TF868: performance. Well, first of all, there are several variants in existence. The original was the TF 868; I have the TF 868B. That implies that there was a TF 868A - but I've never seen one.
First, the spec.:
Inductance: 1 µH to 100 H in 7 decades; measurement at 1 kHz or 10 kHz.
Capacitance: 1 pF to 100 µF in 7 decades; measurement at 1 kHz or 10 kHz.
Resistance: 0.1 Ω to 100 MΩ in 8 decades; measurement at d.c.
Q: 0.1 to 10 at 1 kHz; 1 to 100 at 10 kHz.
tan δ: 0.001 to 0.1 at 1 kHz; 0.01 to 1 at 10 kHz
Since Q = 1/tan δ, the scales (Q and tan δ) when combined give an extended Q measurement range up to 1,000 and tan δ to 10.
Marconi also made a D.C. choke adapter for this unit, enabling the inductance of coils, chokes, etc. to be determined whilst that component was passing d.c. (useful for measuring swinging chokes, for example).
The weight of the item is 12 kg.; H = 11"; W = 19"; D = 10" (approx.)
So it's big and a bit heavy!
Performance:
Obviously I can only vouch for mine. I do own some accurately-calibrated R, L and C components: these give an accurate indication on my TF 868B ('accurate' enough for 99.9% for my purposes
).
Construction.
Internally, very sturdy. However, maintenance is not a trivial task - and that remark ignores the several specially-selected components within it.
I have an original TF 868B Marconi Operating Instructions Manual (ref. EB 868B), but the one I obtained from the 'Net (ref. OM 868B) is much better.
As soon as I can, I will take some photos. and add them to the Gallery, with an accompanying write-up.
Al.
First, the spec.:
Inductance: 1 µH to 100 H in 7 decades; measurement at 1 kHz or 10 kHz.
Capacitance: 1 pF to 100 µF in 7 decades; measurement at 1 kHz or 10 kHz.
Resistance: 0.1 Ω to 100 MΩ in 8 decades; measurement at d.c.
Q: 0.1 to 10 at 1 kHz; 1 to 100 at 10 kHz.
tan δ: 0.001 to 0.1 at 1 kHz; 0.01 to 1 at 10 kHz
Since Q = 1/tan δ, the scales (Q and tan δ) when combined give an extended Q measurement range up to 1,000 and tan δ to 10.
Marconi also made a D.C. choke adapter for this unit, enabling the inductance of coils, chokes, etc. to be determined whilst that component was passing d.c. (useful for measuring swinging chokes, for example).
The weight of the item is 12 kg.; H = 11"; W = 19"; D = 10" (approx.)
So it's big and a bit heavy!
Performance:
Obviously I can only vouch for mine. I do own some accurately-calibrated R, L and C components: these give an accurate indication on my TF 868B ('accurate' enough for 99.9% for my purposes
). Construction.
Internally, very sturdy. However, maintenance is not a trivial task - and that remark ignores the several specially-selected components within it.
I have an original TF 868B Marconi Operating Instructions Manual (ref. EB 868B), but the one I obtained from the 'Net (ref. OM 868B) is much better.
As soon as I can, I will take some photos. and add them to the Gallery, with an accompanying write-up.
Al.
