Here we have a couple of Ampex 4580200-01 bridging transformers, courtesy of Ciminosound.
1:1 turns, 10 K impedance.
http://vacuumbrain.com/The_Lab/Ampex/ampex_bridging.jpg
There is a slight difference between the black and green base models.
Black Base:
150 H
DCR: 1.44 K
Leakage: 25 mH and 146 pf for a predicted resonance of 82 K CPS
Green Base:
188 H
DCR: 1.44 K
Leakage: 19 mH and 167 pf for a calculated resonance of 88 K CPS
Freq plots were fairly identical, there is a slight shift on the rez peak, as predicted.There was a slight rise at the upper end on one of the units.
So the cores are probably the same, but the coils have to be slightly different.
There's that weird bass rise I see from time to time.
Have not figured that one out yet.
http://vacuumbrain.com/The_Lab/Ampex/ampex_bridging_freq.jpg
B-H was a bit different from the norm:
http://vacuumbrain.com/The_Lab/Ampex/ampex_bridging_bh.jpg
1:1 turns, 10 K impedance.
http://vacuumbrain.com/The_Lab/Ampex/ampex_bridging.jpg
There is a slight difference between the black and green base models.
Black Base:
150 H
DCR: 1.44 K
Leakage: 25 mH and 146 pf for a predicted resonance of 82 K CPS
Green Base:
188 H
DCR: 1.44 K
Leakage: 19 mH and 167 pf for a calculated resonance of 88 K CPS
Freq plots were fairly identical, there is a slight shift on the rez peak, as predicted.There was a slight rise at the upper end on one of the units.
So the cores are probably the same, but the coils have to be slightly different.
There's that weird bass rise I see from time to time.
Have not figured that one out yet.
http://vacuumbrain.com/The_Lab/Ampex/ampex_bridging_freq.jpg
B-H was a bit different from the norm:
http://vacuumbrain.com/The_Lab/Ampex/ampex_bridging_bh.jpg