >How does this work?
You know the deal! If I told you I'd have to shoot you! :)
The Wingman acts as a "passive repeater".
Their original antenna was not very effective at UHF because most TV in the USA was in the VHF region but once digital TV came along most (all?) of the channels were at UHF and rather than force their customers to buy a new antenna they came up with this solution - and quite a clever one it is too.
There is a, not very helpful, on YouTube: https://www.youtube.com/watch?v=N5sP7kRoljc
The Wingman is actually two antennas; one for receive (Rx) and one for transmit (Tx). The Rx antenna will be a capable UHF unit which receives the TV signals, it is coupled to the Tx antenna which will be a low gain simple unit.
When a signal is received by the Rx antenna it is passed to the Tx antenna which is located close to the original UHF/VHF antenna. The Tx antenna retransmits the signal and it is received by the UHF section of the original VHF/UHF antenna.
Passive repeaters have been around for a long time but are not often used as there is usually a more efficient way to do the job however they do have their place. Imagine a farmhouse at the bottom of a valley; they can't receive TV because the transmitter is on the other side of the hill and it's too far to run a cable to put an antenna on top of the hill. However a passive repeater made from two decent TV antennas located at the top of the hill with one pointing at the transmitter and the other pointing at the farmhouse may well work.
While I have time on my hands I thought I'd discuss antenna gain too
as it's a much misunderstood subject.
The theory
----------
The first thing to make clear is whoever coined the word "gain" in
regard to antenna performance was an idiot. Antennas do not and
cannot add energy to a radio signal. This is an immutable law of
physics. However we're stuck with the damn word now.
An antenna converts the electrical signals produced by a radio
transmitter into a form of non ionising radiation which we commonly
call a radio wave. You are, of course, well familiar with radio
waves; every time you are unfortunate enough to hear Jon Faine on 774
Melbourne he is annoying you via radio waves. Likewise radio waves
are the basis for your GPS, mobile phone and television and when you
see lightning and hear the radio crackle simultaneously that is also
a radio wave generated by the lightning. Radio waves travel at the
speed of light.
Your UHF CB radio produces around five watts (5W) maximum power, this
is not very much. If the electric kettle in your kitchen used only 5W
it would take around 28 hours to boil one litre of water. When this
5W is transmitted through your radio and via the antenna it spreads
out in the shape of an invisible giant doughnut and any particular
direction sees only a tiny proportion of that 5W energy. This is one
reason why UHF CB has limited range.
The shape in which radio waves are produced by the antenna (our giant
doughnut) is called the antenna "pattern" and is critical to the real
world performance of antennas.
A UHF CB antenna which produces a giant doughnut is wasting a lot of
energy. Why? Well... it is very unlikely we will want to talk to
anyone directly above or below us so all the energy we are
transmitting in those directions is wasted and it would be much more
efficient if we could design an antenna which focused its energy into
a cylinder shape or a deep circle around us. In that way people to
the front, rear and sides would be able to hear us but aeroplanes and
coffins would not and that is, generally, what we want from a CB.
That is exactly what antenna gain is - an antenna which is able to
focus its energy in the desired direction. The ratio or amount by
which it is able to redirect radiated energy from one direction to
another is the antenna gain and is measured in decibels (dB).
Note: Decibels are used to measure ratios and have no native unit so
antenna gain is usually referenced to either an isotropic antenna
(dBi) or a dipole antenna (dBd). In general it will be dBi because
that produces a bigger number and manufacturers like that.
You can think of antenna gain exactly like a torch with a focusing
ability; the tighter you make the focus the further you will be able
to see BUT you will only see a smaller area because you have made the
beam more narrow. If you open the focus up you'll be able to see a
much wider area but you won't see as far into the distance. As always
with energy you cannot get something for nothing.
The real world
--------------
You will see advertisements for UHF CB antennas which give a gain
figure, 4dB, 6dB and 8dB are common and their prices usually follow
the same rising pattern.
Vehicle antennas are almost always vertical and single element which
means any gain they have must come by redirecting vertical energy to
horizontal energy. Such an antenna cannot redirect energy in the
horizontal plane (corrections welcome). In other words it will
produce a circular pattern and is therefore pretty limited in how
much gain it can generate and I doubt if many commercial UHF CB
antennas could actually meet their specification.
The next problem we have is that a vertical antenna is only half of
the antenna system (we'll ignore so called ground independent
antennas for the moment) with the vehicle comprising the other half
and this is where the real world takes over.
The antenna manufacturer has no control over how or where the antenna
is mounted and, especially at UHF frequencies, this make a huge
difference to antenna performance and can easily negate all that
extra gain you thought you were buying. Each installation will be
different but it may well be that 70% of your CB's energy is being
transmitted south and west and only 30% north and east - these
variations are called "antenna lobes" and there is no simple way to
determine your particular antenna installation's pattern.
And, after all that, even if the You Beaut antenna works really well
and is a 4dB improvement over your old one it will only make the
smallest of difference to the signal actually received by another CB
user. ie. It will make an unreadable signal slightly less unreadable
it will not turn it into a fully readable one.
My suggestions: Buy the most popular, and probably amongst the
cheapest, antenna from one of the major antenna manufacturers and
mount it in the middle of the roof - this will give excellent
performance. If you don't wish to cut a hole in the roof a magnetic
mount works well at UHF otherwise a wing mount is probably the next
best.
Comments and corrections most welcome.
MH
They are cheap and almost indestructible and are ground independent.
They also produce the clearest transmission and reception over short (10km?) distances in variable terrain. Frankly, I don't want to hear anybody further away than that anyway, they just become "noise" that gets in the way.
For the odd occasion that we might need longer transmission/reception, we carry a high gain, ground independent antennae. I have never had occasion to fit it.
Mounting position is much more important for performance than how much you spend on some fancy antennae.
Cheers,
Peter
Probably a good option is a spring loaded mount threaded to accept a number of different length antennas unfortunately the SWR goes out the window if they are not well matched.
Thanks Mike for the good explanation of antenna lobes never thought about it much as on the old 27meg super panther ssbs we used to get a bit of skip and found we could talk long distances at times. Guess in those days 27meg's were a bit off with the powers that be so the magnetic base on the roof was a quick way do a "now you see me now you don't"!
where would I mount an antenna on my bus?
Its too high (max legal) to mount anything on top, I could do the bullbar thing I guess.
But I am not sure on the mirror mount thing, maybe illegal? I thought mirrors were the only thing able to be mounted outside the 2.5m wide dimension......
I went through the exercise of 6db vs 9db antenna, found the uni and omni directional BS too hard and got a hand held.
I guess the trick is what do you want it for?
We/I decided I only wanted CB (UHF) for truck/caravan comms. Frankly I prefer 27MHz as the skip gives far better distance (bounced off the ionosphere). None the less the Hams love their 27Meg. However UHF works a treat for us, safe chat with passing trucks and other vanners.
Cheers
Bagmaker
>where would I mount an antenna on my bus?
As mentioned; the middle of the roof is ideal but if that is not possible then somewhere with the maximum surface area of metal beneath is good. A mirror is a bad idea and the bullbar is not much better. Often it's a case of just doing the best you can.
Also, keep in mind that antennas are reciprocal ie. an antenna which receives well will also transmit well so you may be able to try the antenna in different locations whilst listening to a distant repeater to see which location produces the best reception - that location will also produce the best Tx.
patrol03
>I think that it was called signal skip whereby the signal was bounced from somewhere in the atmosphere, but this phenomenum was not a regular occurrence.
Radio signals below around 30MHz will bounce off the ionosphere under the right conditions (UHF CB is much higher at 477MHz and won't) and may be heard around the world. However the ionosphere is a fickle mistress and not properly understood by science. The lower frequencies (7MHz and 14MHz especially) work well in this regard and it is usually easy to make an overseas contact from Australia on these bands. I regularly use my Amateur radio from deep in the bush to chat with friends both across Australia and the world. A radio, a 12V battery and a bit of wire in the trees is all it takes.
There are "tricks" one can do with VHF and UHF frequencies; occasionally a phenomenon called "ducting" occurs (again we don't properly understand it) where VHF and UHF signals are literally ducted by the ionosphere for hundreds of kilometres so it is possible that very occasionally (very) you may hear someone from Adelaide on your Sydney UHF CB, make sure you say "Hi" :)
Another really neat trick for VHF and UHF signals is aircraft or meteor "enhancement". A transmitter with a highly directional antenna (say an eight or more element yagi) is required. The antenna is pointed at a high flying commercial jet aircraft and a short, usually digital, transmission made. A small part of the transmission will bounce off the aircraft and may be received by a station which is well beyond the line of sight of the transmitter.
Meteor enhancement is very similar except a known shower of meteors (of which there are many) is used to bounce the signal. This technique is used for military purposes and can create unbreakable codes which are well beyond my understanding :)
I am surprised more Grey Nomads and bush travellers do not pursue Amateur Radio, it is no longer difficult to obtain a licence - Morse Code is not required - and the basic licence exam for the Foundation Licence can be passed by anyone who is capable of operating a computer, additionally, most of the Amateur Radio clubs run courses to train people for it at little or no cost:
http://www.wia.org.au/licenses/foundation/about/
MH
-- Edited by Mike Harding on Monday 6th of March 2017 06:36:29 PM
Thanks Mike for the explanation.
As a trainee, I think that I slept through the lectures on Antennas. I have always treated them as a 'black art'.
This didn't stop me lecturing CMF Field Artillery Sigs on the subject. Just a matter of reading the book & parroting it off to them. Undoubtedly at the end they remained just as ignorant on the subject as me. (perhaps I just concentrated on voice procedure rather than the techo stuff). But then I also lectured the Drivers on cooking despite being a non cook in those days. Probably a factor in the terrible meals that they produced & I winged about. Our radio comms were always a bit iffy too but we blamed the old WW2? vintage sets.
I have a (free)second hand 40ch 5w set on the Patrol. It was given to me because the pressel switch was cactus so I replaced it with a $2.50 non locking toggle. Not pretty but it works. The aerial is a cheapie mounted on the bracket on the RHS mudguard that was previously used on the old 27meg set that I inherited from my son's junk pile. I put it there because of the ease of installation ... but I was aware of the benefit of a flat metal surface under the aerial.
Works well as do the two hand helds that sit on the dash.
Might have a look at an 80ch set one of these days.
Is an Omnidirectional base.
Some arials are fairly directional.
If signal fades and returns when driving round corners in town.
You have a directional one.
Omni. Signal stays same strength.
Best one is 6 ft GME on a 5 mtr tinnie on the water.
Best ground plane you can get. chuckle.
Or a 30 ft insulated section of your yachts Backstay for HF.
IF you buy a 5w H\Held.
Do yourself a favour and buy one that takes External Antenna.
and 12v power.
Easy to boost when out bush then.
Very informative article and explanation on antennas
Personally I use a small rubber whip 2dB mounted on the front bar and on the opposite side a fiberglass 1.2m 6dB
Both are switchable from in cab, I find with the small 2dB when travelling it has a small range which is good for
picking up traffic close by and keeps the crazies afar away.
Main use of my CB is for talking to trucks on route, hence the 2dB is perfect for that and the 6dB if I want a better range
I also have a Yaesu FT8900r Quad band and a TYT TH9800 Quad band for amateur use using Diamond NR 770HB one for each radio
Also fitted is a Byonics micro trak RTG FA -- For your info to find me -- VK2MIB-10
Cheers
Vince
Mike ...
This brings to mind a situation that confuses me.
I have a winegard TV antena on my Van.
I purchased a Wingman UHF enhancer adapter that was supposed to improve the reception for digital & the combination seems to work well.
But ... When installing it I noticed that there was no metalic contact between the existing aerial & the Wingman array. The mechanical connection is via some plastic studs and both antenna sections are coated with insulating medium
How does this work?
Hi Cupie
>When installing it I noticed that there was no metalic contact
>between the existing aerial & the Wingman array. The mechanical
>connection is via some plastic studs and both antenna sections are
>coated with insulating medium
>How does this work?
You know the deal! If I told you I'd have to shoot you! :)
The Wingman acts as a "passive repeater".
Their original antenna was not very effective at UHF because most TV
in the USA was in the VHF region but once digital TV came along most
(all?) of the channels were at UHF and rather than force their
customers to buy a new antenna they came up with this solution - and
quite a clever one it is too.
There is a, not very helpful, on YouTube:
https://www.youtube.com/watch?v=N5sP7kRoljc
The Wingman is actually two antennas; one for receive (Rx) and one
for transmit (Tx). The Rx antenna will be a capable UHF unit which
receives the TV signals, it is coupled to the Tx antenna which will
be a low gain simple unit.
When a signal is received by the Rx antenna it is passed to the Tx
antenna which is located close to the original UHF/VHF antenna. The
Tx antenna retransmits the signal and it is received by the UHF
section of the original VHF/UHF antenna.
Passive repeaters have been around for a long time but are not often
used as there is usually a more efficient way to do the job however
they do have their place. Imagine a farmhouse at the bottom of a
valley; they can't receive TV because the transmitter is on the other
side of the hill and it's too far to run a cable to put an antenna on
top of the hill. However a passive repeater made from two decent TV
antennas located at the top of the hill with one pointing at the
transmitter and the other pointing at the farmhouse may well work.
MH
M ..
Well bugger me ... What a clever idea.
Thanks .. G