Kontron/Tabor 6010 universal counter still worth getting?

[Hans81]

Hello,

I am aware that the last entry is from 2018.

I would like to rebuild the 1.3GHz option.

Can someone tell me the value of the resistor R24. In the original schematic this value is unfortunately not mentioned.

Thanks a lot

[0xdeadbeef]

Does this help?
BTW: the manual does mention it, but as "SELECTED VALUE"

[Hans81]

This is very helpful. Thanks for the very quick answer.

[EyeDontKnow]

I took a chance and bought a Tabor 6020 parts unit with an "unknown problem".
Before powering it up, I replaced all electrolytics because one was bulging.
With power on, voltages checked good, and it booted as it should (almost, read on...)

 However, with a signal applied at the input(s), error flashes, "No Ref".
It has the factory installed TCXO board.
 TCXO tests good at 10Mhz.
At the ref-board to main-board junction, pin 6 should read 100Mhz.
I'm getting a sine about 115Mhz @ 150mV P-to-P.

For some reason the ref-board is not being recognized by the rest of the system. 
During boot, it only says "6020" , and it should read "6020-1".

[EyeDontKnow]

UPDATE:
 
I believe I got it working.

In the Tabor 6010/6020 manual, "Table 7-4 TCXO and x10 Multiplier Circuit Checks" (tcxo option)... my voltage and hertz readings were way off, especially on pin 6 (output) of the CA3140. It's used as a low-pass filter to the blah-blah-blah. Output on this opamp was  wrong at -12v.... should be about -3.5v.
I looked closely (like really closely with a loupe) and saw some whitish residue under the chip.
I pulled the chip and added a socket. I had 2 old 3140's (used/pulls) so I inserted the cleanest one......but it had the same problem. Darn !!

I also  socketed and replaced  a fresh 74HCT4046 PLL.
Although.... on this factory board they used a 7046 PLL....difference being the 7046 has a "lock detector" output on pin 15 (which on this board is not used (left open).

Still, no change.
Near the end of my rope, I switched that CA3140 to my last and ugliest spare chip.
Bingo..... no more -12v at the output......and a good 100Mhz @80mV sent out of the option board. It now measures freq, and without the "No Ref" error.
The counter now works, though the boot-up display still does not indicate the option "1".
I'll have to do a thorough Performance Check.

=R=