Meanwhile I've modified several LNBs for external LO feed. Therefore I use the NB output to supply the LNB with 25MHz, DC and of course the downlink.
Using my 27 MHz HD-Line HD-BP2 gives me still a DATV Beacon MER of 10.7dB.
The following LNB are not as good as the HD-BP2, I loose about 1dB (!) sensitivity:
OCTAGON Twin Green HQ, Model: OTLG GreenHQ, no Serial No. T1015, SPT SP4202HN, 25 MHz X-Tal,
like OE2ROL did: https://www.oe2rol.com/octagon-lnb-umbau-fuer-qo-100.html
OPTICUM TWIN LTP-04H
Same as AMSAT shows here: OPTICUM LTP 04H Twin LNB
In all cases the Leo Bodnar GPSDO was used. I tried to optimise the LO Power, but still no improvement compared to my old LNB.
To Try: Diavolo Twin. Transformer missing. See here: https://elektronik-muenster.de…lnb-f%C3%BCr-externen-lo/
I want to change, because my own GPSDO will have 10 MHz + 25 MHz.
Any suggestions? Please let me know. Thank you.