Just Sharing This AV-Comm Polariser + Zinwell lnbf

[nelson_b]

Hi --
had a bit of spare time yesterday afternoon and can report that i,v had good results from my AV-COMM since i got it back from being machined to properly fit a l.n.b. ...
set it up on the 1.8 c.m. (6 degrees off centre) and was using the transponders at 1 west ...
7.5 db from the AFN transponder ... that,s as good as any previous setup/results .. that was with the Zinwell and also a BSC 421 (uncut)

 

[moonbase]

They are pipe clamps, they are available over here in inox. I got some spare from BES plumbing supplies in Birmingham. And yes, studding attaches it to the revolver wheel.

scopus,

Thx for the info, found them now.

Rgds

 

[John]

Well, pleasantly surprised myself this afternoon after doing some Cband comparison testing on 40.5West Circular between my existing polariser barrel / single feed combo and the new AV-Comm polariser barrel / Zinwell lnbf...... both systems capable of motorised skew & polarity change.
Tweeked for maximum performance on L &R signals using the motorised single feed lnb set-up which up to now i thought it was giving me the best i could muster ..... scan gave me 32 tp's LHC and 31 tp's RHC.
Next onto the AV-Comm barrel / Zinwell lnbf combo, tweeked for maximum performance .... this scan taken very soon after the 1st one gave ... 33 tp's LHC and 33 tp's RHC.
Using a specific test freq of 3627 LHC , single feed lnb gave 6.7dB on the analyser. Using the new Zinwell combo gave 8dB for the same frequency.
Evaluating H/V performance next on 55 & 58West for new combo.
Just a few poor camera grabs below of scan results....

 

[John]

.... a quick pic of AV-Comm/Zinwell lnbf, next thing to evaluate is to try a cone scalar again. Last time i tried one i obtained just over half a dB more on performance .... you never know when your going to need that little bit extra.

 

[aceb]

Every little counts John ;) I'll look forward to seeing your tests on 55.5 and 58 so I can compare against my systems then I'll move mine onto 40.5 and do the same on that sat.

 

[scopus]

Well, pleasantly surprised myself this afternoon after doing some Cband comparison testing on 40.5West Circular between my existing polariser barrel / single feed combo and the new AV-Comm polariser barrel / Zinwell lnbf...... both systems capable of motorised skew & polarity change.
Tweeked for maximum performance on L &R signals using the motorised single feed lnb set-up which up to now i thought it was giving me the best i could muster ..... scan gave me 32 tp's LHC and 31 tp's RHC.
Next onto the AV-Comm barrel / Zinwell lnbf combo, tweeked for maximum performance .... this scan taken very soon after the 1st one gave ... 33 tp's LHC and 33 tp's RHC.
Using a specific test freq of 3627 LHC , single feed lnb gave 6.7dB on the analyser. Using the new Zinwell combo gave 8dB for the same frequency.
Evaluating H/V performance next on 55 & 58West for new combo.
Just a few poor camera grabs below of scan results....

About time you got it working...

 

[scopus]

Every little counts John ;) I'll look forward to seeing your tests on 55.5 and 58 so I can compare against my systems then I'll move mine onto 40.5 and do the same on that sat.

Same cone is on my AC comm, and I agree with John, it gave me another half dB...every little helps....

 

[moonbase]

.... a quick pic of AV-Comm/Zinwell lnbf, next thing to evaluate is to try a cone scalar again. Last time i tried one i obtained just over half a dB more on performance .... you never know when your going to need that little bit extra.

View attachment 98830 View attachment 98831

John,

How is the bracket holding the skew motor held in place on the AV-COMM barrel?
From the photos it looks like it is bolted to the AV-COMM barrel with two allen bolts? Have you drilled and tapped the AV-COMM barrel so that it can accept a couple of small bolts?

Thx

 

[John]

John,

How is the bracket holding the skew motor held in place on the AV-COMM barrel?
From the photos it looks like it is bolted to the AV-COMM barrel with two allen bolts? Have you drilled and tapped the AV-COMM barrel so that it can accept a couple of small bolts?

Thx

It's drilled and tapped with M5's and then ground flush with the inner skimmed surface to enable the Zinwell to rotate freely. LockTight thread solution also applied to the threads for extra strength.
I'll have a look through some construction pics i took to show a bit more detail.

 

[John]

It's drilled and tapped with M5's and then ground flush with the inner skimmed surface to enable the Zinwell to rotate freely. LockTight thread solution also applied to the threads for extra strength.
I'll have a look through some construction pics i took to show a bit more detail.

This shows it a little better, not quite the finished article but you get the idea.
I ditched the original Velcro coupling idea as it wasn't firm enough and went for drilling and tapping the Zins back plate with 3.5mm counter sunk screws. The back plate was removed first, peeled back the black absorber pad and very accurately located the centre point to drill and tap the metal coupling wheel to the servo motor. Re-fit absorber pad & carefully realign the Zins back plate to get true circular motion with no drift ..... easier said than done.
The gaps in the metalwork were filled in with "GripFill" for added strength.
I removed about 1mm in total from the Zins O/D to enable a good clearance for it to rotate without snagging and also coated the surfaces with Teflon white spray grease to assist rotation and also a small degree of water ingress protection. I intend to fit a top cover over the workings for extra weather protection.
I wasn't a big fan of lnbf's before but this Zinwell lnbf / AV-Comm barrel is really performing well, highly recommended.
PS: I built up the small area of exterior skimming at the back end with about four or so layers of aluminium sticky back tape to get the back end of the barrel all one size.

 

[John]

.... just gets better.
Having used a simple Cband cone scalar in the past yielding an improvement over the conventional Titanium stepped cone scalar, i had a bit of time today to quickly swap out scalars on the AV-Comm / Zinwell combo. There might be room for a little bit more out of it but time is short today.
A quick re-tweek to optomise illumination, and just quoting very simple results as seen on analyser and receiver quality read-out, gave me an increase of 4% from 52 to 56%, analyser up from 7.1dB to 7.6dB.
Just like the Asda add ..... "every little helps".

Few pics below to go with the words.

 

[moonbase]

.... just gets better.
Having used a simple Cband cone scalar in the past yielding an improvement over the conventional Titanium stepped cone scalar, i had a bit of time today to quickly swap out scalars on the AV-Comm / Zinwell combo. ...

John,

Did you get the cone scalar with cap from the Latvian seller on eBay, I see he has some for sale and he generally gets things to the UK quite quickly and at reasonable postage?


Thx

 

[moonbase]

This shows it a little better, not quite the finished article but you get the idea.
I ditched the original Velcro coupling idea as it wasn't firm enough and went for drilling and tapping the Zins back plate with 3.5mm counter sunk screws. The back plate was removed first, peeled back the black absorber pad and very accurately located the centre point to drill and tap the metal coupling wheel to the servo motor. Re-fit absorber pad & carefully realign the Zins back plate to get true circular motion with no drift ..... easier said than done.
The gaps in the metalwork were filled in with "GripFill" for added strength.
I removed about 1mm in total from the Zins O/D to enable a good clearance for it to rotate without snagging and also coated the surfaces with Teflon white spray grease to assist rotation and also a small degree of water ingress protection. I intend to fit a top cover over the workings for extra weather protection.
I wasn't a big fan of lnbf's before but this Zinwell lnbf / AV-Comm barrel is really performing well, highly recommended.
PS: I built up the small area of exterior skimming at the back end with about four or so layers of aluminium sticky back tape to get the back end of the barrel all one size.



View attachment 98837

That's a cracking good improvisation, thx for the close up pics.

If you do get the opportunity to compare the AV-Zinny combo with cone scalar vs the Titanium with hooded scalar on a C band 8PSK frequency I would be most grateful. Preferably something where the signal is just above lock on the weakest performer combo.

Thx

 

[John]

John,

Did you get the cone scalar with cap from the Latvian seller on eBay, I see he has some for sale and he generally gets things to the UK quite quickly and at reasonable postage?


Thx

Yes mate thats the guy, goes under the name "ehead".
He's pretty quick and reliable, had a few things off him now.
I'm going to drop him a line to see if he can make a cone that has a larger dia so as to fit over the AV-Comm barrel etc..... i have had to make a kind of adapter collar to mate the two together. At the moment they are 64.5mm so need something around the 70mm area.

 

[moonbase]

On the subject of cone scalars for C Band, some geezer on "Sat Guys US" looks to have made a home brew mock up of one from a dog feeding bowl, it seems to do the job.

Great improvisation, food for thought perhaps?

Homemade Conical Scalar Ring


Rgds

 

[scopus]

.... just gets better.
Having used a simple Cband cone scalar in the past yielding an improvement over the conventional Titanium stepped cone scalar, i had a bit of time today to quickly swap out scalars on the AV-Comm / Zinwell combo. There might be room for a little bit more out of it but time is short today.
A quick re-tweek to optomise illumination, and just quoting very simple results as seen on analyser and receiver quality read-out, gave me an increase of 4% from 52 to 56%, analyser up from 7.1dB to 7.6dB.
Just like the Asda add ..... "every little helps".

Few pics below to go with the words.


View attachment 98847 View attachment 98848 View attachment 98849

Err, it's the Tesco advert not Asda.
Totally agree here, I get the same improvement as John...

 

[John]

Err, it's the Tesco advert not Asda.
Totally agree here, I get the same improvement as John...

Ohh I feel so silly now. I'm actually sat in Asda car park now lol

 

[Captain Jack]

I don't know if signal levels have increased or what but I am getting 6.8dB from Paksat 38E 4162V (Virtual Uni) with the polariser in place tuned for circular polarity.

 

[John]

I don't know if signal levels have increased or what but I am getting 6.8dB from Paksat 38E 4162V (Virtual Uni) with the polariser in place tuned for circular polarity.

I'll check on mine in a mo, looking at the back of the Zin, what signal readings do you get when the "F" connector is at the "20 to the hour" position

 

[John]

Rgds[/QUOTE]

I'll check on mine in a mo, looking at the back of the Zin, what signal readings do you get when the "F" connector is at the "20 to the hour" position

Nothing too spectacular signal strength wise here CJ on the AV-Zin combo, slightly overcast here in North Notts.