MMDS Set-up Complete Beginner

I can try to get a loan of an original dreambox 600T from a friend to check the BER. I assume the tuner on the 600T is as good as that on the 500T.

Maybe a stupid question, but what is the gain on a standard ch0ru$ mesh? In other words, if I move to a 24 db lance grid am I simply improving the quality of the grid or am I getting extra "gain"?

Well, I get a signal, but it comes and goes. Steady for 20 to 30 seconds - then all pixelated. Would this be an indication that I'm at the fringe of the signal threshold? I can source a 21 dB gain or 27dB gain ariel from sat&cable. Which would you recommend. Again, thanks so much for all the help.

 

Hi ,

I wouldn't just yet go buying an new aerial .Try a booster and if your still getting the problem maybe just adjust the aerial direction it could be out just a fraction.

 

The distance between the power inserter and my box is only 3 feet, so I assume it would be pointless putting a booster in there.

Im no expert, but I would be slow to insert a booster between the downconverter and power inserter. The cable is carrying a signal in 1 direction and power in the other direction. Aren't most boosters one-way amplification? Have you done this yourself or is it just an idea?

How precise does the direction have to be? I have tweaked it so many times now and still have had no luck. The highest signal strenght I have got on my eurovox-tx are:

level: 85%
quality: 55%

Do these seem ok? Do I need to reach a certain percentage in either of these for a steady picture?

 

A booster simply amplify the signal and should be placed between power inserter and TV.
Maybe a booster can help in your situation, maybe not.
If you can get an good one its worth a try.

 

A "booster" amplifies both signal and noise. But it also adds its own electrical noise, so the end result is always a worse "signal to noise ratio". That may not matter, provided that the original signal had minimal noise to begin with. But a noisy signal will be even more noisy.

The best place to boost a TV signal is near to the aerial because the coaxial cable picks up noise on the way down. The signal is "cleanest" near the aerial.Hence if its traveled a long way and then you place into a booster it will amplify any noise its picked up

But as said before the quickest and cheapest way i'd proceed would be to by an adjustable amplifier , place it close to the tv and tweak the level up or down and i think this may work for you. If it doesnt then place it close to the aerial where i suggested and if that doesn't work its a matter of adjusting alignment and or attempting to capturing more microwaves and reflecting them correctly on to the dipole by using differing antenna shapes .

I hope the simple booster works for you

 

Hi Jimme,

I had a the exact same thing happining to me,

turned out the power insiter i was using was only putting out 100mA bought one of the ones from s&c with 350mA output and bingo worked perfect ever since...

Hope this helped...

 

The line between psu and downconverter carry the electrical power for the downconverter.
Its not a good idea to break that connection with a booster.
Btw ground noice will be always amplified from a booster and if there is a good cable in use there is not much chance for picking up additional noise. The noise generated from the booster will be always added independently where the booster is placed.

 

Thanks wiseguy,

The power inserter I'm using came from Sat&Cable. It reads Output: DC 18V 0.3A

So I guess thats not the prob

 

I'll buy a booster tomorrow and give it a go. But as I say the length of cable from the power inserter to the eurovox-tx is only about 3 feet. My understanding was that a booster is designed to amplify a signal over a long length of cable. So I would guess that it will not help me.

 

best of luck and hope it works

 

@Jimme
A amplifyer simply higher the signal strength. If you place an booster at the beginning of a cable run you will get a higher end result because every meter cable eat up signal strength. If you use a good cable there is not so much difference for normal distances if you place the booster at the end.
Your problem could be that the signal strength is near the border between good and bad and a boost could bring the signal into a range your tuner can handle without problems.

 

The Lance 24db grids are very good.
I dont know the exact gain of the Chorus grids ,they vary in size and gain.
Do you have a mesh type grid ?
If you connect the 600T it will tell you alot .
On a dreambox the signal strength should be around 98-99% for a good signal.
BER should ideally be 0 but as long as its <10k it should be stable.
I've seen a few faulty downconverters (Panorama) where the snr drops like you describe every 30 secs or so for a few secs .It could be faulty.What make is it ?
I'm unsure if a booster will make any difference but its prob worth a shot.
The Konig yellow brick booster is supposed to be very good but it might be too strong ,MGB would know better.
Keep at it.

 

Hi Jimme,
I see you are in Cork.Whereabouts ? If you want i may be able to lend you one of the YAGI Integrated aerials, as sold by most of the web sites. I have found them very good, despite the fact that they are not particularly well built.
In fact, for my own install one of these aerials is getting me quality reading of ~75% from a transmitter 30 miles away.From my experience a quality reading of ~ 60% would be sufficient to give you a steady picture.
PM me if you want.

gLog

 

Just tried an adjustable amplifier/booster between the power inserter and box. No luck The level and quality bars didn't move at all.

What is the maximum recommended length of cable from the downconverter to the power inserter? Maybe thats my problem, but I don't want to go breaking the cable unless it might help. Thanks

 

Thanks GLog,

Thats a very generous offer. I hadn't even considered a YAGI. I thought that a lot of people had problems with them.

Are they that good? I'm in East Cork, I recon about 12 or 13 miles from the transmitter (or beam bender). Anyone else able to confirm that have had as much success with a YAGI?

Might get a YAGI or Lance Grid. Any reasons why I should get one over the other? Thanks everyone.

 

Ya, I am using an old ch0ru$ mesh type grid. Would a 24db Lance grid be much of an improvement? How would a YAGI compare (if you've any experience of using one)?

... will give this a go as soon as I can get a loan of a dreambox.

I think it could be a "Panorama" but I will need to check.

Booster didn't seem to help

 

Which booster and which downconverter do you use?
The normal boosters for TV have a gap between 230mhz and 470mhz and doesn't help much for ch*rus downconverters which if214 or if222.

 

i've got both. 24db grid are miles better compare to yagi one

i think it is not just faulty downconverter, but some dreambox (driver)issue aswell
had this issue myself (at the same time usb dvb-t stick worked perfectly, while dm600t dropped snr)- so, i had to switch to PLI lolite image( never had a snr drop after that)
i had to change terrestrial.xml aswell: 674000000 to 673800000 and so on ( wasnt able to scan any transponder with normal settings)

 

Just got a loan of a Dreambox 600T. Here are my settings and levels in the manual scan screen:

Frequency: 714000 KhZ
Inv: Not Checked
Constellation: 64-QAM
Guard: 1/32
Bandwidth: 8MHz
Transm Mode: 8k
Coderate LP: 2/3
Coderate HP: 2/3
SNR: Jumps between 97% and 98%
AGC: 53%
BER: Constatly moving between around 150,000 and 400,000
Lock: X
Sync: X
Use ONIT: Not Checked
Use BAT: Not Checked
Only Free: Not Checked
Network Search: Not Checked

The BER keeps changing but is well over 10K. Any idea if this would this indicate a problem with my grid, downconverter or cable?

 

the ber reading indicates that your received signal is full of errors, sounds like a mis aligned aerial to me , recommend you get some one with a tv meter to point the aerial