Pollin LNB GM201

Nice polish forum with lots of pics from DRO & PLL LNBs:

https://satclub.pl/viewtopic.php?f=113&t=7274&start=70

vy73 DB8TF

How about this article, a very complete and actual overview of 10GHz LNB's.

http://www.pabr.org/radio/lnblineup/lnblineup.en.html

73 de PAoP

Done the oh2aue mod on my GM201 and it works good.

But if you want to do this mod you need badass soldering skills

vy73 DB8TF

oh2aue

Hello,

I have two questions concerning the modification of the LNB for external reference.

1st: In the GM 201 mod you mention that the capacitive pads of the removed xtal can stay in place - does this mean that they can also be removed ?

2nd: Can you give me some hints for removing the xtal ? When I see the huge soldering pads and the small part that can be reached with the soldering iron (when the xtal is still in place) it looks like you have to "cook" the PCB to desolder the xtal....

Any advice - also from oher forum readers - is welcome

73 de Johannes

@ DL5RDI Hallo Johannes,

bei Reichelt gibt es eine brauchbare Heißluftlötstation für 79,95 €.

73 Hans-Jochen, DK1MG

If have this one and it works very good..

Hello,

thanks for your answers. But I do not want to spend 30 or 80€ to modify a € 2,95 LNB ;-).

The easiest and cheapest method is to destroy the XTAL (e.g. with a DREMEL), so you have access to the two pins "through" the desrtoyed housing of the quarz and than you can remove the housing and desolder each leg seperately.

Thanks to Rudi - DK5RQ for this great idea !

Now I modified an OCTAGON and a GM201 each for external reference.

The OCTAGON was a piece of cake - the GM201 needs really skilled hands and eyes and a portion of luck.

73 de Johannes

Johannes, it can be done with 2 soldering irons heating both sides at same time. Just take your time until xtal moves. After, cool the pcb down ...

Picture below of an Opticum LSP-02G, xtal was removed that way. Note: these LNBs goes down only to 24.183 MHz @ room temperature. At lower ref. frq. PLL became completely unstable - strong wobbling. One should always check its operation with spectrum analyser.

Quote from DL5RDI

oh2aue

Can you give me some hints for removing the xtal ?

Some strange - unwanted oxidation around LNB inputs on the bottom side of PCB on every GM-201 (brand new) ...

I've tested IF output level verus PLL ref. FRQ change, using fixed RF source (NB CW) on LNB's input @ approx 10.490 GHz.