CCa Siemens, gold pins, one of the best sounding ECC88 / 6DJ8 / E88CC / 6922 together
with Telefunken diamond mark and Philips and Amperex, possible close matching. I have three different types, even “all grey” D getter, the earliest type from 50s.
Bunch of CCa Siemens used tubes. They are premium, specially selected E88CC, for low noise and microphonics they have been commonly used in old tube test equipment and in radio receivers. For example the king of all tube receivers Siemens 125E101a has used 52 of them. Now, they are very, very rare.
This is type II “gray shield”, double stage getter Siemens CCa from 60s
Double stage getter, gold pins and matched pair (within 2%!!!) of Siemens CCa gold pins ECC88 / 6DJ8 type II
Type III “silver shield” matched pair from 70s