- Jan 31, 2018
- Reaction score
- My Satellite Setup
50E - 30W
2x CM 1.2m Polar Mount/Jack
Gibertini 1m OP100 - STAB HH100 - Inverto Black Ultra 0.2 Twin
Edision Primo IP S2
Venton Unibox HD2
Sony Bravia 55" 4K
- My Location
- South Wales
However a motorised dish can often give a better signal over most fixed dishes, provided the fixed dish has the LNB skewed, whereas the motorised dish will always skew the dish. But all things being equal a fixed dish will be better to dial in the very last drop of signal provided you can skew it.Absolutely correct, and to be expected.
With a motorised dish it may be down to the resolution of the motor moving the dish across an arc and the accuracy of the polarity skew and declination.
For example, a v-box powering a Jaeger 1224 H-H motor generally gives just under 12 pulse counts per degree with a resolution of 1/12th of a degree per click. If a fixed dish has some type of threaded rod for adjustment of azimuth it is easily possible to get a more accurate resolution down to 1/20th of a degree depending of the TPI of the threaded rod and its securing points on a mount.
The same logic applies to azimuth and polarity skew. A fine manual adjustment mechanism should generally provide more accuracy than that automatically allocated by a dish traversing an arc powered by a motor.
I am not familiar with the resolution available using DiSEqC motors so cannot comment on their accuracy.
Does such accurate dish pointing matter, possibly not? It might only come into play when signals being received are extreme fringe and the extra accuracy might get an increase of a few tenths of a dB and achieve a lock.
Where the motorised dish comes into it's own after initial setup is the convenience, all done with a remote control or the press of a button on a receiver/controller. No messing about in the dark and rain with a spanner and a meter.
And with motorised dishes due to resolution and calculation errors (If using USALS) some satellites might be more fine tuned than others.
I have both a HH-100 with a 1m on it and a 1.2m CM with a PM and Superjack, the HH-100 is more accurate and hits the same place from both directions, the CM1.2 PM will vary in signal slightly depending on what direction its travelled to the dish, so I set the V-Box somewhere in the middle so its roughly the same signal from both directions, although that is not wringing the last bit of signal out. I can get it very slightly higher but its so minor and lowers the signal when it approaches from the opposite direction. However I am thinking of trying different magnetic wheels with more poles on the reed sensor to see if it increases usable resolution.