Re: DA-64A/UP Dummy Load specs ?

Jul 24, 2003 1 Replies


J>


>
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>>Hello, all,
>>
>>I have just picked up an ancient US Army Signal Corps dummy load,
>>model DA-64A/UP, made in about 1958 by Ratheon. It is a massive
>>unit, with 12 100 W resistors in it, and forced air cooling. It has
>>some massive coaxial connectors on it that are unfamiliar to me.
>>It is 50 Ohms, though. I was wondering if anyone had the specs on this,
>>with respect to average and peak RF power, and frequency range.
>>
>>Thanks in advance,
>>
>>Jon
>>
>>
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>Pictures? I'd like to see those connectors. :) They could be GR-874.
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Well, I'll get pix soon. No, these are not like GR-874 connectors at all. They are large (1.5 - 2.5" diameter, with convoluted ceramic inserts, and threaded clamping rings. They look like thay are made for very large voltages at frequencies below 50 MHz, maybe. There are 4 adaptors in one of the end covers, and a coax extender in the other. Some of the connector part numbers are : CBRS UG-34/U S276-1306P1 CBIB UG180A/U CBRS UG-222/U


The whole thing is in a cylindrical can 12" diam x 20" long, with removable caps on each end. the caps have really big O rings to hermetically seal the thing, which is why a 45-year old power cord looks like new. (The power cord is to run the cooling blower.)


Jon



OK, you want pictures? Here they are :

whole thing :

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opened up and connected :

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Looking into resistor array :

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showing Cooling fan :

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Coax adaptors in storage :

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If anyone knows anything about this model, especially specs, that would be greatly appreciated.

Thanks,

Jon

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