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Noise on GMRS frequency


8nannyfoe

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I recently saw a video on Youtube where the person is a firm believer that solar power causes noise in his ham radio operations.   It was awhile back and I don't recall the specific frequency he was operating at nor can I remember if his solar powered set up was strickly DC or a DC to AC inverter (either modified or pure sine wave)   At any rate, I am interesting in setting something up solar powered and am looking for GMRS user experience.   If you had noise, please let me know the type of solar set up you had going on during your tests (DC setup mention with PWM or MPPT please),  OOORR  AC inverter and also please mention if it was modified sine wave or pure sine wave).   Thanks in advance!

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Usually there is no way to know if there will be noise until you set everything up the first time. Likewise, noise can be caused by several sources both within your set-up, or from outside sources like transformers, capacitors, or high voltage power lines, and they don't even need to be connected to your set-up to cause those noises.

Best bet before spending money to chase a hidden phantom you don't yet know you have is to try the set-up. If you have noise, try moving the set-up to another location (including the antenna) If you have the same noise in both locations, it'll likely be within your unit. There are filters for the power going to the radio, those would be a good start to see if that resolves your issue, (usually it will at least when operating off vehicle power.)

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I got several solar panels new from the company linked below. I also purchased a few used ones at Ham Radio flea markets. I would recommend something in the range of 20 to 50 watts for the panel.This should be sufficient to keep a small handheld radio or a mobile radio running with the right sized battery pack and solar plane size. 

 

https://www.renogy.com/solar-panels/rigid-solar-panels/

 

I also have several of the MPPT charge controllers from this company. I have several of the GV-5 models. One for a lead acid type when there is nothing else available and several for LFP battery packs.

 

https://sunforgellc.com/gv-4/

https://sunforgellc.com/gv-5/

https://sunforgellc.com/gv-10/

 

I wouldn't recommend the use of any kind of lead acid battery unless you want the cheapest portable battery solution. I've wrecked enough gel-cell and AGM types. They have to be kept on a trickle charger when left sitting around for more than a few weeks. If you don't the batteries self discharge quickly and the plates will sulfate. Once the plates are sulfated the battery is finished.

 

I recommend going with a LFP, Lithium Iron Phosphate (LiFePO4), batteries. They hold a charge for months, some even for a year or more, and don 't get ruined if they sit around only partially charged. The only caveat is the cost . I got a couple of the battery packs from the company at the link below. One was the 6 amp hour BLF-12045W and the 40 amp hour BLF-1240A. Don't forget to get the wall changers for these batteries. The above charge controllers I got were the models designed for LFP batteries, NOT lead acid or LiPO's.

 

https://www.bioennopower.com/collections/12v-series-lifepo4-batteries

 

I also have a 12 volt to 120 volt AC pure sine wave inverter for the rare case where I need 120 volts. I picked up a 300 watt unit which I have set up to work with the 40 amp hour battery.

 

https://gpelectric.com/products/300-watt-pure-sine-wave-inverter/

 

Now a few words of caution about connecting solar panels to batteries. A few people skip the charge controller and wire the solar panel direct to the battery, through a blocking diode. While that will work in an emergency with lead acid types DON'T try this with LFP battery packs!

 

Just about every LFP battery pack contains a battery protection module. The module will disconnect the internal battery cells from the external terminals in the case of a short circuit, over discharge resulting in a dangerous low voltage or when the battery pack reaches max cell voltage on charge. The last one is the killer. A so-called 12 volt panel is really 20 to 23 volts when open circuited. So when the battery reaches the max safe voltage the protection module will disconnect the internal battery pack so it  effectively open circuits the solar panel, which promptly jumps way up in voltage. Most mobile equipment can't handle anything higher than 15 to 16 volts without damage. 

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Usually there is no way to know if there will be noise until you set everything up the first time. Likewise, noise can be caused by several sources both within your set-up, or from outside sources like transformers, capacitors, or high voltage power lines, and they don't even need to be connected to your set-up to cause those noises.

 

Best bet before spending money to chase a hidden phantom you don't yet know you have is to try the set-up. If you have noise, try moving the set-up to another location (including the antenna) If you have the same noise in both locations, it'll likely be within your unit. There are filters for the power going to the radio, those would be a good start to see if that resolves your issue, (usually it will at least when operating off vehicle power.)

I see you have both the GMRS and a HAM call sign.  Was your advise for a GMRS specific system or a ham setup that you had experience with?   The reason I'm asking is I think some of the upper end ham equipment is super sensitive on HF?   I may be totally wrong on that point, but I believe the guy in the youtube video I watched was on HF.  GMRS frequencies may not have the same sort of noise from solar equipment?   And just for reference, what is the device called that filters power going to the radio?  Even model names you had success with?  My cabin is off grid and solar powered with a pure sine wave inverter.  I won't be there for  a couple months and am planning ahead because the delivery service up there takes forever and is quite a PIA. 

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I got several solar panels new from the company linked below. I also purchased a few used ones at Ham Radio flea markets. I would recommend something in the range of 20 to 50 watts for the panel.This should be sufficient to keep a small handheld radio or a mobile radio running with the right sized battery pack and solar plane size. 

 

https://www.renogy.com/solar-panels/rigid-solar-panels/

 

I also have several of the MPPT charge controllers from this company. I have several of the GV-5 models. One for a lead acid type when there is nothing else available and several for LFP battery packs.

 

https://sunforgellc.com/gv-4/

https://sunforgellc.com/gv-5/

https://sunforgellc.com/gv-10/

 

I wouldn't recommend the use of any kind of lead acid battery unless you want the cheapest portable battery solution. I've wrecked enough gel-cell and AGM types. They have to be kept on a trickle charger when left sitting around for more than a few weeks. If you don't the batteries self discharge quickly and the plates will sulfate. Once the plates are sulfated the battery is finished.

 

I recommend going with a LFP, Lithium Iron Phosphate (LiFePO4), batteries. They hold a charge for months, some even for a year or more, and don 't get ruined if they sit around only partially charged. The only caveat is the cost . I got a couple of the battery packs from the company at the link below. One was the 6 amp hour BLF-12045W and the 40 amp hour BLF-1240A. Don't forget to get the wall changers for these batteries. The above charge controllers I got were the models designed for LFP batteries, NOT lead acid or LiPO's.

 

https://www.bioennopower.com/collections/12v-series-lifepo4-batteries

 

I also have a 12 volt to 120 volt AC pure sine wave inverter for the rare case where I need 120 volts. I picked up a 300 watt unit which I have set up to work with the 40 amp hour battery.

 

https://gpelectric.com/products/300-watt-pure-sine-wave-inverter/

 

Now a few words of caution about connecting solar panels to batteries. A few people skip the charge controller and wire the solar panel direct to the battery, through a blocking diode. While that will work in an emergency with lead acid types DON'T try this with LFP battery packs!

 

Just about every LFP battery pack contains a battery protection module. The module will disconnect the internal battery cells from the external terminals in the case of a short circuit, over discharge resulting in a dangerous low voltage or when the battery pack reaches max cell voltage on charge. The last one is the killer. A so-called 12 volt panel is really 20 to 23 volts when open circuited. So when the battery reaches the max safe voltage the protection module will disconnect the internal battery pack so it  effectively open circuits the solar panel, which promptly jumps way up in voltage. Most mobile equipment can't handle anything higher than 15 to 16 volts without damage. 

Sorry, I left out I already have a completed solar powered setup.   My GMRS setup will be installed there in a couple months and Im looking to know if there will be noise on GMRS specific setups/frequency.   I think you are giving example how to set up a solar powered system because you didn't have noise?   The way I worded my question is confusing I guess because in my initial question, I was asking if you HAD noise describe you setup.   Bad wording on my part and am just trying to clear up if you did or didnt have noise with your GMRS setup.  Thanks

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The charge controllers I linked to claim little to no RFI generated.

 

Any type of switching power converter has the potential to generate huge levels of RFI unless it’s well shielded and proper filters on all of the wires going in and out of the box are used.

 

Many radio operators have experienced RFI just from using their table top DC power supply plugged into a wall outlet. Those aren’t the only sources either. You can search for and read the horror stories where people spent weeks or longer only to find it was the LED night light, malfunctioning power supply in a TV, computer was sitting to close to the radio, noise only present when the USB printer cable was plugged in etc.

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round here channel 3 makes it impossible to scan... keeps making a racket causing the scan to stay on the channel. We do have wind turbines near and I know of a few panels. It's not static, it's rhythmic, like a pulse would be. Almost like a repeating signal intent on finding life in space. Very annoying.

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  • 4 months later...

So I have an RT97 setup that is running Solar. It's hooked up to a 50 and 30 watt panel. The 50 watt panel is a Renogy. I forget what the 30 watt is (Zamp?). I have a cheap PWM solar controller feeding into a 35 amp hour SLA battery and also acting as the battery protection circuit.

 

Here is a link to the controller.

https://www.huinetech.com/products/10a-20a-huine-pwm-waterproof-solar-charge-controller-12v-24v-compatible-for-solar-system

 

I have had zero CONFIRMED issued with noise from this setup but today, around 10:00am I had something pushing RFI in on the input frequency of 467.625. The repeater would push it back out everytime you would key up a radio and send the DCS codes. It appeard the RFI would then keep the repeater open for a few seconds to several minutes at a time. 

 

I checked with others in the repeater service area and they had the same experience. I monitored the input frequency from my home but heard no RFI. Granted the repeater is in a much better location for reception than I. If you were close enough or had enough power you could take over the RFI and it would just be heard in the background of your transmission.

 

About a half hour later, gone. Everything working just fine.

Here is a small video clip. Note how it doesn't start until I key the radio. It faded away and stopped about 10 seconds later.

 

 

Edit: it's 8 PM and it's back to doing it again.

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