BATC Forum

Hi all, does anyone have a spare Rocket LNB they would be willing to pass on? I need the one with the plastic lens for POTY feed and 25MHz PLL.
Alternatively, is there an alternative? Another 25 meg PLL LNB and source of POTY lens. What are people using these days?
Trying to use the spare time around these days to get on with unfinished projects
Many thanks, Paul

Search for rocket LNB on Amazon. Lots come up at about £12 - e.g Venton Rocket Twin - these are not PLL, it's just for the lens.

If you have access to a 3D printer the website in the link below has links to some print files for Dielectric lenses, and says they are as good as the milled versions. maybe worth experimenting.
http://www.hybridpretender.nl/poty.html

M0IVJ wrote: ↑

Sat Apr 04, 2020 9:27 am

If you have access to a 3D printer the website in the link below has links to some print files for Dielectric lenses, and says they are as good as the milled versions. maybe worth experimenting.
http://www.hybridpretender.nl/poty.html

Printed lenses are not as good, by several dB. I have seen lots of claims but most seem to be based on "the CW beacons just as strong" type arguments ignoring the fact this is limited largely by the transponder noise floor for larger dishes and inefficiency doesn't matter. That's not the case for DATV where every dB counts, even for fairly large dishes within reason.

<Rant mode>
After all that investment I don't understand why people still baulk at buying a rocket LNB, taking the lens and throwing the rest away. I suppose its the idea it's such a waste to throw away what's actually a quite useless DRO based LNB otherwise, so instead of spending £10 you end up spending a lot more and much time and effort ending up with something that doesn't perform as well in the end.
</Rant mode>

The best home made lens is the Rexolite design from HB9PZK. That's because it was designed for the material dielectric, waveguide dimensions and dish focal length but you would need to get one turned up.

Mike

When I was pulling apart a Red Eagle Rocket LNB for the "red nose" last year, I found that the LO was actually crystal controlled (25Mhz). Wish I'd bought some more, because they don't seem to be so common today!
73 Shaun.

g8vpg wrote: ↑

Sun Apr 05, 2020 7:56 am

When I was pulling apart a Red Eagle Rocket LNB for the "red nose" last year, I found that the LO was actually crystal controlled (25Mhz). Wish I'd bought some more, because they don't seem to be so common today!
73 Shaun.

If only we could find more of those!

For Paul G3NJV,

Are you still looking for a PLL LNB and/or lens ?

If so, please send me your contact details via a PM.

73
Jen G4HIZ