New 10 GHz LNB

[G4GUO]

This looks a very interesting device for our use.
We need to change the reference crystal I think
but much better than those DRO things.
http://www.g4jnt.com/PLL_LNB_Tests.pdf


- Charles G4GUO

[g8gtz]

In Andy's report he says that they don't seem to have the normal front end high pass filtering and by all reports they work well on 10.368 so should also be OK for the TV repeaters at 10.100 MHz.

But beware, there are various model numbers, some are PLL and some are DRO. This list is from the manufacturer:

>how you can see below in the overview (with EAN Codes), we have 7 >different varieties of Optima LNB.
>Only two of them are equipped with the PLL technology.
>
>OCTAGON OPTIMA LNB Single OSLO EAN (4260189991124)
>OCTAGON OPTIMA LNB Single Slim OSLSO PLL EAN (4260189991131)
>OCTAGON OPTIMA LNB Twin OTLO EAN (4260189991148)
>OCTAGON OPTIMA LNB Twin Slim OTLSO PLL EAN (4260189991155)
>OCTAGON OPTIMA LNB Quattro OQLO EAN (4260189991162)
>OCTAGON OPTIMA LNB Quad OQSLO EAN (4260189991179)
>OCTAGON OPTIMA LNB Octo OOLO EAN (4260189991186)

The PLL ones are in short supply on ebay UK but a seller on Ebay Germany has the unit which looks like the right thing and he will
ship across Europe

http://www.ebay.co.uk/itm/Octagon-Twin- ... 416e9d881a

73s
Noel - G8GTZ

Moderation: Edited to correct minor error.

[G4GUO]

I think this is also the right one it says PLL in the ad
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... OC:GB:3160

Got my Chinese MK808 this morning, off to hack!

- Charles

[HB9EGM]

Hi all,

there is also the Avenger PLL321S-2 that uses the same RF chip. I bought two on ebay and did some reception on 10.368GHz with a RTL2832u USB dongle.

It's great to be able to RX narrow band signals on 3cm with such cheap equipment !

73

Matthias
HB9EGM

[G4EWJ]

For TV applications, stations on the continent have been using the lnb with the SUP-2400 70cm converter.

This brings the signal back into the range of a standard satellite receiver, without any need to change the crystal in the lnb.

Brian

[g8gtz]

Oh very neat - one of those "why didn't I think of that" moments

Noel - G8GTZ

[PE5PVB]

You need to replace the 27MHz X-tal for a 25MHz one.

These LNB's work with a frequency multiplier.

Normally:
Low band = 27x361.111 = 9749.99MHz
High band = 27x392.59 = 10599.93MHz

So, when you replace the X-tal for a 25MHz one:

Low band = 25x361.111 = 9027.77MHz (usable for 3cm)
High band = 25x392.59 = 9814.75MHz

[G4GUO]

FWIW I just put a modified (25 MHz xtal) LNB on the spectrum analyser.
The LNB is unstable and the PLL does not seem to lock at 9 GHz.
The 25 MHz carrier is there on the IF output.
I then transmitted a 10 GHz DVB-S signal and was only able to pick it up at 250 MHz
when using the original 27 MHz Xtal.
There is quite a gain roll off at 250 MHz but is was there loud and clear.

I suspect the SUP2400 approach might be a better bet.
As I don't have one I can't test it.

- Charles G4GUO

Update:
On the bright side I have just transmitted 10 GHz DVB-T, 7 MHz channel, 2K and managed
to receive it on my domestic TV (by connecting the output of the LNB into the TV).
So seems as if my LNB/(Stellex YIG on tx) combination is good enough for DVB-T.

[G4EWJ]

I've just got one of these to try. What's the best way of getting the case off?

Brian

[G4GUO]

Hello Brian,

The plastic case can be forced open with a screw driver it just
has plastic catches. Then you have to remove the screws under
the red coloured sealant and lever open the diecast case which is
held fairly solidy with the sealant. Be careful as the track comes away
from the PCB with the slightest amount of heat.

I replaced the Xtal with a 25 Mhz one and the LO wouldn't lock at
9 GHz so in the end I used it unmodified and changed the IF to match
i.e with an IF of 300 - 700 MHz. So it is probably not worth taking to bits.


- Charles