Newsnet on Ka Band A

[John]

Calibrated Spectrum in KA-Band A with self-modified GILAT LNB .

I also exchanged the quartz in 27 MHz.

regards

... did you take any pictures of the modded Gilat through the stages of work - would love to see them.

 

[dreamsat]

Hey John,
I tested the first time today. When it is dismantled I take pictures.

regards

 

[dreamsat]

1. Qarz is replaced by 27 MHz
2. Steam the filter
3. Install the SMA socket and attach the F adapter
4. Make the flange

Big thanks to Graham for the support

 

[John]

1. Qarz is replaced by 27 MHz
2. Steam the filter
3. Install the SMA socket and attach the F adapter
4. Make the flange

Big thanks to Graham for the support

Thanks for that, nice work. Graham (sband) was my inspiration as well with modding Gilat ODU's and helped me out a lot.
I have modded one for Band D and after a bit of careful scalar feed matching to my Gibby 1.2 found it to be a better performer than the stock Inverto Ka/Ku unit that is also being used. I did try a wr42 90°angle transition coming off the Gilat so as to make the whole unit more suitable to be made motorised for H/V use but the matching was poor and performance suffered.

 

[dreamsat]

I bought an adapter. This allows the waveguide to transition much better from rectangle to round. This has a gain of the signal of about 0.8 to 1.0 dB.

best regards

 

[John]

I also used the same transition on one of my Gilat mods when i tried the 90° angle bend approach. I think i will pull the Gilat out of storage at some stage and have a re-think on the feed design. The small section of wr42 waveguide was put in place to accept a 40mm collar for the lnb holder. I think i will remove that and also have a look at trying to get a better scalar match.

...........................................................................................................................................................................................................................................................................................................

 

[dreamsat]

Hello John, where did you buy the 90 ° angle. I'm still looking for something like that.

regards

 

[John]

Mine was from this seller, not seen another that has the same small size though.
Mine is this - - obtained from bay seller 'electro-mavin'
Millitech 45420H-2190 Waveguide 90° WR42 18-26.5 Ghz
( 142710921089 )
The only one i could find at the moment is this one

Waveline 832-2 Gold Plated Waveguide 90° Bend - WR-42, 18-26.5 GHz | eBay

 

[dreamsat]

That is not the right one. The waveguide has to be turned the other way around. (for high).
It looks in the picture almost as if you have built a waveguide cross?

 

[John]

That is not the right one. The waveguide has to be turned the other way around. (for high).
It looks in the picture almost as if you have built a waveguide cross?

We got rid of the transition thats on the actual Gilat itself by sawing off the end section of the casting and bolted straight onto the pcb. I then coated the whole assembly with plastic sealer to keep water ingress out.

..........................................................................................................................................................................................................................................................................................................

 

[dreamsat]

OK, verry good

 

[dreamsat]

Hey John,
do I see this correctly, that the polarity changes when you turn the LNB?

regards

 

[scopus]

Newsnet has a new screen with the ITN news music on a loop. Makes a change from looking at the back of peoples heads I suppose..

 

[John]

Newsnet has a new screen with the ITN news music on a loop. Makes a change from looking at the back of peoples heads I suppose..View attachment 124442

Ooooo that's nice, i tend to still keep an eye on the floor as well as the ladies for the mice lol.

 

[tony smith]

Hi Folks
Not sure if your aware, but SIS Live who provides the Ka capacity, is now finished it's been taken over by NEP Visions,
they still carry on with the Ka band contact, which has 2 or more years to run with ITV, I think the satellite side of NEP is called NEP Links.
I have seen 1 ident that has NEP in place of SIS, it's an ITN uplink I think, but the rest still call up SIS as before

 

[John]

Hi Folks
Not sure if your aware, but SIS Live who provides the Ka capacity, is now finished it's been taken over by NEP Visions,
they still carry on with the Ka band contact, which has 2 or more years to run with ITV, I think the satellite side of NEP is called NEP Links.
I have seen 1 ident that has NEP in place of SIS, it's an ITN uplink I think, but the rest still call up SIS as before

... Hmm, interesting. Thanks for that Tony.

 

[scopus]

Yes, first started to notice the NEP idents two or three months back..

 

[Llew]

Back, but deserted. Where is everybody

 

[John]

Back, but deserted. Where is everybody

View attachment 124518

.. did somebody shout Eeeeeee Mouse ?.

 

[John]

... new feed freq for me on 19.2° East on a very busy 18GHz band again.
18.585 V.

........................................................................................................................................................................................................................................................................................................