Due to space limitations, I use Slimlines for some fixed KU sats. I have had good reception except for the ocassional rain fade. Recently, I thought I would try SL1PLL lnbfs to see if there would be any improvements in reception.

I ordered five SL1PLL lnbfs which I used to test the following:

Day one - Sunny clear skies.

WS Intl DMX521 used for 72 W KU.
Tested on KFTL 11968 H 1666.
Sat Hero signal 77-79 and Optibox Raptor 89 level and 75 quality.
Replaced with SL1PLL.
Sat Hero signal 80-81. Re-scanned and Optibox Raptor 89 level and 76 quality.
Note - SL1PLL takes longer to lock in this station.

DMS Intl JSC321S used for 103 W KU mounted on Slimline shared with two other lnbfs (107 and 97).
Tested on MS10 11940 V 20000.
Sat Hero signal 41 and Optibox Raptor 89 level and 38-40 quality.
Replaced with SL1PLL.
Sat Hero signal 43. Re-scanned and Optibox Raptor 90 level and 43 quality.

Day two - cloudy and overcast.

WS Intl DMX521 used for 83 W KU mounted on Slimline shared with three other lnbfs 89-93-99).
Tested on RTV 11733 H 4439.
Sat Hero signal 41-42 and Optibox Raptor 89 level and 38-40 quality.
Replaced with SL1PLL.
Sat Hero signal 44-46. Re-scanned and Optibox Raptor 89 level and 41-42 quality.

Sonicview Galaxy twin output used for 101 W KU mounted on Slimline shared with three other lnbfs (85-95-105).
Tested on BVN 12120 V 30000.
Sat Hero signal 48-49 and Optibox Raptor 90 level and 71 quality.
Replaced with SL1PLL.
Sat Hero signal 49-50. Re-scanned and Optibox Raptor 90 level and 71 quality.

WS Intl DMX521 used for 97 W KU mounted on Slimline shared with two other lnbfs (103-107).
Tested on University 12115 V 22525.
A-Sat Hero signal 44-45 and Optibox Raptor 90 level and 69-70 quality.
Tested on River Broadcasting 11966 H 22000.
B-Sat Hero signal 57-59 and Optibox Raptor 89 level and 74 quality.
Replaced with SL1PLL.
A-Sat Hero signal 41-42. Re-scanned and Optibox Raptor 90 level and 43 quality.
B-Sat Hero signal 63-64. Re-scanned and Optibox Raptor 90 level and 76 quality.
Note - Went back to using WS Intl DMX521 due to not being able to lock in Al Jazeera at 12150 H 20000. The DMX521 locks in at 89 level and 69 quality.

WS Intl DMX521 used for 125 W KU.
Tested on Create 12182 V 30000.
A-Sat Hero signal 49-52 and Optibox Raptor 90 level and 71 quality.
Tested on OETA HD 12112 V 8703.
B-Sat Hero signal 45-47 and Optibox Raptor 89 level and 70 quality.
Tested on Montana 12106 V 2398.
C-Sat Hero signal 58-64 and Optibox Raptor 89 level and 75 quality.
Tested on SD07 12175 H 4444.
D-Sat Hero signal 46-50 and Optibox Raptor 89 level and 42 quality.
Replaced with SL1PLL.
A-Sat Hero signal 49-50. Re-scanned and Optibox Raptor 90 level and 71 quality.
B-Sat Hero signal 41-43. Re-scanned but won't lock in.
C-Sat Hero signal 57-63. Re-scanned and Optibox Raptor 89 level and 74 quality.
D-Sat Hero signal 45-47. Re-scanned and Optibox Raptor 89 level and 42 quality.
Note - Went back to using WS Intl DMX521 due to not being able to lock in OETA HD at 12112 V 8703.

Not a controlled testing approach, but over all I am pleased the SL1PLLs were able to improve some sats. I didn't bother testing some of the remaining fixed sats because the signal levels are adequate. May go back and swap an SL1PLL with another SL1PLL again on 97 and 125 just to see if there are any discrepancies.