[Milsurplus] 800cps inverter on Craigslist in Portland

[Richard]

Yes, as noted it's a bit light.  I use an 800-1 inverter for my TBW, and 
dc input is 28 volts 55 amps key-down.  The 800-1 inverter is also known 
as a Screaming Mimi, I measured 85 or 90 dB at three feet, about the 
same as a subway train running through the shack.  It's in a 
noise-reducing box, 3/4 inch plywood lined with 2 inch fiberglass batts, 
also with an exhaust fan as it throws off significant heat.  The noise 
is all magneto-striction, mostly around 1600 cycles, so there is no 
cure.  Maybe 1600 cycles couples to the air better than 120 cycles...  
Anyway, the box reduces the noise to 50 dB, conversation level, and 
depending where you stand you hear nothing or a distant whine, which 
adds ambiance to the shack and impresses visitors.

Richard, AA1P


O 11/16/2017 03:21 AM, Michael Hanz wrote:
> The GO-9 800~ load ranges from about 770VA to 820VA, IIRC, so this 
> inverter is a little bit light at 500VA.
>
> I use an old Behlman 100-C lab AC supply to power mine up, although 
> the normal rotary inverter is usually the Eclipse 800-1 (or PU-43 with 
> its CN-10A external regulator).
>
> 73,
> Mike  KC4TOS
>
> On 11/16/2017 2:05 AM, Robert Goff wrote:
>> Just noticed this today:
>>
>> https://portland.craigslist.org/mlt/clt/d/wwii-us-signal-corps-inverter/6383884175.html 
>>
>>
>> Output is 80V, so would still require a transformer for use with GP,
>> GO and TBW type gear.
>>
>> I'm curious what others have done to overcome the 800 cps problem.
>> I've looked into motor VFD's, but all the ones I've seen top out at
>> 400 or so.  Any brighter ideas?
>
>
>
>
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