A not very scientific Comparison Test

[Vipersan]

Last Week Nelson loaned me a Zinwell ZCF-D21B to play with ..
So today I popped out the ESX241 that deals with linear on Cband (Christina)
Keep in mind this lnb is about 3 degrees offset from focus ..
I chose for the Test the only transponder I can currently lock at 37.5W - Silverbird ..
First checked that it was locked solid ..which it was at around 8.7db ..
Then swapped it out with the Zinwell ..
Also take note I cannot change the feed rings nor adjust these as the plate is fixed and cut to allow close grouping on the other lnbs ..
So ...a straight swap ...positioning the Zinwell to exactly emulate the ESX position wise ..
Well ..
Nelson was right ...the gain had increased and was reading 9.5 on the F15 ..
BUT ...the signal was breaking up all the time and would not lock solid ..
So I'm assuming a higher S ...but lower Q ...
I'm not well enough atm to stay up ladders for long ...so swapped back to the ESX which again provided a solid lock ...of Silverbird but try as I might I could not get the Sig level above 8.7 ..
It may well be that more playing around with the Zinwell might well be effective ...but for now remains a curiosity ?
Higher gain ..but lower Q ...OR instability ?
I may well invest in one of these shortened stubby lumps to play with next year ...
possibly on Carl ...who is more accessible ..
It may be these shorter lnb feeds which do seem to have a greater capture range for signal...
ie wider acceptance angle...may be better suited to Offset dishes..
rgds
VS

 

[s-band]

Phase noise?

Try it on a beacon or other CW signal, looking narrow band on an SDR. Otherwise, X polar or something from an adjacent sat? No time to play at the moment so I've not tried my Zinwell yet.

 

[nelson_b]

Last Week Nelson loaned me a Zinwell ZCF-D21B to play with ..
So today I popped out the ESX241 that deals with linear on Cband (Christina)
Keep in mind this lnb is about 3 degrees offset from focus ..
I chose for the Test the only transponder I can currently lock at 37.5W - Silverbird ..
First checked that it was locked solid ..which it was at around 8.7db ..
Then swapped it out with the Zinwell ..
Also take note I cannot change the feed rings nor adjust these as the plate is fixed and cut to allow close grouping on the other lnbs ..
So ...a straight swap ...positioning the Zinwell to exactly emulate the ESX position wise ..
Well ..
Nelson was right ...the gain had increased and was reading 9.5 on the F15 ..
BUT ...the signal was breaking up all the time and would not lock solid ..
So I'm assuming a higher S ...but lower Q ...
I'm not well enough atm to stay up ladders for long ...so swapped back to the ESX which again provided a solid lock ...of Silverbird but try as I might I could not get the Sig level above 8.7 ..
It may well be that more playing around with the Zinwell might well be effective ...but for now remains a curiosity ?
Higher gain ..but lower Q ...OR instability ?
I may well invest in one of these shortened stubby lumps to play with next year ...
possibly on Carl ...who is more accessible ..
It may be these shorter lnb feeds which do seem to have a greater capture range for signal...
ie wider acceptance angle...may be better suited to Offset dishes..
rgds
VS

Hi .. V.s
Did you try any other transponders ? never had any effects like that on the one i,m using on the 1.8 offset .. just better linear signal levels .. no breakup issues ... the one i left with you is brand new and has not been on a dish before ... always the chance that the l.n.b has a fault
cheers ....

 

[John]

My dish is chained down flat at the mo VS because we were supposed to be having strong gale force winds last night and today here in North Notts but it has been as still as a millpond !.
Once i know it's safe to get back up i'll have a look at that sat & frequency with my Zinwell and another single feed lnb for comparison and report back ;)

 

[scopus]

Ok here on the CM 1.8 along Hip TV, no break up..
Possibly as you say VS, better suited to an offset dish??

These are taken off the Cheapo Openbox V8S, must say for the money they are great, ain't much this box has not found using the accurate blind scan.

 

[Channel Hopper]

Higher gain ..but lower Q ...OR instability ?
VS

Almost certainly a stability issue, but there is a small chance the additional gain into the front end of the tuner is causing the loss of lock.

If you have a spectrum readout that goes outside the full band you could see if the cut off filters at each end are defective, or even if the manufacturer has got rid of the lower pass circuitry completely.

 

[Vipersan]

If I get chance I'll re-fit the Zinwell ...but chances are I'll be buying one of my own before long ..
An interesting and curious beast ..and a must for my collection ;)