and a gold pin on the other end marked 1N21B
I have some other diodes like it from slotted lines. How do
you tell how fast they are?
1N25 series ~ 1-2GHz (L-band)
1N21 series ~ 2-4GHz (S-band)
1N23 series ~ 8-12GHz (X-band)
1N78 series ~ 12-18GHz (Ku-band)
1N26 series ~ 18-26.5GHz (K-band)
1N53 series ~ 26.5-40GHz (Ka-band)
They of course work at lower frequencies, but the construction optimises the noise figure in the microwave frequency range above.
I've most commonly come across these as part of General Radio slotted line and impedance meter products, usually 1N21 and 1N23 in mixer and rectifier applications.
Craig
