diy solar

diy solar

Ham Radio and Inverters

Thanks for all the info and feedback , guys. The pointers are really appreciated and I am in contact with the seller who is about 800km away. He just sold another 830s with matching external speaker and auto antenna tuner for about $450 ( our Rands converted ) which I missed. Will report back soon.
 
I had an 820 for a while after upgrading from the 520 and liked both rigs. Basically solid state rigs with tube finals.

My friend had the 830 and I was always envious of the digital display.

If it has the filters that is a plus. Here are some on Ebay for comparison.

If it is a Kenwood TS-830S "Gold Label", it comes factory equipped packed with all filters. I am fortunate enough to have Gold Label in the shack, and will be in my will...? 73 de Mike.
 
I've really been around and around trying to figure out how to have a relatively noise free environment while running a solar inverter and shortwave radios at the same time.

The first conclusion I have come to is for small radios with their own aerial in the same or next room as the inverter..........you can't. It is simply too noisy on AM radio and lower short wave bands.

I started with a Giandel 2000 watt and it was terrible with RF emissions. It sprayed RF all over the place.

Then I read that Samlex Inverters were way better with RF. So I dropped $550 for one. Once again my AM bedside radio was blasted with RF. Unusable. Then I hooked that radio to an outdoor antenna and it was greatly improved.

Then instead of using a shortwave radio (I have MANY) I used a shielded RTL-SDR device. An SDRPlay RSPdx. Then I hooked it to an outdoor antenna and there is almost no RF interference at all. All you can see are the signals in the pic below. No hash or interference or floor noise much between the signal peaks.

View attachment 10312

By the way, how many of you know that AM radio signals travel for hundreds and sometimes thousands of miles at night? There are a lot of high power (clear channel, 50,000 watts) radio stations.

At any rate here is what I have learned in a nutshell.

- The Samlex inverters are way better than Giandel as it relates to RF emissions.
- Better does not mean perfect. A nearby AM radio or shortwave radio up to about 7 MHz with an indoor aerial will experience severe interference.
- A shielded RTL-SDR device can eliminate most of the remaining RF interference.
- I have several shortwave receivers and best results are obtained when the Solar Inverter is turned off when I am trying to dig signals out of the muck. They are quite useable above 5 MHz 99% of the time. Also as an interesting note the power supply at the left of the picture below is really noisy as it relates to RF as well. I have it hooked to one radio as a power source. Bad idea.

View attachment 10313

- While it is fun to play with the old shortwave radios, in a grid down situation when the solar HAS TO POWER THEM, an RTL-SDR device will need to be used. For the most part the SDR's are technically superior to the old boat anchors but not as much fun.
- Need to get some ferrite chokes to see if the RF can be reduced further.
- Greater distance to the antenna improves the situation.
Any modified sine-wave inverter is likely to spray harmonics all over the MW and SW bands.
 
Any modified sine-wave inverter is likely to spray harmonics all over the MW and SW bands.

I think it depends more on the design. I had a Trace 2512 modified sine wave inverter for many years and it was pretty good about spewing RF. These days I am guessing that only cheapie manufacturers are making modified sine wave inverters and so they probably do all spew RF. Modified sine doubtless creates more harmonics and hash but good engineering can suppress it.
 
Where there is a will there is a way Pierre.

I currently DX (and contest a little) from an off grid shipping container outside of town in AZ.

Elecraft KX3 and KXPA100 powered by 12v nominal LiFePO4. I can add a KPA500 amplifier powered from a 48v nominal LiFePO4 powered by a 3KW pure sine inverter.

The equipment is a bit better than my sketchy Novice station in 1972 ! The fun factor is still the same !!
Joeham. What 3KW pure sine inverter are you using in your shipping container to operate your KPA500? How's the RFI from it? Is it 12v?
 
Joeham. What 3KW pure sine inverter are you using in your shipping container to operate your KPA500? How's the RFI from it? Is it 12v?

No it’s a WZRELB 48v.

Has some RFI but I still put up decent scores in the CQWW 160m CW contest with the setup.
 
I've really been around and around trying to figure out how to have a relatively noise free environment while running a solar inverter and shortwave radios at the same time.

The first conclusion I have come to is for small radios with their own aerial in the same or next room as the inverter..........you can't. It is simply too noisy on AM radio and lower short wave bands.

I started with a Giandel 2000 watt and it was terrible with RF emissions. It sprayed RF all over the place.

Then I read that Samlex Inverters were way better with RF. So I dropped $550 for one. Once again my AM bedside radio was blasted with RF. Unusable. Then I hooked that radio to an outdoor antenna and it was greatly improved.

Then instead of using a shortwave radio (I have MANY) I used a shielded RTL-SDR device. An SDRPlay RSPdx. Then I hooked it to an outdoor antenna and there is almost no RF interference at all. All you can see are the signals in the pic below. No hash or interference or floor noise much between the signal peaks.

View attachment 10312

By the way, how many of you know that AM radio signals travel for hundreds and sometimes thousands of miles at night? There are a lot of high power (clear channel, 50,000 watts) radio stations.

At any rate here is what I have learned in a nutshell.

- The Samlex inverters are way better than Giandel as it relates to RF emissions.
- Better does not mean perfect. A nearby AM radio or shortwave radio up to about 7 MHz with an indoor aerial will experience severe interference.
- A shielded RTL-SDR device can eliminate most of the remaining RF interference.
- I have several shortwave receivers and best results are obtained when the Solar Inverter is turned off when I am trying to dig signals out of the muck. They are quite useable above 5 MHz 99% of the time. Also as an interesting note the power supply at the left of the picture below is really noisy as it relates to RF as well. I have it hooked to one radio as a power source. Bad idea.

View attachment 10313

- While it is fun to play with the old shortwave radios, in a grid down situation when the solar HAS TO POWER THEM, an RTL-SDR device will need to be used. For the most part the SDR's are technically superior to the old boat anchors but not as much fun.
- Need to get some ferrite chokes to see if the RF can be reduced further.
- Greater distance to the antenna improves the situation.
I was wondering which model Samlex inverter you were using and if you were able to finally eliminate the EMI/RFI? I have tried numerous inverter and have had no luck. My ham radio antennas are all outdoor antennas but are only about 40' away from my solar CC and Inverter. They pick up lots of noise on nearly all of the HF bands. Mostly birdies about every 30-40Khz.

My Morningstar TriStar PWM charge controller is QUIET on all of the HF/VHF/UHF bands. This CC is great. Now all I need to do is find a quiet Inverter.
 
I was wondering which model Samlex inverter you were using and if you were able to finally eliminate the EMI/RFI? I have tried numerous inverter and have had no luck. My ham radio antennas are all outdoor antennas but are only about 40' away from my solar CC and Inverter. They pick up lots of noise on nearly all of the HF bands. Mostly birdies about every 30-40Khz.

My Morningstar TriStar PWM charge controller is QUIET on all of the HF/VHF/UHF bands. This CC is great. Now all I need to do is find a quiet Inverter.

My Magnum inverters do pretty well. Mine are within the loop of my main antenna and there is no prblem. My Midnite Classic 150 makes some hash on 80 meters but since I only do 80M at night it isn't a problem.
 
Are low frequency inverters not much RFI quieter than high frequency ones ? Also , I once used a switch mode 12v 30A
power supply on my HF rig and the noise level was a constant S5 on receive.
 
A few tips - I nearly buried all my output power cords in ferrite. Helped, but discovered that many devices are quite good at putting noise back into your house wiring for those devices that plug in directly, and have no power cords you can wrap.

Hence I recommend any swl / amateur to look into the TrippLite ISObar power outlets. Filters the low bands, as well as VHF from getting fed back into the house wiring. Got a few around - mostly the entertainment center, also in the garage for various items and wallwarts powering stuff. Expensive compared to grocery-store extensions, but worth it when it nails that gnarly little squeal you've been chasing down for the last 20 years. :)

For rx-only, you may want to look into the KK5JY project site about the "on ground loop" antenna for great s/n. IF your ground is poor, you may also want to look into a heavy duty CMC ot common-mode-choke at the end of this as well.

Samlex inverters - it's my go-to brand for general rf-quietness.
 
My radio's run on 12V, unless an amp is needed, I'm good to go. Throw some wire in the trees, and i'm there.
 
I have the MPTSolar LV2424 MSD and the RFI is terrible. Noise is coming from everywhere and is extreme when solar is charging.

Has anyone had good success with mitigation efforts?
 

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Is there any difference if you run a temporary test by powering the 7300 solely from a battery?

I'm assuming an outdoor antenna, and not a cb-mag mount sitting on top of your power supply. Basically too many unknowns here on what you have / have not tried.

My thought is common-mode problems. If you don't have one, get a DECENT one and place it in your transmission line. I use the CMC chokes from MyAntennas , especially for the low bands. A couple of snap-on's just don't cut it.

And that's just common mode - but you still could have direct radiation issues too. So basically not enough info on your setup and history to provide anything really specific.
 
Is there any difference if you run a temporary test by powering the 7300 solely from a battery?

I'm assuming an outdoor antenna, and not a cb-mag mount sitting on top of your power supply. Basically too many unknowns here on what you have / have not tried.

My thought is common-mode problems. If you don't have one, get a DECENT one and place it in your transmission line. I use the CMC chokes from MyAntennas , especially for the low bands. A couple of snap-on's just don't cut it.

And that's just common mode - but you still could have direct radiation issues too. So basically not enough info on your setup and history to provide anything really specific.
The 7300 is in the house and not connected to the off-grid setup. I am a ham, so not using a CB antenna but a 40m inverted-vee relatively close to the inverter on one end of it, which is probably the biggest reason for the RFI and not an easy fix.

I am not familiar with the CMC and was hoping to eliminate as much of the RFI at the source. This works on the antenna. Are you using one?
 
Trying not to turn this into an amateur radio thread ...

I use several different inline CMC chokes (aka common mode chokes, usually of ferrite design) depending on the gear. MyAntenna, Palomar Engineers, MFJ, and Balun Designs LLC come to mind. Usually at the rig off a 1 foot jumper. (do not barrel directly to rig)

These chokes work both ways: noise introduced on your chassis by the inverter, dc wiring can travel along the outside of the braid of the coax, right up to your feedpoint, and then right back down to the receiver - albeit it is no longer common-mode, but transmission line mode noise. The chokes help prevent *both* ingress and egress of noise.

It gets worse usually as you go lower in frequency, so an MFJ may make a slight improvement, but a Palomar Engineer or higher quality unit can tame things significantly at 160m and up.

So, if your rig is attached to your solar setup battery, the inverter noise can travel along the cabling and not always be directly radiated into the antenna. So two problems. You can attack one angle easily with the inline CMC choke. If that makes an improvement, then you can adjust or change to a different antenna design. A delta loop perhaps.

Also consider putting one of the aforementioned TrippLite IsoBar's at the output of your inverter, and power your AC things from the IsoBar.

Then there is the matter of having a good RF ground, not just an electrical safety ground. And at 10m, you can easily have what appears to be a very long run of grounding which is worthless at that freq.

Anyway, you can see one has to be willing to do empirical things to see if they make a difference - each setup is different.
 
Here is a great resource about chokes :


I have found that my Victron MPPT is much a worse offender than my Schneider SW 4048 inverter but I have just choked everything as much as possible. It could be the MPPT part of your AIO unit that is the issue.

RFI is now mitigated, but not gone.


I believe @K8MEJ has tried to work with Victron on the issue but not sure how responsive they were to his efforts.
 
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In my Victron environment, mix 31 ferrites on all inputs and outputs keeps the inverter noise to a minimum. However, it's insufficient to tame the horrible noise coming from the solar charge controllers, especially under high load. If want to see some data, read the attached. This is what I sent to Victron.
 

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Very good write-up and hope they take this problem seriously.

In the meantime, I see what appears to be an insufficient amount of chokes - like only 3 large and small snap-ons. In this nasty case, to even make a dent, plan on using 6 or even more on each input and output.

Also in the meantime, is there anything at the back of the 7300, like a whole string of these snap-on's, or better yet, a large inline Palomar Engineer / MyAntenna or even the measly MFJ-915 ?


It takes something like these to even make a dent for me on 160 / 80 meters. Actually they make a big dent, whereas the mfj was just a teaser. :)

This won't solve direct-radiation to the antenna itself. Nor will it fix a noisy 13.8v supply source attached to your controller. But it will put the hurt on common-mode which might make operations tolerable.
 
A cheaper thought - after seeing the pics in the pdf, have you tested any shielding?

That is, a simple test of putting kitchen foil over basically the face of the controller, and securing with blue painters tape to keep it in place to see if shielding makes any difference at all?

I know you'll be safe if you try this after seeing all your switches in your setup. If external shielding helps, then maybe something more permanent - like EMI spray on the inside of the case etc etc...
 
Note: even if a good CMC common-mode choke at the back of the rig doesn't immediately solve all the problems, it is not a wasted investment.

Unless the shield braid of your antenna is part of it's design, by severely attenuating the common-mode, it will help preserve your antenna directional pattern, and may serve as an aid to positioning the antenna to put the inverter noise into a null. Without a good CMC, the pattern may be more or less random / omnidirectional, and noise-nulling from direct radiation may be frustrating.

Near inverters, a balanced antenna design, such as a delta loop rather than a vertical or standard dipole may help.

Curing these problems are always a multi-faceted approach. The simplest solution to one facet is to use a GOOD common mode choke at the back of the rig. It's a good start to just one variable.
 
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