Recent content by ouagadougou

SHOWTIME !! I just wish I could get it here in Lagos but I need a bigger dish. Cheers.

I am absolutely sure. The best transistors on the market have 0.3 to 0.35dB Noise Figure at room temp but you will not achieve this in a working LNA/LNB because of input losses before the transistor. Most LNB's use a waveguide coupled to a microstrip input to the 1st transistor and this has...

The Invacom has a claimed Noise Figure of 0.3dB in reality this is just sales talk. It is much more likely to be between 0.6 & 0.8dB for an ambient operating temperature in air with no assisted cooling. The losses are at IF so they do not have a direct affect on the LNB input noise figure...

The whole purpose of the OMT is for dual pol transmit/receive applications so I still doubt you will find something suitable for a dual pol receive only application. Even dual pol LNB's are a compromise due to the dual probes in the waveguide to coax transition in the LNB. The Andrew devices...

That may well be (dont have 1 in front of me) but the dual pol transition has more insertion loss than a straight connection to a single LNB. VSWR does not not necessarily have any direct relationship to insertion loss and the dual pol transition definately has insertion loss. This insertion...

Its difficult to make a dual polarised solution using these rectangular flanged LNB's and maitain the low noise performance because the LNB's have Rectangular WaveguideRectangular75 waveguide ports. Single polarised low noise systems will work better. If the feedhorn has a WR75 flange then...

You could use some small mirrors 1cm square and place them on the main 2.4m reflector at various points. If you point the dish at the sun (I know this may be a problem in your case) then the reflected light will tell you exactly where the focal point is and it will show you if any part of the...

I agree with you Rolf that this is a super little meter but the one I have doesnt like low symbol rates which might be a problem in some cases. Cheers.

_www.satpimps.com apologies if this is not allowed !!

I dont think the effort is wasted mate its just times change. I am sure something similar will be back eventually. Lots of other excellent forums around including this one. Cheers.

You are going to have to look for a consensus on all 3 points from various posts. Also try to weed out the ones who push a brand/type for personal gain. Its not easy. Even the Anorak enthusiast gets variability across a batch (I have built a few LNA's at home) but thats ok if the published...

I have recently tried a DLink DI-624 and I have to say its the worst box I have ever used. Very unstable on various Firmware versions. It is the only box available here in Lagos that can do PPPoE and Wireless but it doesnt do both with stability. Wired ethernet connections are stable though...

You could buy a Spectrum Analyser add-on for your Oscilloscope that covers the IF frequency band. There have been some good home brew projects around using TV/Sat Tuners as the RF part for home made Spectrum Analysers that used Oscilloscopes as displays. Its normally quite a big home brew...

7w does vary in level a bit over 24hours.

I think publishing test results that show the variability in perfomance across a batch of LNB's of the same type is well worth doing. I personally dont believe many of the parameters published with these mass market LNB's especially Noise Figure and I think everyone else should treat them with...