Just Sharing This AV-Comm Polariser + Zinwell lnbf

[John]

I got a couple of these direct Pololu - Micro Maestro 6-Channel USB Servo Controller (Assembled) They go up to 24 channels for servos + other I/O
It cost a fortune in tax etc as they sent it by Fedex.
Didn't you find somewhere selling them in the UK, John?

Edit: Found a UK link Micro Maestro 6-Channel USB Servo Controller (Assembled) | 1350 | Pololu

Yep, thats the place i got mine from.

 

[John]

Hi,

Would any of the AV-Comm guys who are up and testing please be able to carry out a test using the AV-COMM / Zinwell and compare it against a Titanium C Band LNBF for linear H/V signals? There are a few linear polarity C Band satellites out West but not much out East. A test on an 8PSK signal would be preferred rather than QPSK if that is possible?

No worries if you are all busy testing other stuff, fully understand the excitement and the need to get on with your own tests. I will try to rig something up ASAP.


Rgds

.... Just re-reading this
Do you mean to substitute the Zinwell for the TiT on the barrel and align the TiT in the barrel for H/V ...OR, use the TiT on it's own with no barrel and orientated for H/V ?. It's not you--it's me lol.

 

[scopus]

Yep, that's the baby. I don't use it in it's "automatic" mode but i think Chris (scopus) will get around to using it to it's full potential when he gets time.
It comes with a 9volt psu that is 120v only on it's primary so you will need a UK psu.

Yep the transformer that comes is useless overe here. Also be careful, some of the 9V transformers I have are not regulated and push out upwards of 15V, so make sure it is a regulated type.

 

[moonbase]

.... Just re-reading this
Do you mean to substitute the Zinwell for the TiT on the barrel and align the TiT in the barrel for H/V ...OR, use the TiT on it's own with no barrel and orientated for H/V ?. It's not you--it's me lol.

John,

My hoped for comparison is as below:

1. Titanium LNBF and scalar, no AV-COMM barrel
To test signal level on Linear polarity signal(s), preferably 8PSK rather than QPSK, even better would be both 8PSK and QPSK.

versus

2. Zinwell LNBF in AV-COMM barrel and scalar
To test signal level on Linear polarity signal(s), preferably 8PSK rather than QPSK, even better would be both 8PSK and QPSK.


Rgds

 

[moonbase]

I did matey, i forgot about those. Never did get around to implementing it.
Interesting bit of kit, especially if you like things to be PC based .... thinking about you @MB.

It looks an interesting bit of kit that is connected externally to a PC via a USB port then controlled by the PC. I am not sure how it would physically connect to the servo motor to provide power. If I could fathom out how to connect it up it does have appeal.


Rgds

 

[moonbase]

That's the one MBA and one I'll be buying soon-ish myself.

CJ,

Do you wish to consider a mini "multi buy" to try to save on postage from the USA? I can shelve the actuator order for the time being to make it a simple "multi buy" of these servo controllers?


Rgds

 

[s-band]

It looks an interesting bit of kit that is connected externally to a PC via a USB port then controlled by the PC. I am not sure how it would physically connect to the servo motor to provide power. If I could fathom out how to connect it up it does have appeal.


Rgds

Only the interface runs from the USB 5V. You supply a high current 5V (or what ever the servo needs) via the interface board then run 0V, pulse, +5v (High current) to the servo(s).

 

[John]

John,

My hoped for comparison is as below:

1. Titanium LNBF and scalar, no AV-COMM barrel
To test signal level on Linear polarity signal(s), preferably 8PSK rather than QPSK, even better would be both 8PSK and QPSK.

versus

2. Zinwell LNBF in AV-COMM barrel and scalar
To test signal level on Linear polarity signal(s), preferably 8PSK rather than QPSK, even better would be both 8PSK and QPSK.


Rgds

Understood.
Right your next mission, should you choose to accept (also to save me searching all over the place) .... is to tell me specifically which satellite / freq / polarity /channel etc you want me to attack

 

[blademedia]

John do you have the matching scalar for the polariser.

 

[Captain Jack]

CJ,

Do you wish to consider a mini "multi buy" to try to save on postage from the USA? I can shelve the actuator order for the time being to make it a simple "multi buy" of these servo controllers?


Rgds

Happy to save on any costs!

 

[John]

John do you have the matching scalar for the polariser.

Iv'e got the AV-Comm High Efficiency flat scalar BM that i used on my 2.2 Precision PF dish plus bog standard flat scalars, .... for my current 1.8 CM OS Cband feeds i use either a stepped conical or straight cone scalar. Tell me more

 

[moonbase]

Understood.
Right your next mission, should you choose to accept (also to save me searching all over the place) .... is to tell me specifically which satellite / freq / polarity /channel etc you want me to attack

John

I accept the mission but I am not sure if you will be able to receive the C Band signals, it is from 68.5 East, any of the 8PSK/QPSK from there will be OK but it needs quite a large dish. For the test, I thought that any of the satellites that carry Linear polarity C Band signals will do, provided they are receivable in the UK on the dish available to the tester, most of them are westerly.

At a quick check, 46E, 38.0E, 31.5W, 37.5W, 43.1W, and 45.0W carry Linear polarity C Band signals. Ideally, a perfect test would be a signal where both of the test setups get a lock/picture but one test setup is close to threshold. That should give me an idea of the improvement available with the best test setup. My hope is that the Zinwell/AV-COMM setup is a better that the Titanium LNBF setup by a few db.


Rgds

 

[moonbase]

Happy to save on any costs!

CJ,

I will create a "mini group buy" topic to see if any other forum members wish to order the APC from Ricks, if they do then hopefully it will reduce shipping costs further.


Rgds

 

[John]

John

I accept the mission but I am not sure if you will be able to receive the C Band signals, it is from 68.5 East, any of the 8PSK/QPSK from there will be OK but it needs quite a large dish. For the test, I thought that any of the satellites that carry Linear polarity C Band signals will do, provided they are receivable in the UK on the dish available to the tester, most of them are westerly.

At a quick check, 46E, 38.0E, 31.5W, 37.5W, 43.1W, and 45.0W carry Linear polarity C Band signals. Ideally, a perfect test would be a signal where both of the test setups get a lock/picture but one test setup is close to threshold. That should give me an idea of the improvement available with the best test setup. My hope is that the Zinwell/AV-COMM setup is a better that the Titanium LNBF setup by a few db.


Rgds

Mission Impossible Control reporting back .... Can't do 68.5 East due to next door's house gable end. All the other Eastern sats you quoted are ok and all West sats are ok up to 65W.
I'll bookmark the mission for when i get the barrel/Zinwell combo up on the changer and then we will go for it. At the moment there are three different Cband configs on the changer plus the Ka stuff and there just 'aint no more room

 

[aceb]

38E would be a good choice, marginal signals, mix of signal types and high enough above the horizon to minimise any ground noise effects.

 

[John]

38E would be a good choice, marginal signals, mix of signal types and high enough above the horizon to minimise any ground noise effects.

Thanks for that @aceb

 

[scopus]

First taste of linear, Virtual University off Paksat at 38E..........
The orbital postion needs correcting on my receiver

 

[John]

Hi,

Can anyone please tell me why the AV-COMM barrel has been skimmed at both ends? I can see the reason for one end to allow the scalar to fit but cannot see why the other end that the Zinwell LNB slides into was skimmed? Is there a use for the LNB end being skimmed that we are not aware of?

Thx

... I have the answer from the horses mouth now.
It's purely as an aid to doing the larger amount of skimming on the rest of the barrel.
Apparently the barrels are "Sand Cast" and that small section is machined off first so as to give the skimming lathe an accurate base to work from to complete the larger skimming jobs.

I'm seriously thinking about having a 1mm skim took off the whole outer surface of the barrel .... would add a nice finishing touch to it ??

 

[Captain Jack]

I quite like the "AV Comm" logo on it, actually.

The combo continues to impress. Blind scanned 40W with TBS5925 - 63 transponders locked with 283 services, with signal levels between 0.5db and 3db(!) higher than my last scan ...and this is on a gray, damp morning.

 

[moonbase]

...I'm seriously thinking about having a 1mm skim took off the whole outer surface of the barrel .... would add a nice finishing touch to it ??

John,

If done in a lathe, it might look a bit odd around the AV-COMM logo, you would end up with smooth shiny skimmed areas either side of the logo then a shiny skimmed logo then a grey gritty cast band around the barrel within the logo length. Unless of course you completely skimmed off the logo to get to a smooth cylidrical barrel? The logo seems to be approx 2mm high?

I like the logo, it gives the unit "respect".

Rgds