Famaval 2.4 vs Pasat 2.4, experiences in real live?

[Salva]

Hi there, I had a 2.4 installed that the January wind blow off, long story, I know what to expect from a well installed and adjusted 2.4 antenna I had a 2.4 DTH antenna+Invacom quad and got all the 2A/2B 24/7, 2Dv's 24/7, 2Dh's up to around 21:00. (Gandia)

I am currently using a small offset dish and going to reinstall a 2.4 antenna again, I have doubts on whether the 2,4 (2,5) Pasat performs better or worse than the Famaval 2.4.

Any experiences with both antennas in the same area?

Thanks for your help.

 

[woborny]

2Dh's up to around 21:00. (Gandia)

some 2.4 famavals i have done have had some of the 2dhs until about 8 ish...
but saying that there are times when I can get 2dhs 24/7 on my 1.8!
have not tried the pasats recently, but on many of the ones I have seen that were installed in the area over 5 years ago struggle to get the 2dhs at around 6/7pm...maybe there is a new batch....

although (member on here) "joddle" has one installed (seearch for his posts - his fortecstar fell over in the storms earlier this year) and he get 2dhs quite well - although he is like 60kms away in just south of valencia which really makes a difference....10kms west and signals become a pain again...in fact I managed to get some 2dhs on a 1m dish in el saler mid afternoon!!!!!

 

[Salva]

Just to spice the thread this is what happened to my old DH antenna:



The January wind just took it away and it landed on the neighbour's roof, 15 mtrs away.

[fieldset=Admin]In future please upload any photos to our server do not link them[/fieldset]

 

[Huevos]

The January wind just took it away and it landed on the neighbour's roof, 15 mtrs away.

Good job it didn't kill someone.

The Pasat is a few centimetres bigger. I think Pipino has fitted some. The thing with the Famaval 2.4 though is you can extend it to 3.1 metres if you find you need a bit of extra signal after buying the dish.

 

[Salva]

The thing with the Famaval 2.4 though is you can extend it to 3.1 metres if you find you need a bit of extra signal after buying the dish.

Well the thing is that I have installed a few DH's of 2.4 and 2.7, you have to fiddle a little bit to get the face of the dish rigth with the back struts, but once you do they are ok. My old supplier no longer have them so I have not to decide on either Pasat or Famaval.

I don't think it is worth the 3.1 extension, it will jut give you a more "secure" lock on 2Dv's and you will get a few extra minutes, say half and hour, on 2Dh's. I did back on 2005 a small explanation on what was happening on 2D on this area (Gandia), it was done with an 1.8 antenna and I did it to understand the gain you will get with bigger antennas. The interesting bit is how the signal drops like a stone 3 or 4 db (c/n) and that explains why a bigger antenna will not help.

I am attaching that document, it contains some errors, but I never corrected them.

 

[Huevos]

I did back on 2005 a small explanation on what was happening on 2D on this area (Gandia), it was done with an 1.8 antenna and I did it to understand the gain you will get with bigger antennas. The interesting bit is how the signal drops like a stone 3 or 4 db (c/n) and that explains why a bigger antenna will not help.

How is it possible to produce an accurate graph of what is happening to the signal level if you are using a dish which is too small to measure it at the lower end? What I am getting at is with my meter for example if C/N drops much below 7.4 dB the meter loses lock so it's impossible to know what C/N is below this figure.

Also your graph says there is a 2 dB change in C/N on 2D verticals. I don't see anything like that, probably more like 0.7 dB.

P.S. I think your test gear must be calibrated different to mine because with mine the cut off for reasonable reception is about 8 dB C/N. With a Pace 2600 CI 7.7 dB is just about enough. Your graph shows 6.9 as your threshold.

 

[Salva]

How is it possible to produce an accurate graph of what is happening to the signal level if you are using a dish which is too small to measure it at the lower end? What I am getting at is with my meter for example if C/N drops much below 7.4 dB the meter loses lock so it's impossible to know what C/N is below this figure.

Also your graph says there is a 2 dB change in C/N on 2D verticals. I don't see anything like that, probably more like 0.7 dB.

P.S. I think your test gear must be calibrated different to mine because with mine the cut off for reasonable reception is about 8 dB C/N. With a Pace 2600 CI 7.7 dB is just about enough. Your graph shows 6.9 as your threshold.

I have a Prolink 4C+, actually to measure the c/n the meter just works on the analogue domain, so it can measure say c/n up to 0.1 db (in theory), the c/n on that sense depends very much on where you take the reference level, on the 2D's is easy i tend to go on a "empty" area you just have after the last transponder. Diferent reference frecuency can give give you sligtly different c/n, in my personal experience anything below 6.5db will not be receivable by any receiver, from there to 7.5db will depend on the receiver and from 7.5-8db will be picked up by any receiver.

I was interested not very much on the absolute level, but on the differences, so that say that I have a drop of 3db I know that to compensate it I need a 3db more gain out of the antenna. Or if I install a bigger antenna, how may hours will I get.

The antenna that I did the test with was a Precission 2.0M (now Andrews) but I beliebe that it had some performance issues since it performed like a 1.8-1.9m.

What I did was write a small program to log the values over a week, first signal, then c/n, then BER, and then correlate them on excel, not very scientific but was enough for me.

 

[pipino]

hi m8,
if you know a company around gandia area called BASE run by a well know guy called Paul,he uses PASAT aka the Bulgarian dish for years now,to be honest with you from the extensive tests done to make a difference between both dishes i would say not much of a difference speacialy if you are targeting 2D H (BBC2 transponder) i saw a test done with both dishes in the same location PASAT had a bout 20min extra then Famaval ,then again LNBs have some role there too(invacom quad with ADF120 Feedhorn)...best regards

 

[woborny]

or you could visit tecatel (in beniarjo) who will probably have the dishes lined up outside....
according to their site they do all sorts of dishes
and maybe they have some data you could have...

however
i have seen a pasat in marx (sharp LN and it loses 2dHs about 1 hour before a famaval less than 500m away
i have seen a pasat in la drova (invacom quad) and it loses 2dHs about 3 hours before a famaval less than 1km away
i have seen a pasat (invacom twin) in oliva and it keeps 2dHs about 1/2 hour after a famaval in the area.
even fam dishes with the extention panels only hold the 2dhs in for 1/2 to 1 hour longer...(but do keep the 2dvs in much longer than those without)

and, even though it is a strange point to mention, i prefer the famavals over the pasats, due to the way they mount onto the stand. the fams clamp and grip onto the stand, whereas the pasat are hold on by 4 (or 6?) bolts screwed pressing onto the stand...

 

[Salva]

I have a Prolink 4C+, actually to measure the c/n the meter just works on the analogue domain, so it can measure say c/n up to 0.1 db (in theory), the c/n on that sense depends very much on where you take the reference level, on the 2D's is easy i tend to go on a "empty" area you just have after the last transponder.

This is what I meant, this is a measurement taken on a 80cm antenna, invacom quad offset on the transponder located in 10.906V (2Dh), this is well below digital reception but still I can measure the C/N at around 2.9-3db.

On that sense a further 4db will be needed, if a 80cm antenna has a gain of say 39dbi and a 1.80 has a gain of 45dbi installing a 1.80 antenna will increase my C/N in 6db which will be enough. I have taken this measurements at 18:00. This is how I judge if a increase in size makes sense or not.

 

[Salva]

however
i have seen a pasat in marx (sharp LN and it loses 2dHs about 1 hour before a famaval less than 500m away
i have seen a pasat in la drova (invacom quad) and it loses 2dHs about 3 hours before a famaval less than 1km away
i have seen a pasat (invacom twin) in oliva and it keeps 2dHs about 1/2 hour after a famaval in the area.
even fam dishes with the extention panels only hold the 2dhs in for 1/2 to 1 hour longer...(but do keep the 2dvs in much longer than those without)

and, even though it is a strange point to mention, i prefer the famavals over the pasats, due to the way they mount onto the stand. the fams clamp and grip onto the stand, whereas the pasat are hold on by 4 (or 6?) bolts screwed pressing onto the stand...

I guess in the end this will be down to mechanical preference rudder than performance preference.

I see that there is dispersion in performance even within the same brand of antennas, prices are similar as I am seeing.

 

[Huevos]

this is well below digital reception but still I can measure the C/N at around 2.9-3db.

Ok, I see what you mean now, you are comparing background noise level between transponders with the transponder peak. You've got a few things working against you though, like the signal in the opposite polarity, and that you don't know what the noise level is in the peaks just because noise on an adjacent frequency is lower.

fam dishes with the extention panels only hold the 2dhs in for 1/2 to 1 hour longer...(but do keep the 2dvs in much longer than those without)

What are you saying? Do you really mean a 3.1 dish loses the verticals? I've not even heard of a 2.4 that won't receive the verticals 24/7 unless it is not aligned.

Also, just bolting on the extender panels isn't going to do much unless you change the feedhorn, or have an adjustable one that will correctly match the lower f/d ratio of the extended dish.

 

[pipino]

i even get the 2D Verticals 24/7 with a channel master 1.80 ,i´v always been against 3.10 famaval´s extention panels ,to many pieces would def make some loses

 

[woborny]

I've not even heard of a 2.4 that won't receive the verticals 24/7 unless it is not aligned.
.

thats not in all all cases but in some extreme cases where I have tried the extentions to try and improve reception....you need to see where some companies have installed the dishes that i have visited......where the "line of sight" is obstructed by trees (which have grown since install), houses (new builds and old) or even mountains (bit obvious that if you are in its shadow for most of the am until late afternoon then reception may well be a bit tricky!)

 

[park_gate]

I have a Prolink 4C+, actually to measure the c/n the meter just works on the analogue domain, so it can measure say c/n up to 0.1 db (in theory), the c/n on that sense depends very much on where you take the reference level, on the 2D's is easy i tend to go on a "empty" area you just have after the last transponder. Diferent reference frecuency can give give you sligtly different c/n, in my personal experience anything below 6.5db will not be receivable by any receiver, from there to 7.5db will depend on the receiver and from 7.5-8db will be picked up by any receiver.

Could you please confirm if you know if the c/n get worse because the carrier gets weaker rather than the noise getting stronger?

The reason I ask is I've noticed BBC2 has a stronger signal than BBC1 in the early evening but a poorer signal quality. I was wondering if what was happening was an increase in 2A or 2B signals causing intermode interference?

Terry

 

[Huevos]

I was wondering if what was happening was an increase in 2A or 2B signals causing intermode interference?

Terry

2A/B signals are not present. Those are hi band. BBC2 is lo band. BBC2 can't be swamped from hi band because the LNB is in lo band mode.

 

[park_gate]

2A/B signals are not present. Those are hi band. BBC2 is lo band. BBC2 can't be swamped from hi band because the LNB is in lo band mode.

Not true as the front end will see everything. The Lo band and Hi band are after the mixer (see diagram below).

Non linearities in the LNB front end will cause intermediation products such as the following:

[FONT=&quot]10773 BBC2 England .....2 x 11662 - 12560 = 10764
10773 BBC2 England......2 x 11720 - 12643 = 10797
10803 BBC2 Wales.........2 x 11261 - 11720 = 10802
10714 Film 4...................2 x 11662 - 12607 = 10717[/FONT][FONT=&quot]
[/FONT]
I only have the meter built into a sky box which shows the signal strength and quality falling for 2D thought the afternoon and evening.

I don’t trust the signal strength indicator in the box and believe it will go down if the noise floor goes up.

Does anyone with a decent spectrum analyser know if the noise floor is going up or the signal strength is going down or a combination of both?

It would be interesting to know what 11662, 11720, 12560 and 12643 are doing.

Terry

[fieldset=Admin]please upload to our server do not link to another[/fieldset]

 

[Huevos]

Not true as the front end will see everything. The Lo band and Hi band are after the mixer (see diagram below).

Non linearities in the LNB front end will cause intermediation products such as the following:

[FONT=&quot]10773 BBC2 England .....2 x 11662 - 12560 = 10764
10773 BBC2 England......2 x 11720 - 12643 = 10797
10803 BBC2 Wales.........2 x 11261 - 11720 = 10802
10714 Film 4...................2 x 11662 - 12607 = 10717[/FONT][FONT=&quot]
[/FONT]

Do you really believe the first harmonic intermod products are going to be stronger than a 70 dBuV on band signal?

I only have the meter built into a sky box which shows the signal strength and quality falling for 2D thought the afternoon and evening.

The meter built into the box is on 11778V, i.e. Astra 2A North beam. It is nothing to do with 2D.

I don’t trust the signal strength indicator in the box and believe it will go down if the noise floor goes up.

Why do you believe that?

Does anyone with a decent spectrum analyser know if the noise floor is going up or the signal strength is going down or a combination of both?

I've got a spectrum but it depends what you mean by decent. Signal level drops. No noticeable change in the noise floor.

It would be interesting to know what 11662, 11720, 12560 and 12643 are doing.

11622 is on Eurobird 1. Pretty weak here. Requires a well aligned 80cm dish here for solid reception. On a 2.4 dish it is already 3dB down due to the alignment error (if the dish is aligned to 28.2).
11720 is a strong south beam transponder.
12560 is on Eurobird 1. It's a vertical transponder so would not interfere.
12643, again another weak, off axis signal from Eurobird 1.

 

[park_gate]

Do you really believe the first harmonic intermod products are going to be stronger than a 70 dBuV on band signal?

I believe it is possible for two strong signals to mix in the front end and generate a smaller 3rd order intermod signal which is similar in amplitude to the weak 2D signal. It doesn’t have be larger just similar in amplitude to interfere with the 2D signal.

Invercom quote a 3rd order O/P IP > 15 dB. I assume that’s a typo and should be 15 dBm. If I had the figures I could do the calculations to see if it could cause a problem.

What does the 70 dBuV correspond to? Is that the strength of the 2D signal at the output of the LNB? What is the strength of the south beam signals?

The meter built into the box is on 11778V, i.e. Astra 2A North beam. It is nothing to do with 2D.

If you go into the installers hidden menu you can do a manual tune and a signal strength test for any of the transponders. I’ve found it very effective for aligning dishes or though for fine tuning it’s best to look at a picture just as it is starting to pixilate and adjust for minimum pixilation.

Why do you believe that?

If you change the FEC the signal goes away which is clearly nonsense. I believe the signal strength meter is more like a carrier to noise measurement.

I've got a spectrum but it depends what you mean by decent. Signal level drops. No noticeable change in the noise floor.

Ok so it looks like there isn’t a significant change in the south beam power.

Is there any difference between the noise floor between the horizontal and vertical polarisations?

11622 is on Eurobird 1. Pretty weak here. Requires a well aligned 80cm dish here for solid reception. On a 2.4 dish it is already 3dB down due to the alignment error (if the dish is aligned to 28.2).
11720 is a strong south beam transponder.
12560 is on Eurobird 1. It's a vertical transponder so would not interfere.
12643, again another weak, off axis signal from Eurobird 1.

So apart from the 12560 signal what is the level of these signals? Are they still strong enough to cause a problem?

Terry