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Author Topic: Eico 730 Modulator  (Read 2100 times)
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k5ygc
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« on: November 03, 2021, 06:31:10 AM »

Has anyone found a replacement OPT for the modulator? Or would it be best to have it rewound? Thanks Mark K5YGC       Email is kc5ygc1@gmail.com
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W3GMS
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« Reply #1 on: November 03, 2021, 10:09:30 AM »

You may want to consider a modulation transformer from a Johnson Ranger.  Another choice, but not sure if it would fit in would be an ART-13 mod transformer, but based on what you modulating, make sure the turns radio is good. 

Joe-W3GMS
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« Reply #2 on: November 03, 2021, 04:34:42 PM »

Has anyone found a replacement OPT for the modulator? Or would it be best to have it rewound? Thanks Mark K5YGC       Email is kc5ygc1@gmail.com

If we are discussing plate modulation the modulation or OutPut transformer should require this:

The Impedance ratio is ~ 2.2:1 (Primary to secondary), so the turns ratio should be ~ 1.5:1, (Primary to secondary).

Phil - AC0OB
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K9MB
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« Reply #3 on: November 03, 2021, 06:44:54 PM »

A Stancor A3893 might work. Here is the data on footprint.
If it will fit on the chassis, it is rated at 60 watts, so will easily handle the pair of EL34s.

I may have a used one.

If you want me to check, please email me. Good at qrz


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