Just Sharing This 2.2mtr Elite / Precision resurection... Part 2.

[John]

... dish cam now up and running but installation chained and roped down due to winds getting a bit frisky so no final feed adjustments until it settles down a bit.
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[nelson_b]

Superb job done ....

And yes its much to windy for big dishes today ...

 

[John]

This Norsat 8000RI turned up today to try on the 2.2 and evaluate between a JRC dedicated 4.5 - 4.8GHz lnb.
For anybody in the UK wondering what the cost would be to import one of these iv'e included some information .... Customs etc.
The unit was obtained from Max at eSatcom.com, Jamaica New York, with very speedy turnaround and excellent communications at a cost of £165.27 inc vat, shipping & PayPal fee.
Total cost = £210.06


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[Huevos]

What are you hoping to receive?

 

[John]

What are you hoping to receive?

It's more of a convenience thing on this 2.2 reflector, I haven't got the lnb changer option to change from a 3.6-4.2 lnb over to a 4.5-4.8GHz lnb so this is a bit of an exercise to evaluate if an all in one 3.6 to 4.8GHz Cband lnb gives acceptable performance.
>What are you hoping to receive?[/QUOTE]< the same as what i see now from 40.5° West & 65° West only with a bit more reflector gain from the 2.2 mtr, plus anything else that might turn up across the arc whilst scanning for new stuff. I'm not expecting any great leaps in acquiring or locking any more content because the reflector really needs to be bigger but there's the thrill in the chase to be had even if the found signal can't be locked..... that's when i hand it over to Feedsat or qwer to tell me what it is lol. Future 4.5 - 4.8 GHz downlinks might be possible ?. If you don't try-you don't get

 

[John]

This Norsat 8000RI turned up today to try on the 2.2 and evaluate between a JRC dedicated 4.5 - 4.8GHz lnb.
For anybody in the UK wondering what the cost would be to import one of these iv'e included some information .... Customs etc.
The unit was obtained from Max at eSatcom.com, Jamaica New York, with very speedy turnaround and excellent communications at a cost of £165.27 inc vat, shipping & PayPal fee.
Total cost = £210.06


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View attachment 104985 View attachment 104986

And for the curious amongst us , this is what they look like inside.

** A rudimentary hook up to a signal source of 3550 GHz, it still produces a usable output according to the Promax
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[moonbase]

And for the curious amongst us , this is what they look like inside.

** A rudimentary hook up to a signal source of 3550 GHz, it still produces a usable output according to the Promax
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View attachment 105015

It looks well made, robust and sturdy for sure.

Rgds

 

[John]

... had an hour or so re-furbing an old single choke scalar to try on the 2.2. Cut down a cheap scalar ring to attach to it to enable adjustment and fixing to the AV-Comm barrel.
** @blademedia ... I also found the original front waveguide section of it before it got removed and it seems to have sat about 7mm down from the front edges of the scalar ring.
Just about all prepped - needs a coat or two of paint now.

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[blademedia]

... had an hour or so re-furbing an old single choke scalar to try on the 2.2. Cut down a cheap scalar ring to attach to it to enable adjustment and fixing to the AV-Comm barrel.
** @blademedia ... I also found the original front waveguide section of it before it got removed and it seems to have sat about 7mm down from the front edges of the scalar ring.
Just about all prepped - needs a coat or two of paint now.

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Thanks John. i will pick a few parts up for it, will be interesting to see how it performs,

 

[John]

... had an hour or so re-furbing an old single choke scalar to try on the 2.2. Cut down a cheap scalar ring to attach to it to enable adjustment and fixing to the AV-Comm barrel.
** @blademedia ... I also found the original front waveguide section of it before it got removed and it seems to have sat about 7mm down from the front edges of the scalar ring.
Just about all prepped - needs a coat or two of paint now.

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... Although it's been raining heavily and pretty cold last night i decided to have a look at optimising the feed with correct placement of the scalar ring. The conventional shaped one was pretty easy to do but the single choke one gave way to a bit of a surprise. Using 53° East- 3675 RHC using either scalar gave me 13.6dB C/N on the Promax which was about a 3dB increase or so from what was obtained off the 1.8 CM. Completely removing the scalar, as in the pic, the C/N went up to 15.1 dB. Performance checks over the arc on known previous performances off the 1.8CM showed substantial improvement so left it running like this for the time being.
I'll look into this a bit more when it warms up a bit outside.
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[s-band]

And for the curious amongst us , this is what they look like inside.

Thanks for the pic, it's very interesting. It seems that the LO is completely separate. It looks like it would be simple and safe to feed an external (PLL) LO. I wonder why they don't make a PLL version.

 

[moonbase]

...Completely removing the scalar, as in the pic, the C/N went up to 15.1 dB. Performance checks over the arc on known previous performances off the 1.8CM showed substantial improvement so left it running like this for the time being...

John,

I noticed something similar using a Precision 1.5m on 10E. I got a marginally higher signal level without the flat scalar being in place. However, as I was using only a 1.5m dish and was struggling a little to get some signals I just put it down to the fast that the marginal gain was from having more dish surface area due to no shadow from the scalar.

With a 1.5m dish on C Band there might be more impact from scalar shadow. However, on a Precision 2.2m dish, the scalar shadow is lower impact in terms of dish surface so your observations are a lot more valid than my quick bodge setup on a 1.5m.

Rgds

 

[John]

John,

I noticed something similar using a Precision 1.5m on 10E. I got a marginally higher signal level without the flat scalar being in place. However, as I was using only a 1.5m dish and was struggling a little to get some signals I just put it down to the fast that the marginal gain was from having more dish surface area due to no shadow from the scalar.

With a 1.5m dish on C Band there might be more impact from scalar shadow. However, on a Precision 2.2m dish, the scalar shadow is lower impact in terms of dish surface so your observations are a lot more valid than my quick bodge setup on a 1.5m.

Rgds

I'll look into it a bit more MB, that reflector installation is approx 15 feet off the ground and i'm wondering if that, along with a very cold ground temp is not producing any or much ground noise around the reflector edge ? ... might change a bit when the temperature rises ?. Perhaps if the phase spot is slightly more into the barrel throat then the front rim of the barrel might be operating as a bit of a scalar function ?. It would be a bonus if i can manage to run without a scalar, i want to strap an Inverto Ka/Ku lnbf directly onto the AV-Comm barrel directly underneath for a bit of a test.

 

[moonbase]

John,

Your comment about the barrel throat possibly acting as a partial scalar would equally apply to an LNBF such as a Tit or Zinwell without a scalar. You could be busy testing out variables.....

It would be interesting to see what "blademedia" observes with the 2.4m DH antenna if the opportunity was there for a with/without scalar test?


Rgds

 

[blademedia]

Come on guys, what's this trying to tell you ;)

 

[John]

Come on guys, what's this trying to tell you ;)

Errrrrrrrrrrr, gimme a clue

 

[moonbase]

Come on guys, what's this trying to tell you ;)

We dont need scalars for C band with big prime focus antenna with low F/D ?
Is it related to narrow beamwidth and low F/D ?

It can't be a gain from less shadow on the dish with the scalar removed in the case of John's 2.2m, the shadow impact is negligible compared to the surface area?

Is the flat scalar somehow partially blocking the periperal contribution to the illumination of the LNB feed point? The more central dish face illumination to the LNB feed is OK but the outer edge illumination to the LNB feed is reduced with the scalar in place?


Rgds

 

[scopus]

I'll look into it a bit more MB, that reflector installation is approx 15 feet off the ground and i'm wondering if that, along with a very cold ground temp is not producing any or much ground noise around the reflector edge ? ... might change a bit when the temperature rises ?. Perhaps if the phase spot is slightly more into the barrel throat then the front rim of the barrel might be operating as a bit of a scalar function ?. It would be a bonus if i can manage to run without a scalar, i want to strap an Inverto Ka/Ku lnbf directly onto the AV-Comm barrel directly underneath for a bit of a test.

Have you tried that cone scalar? You know the one from that guy in Poland...might be worth a punt.

 

[John]

Have you tried that cone scalar? You know the one from that guy in Poland...might be worth a punt.

Nope, but i'll try 'owt once

 

[Llew]

Nope, but i'll try 'owt once

Except incest and Morris Dancing as the man said (hopefully).