Bullseye LNBF

[Marcus D. Leech]

Does anyone know of documentation out there for modifyng the BullsEye
LNBF (Ku-band, for QO-100) for external REF?

My experience with modifying other consumer LNBFs for external reference
has been a "mixed bag", due to the fragile nature of the
  traces that are typical on these boards.

[Sweet Thing]

Assuming it has ADRO as the oscillator a probe near the DRO with a subharmonic frequently will allow you to injection lock.No other circuit mods needed

--
--
You received this message because you are subscribed to the Google
Groups "Society of Amateur Radio Astronomers" group.
To post to this group, send email to sara...@googlegroups.com
To unsubscribe from this group, send email to
sara-list-...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/sara-list?hl=en
---
You received this message because you are subscribed to the Google Groups "Society of Amateur Radio Astronomers" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sara-list+...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/sara-list/c45d9777-9e71-43f7-9f49-cabe28131f88%40gmail.com.

[Marcus D. Leech]

On 2025-12-21 15:49, Sweet Thing wrote:

Assuming it has ADRO as the oscillator a probe near the DRO with a subharmonic frequently will allow you to injection lock.No other circuit mods needed

It's a PLL design, with a 25MHz TCXO on-board. 

To view this discussion visit https://groups.google.com/d/msgid/sara-list/CABZjMtvLC5AzwrvTB-0myRhk02FTjtq-fhsjy8TBGb-QxhDPTA%40mail.gmail.com.

[Robert Kiendl]

You could use this schematic here. It's kinda reprogramming the internal pll via ref frequency output. Works pretty well since i use it for other operations .
https://github.com/g4eml/Bullseye-Calibrator


-----Ursprüngliche Nachricht-----
Von: sara...@googlegroups.com [mailto:sara...@googlegroups.com] Im Auftrag von Marcus D. Leech
Gesendet: Sonntag, 21. Dezember 2025 21:47
An: Society of Amateur Radio Astronomers
Betreff: [SARA] Bullseye LNBF