[RFI] Inverters?

Sun Sep 20 14:25:17 EDT 2020

I know I’ve run the little air cooled EU2000 24x7 for 6+ days post Sandy, but I’d say more than 1/2 the day, it was at minimum throttle (ecothrottle) as it was running the CPAP and the solenoid for the natural gas. A few LED lights, and whenever the fridge kicked in
Nearly bought a fixed unit after that, bust since then, the unit has had maybe 10 hours, most as test time

--  
73 de KG2V
Charlie

> On Sep 20, 2020, at 1:06 PM, Kim Elmore <cw_de_n5op at sbcglobal.net> wrote:
> 
> My standby generator is *not* portable and is a split-phase 240 VAC alternator  It’s a 13 kW natural gas fueled Generac unit. It’s air cooled and says it’s not intended for 24/7 use. That said, we’ve had to use it for a couple of days on end and it’s been reliable. The 24/7-rated units are all liquid cooled; none of the air-cooled units are. No matter what, I’ll have to change the oil and filter every 50-100 h on this unit so it’ll have to be stopped for that. It also burns more oil than a liquid cooled unit, so that needs monitoring as well. 
> 
> While it has a large potted regulator module and another potted battery charging module in it, it is always RF-silent. 
> 
> Kim N5OP
> 
> "People that make music together cannot be enemies, at least as long as the music lasts." -- Paul Hindemith
> 
>>> On Sep 20, 2020, at 11:25 AM, Charles Gallo <charlie at thegallos.com> wrote:
>>> 
>> I have an EU 2000. Only place I can hear it (I’ve tried a few different setups) is on 80m (note: not tried on 160)
>> Took the extension cord for it, put a few (4? Would have to look) through a type 43, and then it was VERY hard to detect. I’ve been very tempted to open it up, and put the ferites right before the outlet, but haven’t 
>> 
>> --  
>> 73 de KG2V
>> Charlie
>> 
>>> On Sep 20, 2020, at 12:10 PM, Kimo Chun <kimochun at gmail.com> wrote:
>>> 
>>> All good advice. It is safe to assume that virtually all inverter
>>> generators generate rfi noise. It is safe to assume that the bulk of their
>>> market/customer doesn't care about or need clean outputs so they don't care
>>> either. I used to have one of the last generation of completely shrouded
>>> conventional Honda generators EX3300. It was stolen. I wish I had it now.
>>> Honda doesn't make them anymore. Too bad.
>>> 
>>> Though I have not tested newer delivered models, the original EU1000 and
>>> larger models all generate RFI. It was more prevalent/noticeable on lower
>>> frequency bands, say 20m and lower. I have one EU1000 that was modified by
>>> a top notch engineer/ham friend to minimize this. I don't have the details
>>> nor have I taken it apart to learn what was done. I just bought it off him
>>> as he was moving. We've successfully used homebrew inline common mode
>>> chokes using Type 31 cores on AC extensions leaving the generators that
>>> have worked OK. No, I didn't do measurement tests (I could) but it was fine
>>> for our Field Day operations. For a fixed, longer term situation more
>>> testing would be in order. A friend bought a Honda 7kw model that had the
>>> same problem. I don't know if he was similarly successful. I didn't follow
>>> up.
>>> If you want to circumvent this issue purchase a conventional generator and
>>> stay away from inverter types. Otherwise, be prepared to clean it up
>>> yourself.
>>> 
>>> The other issue people don't pay attention to is generator design and
>>> application. None of the typical home power backup generators (Generac,
>>> etc.) offered are for continuous - off grid use. You can use them for some
>>> hours per day or perhaps for a few days (see their instructions) at a
>>> time.  If you are looking for near continuous power after a hurricane for
>>> possibly a few weeks (your fuel problem notwithstanding) you need a much
>>> better, different generator designed for that. It will often run at lower
>>> RPM and have other heavy duty design features which require significant
>>> monitoring and maintenance.
>>> Or use their commonly sold one and pray and accept their failure. Say,
>>> purchase a new one after each major use, assuming it did last through that
>>> event. Perhaps a viable risk.
>>> 
>>> 73, Aloha
>>> Kimo Chun KH7U
>>> 
>>> 
>>> 
>>> Date: Sun, 20 Sep 2020 06:46:45 -0700
>>> From: Dave Cole <dave at nk7z.net>
>>> To: rfi at contesting.com
>>> Subject: Re: [RFI] Inverters?
>>> Message-ID: <58123b6c-8262-97ab-1929-dfb0c78f0b51 at nk7z.net>
>>> Content-Type: text/plain; charset=utf-8; format=flowed
>>> 
>>> The best test is to bring a portable shortwave radio, and listen before
>>> you buy...  Most places, have a demo generator set up.Make it clear to
>>> the vendor that if the unit is generating RFI you will be returning it,
>>> with the expectation of a full refund.
>>> 
>>> 73, and thanks,
>>> Dave (NK7Z)
>>> https://www.nk7z.net
>>> ARRL Volunteer Examiner
>>> ARRL Technical Specialist, RFI
>>> ARRL Asst. Director, NW Division, Technical Resources
>>> 
>>>>> On 9/19/20 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
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