Specs of a modulation transformer?

[ja1xct]

Can anyone tell me what the specs are for the following Chicago Transformer?
・CAT 7472230
・564667　　8800-C
This looks like a modulation transformer of the ART-13.

73,
Yasuhiro  JA1XCT
JAPAN

[Steve - WB3HUZ]

I don't know if it is the same transformer, but the specifications on the ART-13 modulation are found at the link below.

http://www.amwindow.org/tech/htm/modtran/misc/art13.htm

[WBear2GCR]

Fwiw,

you can determine the specs of any random transformer via bench testing.

The main things you'd want to know are the turns ratio, the primary and/or secondary inductance, and then the measured frequency response using a known and appropriate secondary load resistance.

since transformers are "ratio" devices - they actually do NOT have a real "impedance" - rather the number of turns and the core determines the primary inductance, which in turn determines the lowest frequency it can handle vs. some impedance - and the number of turns will then also relate to the current/power it can handle at a given impedance...

So, in the case of an RF mod transformer, the impedance that the secondary is actually connected to will determine the "proper" primary impedance that ought to be there for optimal power transfer.

Otoh, if it is important to know if it an original transformer for a specific rig, this won't help at all!

                      _-_-WBear2GCR

PS. Greetings from this side of the big pond! Hope to work you on 80m AM on the day that perfect and magic conditions happen to exist!! 

[k4kyv]

One other thing it is important to identify is the start and finish terminals of the windings, since the "start" end of a winding may not be as well insulated as the "finish" end, and the internal capacitance may be greater at the "start" end.

Wire up a mod xfmr with those connections reversed,  and at best you may degrade high frequency response, and at worst, blow the transformer.

[WA1LGQ]

 Don, if you were measuring the capacitance of the terminals, what do you use as a reference? Do you measure between the terminal and the laminations? To another tap? To another winding? Thanks........Larry

[k4kyv]

Don, if you were measuring the capacitance of the terminals, what do you use as a reference? Do you measure between the terminal and the laminations? To another tap? To another winding? Thanks........Larry

I would  measure from the terminal in question to the laminations, and to each end of the other windings that are separate from the one being measured.

You may or may not get any meaningful results.