My downlink (DL) is realized by using an old 40cm off-set dish on my roof deck, something I mentioned before. On recommendation of an old friend, I bought a Venton EXL-S Rocket Single LNB. So far so good, this LNB served me on many contacts. Using the beacon feature of SDR-Console made it possible to have those contacts. However, during my tests using analogue equipment, drift from this particular LNB was noticeable.
I understood the Venton LNB is primarily useful with with POTY "dual band" feed, as it keeps the centre hole to a minimum. Fair enough.
For my setup, I decided to use two separate dishes for UL and DL, hence, the size of the DL LNB is irrelevant to the UL feed geometry. As a matter of experimentation, I replaced the Venton LNB with an Octagon OSLO LNB in the 40cm DL dish setup. This LNB was purchased many years ago, when I was active on 3cm rain scatter and wanted to experiment a little bit with commodity gear. To my surprise, the Octagon LNB is a lot more stable, once at temperature. It also appears to be more sensitive than the Venton. Aperture is the name of the game here, I figure. Hmmm, maybe I should have used this LNB from the get-go and saved the few Euros by not buying the Venton LNB.
Still, there might be a use for the Venton LNB. As mentioned in my previous post, I am considering to use a single dish for DL and UL. With its smaller form-factor, the Venton Rocket might be the better choice when placed inside the UL feed helix in a single dish arrangement.
I will post my further experiment on this blog, so, stay tuned.
BTW, occasionally, you might be able to hear me on the transponder. Feel free to give my a call ;-)