AGC constant at 79% on all channells

[davidcmadrid]

Captain Jack ..last week on a 1.2m dish i got C+ Liga etc on Astra 1F ( 19.2e ) etc at 99 - 100% SNR ( which frankly I would expect ) now I get 1F at anything between 50 and 75% depending on the channell / TP . The AGC had been down around 30% and i still got SNR 99%. In any case the AGC up untill yesterday varied and had a different value on differing tps



This is seperate to the loss of 2F on the smaller dish ( though on that point down the road , its still being recieved with a 1m dish ) again pointing to something having gone wrong.

The question therefore is if the tuner can somehow partially fail . If the AGC varied as it had done up untill yesterday i would automatically assume something was wrong with the dish / lnb / cable and wouldnt suspect something wrong with the tuner itself.

[davidcmadrid]

Ok. I found the problem, I decided to eliminate anything dish and feed related from the equation, the first thing I took out of line was the Spaun amplifier I had installed at the antenna site ( i have a long cable run ) ... i just put a double female in , in its place and all problems were resolved. Trusts my " trusty " vu+ ( original ) was not letting me down at all. Im sorry I didnt do this trouble shooting before posting but the AGC ( and random " tune failed " message threw me a curve ball , its now varying as it was before so every symptom related it seems to the blown amp.. Thank you all for your willingness to help and offer advice , its a great community and hopefully some day I can give back to it as you have tried to help me.

Incidentally in relation to 2F i can say that its the strongest I have seen it in Madrid ( even before the amp blew ) so either that amp was only holding things back or Madrid has benefited from the change. ( SNR 55% on a 1.2m motorized )

[Rob van der Does]

Thanks for letting us know!

[manicscrewdriver]

I'm assuming here that its a powered amp your are talking about

If you need to replace the amp i can strongly recommend a Vision one. I do believe they are branded as Terra outside of the UK.

Before you condemn the Spaun amp, have you tried turning it down a bit. If the amp is set to high it will cause clipping of the signal and the MER (modulation error ratio) readings will become unacceptable.

In other words it will wreck the signal quality.

[davidcmadrid]

Thanks ,it was an inline amp , its toast ..as it turns out its not needed. The system was designed for fringe reception but it was overkill for the run of coax involved ( apparently ).

[manicscrewdriver]

Alls well that end well them

[Rob van der Does]

I can't see any amplifyer doing a good job anyway, as both noise and signal will be amplified equally.
Only in case of very long feeds an LNB with build in amp might be worth a try (Inverto has those).

[manicscrewdriver]

As the guy who trained me all those years ago always used to drum in to me, only amplify the signal if it a good clean one. If you get a poor signal and amplify it it will just be a stronger poor signal.

Or as he put it. You can't polish a turd. Doesn't matter how much you polish it, its still a turd

Nothing wrong with amplifying a signal as long as a good quality amp is used. I always used to use Fracarro inline amps, although i always found it cleaner if you used a powered amp rather than an in line one.

Nano

[twol]

Incidentally in relation to 2F i can say that its the strongest I have seen it in Madrid ( even before the amp blew ) so either that amp was only holding things back or Madrid has benefited from the change. ( SNR 55% on a 1.2m motorized )

Yep, with the 2F UK spot beam you can see where the BBC engineers go on holiday there is a definite Southern lobe to the beam