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.
Ham Radio and Inverters
- Thread starter hagensieker
- Start date
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 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.
boondox
Chief Engineer, RedNeckTech Industries
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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.
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.
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.
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.
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.
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.
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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K8MEJ
Owner, Off-Grid Power Systems
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.
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.
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...
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.
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.
K8MEJ
Owner, Off-Grid Power Systems
I have not tried extra shielding, yet, because the entire case is aluminum and bonded to the same ground reference. However, the terminals are not fully shielded and I could try that. There are a lot more chokes than can be seen in the pictures, but not as many as you suggest. Each positive battery lead has three in series (four batteries). Also, on the inverter side there are three more stacked cores on each positive and negative input as well as the AC input and output. The inverter itself is pretty quiet. On the large MPPT, there are torroids with four turns at the panels and then again at the input to the MPPT and the output to the bus bars. I used split cores on the battery connections and when that MPPT provides a high charge, those split core ferrites buzz and chatter like crazy.
When I'm operating with the camper, I do have line isolators (1:1 current chokes) on the antenna side and the radio side. That helps reduce the trash generated by other RVs. But I still have to turn off my own MPPT. My designs going forward (on RVs) will use multiple, smaller MPPTs rather than the very large ones.
When I'm operating with the camper, I do have line isolators (1:1 current chokes) on the antenna side and the radio side. That helps reduce the trash generated by other RVs. But I still have to turn off my own MPPT. My designs going forward (on RVs) will use multiple, smaller MPPTs rather than the very large ones.
Thanks to all for their input and experience.
My 7300 is not connected to the inverter output, battery or charger inputs, it is totally isolated.
I don't need any more noise contributed by the unit in the audio spectrum with chattering ferrite cores.
The antenna's close proximity does not help and I think that is going to be my first step is move it to the other side of the property with an additional run of coax. I can move one end of the inverted vee to see if it changes. I have not discerned how far this noise is propagating around the neighborhood.
My 7300 is not connected to the inverter output, battery or charger inputs, it is totally isolated.
I don't need any more noise contributed by the unit in the audio spectrum with chattering ferrite cores.
The antenna's close proximity does not help and I think that is going to be my first step is move it to the other side of the property with an additional run of coax. I can move one end of the inverted vee to see if it changes. I have not discerned how far this noise is propagating around the neighborhood.
For ideas and solutions, google how to fix noise on an SSB radio on a boat. Sailboats use SSB (HF) radios and hove lots of noisy equipment in close proximity, MPPT controllers, inverters, refrigeration compressors, etc. Noise mitigation is a part of every installation. The interference also works the other way, commonly keying an SSB will cause an autopilot to veer off course. Ferrites are the usual solution.
Thanks, I will search for some ideas.
I spent a good 10 years of my life fixing the Atlas brand of ham radios where a larger number of them were used on sailboats. Saltwater corrosion was their biggest enemy.
ko6kL
New Member
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thank you for your effort to bring this up with the factory. ko6kL Did you get a letter back ?
K8MEJ
Owner, Off-Grid Power Systems
Nothing yet
K8MEJ
Owner, Off-Grid Power Systems
After some delays, there has been some progress here. I contacted the CEO of Victron to escalate my request and I got his attention. The engineering team is aware of the issue and Victron has committed to future product updates with their MPPT controllers. Some are coming soon, but the larger units will require some time to get to production. They also sent me two 100 amp DC line filters to place on the PV input and battery output. They believe the line filters will reduce the noise substantially coming from the PV side. I will try to get those installed soon, but it'll be a while before we get strong enough sunlight here in Ohio to generate enough energy to full load up the MPPT controller and I don't have a large enough power supply to simulate the full PV input. So I'll have to wait until Spring before I can really find out if the line filters help with the noise.
K8MEJ
Owner, Off-Grid Power Systems
I don't expect they will. The engineers suggested two different line filters to help my issue until they can redesign the larger chargers. They told me some of their smaller MPPTs that will be released soon should be quieter than the models they are replacing. My 100amp MPPT is super noisy but my 30amp MPPT is very quiet. They offered to replace the 30 but I don't think it's necessary. When I hear that a new 100amp MPPT is released I'll definitely order one and test it.
Larry Claggett K8OMA says to tell you hello. I chatted with him this morning on 3.815. There's a morning roundtable with a bunch of Ohio hams. Maybe you could join in some time. Right now I'm lucky to check in once a month but the other guys are on every day and they're a pretty technical bunch. Check it out sometime.
Cya!
K8MEJ
Owner, Off-Grid Power Systems
Wooops
I thought I was replying to a direct message. Sorry about that!Similar threads
