I have a NOS Thoardarson inductor T45557 and would like to know its ratings if someone out there has an old catalog. I measures about 18H with my HP bridge.
Thanks.

If no catalog info comes forward on that #.

Thats a different / old ? designator .....but you didn't give the accompanying DC resistance spec of the unit also....but, optionally guesstimating for an ~400§Ù DCR value.
With a unit having a moderate core area... not being engraved in stone, but.....one would expect it to be in the 75 ma vicinity, with that rather high inductive value that you measured. And ...hey....that sounds like middle to high end of the road spec for old radio receiver use...but no high powered transmitter power supply use.
If a smaller core sized unit was used, more for its inductive value than brute power filtering, it could even be as low as 15-30 ma with a unit of
900§Ù DCR.

Tech referencing:
http://thordarsonmagnetics.com/getPDF.php?track_id=54.pdf

73's de Edd

:If no catalog info comes forward on that #.
:
:Thats a different / old ? designator .....but you didn't give the accompanying DC resistance spec of the unit also....but, optionally guesstimating for an ~400§Ù DCR value.
:With a unit having a moderate core area... not being engraved in stone, but.....one would expect it to be in the 75 ma vicinity, with that rather high inductive value that you measured. And ...hey....that sounds like middle to high end of the road spec for old radio receiver use...but no high powered transmitter power supply use.
:If a smaller core sized unit was used, more for its inductive value than brute power filtering, it could even be as low as 15-30 ma with a unit of
:900§Ù DCR.
:
:Tech referencing:
:http://thordarsonmagnetics.com/getPDF.php?track_id=54.pdf
:
:73's de Edd
:Thanks Edd. The DCR of this unit is 190 ohms and it is rather large . . .about the size of a power transformer you would find in a Zenith 8S series radio and it weighs just over 5 pounds. For an inductance of 18H a DCR of 190 is not too bad in terms of L/R ratio. I agree that it is an old designation number and my reference sheets do not include it. Tom
:
:

I don't find that number in Thordarson catalogs for 1934 and 35. The part numbers in these catalogs are shorter than your number; a letter "T" followed by 4 digits. Sometime between 1935 and 1941, they changed the numbers to alpha-numeric. For instance, a 22 H audio reactor has the part number T-18C92, where the "C" stands for choke. Other part numbers would have a letter "R" for power, "A" for audio, "S" for output, etc..

Your inductor's number may be a "house" number for a unit supplied by Thordarson to an equipment manufacturer.

Meade

::If no catalog info comes forward on that #.
::
::Thats a different / old ? designator .....but you didn't give the accompanying DC resistance spec of the unit also....but, optionally guesstimating for an ~400§Ù DCR value.
::With a unit having a moderate core area... not being engraved in stone, but.....one would expect it to be in the 75 ma vicinity, with that rather high inductive value that you measured. And ...hey....that sounds like middle to high end of the road spec for old radio receiver use...but no high powered transmitter power supply use.
::If a smaller core sized unit was used, more for its inductive value than brute power filtering, it could even be as low as 15-30 ma with a unit of
::900§Ù DCR.
::
::Tech referencing:
::http://thordarsonmagnetics.com/getPDF.php?track_id=54.pdf
::
::73's de Edd
::Thanks Edd. The DCR of this unit is 190 ohms and it is rather large . . .about the size of a power transformer you would find in a Zenith 8S series radio and it weighs just over 5 pounds. For an inductance of 18H a DCR of 190 is not too bad in terms of L/R ratio. I agree that it is an old designation number and my reference sheets do not include it. Tom
::
::