[RFI] Inverters?

[Don]

> I would be very interested in the tests on small inverter generators, 
> including the Honda, Northern tool's Power house, Yamaha, and Harbor 
> Freight. Including the RFI tests.
>
> I have 2 Honda's and my son has the Power house, and both have had 
> good luck with them.
>
>
> On 9/21/2020 6:57 AM, Hare, Ed W1RFI wrote:
>> When QST reviewed generators a few years back, we noticed a wide 
>> range in the stability of the motor speed and thus voltage vs load. 
>> For some, when we keyed a kW amplifier, the motor speed remained 
>> pretty steady. For others, the motor speed dropped significantly, 
>> then picked up, but during the drop, the voltage dropped as low as 
>> 60V from a 120V generator.  If the amp remained keyed, the motor 
>> picked up speed again, but then when unkeyed, the speed and voltage 
>> rose.  This would be a show stopper for high-power portable operations.
>>
>>
>> ________________________________
>> From: RFI <rfi-bounces+w1rfi=arrl.org at contesting.com> on behalf of 
>> Jim Brown <jim at audiosystemsgroup.com>
>> Sent: Sunday, September 20, 2020 11:45 PM
>> To: rfi at contesting.com <rfi at contesting.com>
>> Subject: Re: [RFI] Inverters?
>>
>> Hi Warren,
>>
>> Several observations. First, buying ANY generator for anything more than
>> FD operation should be done as an engineering project. Some of the
>> design criteria are
>>
>> 1) what are your loads? Grab a clamp-on Ammeter and measured them --
>> don't go by nameplate, which are always worst case. Don't have a
>> clamp-on ammeter? It's a VERY important tool to own. Look for one that
>> measures relatively SMALL currents -- you want 5-10A full scale, maybe
>> 20A or 30A. Unless you're seeing very large loads, nothing more than 
>> 50A.
>>
>> 2) Our average load 24/7 is less than 1kW; it goes up (a lot) when
>> cooking with electricity, running A/C, contesting legal limit, and a
>> bit with large fans that are part of an HVAC system.
>>
>> 3) Does your gen need to run well motors? My EU6500 Honda (inverter) gen
>> does NOT like to run my well motors. A traditional gen half that size 
>> will.
>>
>> 4) How much of your loads need to be on gen? I found that I could run my
>> 22 cu ft fridge, computers, lighting, and moderate size home
>> entertainment system on my Honda 2000i in economode. To do that, I had
>> to have some of those loads redistributed between legs of 120/240 so
>> that all I needed for those functions were on the same leg. Easy to do
>> at the breaker panel. Our cooking is propane, so I boil water for coffee
>> on the stove when on the gen. Don't try to run the microwave.
>>
>> 5) Consider propane. My EU6500 has been converted, W6GJB converted his
>> 2000i, and is going to do mine. A $22 can runs 20 hours or more in
>> economode, depending on loading.
>>
>> 6) Doing county expeditions in very quiet places for CQP and 7QP using
>> W6GJB's 2-position contesting trailer with antennas on a pneumatic mast
>> and the gen on the back of the pickup it's hitched to, we found that we
>> needed a good noise filter. The one that Glen and I came up with was
>> added to the Handbook a few years ago. If it's not in yours, you can
>> find details in the latest version of k9yc.com/RFI-Ham.pdf  I should
>> plug directly into the gen -- it's the AC cable that radiates noise
>> common mode, the filter kills that.
>>
>> This filter is designed for HF; for 6M and above, see my recent
>> recommendations for coax TX chokes for VHF/UHF, using them as a
>> guideline for AC cable the size of the coax in those recommendations.
>> For 6M, use two turns of RG8 through a Fair-Rite #31 1-in i.d. clamp-on;
>> for best suppression, use 2-4 of these 2-turn chokes in series. See the
>> photo in the pdf.
>>
>> 7) As others have noted, consider duty cycle. Most low cost gens, even
>> the good ones, are designed for intermittent operation. My most
>> demanding need when on geen is keeping the fridge cold enough to prevent
>> spoiling. When running the 2000i, I typically keep the duty cycle below
>> 60%.
>>
>> 8) It's important to realize that worst case loads are usually starting
>> a motor; once the motor is running, the load drops a LOT. It's starting
>> my well motors that the EU6500 doesn't like. When in doubt, START your
>> gen with no load on it, then connect the load, and once it's stabilized
>> (usually under a minute, could be more with well motors), then kick it
>> down to economode to save (a lot of) fuel.
>>
>> Master DXpeditioner AA7JV, drastically reduced the amount of petrol he
>> had to carry on the boat for his trips by using power amps that could
>> run on batteries that were float-charged by the generators running in
>> economode. George is a VERY smart engineer, and one of my heroes!
>>
>> 73, Jim K9YC
>>
>> On 9/19/2020 9:23 PM, Warren Wolff via RFI wrote:
>>>     I am considering the purchase of an emergency back-upgenerator.  
>>> For the first time, I have encountered unitstagged as “inverters”.  
>>> Does this mean that some systemsare AC generators while the 
>>> “Inverter-types” generateDC and then convert it to AC?    “Inverter” 
>>> immediatelyprecipitates the worry of RFI.  Comments, please.
>>> WarrenW7WY
>>> _______________________________________________
>>> RFI mailing list
>>> RFI at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/rfi
>>>
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