Hillsborough
Sheffield
S6 2LL
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ATV Stock Aerial Tests (Also see ATV`s tests of FM / DAB antennas)
This page contains the test results for all the aerials we recommend/stock for the different groups. The results are arranged in tables as follows :
The C/D group aerials we stock
I thought long and hard about how to make the test results relevant and comparable with
each other, and have decided to show all readings (in dBμV ) relative to a DM Log Periodic aerial. The latter has a pretty flat gain curve and thus is an ideal control aerial.
Quite apart from anything else, wherever possible (i.e. in reasonable signal areas), Logs
should be used as a matter of course, so the table(s) will show how much gain you have to
make your decision on antenna choice. Note how the Log performs pretty well (in terms of
gain) against small/medium wideband Yagis at the bottom of the band(s) but falls behind
as the frequency rises.
For those who are interested I reckon that the gain of a DM log would be about 6 dB at the bottom of the band, then rising by about one dB in the middle, before dropping again at the top end. These are the figures I used when calculating the absolute gain for the graphs.
The absolute gain figures are conservative estimates, though they are accurate relative
to each other. Remember that all aerial test readings are approximate anyway, as
far as I`m aware no lab will even guarantee accuracy better than +/-
Note this is dBd, gain compared to a half wave dipole, NOT the (dishonest ? ) dBi....
Differences in the test results of one dBμV on any individual frequency should be disregarded, manufacturing tolerances or a truck going over a hill somewhere between the test site and the TX could easily account for those ! Furthermore the response of any aerial is not linear, its gain curve will have bumps and dips in it. That said, a 1dB difference
across the whole band is significant, and an increase (or decrease) of two or three dB is
very significant. It should be remembered that 3 dB is a 40% higher signal level and such
an increase at the aerial (as opposed to through an amplifier) is very difficult to achieve.
Obviously if you live in a decent reception area these amounts of signal variation are not important, but if that`s the case, you should just use a Log Periodic anyway !
In order to give some idea of the gain of the aerials we also included a 46 element Tri Boom Yagi which is very similar in performance to a DAT45, on the tables. We do not stock Tri Booms, but for those who know of them, the figures could be illuminating. Overrated.......
I didn`t test the DAT 75 because it was too unwieldy, but Televes report it as being about
the same as a DAT 45 at CH21, rising to +1dB at CH45 and peaking at +2dB by CH62.
Always remember, things aren`t always what they seem.
It should be borne in mind that gain is not everything, which is why Logs are still one
of the best aerials despite being having relatively low gain figures.
Impulse noise rejection, directivity, out of band rejection, cross polar rejection and
front to back ratio and can all have significant effects on the quality of the received signal.
Having said that, gain is a function of the others (apart from impulse noise rejection) as it demonstrates that the antenna is performing efficiently. Indeed gain must be a function of the others. Why must ? Well an aerial is a passive device, the only way it can increase its gain (in a particular direction) is at the "expense" of gain in the other directions. As an aerial`s gain increases, its acceptance angle (and its Cross Polar Rejection come to that) decrease. They must do, there is no other way for the aerial to increase its gain.
All of the above is before you even start talking about wind loading considerations and/or build quality. Fortunately, we know what we`re talking about when it comes to the latter.
There are no “Bacofoil aerials” here.....
As expected the A group
aerials display the biggest
superiority in gain over
widebands. In fact such is
the widebands inferiority
that there is no such thing as a
“High Gain” wideband aerial
for the A group frequencies.
We recommend the DM log
for strong signal areas, the
Log 40 for medium signal
areas, the Yagi 18A for poor
signal areas (outdoor installs)
and the XB10A for loft installs.
The XB16A is for those with
the most marginal signals for
outdoor installs, unless
you`ve got a massive loft !
The dimensions of the aerials can be found on the relevant table.
The prices of the aerials are on the Online aerials page.
For the curves of other
relevant aerials including
a Contract 10A and a
Tri Boom 75 click here.
the results are explained above.
We recommend the
DM log for strong
signal areas areas,
the Log 40 for medium signal areas, the Yagi 18B for poor signal areas (outdoor installs) and the XB10B for loft installs.
The XB16B is for those with
the most marginal signals for outdoor installs, unless
you`ve got a massive loft !
The dimensions of the aerials can be found on
the relevant table.
For the curves of other relevant aerials including
a Contract 10B and a
Tri Boom 75 click here.
the results are explained above.
We recommend the
DM log for strong
the Log 40 for medium signal areas, the Yagi 18CD or the DY14WB
for poor signal areas.
The XB16E is for
those with the most marginal signals and outdoor installs, unless you`ve got a huge loft !
The dimensions of the aerials can be found on the relevant table.
The prices of the antennas are on the Online aerials page.
For the curves of other relevant aerials including
a Contract 10CD and a
Tri Boom 75 click here.
We recommend the DM log for strong signal areas,
the Log 40 for medium signal areas, the Yagi 18K or XB10K for poor signal areas. The XB10 is particularly suitable for loft installs due to its relatively small size for its gain.
The XB16K is for those with the most marginal signals, and outdoor installs, unless you`ve got a massive loft !
The dimensions of the aerials can be found on
the relevant table.
Notice the significant superiority of the K group aerials over the wideband.
In fact such is the wideband inferiority that there is no such thing as
a “High Gain” wideband
aerial for the K group frequencies.
For the curves of other relevant aerials including
a Tri Boom 75 click here.
the results are explained above.
An E group aerial is a
“semi wideband” whose response is optimised for the middle/top of the
band, at a cost of some gain down at the bottom,
see Group Gain Curves.
We recommend the
DM log for strong signal areas,the Log 40 for medium signal areas,
the Yagi 18E or the DY14WB for poor signal areas and the XB16E is for those with the most marginal signals and outdoor installs, unless you`ve got a huge loft !
The dimensions of the aerials can be found on the relevant table.
For the curves of other relevant aerials including
a Tri Boom 75 click here.
We recommend
the DM log for strong signal areas, the Log 40 for medium signal areas, the DY14WB for poor signal areas and the XB22WB for those with
the worst signals.
For use on boats and caravans we always recommend the DM Log.
I`m not really a fan of wideband Yagis, but as one can see from the graph the DY14WB & XB22WB have exceptional performance. Bearing in mind the fact the DY14 is only 5ft long its gain figures are remarkable and this makes it more suitable for loft installs than the XB22.
The dimensions of the aerials can be found on the relevant table.
For the curves of other relevant aerials including
a Contract 10WB and a
Tri Boom 75 click here.
Notes.
There is no wideband aerial which will give “high gain” at the bottom of the band.
If you must have a wideband, and you`re sure you require more gain at the bottom end, you`re best
option is to diplex an A group with an E group, or even an A group with another (high gain) wideband if
you already have one of those. Remember that most people don`t need a “high gain” aerial though !
The above table is a summary of the A group results, full results.
In our tests other models of 18 element A group gave around 3dB (average)
over the A group, relative to the DM log.
B Group Aerials
The above table is a summary of the B group results, full results.
In our tests other models of 18 element B group Yagis gave between 4.2dB and 4.6dB (average) over the B group, relative to a DM Log.
C/D Group Aerials
The above table is a summary of the C/D group results, full results.
In our tests other models of 18 element C/D group gave between 4.1dB and 4.8dB (average) over the C/D group, relative to a DM Log.
K Group Aerials
E Group Aerials
The above table is a summary of the E group results,
Wideband Aerials
The above table is a summary of the wideband group results, full results.
Typical models of Yagi 10 element wideband average between 1.0 and 1.3dB *.
Typical models of XB5 wideband average between 1.2 and 1.9dB.
Typical models of Yagi 18 element wideband average between 1.7 and 2.8dB.
Typical models of XB10 wideband average between 3.1 and 4.0dB.
* All figures are average over the whole band relative to a DM Log.
A Group Aerials
The above table is a summary of the K group results, for full results click here.
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