L4 is an axial inductor (3 bands short standard)
Brown Red Gold
http://coil32.net/online-calculators/inductor-color-code-calculator.html
RESULT: Value and tolerance: 1.2 µH, ±20%
Some of my Plus/4 motherboards have this version of the inductor.
In the service manual the sub is part number 325570-01 (also used on C16 motherboard)
On 1 of my C16 motherboards it has: NYT WEE 1.2 UH 10% 8242
Does anyone know what the Current rating would be?
Would a replacement be Bourns 78F1R2K-RC or Bourns 77F1R2K-TR-RC or something else like the EPCOS below?
These 2 Bourns inductors are some I found on Mouser
EPCOS 1.2 μH ±10% Ferrite Leaded Inductor, Max SRF:185MHz, Q:55, 1.15A Idc, 180mΩ Rdc BC
(EPCOS Mfr. Part No. B78108S1122K000 )
Plus/4 Service manual
http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/plus4/Plus_4...(1984_Oct).pdf
This is a tinyurl for the service manual https://tinyurl.com/y9lqe4pu
It is on page "8" (pdf page 13) Plus 4 Schematic #310164 (2 of 4) it is connected to the rf modulator (pin 3)
C21 & L4 were missing on 1 of my spare Plus/4 motherboards.
I have replaced C21.