A quiet 12v DC to 110v AC Inverter?

Norm - W7CK

Although I am running a Flex 6700, please forgive me for asking a question that isn't directly related to Flex.

I have the need for a 12v DC to 110v AC Inverter.  All of the ones I've trid over the years (mostly cheap ones) produce a lot of hash, RFI, interference on the HF and sometimes VHF bands.

Now I'm looking for an Inverter that is RF QUIET.  Does such a beast exist?  Can anyone provide any insight, suggestions or solutions?    In the past I've tried ferrits, but they really didn't do much to shield the noise.

My station here is 100% solar and you wouldn't believe how noisy some of the new solar equipment can be.

HELP!   

VK7WH Winston

I had the same problem trying to find a quiet inverter for my solar powered remote site, and after much searching and testing I eventually discovered such an inverter does in fact exist, although I'm not sure if they make it in a 110 Volt version. It is sold under the brand name Projecta. You can google for the details. They make several models in a number of power levels. The one I have is their flagship range. I have the 2KW version. I'm out of the shack at the moment, but I can email you further details when I get home later in the day, if you would like. However , as I mentioned, I'm not sure if they make a 110 volt version. Good luck de Winston VK7WH

VK7WH Winston

Sorry, I forgot to mention, Projecta is an Australian Company based in Melbourne. I can speak to the on Monday to see if the make a 110 version if you wish

Norm - W7CK

Winston, thank you for responding.  I'm interested in getting a little more info on the Projecta brand if you come across any.

While a 2KW Inverter would be a little overkill, I'm willing to give it a try. if it is fairly efficient in standby mode then it really doesn't matter if it is a little larger than needed.  My demand may increase in the future.

What voltage Inverter are you end up using at your solar site?  

Norm - W7CK

Winston,

I went out to the Projecta web site and it took me a moment to realize that all of their inverters are 240v 50hz output.  That won't work for us here in the US.  We require 110v 60Hz.

Thanks though!

VK7WH Winston

Yes, Norm, I did mention that to you., however I do wonder as it is inverter technology, using a microprocessor and software, they may make a 110V 60 Hz version for the overseas market. The unit is designed in Australia but manufactured in Taiwan so they may have licenced the technology to someone else to distribute to the global market. Yes, the IP2000 has an extraordinary low idling current in sleep mode. For memory it is around 5 miilliamps. Some other makes have an idling current around an Amp! The other reasons I chose the IP2000 was that this model has an automatic change over to mains or generator power, which could be useful in the future., and at the power level I am using it just loafs along and barely gets warm and, most importantly, it has very low RFI. The other models available are the IP600 and the IP1000., which have all of the features of the IP2000 except for the auto changeover. By the way, I have no connection with Projecta. I just love the IP2000! What a shame if it is not available for you market, as I am sure it would suit your needs. Good luck Winston PS, sorry that this is a little off topic.

WX7Y

Here is a good ARRL review for a few different types of inverters that may be what you want to look over http://www.centralmiarc.com/docs/Reviews/dcacmaha.pdf 73 Bret WX7Y

AA0KM

Look for Pure Sinewave and not Modified. That may help too

dlwarnberg

Norm.. am curious.. why take 12v DC and up-convert it to 120v AC only to feed that to a power supply that down converts that to 12v DC to run the radio??  Why not just use the 12v?

Example, in my shack I too am solar, 100w panel on the roof, feeding a TrakMax MPPT 12/24 volt charger charging two 12 volt VMAX solar SLR100 batteries (100 amp hour each), I run that into a line conditioner (12v to 12v) forget which one I have and that then feeds my RIGRunner 4005i to power all my equipment... this is really setup for power outages or hurricane prep (I live in Florida) but we also use it during field day... 

My biggest noise maker is the DC pool pump, solar to inverter to DC pool pump, saves lots of money in electricity but the RFI is crazy...

Anyway just curious.

PS, for an inverter look at a Pure Sign Wave inverter, they will be your best bet

David, KK4QOE

Norm - W7CK

I'm not up-converting to run radio equipment.  My radios are all running off of 12v directly as well as external disk drives, router, POE switch, surveillance equipment, etc.  The inverter is for 120v AC like my large monitor, computers, fans, TV, some 120v lighting, etc.  I'll use this at the house as well as on the 5th wheel.  I just want it to be as quiet as possible.

dlwarnberg

Ahh... now I understand.. thanks and good luck

Walt

You might google up marine inverters - the ones for boats usually have FCC type B ratings so that marine HF will be usable.  Pretty pricey, but most are quality units and if they can stand bouncing around in the bottom of a boat for many years ( I only changed mine out after the last one lasted 18 yrs.) then they should do a fine job on land.

And there are many that are made in the US and available from US suppliers, both near the east/west coast or on the internet.

Cheers !

Walt

Oh - there are also FCC Class A units too - cost twice as much and come in at about 50 lbs.  But on land, the weight may not be an issue.

Cheers !

VK7WH Winston

Morningstar make a 300 watt pure sine wave inverter. I'm not sure if this is large enough for you. I don't have any first hand experience with this inverter, but I do have a Morningstar 60 amp MPPT solar regulator which is very quiet. Might be worth a look. Morningstar make excellent equipment.

Norm - W7CK

Well after much research, phone calling, more research and then finally pulling the trigger, I've now got an inverter that is pretty darn quiet.  For those that are interested, my research narrowed the selection down to a Samlex PST-2000-12 which is rated at 2000 watts continuous and 4000 watts surge.  This inverter was recommended to me by Sun & Wind Solar out of Flagstaff (I have no affiliation with this company).  They gave me a phone number and suggested I give Samlex a call, describe how I was going to use the inverter and and ask them any questions I might have.   I gave them a call and was really surprised when I was immediately transferred to an engineer.  He recommended any of the PST model inverters.  He said all inverters create RF noise but the PST series is the quietest they make.  He answered several other questions and didn't make me feel rushed.  It was very pleasant.   If this is any hint of what their service department is like, its a breath of fresh air!!!  Nothing like Flex Radio service mind you, which is the best!!!!!

When my new inverter first arrived, I temporarily hooked it up using some small cables coming off of my RIGrunner which is fed from my 12v battery bank.  This is the worst way to hook up an inverter.  There is little to no dampening affect from the batteries and the cable is not heavy enough to provide more than 300-400 watts maximum.  An inverter should be connected directly to the battery bank with short cables of a gauge adequate to handle the amperage required by the inverter.   But, I was anxious to give it a test.

I quickly plugged in a few items, 2 large fans, a couple lights and a soldering iron.   My Flex runs directly from the same RIGrunner that the inverter was plugged into.

I opened up 4 panadapters each on a different band.  I then noted noise floor and watched the panadapters as I turned on the inverter.  I couldn't believe it - basically no change other than a slight rise on 80m.  No birdies that I could detect at all.  I loaded up the inverter by turning on some of the devices I had attached to the 120v side and still nothing really happened on the panadapters.  I checked several bands, listened to some AM broadcasts and eventually decided it was a complete success. 

I'll be installing the inverter in my 5th wheel this week.  The 30 watt PWM charge controller I put in there 3 years ago produces very little RFI - a couple birdies outside of the ham bands.  I have 3 - 140w panels and 4 - 6v gulf cart batteries wired into a 12v bank.  I'll now have a solar system for my 5th wheel that is REALLY quiet.

For any of you folks that have a boat, RV, cabin or just want to build a solar powered station, I highly recommend this inverter.

I have absolutely no affiliation with Samlex.

    

dlwarnberg

Very nice.... FYI, for batteries you might take a look at the VMAX, I have twin 100 amp hour 12 volt batteries that I've had now for 4 years and ZERO issues..

http://www.vmaxtanks.com/Solar-Batteries_c_21.html

I found these years ago and have been very pleased..

Good luck and great info

Thanks

Norm - W7CK

Thanks for the battery info David.  I've been using the 208 Ah golf cart batteries from the club stores.  The ones in the 5th wheel are 6 years old and still working great.  I've had panels on the 5th wheel for a little over 3 years now and they keep the batteries topped off nicely.  The whole solar adventure has been lots of fun.  I'll keep the vmax site book marked and maybe give them a try when I replace the 5th wheel bank.

Thanks again!

Roger Rockwell/na4rr

Hi Norm,

Great timing on this.  I'm going through the exact same process.  Glad you've done the leg work.  The converter in my RV is generating an unbelievable amount of noise so I'm going to start there and then move on to inverter and solar.   I had an IOTA in the last rv an never had a interference  it.  Do you have a switching system from shore to inverter?  What controller are you using for the solar? 

thanks
roger

Norm - W7CK

I do have a switching system shore power to charger/converter.  I've been on solar for the past 3 years, so I never have my 5th wheel plugged into shore power. I can't say how quiet mine is.  I'd actually have to go and test it.

When I purchased my converter, I did a lot of research and even called the company - Progressive Dynamics.  The technician told me he had several hams that have bought the Progressive Dynamics Inteli-Power 4600 to keep their batteries charged up and have had good success with it.  He said it had quite a bit of filtering designed into the converter.  Once again, Its been in my 5th wheel for a while but since installation, I've never really turned it on other than the initial test.  Its a really nice 4 stage charger with pretty good filtering and is a direct replacement for the standard converters found in most campers, 5th wheels, motorhomes, etc.  It even has a boost override button that lets you really dump the amps to the battery system if you are charging from a generator and only plan to run the generator for a short period of time.  Sorry but my XYL just had surgery otherwise I'd cart a rig over there and test it out for you.

The solar charge controller is just an inexpensive Solar 30 PWM controller built in China and sold for about $30.  No hash, birdies, or noise of any kind.  A friend of mine also has one and they are extremely quiet.  Stay away from MPPT controllers as they are generally noisy and nearly impossible to quiet down unless you are able to have a lot of separation between CC and your other gear.  I've tried several MPPT controllers and have never found a quiet one yet.  Midnight Sun makes a unit called The Kid, which is for marine use.  It was terrible!  Birdies every 25 Hz or so from 160-10m.  I tried everything to quiet it down and was unsuccessful.  It may have been my particular installation configuration so your mileage may vary.  Be careful because most of the solar equipment I've come across is non-refundable.  

Make sure you ground the outside cases of all of your solar equipment including the inverter.  A true or full sine wave inverter is often quieter if you ground the outside case to the NEG leg of the battery system and the frame of the RV if present.  Only ever do this with a true/full sine wave inverter. Grounding the outside case of a modified sine wave inverter will most likely destroy the unit.  Consult the manufacturer.

 Hope this helps!