SATELLITE DISH SIZES IN THE UK 
PURPLESAT MOTORISED SATELLITE SYSTEMS
WHAT YOU CAN GET AND WHERE 
FIRST HAND KNOWLEDGE & REAL TESTS not EIRP 'PREDICTION' MAPS & CLAIMS.
ADJUST DISH SIZE DOWN FOR SOUTH OF UK & UP FOR NORTH for MENA & MOST SATELLITES. ADJUST UP FOR OUTER LNBs ON MULTI LNBs
ADJUST UP FOR LARGE TOWN, CITY & INDUSTRIAL 'LOCAL' NOISE LOCATIONS &/OR VIEW. ADJUST DOWN FOR SHELTERED/ LOW NOISE RURAL LOCATIONS &/OR VIEW. ADJUST DOWN FOR fecs BELOW 3/4 & ADJUST UP FOR  FECs ABOVE 3/4 [ON DVB-S/QPSK] ADJUST UP  FOR fecs BELOW 2/3 & DOWN FOR  fecs ABOVE 2/3 [ON DVB-S2/QPSK]
ADJUST UP FOR LOW SYMBOL RATES BELOW 10000-30000.

 ADJUST DOWN FOR POWER LEVELS ABOVE 50dBW & UP FOR OVER 50dBW 
**SOME CHANNELS CAN STILL VARY DUE TO *MANY VARIABLES INCLUDING  BREAK UP LEVEL VARIATIONS/ WITH TRANSMISSION TYPE/ QUALITY & POWER, INTRA TP/ POL & SATELLITE NOISE / SECONDARY HARMONIC EFFECTS, TUNER & LNB WHOLE BAND PEAKS & TROUGHS & LNB <>TUNER MATCHING OF THESE etc.**
photo strip

30cm
test dish only.
East Lmit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e 45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e 25.5e 23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w... 85w West Limit 
DISH SIZES POWER SCALE
APROX 2-3000 TV & RADIO CHANNELS/ UP TO 20 SATELLITES
39cm Camping dishes
East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e  52e 50e 47.5e 46e 45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e 25.5e 23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w... 85w West Limit 
DISH SIZES POWER SCALE
APROX 4000 TV & RADIO CHANNELS/ UP TO 25 SATELLITES
43-45-50cm Sky Z1 dishes
East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e 45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e 25.5e 23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w... 85w West Limit 
DISH SIZES POWER SCALE
APROX 4-7000 TV & RADIO CHANNELS / UP TO 30 SATELLITES
60-65cm dishes & Sky zone 2 dishes

East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e  46e 45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e 25.5e  23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w
7w 7.3w 8w 11w 12.5w 14w 15w 18w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w.... 85w West Limit 
DISH SIZES POWER SCALE
APROX 5-10,000 TV & RADIO CHANNELS/ UP TO 40 SATELLITES

70cm
dishes

East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e 45e 42e 39e 36e 33e 31.5e 30.8e  28.2/5e 26e 25.5e  23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w .... 85w West Limit 

UP TO 10500 TV & RADIO CHANNELS/ UP TO 42 SATELLITES

PURPLESAT MOTORISED SATELLITE SYSTEMS
80cm dishes

East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e 45e 42e 39e 36e 33e 31.5e 30.8e  28.2/5e 26e 25.5e  23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w 20w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w.. 85w West Limit 
DISH SIZES POWER SCALE
UP TO 11000 TV & RADIO CHANNELS
90cm dishes
East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e 45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e  25.5e  23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w  14w 15w 18w  20w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w ...85w West Limit 
DISH SIZES POWER SCALE
UP TO 12000 TV & RADIO CHANNELS (PLUS C BAND CAPABLE > 50 CHANNELS)

1m dishes
East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e 45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e 25.5e  23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w 20w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w  61w... 85w West Limit 
DISH SIZES POWER SCALE
OVER 12000+ TV & RADIO CHANNELS (PLUS C BAND CAPABLE > 60 CHANNELS)

1.1m dishes
East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e  45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e 25.5e 23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w  20w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 47w 55.4w 58w  61w... 85w West Limit 
DISH SIZES POWER SCALE
OVER 12,000 TV & RADIO CHANNELS (PLUS C BAND CAPABLE > 80 CHANNELS)

1.2m dishes
East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52e 52e 50e 47.5e  46e 45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e 25.5e 23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w 20w  22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w.... 85w West Limit 
DISH SIZES POWER SCALE
OVER 12,500 TV & RADIO CHANNELS (PLUS C BAND CAPABLE > 200 CHANNELS)1.8m dishes
East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e 45e 42e 39e 36e 33e 31.5e 30.8e 28.2/5e 26e 25.5e 23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w* 3w 4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w 20w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w 61w ... 85w West Limit 
DISH SIZES POWER SCALE
OVER 13,000 TV & RADIO CHANNELS (PLUS C BAND CAPABLE > 200 CHANNELS)

PURPLESAT MOTORISED SATELLITE SYSTEMS
2.4m dishes
East Limit 77e 75e 72e 70.5e 68.5e 66e 62e 60e 57e 53e-52.5e 52e 50e 47.5e 46e 45e 42e 39e 36e 33e 28.2/531.5e 30.8e e 26e 25.5e 23.5e* 21.6e 19.2e 16e 13e 10e 9e 7e 4.8e-5e* 3e
0.8-1w*3w  4w 5w 7w 7.3w 8w 11w 12.5w 14w 15w 18w  20w 22w 24.5w 27.5w 30w 34.5w 37.5w 45w 47w 55.4w 58w  61w ... 85w West Limit 
DISH SIZES POWER SCALE
OVER 14,000 TV & RADIO CHANNELS (PLUS C BAND CAPABLE > 200 CHANNELS)
Nilesat 201 / BADR 5 & 6 may be possible.

PURPLESAT MOTORISED SATELLITE SYSTEMS
ALL DATA CORRECT AT TIMES OF TESTING- SATELLITES/ BEAMS/ TPs & CHANNELS CAN CHANGE WITHOUT NOTICE
BASED ON QUALITY PURPLESAT INSTALLATIONS & TRUSTED REPORTS ONLY.
THIS IS FOR KU BAND ONLY-  FOR C BAND DISH SIZES >>> SEE HERE
BEAMS / TPS CAN VARY WITHIN A SATELLITE POSITION-
DOES NOT INCLUDE ALL WEAKER BEAMS & TPS OR SATELLITES AT EACH LOCATION (eg 26e BADR4 not BADR 5 or 6 ..... 7w Nilesat 101/102 not 201)
FOR VERY DETAILED UK RECEPTION REPORTS FORNilesat 101- Nilesat 102- Nilesat 201 @ 7w- Eutelsat 7 West A (AB7) @ 7.3w & Arabsat - BADR 4/5 & 6 @ 26e & ADMC reports SEE ALSO >>>> STRONG CHANNELS LISTS

CHANNELS ONDVB-S2 8psk TPs HAVE  HIGHER LOCK LEVELS THAN DVB-S. HD ON DVB-S A LOWER LOCK LEVEL THAN SD.
SINGLE CHANNELS ON SINGLE TPs ON LOW POPULATED (LOW NOISE) SATELLITES CAN HAVE MUCH LOWER LOCK LEVELS. 
*For those new to satellite, some changes include > 43w's / 7.8w / 40e / 31.5e/ 2e / 4e Europe KU beams NA ATM.
58w BT Europe feed NA ATM..
*many new satellites added & many new satellites added/ changed on existing positions*
77e EAST LIMIT FROM SE ENGLAND <<<>>> 85w WESTERN LIMIT FROM SW IRELAND

********
SOME MORE DETALED INFORMATION

90cm dishes
*****
As above 80cm - 85cm with gradually improving towards a 1m reception with the popular FREE MOVIES on ARABSAT (BADR4) @ 26e usually coming in at about a QUALITY 85cm (quality 80cm minimum with rain margin possible) or above and better reception on Nordic beams (1w/5e/) etc... 88- 95cm may give 4w reception on the east of the UK ... 7.3w can actually be slightly esasier at this size & overtake 26e's normally easier reception, due we think to the stronger & more populated 28.2e & increased bleed over from the wider beam width on the smaller dishes that 7.3w doesn't suffer the same with 5w & 7.8w/8w.
Some 7w- Nilesat 102 reception is possible, especially in the evening & early morning of some of the strongest vertical channels.
Some C Band reception is possible with a suitable C Band LNB & settings. 

*****

1m dishes 
*****
All above plus better BADR4 @ 26e reception in serous bad weather + better 16e Better 23.5e non UK beams, better 10e better 4.8e  & 18w 
Better Nordic beams on 1w & poss' 23.5e Nordic beam reception.. better 4w / 4e plus 7.3w reception of 500+ channels & 15 FREE MOVIE CHANNELS & Nilesat  102 reception of strong verticals . - more later on in the evening & early morning UK time. Possible intermittent reception of the strongest Horizontal channels very late at night very early morning on a 1.1m and a 1m has some limited C Band reception ability & possible reception of 60e 70.5e 75e [ideally requires a high, good low horizon view & ideally east side UK location].


1.1m dishes 
*****
As per 1m .. with a %  improved bad weather persistence plus main improvement areas being @ 7w reception, more English channels, better Nordic beams, including 4w, 15.8e, 4.8e (Viasat HD), 1w, 10e, 7e. & some feeds. Better C Band reception with the correct LNB & settings.

1.2m dish  
*****

As above all better reception plus Nordic beams 4w/ 4.8e/ 1w and 23.5e Nordic beam & more & better reception of Nilesat 7w & longer in the day - more late on & early morning and improved C band reception with suitable C Band LNB & settings.

1.8m dish  
*****

As above plus noticebly better reception on 7w verticals all day plus stronger & more on horizontals on 7w earlier in the evening and more or all later on at night. Possible limited BADR6 reception in the south and much improved C Band reception.

2.4m dish  
*****
All above better reception plus much more 7w Nilesat horizontalsreception ealier in the afternoon & consistent 3pm.  Possible limited BADR6 reception and much improved C Band reception.

3dish  
*****
As above all better reception plus all Nilesat 7w horizontals 24/7 ... and possible BADR6 & possible Nilesat 201  reception and more C Band reception.

3.6dish  
*****
As above all better reception plus improved chances of reception of BADR6 & Nilesat 201 and various beams & much weaker C band reception in the UK.
PURPLESAT MOTORISED SATELLITE SYSTEMS

SATELLITE DISHES

TRUE DISH SIZES BY 'AREA' : SOME SAMPLE MANUFACTURERS


Many manufacturers use various measuring methods & model numbers that do not relate to the dish size -

For this report data all sizes are for the reflector only and do not include any supporting rim or curved or raised edge to give a more reliable like for like comparison on area- these are for Width+ Depth /2 or the equivalent area of a round circle (& thus PIR2 on the measure will give the surface area but we do not do that because there is no need as we know the outcome & do not apply the offset measure as that is also included relatively in the difference in the  height & width).

The original offset dish size measurement is considered to be the width only as the dish & LNB both see a circle with the diameter of the width size at the angle of offset, this is the basic principle on paper of an offset angle, unfortunately once applied in the real world there are an infinite number of variables that modify this simple basic theory & so the area measurement in the flat proves to be the better overall measure that also factors in the design/ offset angle effect indirectly, the width & height & the beam width characteristics & works to all dish shapes etc.  
Design engineers at the following companies have used the area measure, Channel Master, Andrews, ASC Signal, Raven, etc.. all the companies that have been behind the brand name Channel Master- eg: the Channel Master 1.2m's model number is Type 125 - the dish is 1.3 x 1.2 /2= 125 .
Raven on their own products use this measure,Prodelin, Patriot, Hirschmann, Fraaccaro, Gibertini, Triax etc. (all well respected industry companies) have all used this measure.


Triax (steel press dishes)
These dishes are generally consistent in quality control. They are pressed steel faces - the steel is then zinc phosphate treated & powder coated polyester this combination does give a very good long term rust proofing to the face & can stay 100% rust free for over a decade.
Their AZ/ELs are very well designed with a high pole grip clasp design & many lateral strength additions with a galvanized steel substantial curved box shaped support for retaining the dish shape & all nuts & bolts are zinc plated - most stay rust free - rust may creep in if the surface is damaged on fitting. The feed arms are pressed aluminum box section & UV resistant plastic fittings.
Elevation adjustment is considered difficult to fine tune but once set they are very solid & have several lateral strengthening aspects to the pressings. Triax are one of the best AZ/EL designs we think & there are cheaper copies badged under several names.
Objective criticisms > as above in red & The steel in the AZ/EL clasp could be higher tensile,  the bolt sizes for the AZ clamps could be increased or a 3rd added, the lnb holder design would be better IOO if lnbs can be swapped without removing the holder, the feed arm could be strengthened for multi lnb use, the size of the face nuts & bolts could be increased &/or to supply nylocks locking nuts. Feed support arms for the 78 88 & 1.1 would be a nice addition or as an optional extra..


Model   W          H         = to round dia  area

TD56 = 50cm x 55cm = 52.5cm

TD64 = 60cm x 65cm = 62.5cm

TD78 = 70cm x  78cm = 74cm

TD88 =85cm  x 95cm = 90cm

TD1.1 = 1m x 1.1m = 1.05m (or 1.025 some models)

Gibertini

65 = 63cm x 67.5cm = 65.25cm

75 = 72cm x 77cm = 74.5cm

85 = 81.5cm x 87cm = 84.25cm

1m = 94cm x 1.01cm = 97.5cm

1.25m = 1.21m x 1.3m = 1.255m

1.5m = 1.5m x 1.61m = 1.555m



Orbital

80cm = ......cm x ...... cm = 74-76cm

1m = 95cm x 105cm = 1m  steel

1m = 95cm x 105cm = 1m  aluminium

 ISS (& Technomate badged ISS) 

65cm = =

80cm = = 78cm

1m = = 98cm

NEW Technomate badged Triax look dishes 

1m = 92 x 98cm = 96cm

TELEVES

1m = 1.05m on area

PENTA

68 = to a 68cm round dish on area

85 = to a 85cm round dish on area


 Channel Master  
(Channel Master/ Andrews / asc Signal / Raven / Skyware)


90cm = 90cm x 98cm = 94cm

1m = 1m x 1.05 = 1.025m

1.2 m = 1.22m x 1.32m = 1.27m

1.8m = 1.8m x 1.9m = 1.85m

2.4m = 2.4m x  2.46   = 2.43m

 PRODELIN 

1.2m = 1.24m x 1.28m = 1.26m

1.8m = 1.84m x 1.88 = 1.86m

2.4m = 2.44 x 2.47 = 2.455m
 

3m = 3m x 3m eg pf = 3m

3.7m = 3m x 3.7m eg pf = 3.7m

(#General example sizes- manufacturers demensions & designs can be subject to change over the years- eg: the earliest Channel Masters are different to the latest versions).


HOW TO MEASURE A DISH 

 (TO COMPARE SURFACE AREA v SURFACE AREA or THE OFFSET MEASURE).

For this comparison chart dishes are measured by reflective surface area equivalent to a round CIRCLE of that diameter only

(or Width + Height / 2) and are for offset design with a single LNB & do not include appying the offset angle!. 

Most manufacturers and resellers routinely quote different measuring methods or model numbers that do not relate directly to the reflector area so you need to ensure that for any dish tested, the dish size is the reflector area to compare like for like & should not include any supporting rim area.

There is a method of using the offset angle so that the width is then the quoted size & the height is deemed the same as viewed in offset, although this looks simple on paper, this is not quite as reliable a relative measure in the feild as the area measure as it assumes there are no other variables whereas there are potentially an infinte number of variables once the basic theory is applied to the real workd, although it looks simpler, the area measure could be deemed a 'roughing out' measure, but is actually a much more complex reflection of these and does include the effect of the offset angle. 
Many manufacturers & resellers quote height of reflector or height including the supporting rim which exaggerates the true comparatuve  reflector size or may use misleading model numbers.

The area measuring method we have used here also demonstates results manufacturers have acheived with the same surface are.

This does not allow for multiLNB installations where outer LNBs on multi LNB systems require a larger dish to allow for the loss in offset depending how far out of the focus point they are (excluding Toroidal dishes) and to allow for any insertion loss &/or added noise of diseqc 1.0 or 1.1 switches. (see also different measuring methods & different types of satellite dishes).

All figures are based on test sites around the UK & our baee in the center of the UK & can still vary due to local interference conditions (town/ city & rural locations & town/ city & riural views), weather conditions and footprint fringe variations in different areas in the UK.

All tests are based on good quality dishes in good condition , sensitive LNBs, good cabling practices & sensitive receivers. 
These results will not be the same if using cheaper products 'anywhere' in the process or poorly installed in any way.

A 1M MOTORISED SATELLITE SYSTEM USING ALL QUALITY APPROVED  EQUIPMENT PROFESIONALLY INSTALLED
CAN BE VERY DIFFERENT FROM THE CHEAPEST EQUIPMENT BADLY INSTALLED.

*most signals reduce the further north in the UK & increase further south in the UK except certain northern Europe beams / Nordic beams such as 1w 5e 23.5e Nordic/ N Europe beams, these N European / Nordic BEAMS can increase as you go north & east of the UK - These can be low or too low on smaller dish sizes - especially 23.5e's.
PURPLESAT MOTORISED SATELLITE SYSTEMS


Other types of satellite dishes

Prime Focus dishes.

Take care in comparing offset dishes with prime focus dishes of the same area as their characteristics are different.

Prime focus satellite dishes offer better local noise & ground noise temperature figures due to the steeper elevation angle & deeper parabola as apposed to the lower elevation & shallower parabola of offset dishes that expose the dish face to more ground & local noise.

The deeper parabola of the prime focus dish gives better ground & local noise & radiation protection to the LNB compared to the more exposed LNB position of the offset dish.

Prime focus dishes are of a deeper parabola & give different beam width characteristics than offset dish of the same surface area/ size- this can be an advantage for satellites wide apart or a disadvantage if it causes more noise to be received from adjacent space & nearby satellites.

The whole surface area of a prime focus dish is what is reflected in to the LNB (except any shadow cast by the LNB & feed support arms) where as the offset dish is deemed to be only as large as the LNB offset angle sees and  the greater height measurement is deemed to be reduced to it's width measurement. So a prime focus dish of 1m round is equal to an offset dish of approximately 1m wide by 1.05m high (less LNB / feed arm shadow loss).

The prime focus dish suffers from loss of reflector area due to the signal shadow cast by the LNB & feed support arms compared to the offset dish that does not cast a shadow- usually deemed a quite low loss on dishes over 1.2m

Sky ZONE 1 & 2 dishes & horizontally oval dishes

These are also offset dishes but are wider than their height. This gives a narrower beam width horizontally for their size, giving better separation from other nearby satellites, but a deeper beam depth allowing for better reception of stacked satellites in the same location - a very efficient design for a small dish & used on larger dishes. Zone 1 sizes have varied over the years & from diferent manufacturers from c. 43cm on area to 50cm on area & there is a 54cm zone one from Raven & some are a wider, flatter oval tha othees. 

The Sky dishes are also paired with feedhorn/ scala ring matched LNBs that are are optimised for use on Sky @ 28.2/5e only. They do require special modification to work as efficiently on all other satellites.


Double reflector dishes

Toroidal Gregorian Cassegrain

Toroidal dishes use a second reflector to allow much wider multi LNB setups without the usual loss at the edges - all LNBs function similarly to being in the centre of the dishes focus. Some of these have been used to cascade 20+ LNBs / diseqc switches & satellite positions.

Gregorian dishes uses a second reflector where the LNB is usually positioned and the LNB then is positioned between the 2nd reflector & the main reflector facing the opposite way- The advantage is deemed a better focus.

Cassegrain dishes are usually prime focus & use a mushroom shaped reflector / collector in the middle of the dish tpo reflect the signal tp an LNB at the back of the dish & claim higher efficiency for their size.

Odd shaped dishes

Penta 68 = to 68cm round on surface area.
Penta 85 = to 85cm round on surface area.

A large number of professionals in the commercial satellite industry consider these dishes as the industry joke dish,  many consider the shape & performance claims very suspect. The absence of a dedicated feed horn for these dishes to match the almost square shape (on it's side) is deemed a major failing on their part to give any credibility to it's odd & basic physics rule breaking shape & instead giving rise to increased noise problems being able to enter a standard round LNBf' feedhorn, scalaring & waveguide design from the 4 crescent shaped gaps it produces which, on a basic meter & a spectrum analyser that shows a spectrum of power not signal quality measurements that can appear as a higher signal strength, but instead be energy from noise behind the dish and that the much higher retail costs & low quality of the flimsy dish face unwarranted in practical terms and are instead deemed an amusement & bought only by un-knowledgeable individuals.

We cannot comment too much*** on their performance or cost effectiveness & consider them instead an option for those who see them as an attractive alternative to the traditional oval offset dish with good quality AZ/EL & LNB arm and some other good points. As for the floppiness of the steel version dish face we do agree we have witnessed this & that they can distort in even mild wind but also that they seem to return well to their intended shape & haven't seen a distorted one as yet, although their odd shape does make it difficult to establish whether they are bent or not. The offset angle however, seems to be higher giving an almost prime focus look about the LNB position, this can give the LNB a larger view of the dish than in a lower offset angle and although this normally gives rise to higher noise - in the case of the Penta the basic rules have already been thrown away as it were so it's just as likely to give a gain than more noise.The wider edges (for that size/s) may also give a narrower separation, however the 'points' of the square add to the instability in wind. 

TESTS RESULTS: PENTA 68 v Sky dish.  Penta 85 v Triax TD88

In recent extensive tests we found that the Penta 68 was matched or bettered by a Sky dish (zone 2- 64cm) on all the main quality measures of BER/ SNR/ MER/ by a Sky zone 2 dish(64cm) & Triax 64(62.5cm) & 78(74cm) dishes using a surface area like for like test where the larger dish surface area in each case was masked to give exactly the same surface area.
 
The Sky dish was found to be very efficient indeed per surface area if the offset LNB antennae & oval offset feedhorn design was used correctly on all satellites and the stability of the sky dish proved one of the best designs & build quality per size & offered very high wind speed functionality & very high wind speed survival c. 120klph / 220klph on quality Raven Sky dishes - we think the Penta could become bent inside out at those speeds.

The floppiness of the steel Pentadish face was found quite unstable in quite moderate wind speeds & would distort too easily losing signal compared to calm weather. Worse still, they demonstrated a disturbing resonance/ flapping behaviour in strong side winds that could potentially damage a motor prematurely and not recommended for exposed locations or coastal use. The Penta85 has a supporting bar at the back showing that the designer/ manufacturer have recognised the faults with the unstable shape compared to an oval dish. We also found the overall weight quite excessive for the size & stability of the dish.

SPECTRUM Analysis

When we analysed the signal from a Penta 68 & 64cm Sky zone 2 dish (surface area matched), the Penta 68 appeared to be the greater signal on a professional Rover STC satellite spectrum analyser - particularly at the higher end of KU band- however when we observed both signals in all the quality measures, the lower signals from the Sky dish were 'higher' in quality measures than those from the Penta & also this was reflected in satellite receiver on screen measures. We believe this to be added power from noise entering the round LNB feedhorn from the crescent shaped gaps caused by the square shape of the Penta. In rural areas we beleive these noise issues would decrease & in city areas become more pronounced.

Taking these findings into account, we still install the Penta dishes for aesthetic reasons over performance but do not agree with the manufacturer's performance claims, dish face stability in strong winds & believe that the AZ/EL & feed arm is well made except for the elevation pivot & general feed clamp design, we don't have long term durability measures for wind tolerance, paint finish, UV & rusting.
PURPLESAT MOTORISED SATELLITE SYSTEMS