WRFP399

Yeah...whatever you Motorola Snobs are just angry my 200 dollar Retevis RT97 does the same thing.
 
 
 
::Heavy sarcasm::

Yeah...whatever you Motorola Snobs are just angry my 200 dollar Retevis RT97 does the same thing.
 
 
 
::Heavy sarcasm::

Thanks for sharing that .  My RT97 is mounted in a box on the side of it's tower in the Texas sun .  I tested it buy talking to a motormouth that lives in the next town 15 miles away  in 105 deg summer heat . He talks nonstop sometimes for 9 to 12 minutes without unkeying .  I did put an air vent in it's box made from pvc pipe that came out top and turned down to keep the rain out .  It's been up and working fine for 2 years now with no problems .  It is at 70' with a 30 mile range to a mobile .  I am well pleased with it . 

RT97 “Duty Cycle”
 
I had a replacement RT97 come in today as a replacement for one that failed. The prior failed as it would not longer talk to a computer for programming. The TX/RX worked fine. I decided to test this new units “duty cycle” and heat displacement abilities.
 
The first thing I did was open it up and see what it has internally to bridge the transmitter to the aluminum outer housing. The bottom of the RX/TX unit has large fins cast into its aluminum body. It appears to be bedded in thermal paste to make a conductive path the aluminum outer housing.
 
I took a food thermometer and put it into the thermal paste. The unit was at 70 degrees.
 
The “Test”:
 
Stage One: I had it transmitting on high power. The transmission was broken up into three 1 minute sections with 10 seconds between each followed by a whole 2 minutes of TX. The transmitter rose from 70 degrees to 82 degrees. Hardly warm to the touch. (12 degree rise for 5 min Total TX w/ 40 seconds rest)  
Stage Two: I gave it about 2 minutes of rest and hit it with two more sessions of 2 minutes transmissions, separated by 20 seconds. It had fallen to just below 80 prior to and rose to 89 after.(9 degree rise for 4 min Total TX, w/ 2 min 20 seconds rest)  
Stage Three: I finally let it sit for 1 minute and did five more sessions of 2 minutes transmissions, separated by 20 seconds. The temp started at 88 and rose to 102 (14 degree rise for 10 Min Total TX w/ 2 min 20 seconds rest)  
End total of 19 min of TX w/ 3 min 20 seconds of rest. The temp rose from 70 degrees to 102 degrees.
 
What I find interesting is that after the radio “warmed up” it took significantly more time to heat up further. I expected the 10 min spent TX'ing in Stage 3 to raise it more than it did. At the end after only about 60 seconds of rest it already had dropped to 94 degrees from a high of 102. I did not repeat this test on low power but I can only assume it would take longer to heat up.
 
Being as my use with these repeaters are outdoors here in Alaska it doesn’t appear that heat will be an issue for me. During the winter our avg daily temp is around 20 degrees and we only get to an avg daily temp of 60-65 in the summer. This leaves a lot of head room. The cooler ambient temperatures should further increase the rate of heat dissipation as my home was 70 degrees to start with. Anyone see any flaws with my logic?

The main 625 repeater is "off" as it ran low on power from all the "abuse" I was putting it through. While that is off and charging I am thinking about putting up the second RT97 tonight near Mt. Baldy to see how it works with that national net. Just gonna drop it on the ground somewhere with a battery and roll up J-Pole stuck in a tree. 

As an update we have been heavily overcast here for about 2 weeks. So much so it appears the panels are making little power.  I have connected into myGMRS nets on Sundays, a Wed Tech Net and the Sat Family Fun Net with Santa. Each was about 2 to 4 hours of TX time each. On Sunday, 12-19-21, at the start of the net the repeater went off-line. I assume the battery protection circuit kicked in. This is the first time the repeater went down this year.
Yesterday, 12-20-21, it was heavily snowing all day, so little to no charge. Today, 12-21-21 (Winter Solstice) we have direct sun. The sun isn't reaching the panels until around 11:00AM and it will be gone by 4:00PM. The sun is also at a very low angle. This week it seems like I have a chance for 2 mostly sunny days and a few partly cloudy ones. Guess we will see if that is enough to bring the battery back up to 12.6 volts from 11.2 and turn the repeater back on.

On the plus side we are going to be gaining daylight at a rate of about 4 minutes a day from here on. By February we will be back to around 8 hours of sunlight. 

I attached a photo I took around 11:15AM today of the repeater site. The ridge line you see runs east/west so the face of the ridge is nearly due south. The shadow you see is caused by the opposing mountain blocking the sun. The sun is able to get the site around 11:00AM due to a valley that runs north/south on the east side of the mountain. As the sun continues to rise it is able to stay over the top of the mountain. It kind of follows the contour the mountain if you will. I attached a time-lapse image I stole illustrating the suns arc during winter for reference.

For those asking why I didn't put it up higher, it is b/c it's too hard to get to (the grade is steeper than it looks) and the summit has no good place for it. No poles to place it on to keep the panels above the snow line and it would be too easy for hikers to tamper with it.  This spring I am going to relocate it further west down the ridge line several miles. This will increase it's RF footprint into populated area and pull it further from hikers.

Anyway, this has been a fun project for me.

It depends on your climate and how much use it will see. 

The RT97 draws about 2 amps on high power and .09 amps when in stand-by.

I am running an RT97 on solar power here in Alaska. During the summer when we have lots of sun a 9 amp hour battery and 30 watt panel do just fine. Everytime I checked on it the battery was at 100% capacity. During the winter we have a few issues that make it more difficult. During winter solstice there is only around 4 hours of sunlight.  We also have cold weather to deal with. Drop a lead acid battery to around 0 degrees F and you are down to around 80% of its capacity. Last winter I had it running on a 30 watt panel and a 14 amp hour battery. It wasn't enough. By November the battery was already being run down to the cut off voltage of 11.2 volts. 75% of last November the repeater was down. We didn't have enough snow to prevent me from getting to the site so I was able to get to it and swap it battery out for a 9 amp hour one I had. Yes it is smaller but I wanted to save the larger, more expensive, battery from damage. It lasted for about a week before going down again. I would come back up after a week or two for a few days and then go down again. From there it only got worse. The solar controller shut down the repeater for the majority of winter. Low voltage and cold temperatures resulted in a frozen battery sometime between December and February. Once frozen the voltage dropped to near zero and the solar controller shut down completely. My repeater site is inaccessible once winter sets in due to snow level and steep grades.

This spring I changed a few things. Keep in mind all my components need to be hiked up to about 2400 feet by hand. The components had to fit in or attach to a backpack or two.

POWER GENERATION:
This spring I added a 50 watt panel. This brought up the solar power to 80 watts total. The 80 watts of panels should generate enough solar energy on a 4 hour cloudy day to replace the 2.2-ish amps that the RT97 uses while in stand-by for 24 hours. I based this on monitoring the output of the panels on an overcast day this summer. I waited until the sun's elevation (as informed by a smartphone app) matched that it in the winter and saw the battery being charged at a rate of about 800 milliamps.  4 hours at 800 is 3.2 amps.  That is 1 extra amp...in theory. 
POWER STORAGE:
I upgraded to a 35 amp hour battery and put it underground by over a foot. Just being a foot underground shields the battery from the extreme highs and lows. At that depth theory says it should be at the avg daily temperature. If this setup works through the winter I am relocating the repeater to an even more remote location and will try to get the battery further down. Being underground also has the benefit of keeping the battery cool in the summer, which in theory, should prolong it's life. This 35 amp hour battery chould, in theory, keep the repeater running in stand-by mode for about 13 days or it could support about 14 hours of non-stop transmission in the winter with ZERO solar input. This factors in a 20% reduction in capacity due to cold temperatures.

With these two upgrades the battery should really never be run low unless we have significant activity on the repeater without any days of decent solar generation. The larger battery helps store "extra" power from the sunny days and/or the additional hours of overcast days before/after winter solstice. This keeps the battery at a higher level of charge. Being kept at high charger levels and buried underground protect it through the colds snaps. 

Since I implemented the changes the repeater has been running 24/7. The past several weeks have been COLD here. The avg daily temperature as been between -5 and 5 degrees fahrenheit. Lows have been down below -20 degrees. For the past two weeks I have connected into the myGMRS national net for about 4 hours on Sundays. This has resulted in about 3 to 4 hours worth of transmission time each Sunday on the repeater as people talk across the nation. So far the battery appears to be doing fine as the repeater has not gone down. Hours of sunlight will continue to decrease through December at which point it will start picking up again. The skies will also start to be clear of clouds more often as we push past mid winter. 

So for me, it looks like 80 watts of solar power and a 35 amp hour battery are needed but again that is due to cold winter conditions with low sun levels. I don't know where you are but if you are in the lower 48 I would say the system could be more like my first attempt, 30 watts solar and a 9 amp hour battery and I would bet a 50 watt solar and 14 amp hour battery would give some extra head room.

I have a few other posts up detailing my experiences with the RT97. If you register you can browse them.

Solar Panel:  
https://www.amazon.com/Renogy-Monocrystalline-Efficiency-Charging-Applications/dp/B07GTH79JP/ref=sr_1_4?crid=2OBPM6JH5RIF2&keywords=50%2Bwatt%2Bsolar%2Bpanel%2Brenogy&qid=1637621917&sprefix=50%2Bwatts%2Bsolar%2Bpanel%2Breno%2Caps%2C318&sr=8-4&th=1

Solar Controller:
https://www.amazon.com/dp/B07Q79TC2L?ref=nb_sb_ss_w_as-ypp-ro-model_ypp_ro_model_k0_1_10&crid=LSOHLRTW8QW2&sprefix=10+amp+sol
 
Battery:
https://www.batteriesplus.com/productdetails/slaa12=35c


Battery-S-12330.pdf

I found that an HT in a car without an external antenna suffers greatly. That same HT with a simple 1/4 wave mag mount pulls in far more signals and pushes out much further.
 
I have been scanning the FRS channels, 1-14 here in Anchorage Alaska and hear a fair amount. Just today in my 30 min ride home I heard  car to car communication, flaggers, kids in apartment buildings talking about a class and school mates, construction crews working on large buildings, a business warning it's employees about a bear near the porta-johns...

Pretty sure you can just link your repeaters together but then you can also link into the myGMRS Network when you want.
 
I see a few repeater networks on the myGMRS Network map that don't routinely link into the regional hubs.
 
There are three nodes in Minnesota that are all linked. I link into them from time to time as well.

It's interesting that as the sun comes up my voltage is dropping. Maybe that is the "edge of cloud" effect but instead of cloud it's the snow covered mountain?
Voltage dropped to 13.45 and amps dropped slightly to .68.
 

As an update we have been heavily overcast here for about 2 weeks. So much so it appears the panels are making little power.  I have connected into myGMRS nets on Sundays, a Wed Tech Net and the Sat Family Fun Net with Santa. Each was about 2 to 4 hours of TX time each. On Sunday, 12-19-21, at the start of the net the repeater went off-line. I assume the battery protection circuit kicked in. This is the first time the repeater went down this year.
Yesterday, 12-20-21, it was heavily snowing all day, so little to no charge. Today, 12-21-21 (Winter Solstice) we have direct sun. The sun isn't reaching the panels until around 11:00AM and it will be gone by 4:00PM. The sun is also at a very low angle. This week it seems like I have a chance for 2 mostly sunny days and a few partly cloudy ones. Guess we will see if that is enough to bring the battery back up to 12.6 volts from 11.2 and turn the repeater back on.

On the plus side we are going to be gaining daylight at a rate of about 4 minutes a day from here on. By February we will be back to around 8 hours of sunlight. 

I attached a photo I took around 11:15AM today of the repeater site. The ridge line you see runs east/west so the face of the ridge is nearly due south. The shadow you see is caused by the opposing mountain blocking the sun. The sun is able to get the site around 11:00AM due to a valley that runs north/south on the east side of the mountain. As the sun continues to rise it is able to stay over the top of the mountain. It kind of follows the contour the mountain if you will. I attached a time-lapse image I stole illustrating the suns arc during winter for reference.

For those asking why I didn't put it up higher, it is b/c it's too hard to get to (the grade is steeper than it looks) and the summit has no good place for it. No poles to place it on to keep the panels above the snow line and it would be too easy for hikers to tamper with it.  This spring I am going to relocate it further west down the ridge line several miles. This will increase it's RF footprint into populated area and pull it further from hikers.

Anyway, this has been a fun project for me.

It depends on your climate and how much use it will see. 

The RT97 draws about 2 amps on high power and .09 amps when in stand-by.

I am running an RT97 on solar power here in Alaska. During the summer when we have lots of sun a 9 amp hour battery and 30 watt panel do just fine. Everytime I checked on it the battery was at 100% capacity. During the winter we have a few issues that make it more difficult. During winter solstice there is only around 4 hours of sunlight.  We also have cold weather to deal with. Drop a lead acid battery to around 0 degrees F and you are down to around 80% of its capacity. Last winter I had it running on a 30 watt panel and a 14 amp hour battery. It wasn't enough. By November the battery was already being run down to the cut off voltage of 11.2 volts. 75% of last November the repeater was down. We didn't have enough snow to prevent me from getting to the site so I was able to get to it and swap it battery out for a 9 amp hour one I had. Yes it is smaller but I wanted to save the larger, more expensive, battery from damage. It lasted for about a week before going down again. I would come back up after a week or two for a few days and then go down again. From there it only got worse. The solar controller shut down the repeater for the majority of winter. Low voltage and cold temperatures resulted in a frozen battery sometime between December and February. Once frozen the voltage dropped to near zero and the solar controller shut down completely. My repeater site is inaccessible once winter sets in due to snow level and steep grades.

This spring I changed a few things. Keep in mind all my components need to be hiked up to about 2400 feet by hand. The components had to fit in or attach to a backpack or two.

POWER GENERATION:
This spring I added a 50 watt panel. This brought up the solar power to 80 watts total. The 80 watts of panels should generate enough solar energy on a 4 hour cloudy day to replace the 2.2-ish amps that the RT97 uses while in stand-by for 24 hours. I based this on monitoring the output of the panels on an overcast day this summer. I waited until the sun's elevation (as informed by a smartphone app) matched that it in the winter and saw the battery being charged at a rate of about 800 milliamps.  4 hours at 800 is 3.2 amps.  That is 1 extra amp...in theory. 
POWER STORAGE:
I upgraded to a 35 amp hour battery and put it underground by over a foot. Just being a foot underground shields the battery from the extreme highs and lows. At that depth theory says it should be at the avg daily temperature. If this setup works through the winter I am relocating the repeater to an even more remote location and will try to get the battery further down. Being underground also has the benefit of keeping the battery cool in the summer, which in theory, should prolong it's life. This 35 amp hour battery chould, in theory, keep the repeater running in stand-by mode for about 13 days or it could support about 14 hours of non-stop transmission in the winter with ZERO solar input. This factors in a 20% reduction in capacity due to cold temperatures.

With these two upgrades the battery should really never be run low unless we have significant activity on the repeater without any days of decent solar generation. The larger battery helps store "extra" power from the sunny days and/or the additional hours of overcast days before/after winter solstice. This keeps the battery at a higher level of charge. Being kept at high charger levels and buried underground protect it through the colds snaps. 

Since I implemented the changes the repeater has been running 24/7. The past several weeks have been COLD here. The avg daily temperature as been between -5 and 5 degrees fahrenheit. Lows have been down below -20 degrees. For the past two weeks I have connected into the myGMRS national net for about 4 hours on Sundays. This has resulted in about 3 to 4 hours worth of transmission time each Sunday on the repeater as people talk across the nation. So far the battery appears to be doing fine as the repeater has not gone down. Hours of sunlight will continue to decrease through December at which point it will start picking up again. The skies will also start to be clear of clouds more often as we push past mid winter. 

So for me, it looks like 80 watts of solar power and a 35 amp hour battery are needed but again that is due to cold winter conditions with low sun levels. I don't know where you are but if you are in the lower 48 I would say the system could be more like my first attempt, 30 watts solar and a 9 amp hour battery and I would bet a 50 watt solar and 14 amp hour battery would give some extra head room.

I have a few other posts up detailing my experiences with the RT97. If you register you can browse them.

Solar Panel:  
https://www.amazon.com/Renogy-Monocrystalline-Efficiency-Charging-Applications/dp/B07GTH79JP/ref=sr_1_4?crid=2OBPM6JH5RIF2&keywords=50%2Bwatt%2Bsolar%2Bpanel%2Brenogy&qid=1637621917&sprefix=50%2Bwatts%2Bsolar%2Bpanel%2Breno%2Caps%2C318&sr=8-4&th=1

Solar Controller:
https://www.amazon.com/dp/B07Q79TC2L?ref=nb_sb_ss_w_as-ypp-ro-model_ypp_ro_model_k0_1_10&crid=LSOHLRTW8QW2&sprefix=10+amp+sol
 
Battery:
https://www.batteriesplus.com/productdetails/slaa12=35c


Battery-S-12330.pdf

Update: Has not come back online. I don't know why. I don't know if the battery froze, the solor controller messed up, or the RT itself is down. I doubt the battery is frozen based on the following experiment. I also doubt the panels are not producing enough power to charge up the 35 amp hour battery.
 
 We have had a week straight of clear sky's and it's getting at least 3 hours of good sun a day. I conducted an experiment. Iook a 14 amp hour battery, drained it with a 2 amp load. It drained until the the cut off circuit of the same brand/model solar controller cut off the load (11.2 volts when cut off and rose to 11.8 without a load). I then put the battery outside in -5 to -20 degree F weather for 48 hours. The battery did not freeze.
 
Today I put a 30 watt solar panel on it to see how it reacts. 
 
The 30 watt panel quickly, as in a minute or so, reached a voltage of 14.5 and the solar controller turned the load back on as it saw a voltage greater than 12.6. The battery was seeing a .75 amp current at 14.25 volts flowing to it from the solar controller.
 
So the repeater should have come back online, at least during sunlight hours. I may be able to snow shoe to it to see what is going on but I don't know. May have to wait for spring that (April/May)
 
 

Hi guys thought I'd say hi to the fellow Alaska GMRS guys. Just started in the GMRS world for communication in the local Anchorage area though I'm from Eagle River. My brother in law wanted to sell me on getting a HAM license but figured I'd start with GMRS in my Jeep. So hoping to hop on the E.R. repeater and hopefully hearing some traffic. Channel 20 has had some traffic, but otherwise its been pretty quiet.  Hope to hear from you guys and thank you WRFP for setting up repeaters that's super cool and handy.

Lets not give it too much credit. The VX-231 with it's stock UHF antenna was also making the trip to the repeater but just not as well. Here is an image showing the terrain. You can see how it is clearly not line of sight but the tall steep walls of the ridge lines clearly have something to do with the reception. The j-pole is good for cleaning up a weak signal at the edge of reception and or getting you out and over heavy vegetation on forest floors. I even tried it much further back with just the stock antenna and was able to kurchunk the repeater but the signal was too weak to make out anything. 1st image the the distance to the repeater from the camp. The 2nd image is an approximation of the path we took and where I was able to kurchunk the repeater from. Just prior to fording the river I was able to radio back and speak with someone.

Another option is Vertex. Used VX-231 radios can be found for 30-40 dollars on eBay and they have excellent performance for GMRS use. The programming software can be found pretty easy and the USB cables on eBay work.
 
If you decide to go this route I can help you select the right radio, cable and software. PM me if needed.

I have been looking to grab up a pair EVX-S24 radios. I like the form factor. 

I have two. Both are N9TAX. One I modified by removing the RG58 and replacing it with RG400. It it attached to my repeater (RT97). The antenna has been in a tree for about 2 years now. It does what I need. Once I get the repeater to a more permanent position I will switch out to a more traditional antenna. 
The second is again an N9TAX SlimJim tuned for GMRS. 16 feet of RG58. I use it when backpacking once we set up camp. It definitely helps extend the range. This summer I used it to get back into my GMRS repeater which was behind some heavy obstructions (think mountain). Its hard to see, but in the photo its in the tree to the right of the tent. The antenna itself is up near the top third of the photo. It was attached to a 5 watt Vertex VX-231. There was no cell service back here. This was our only means of reaching back. The repeater was about 15 miles away behind the mountain on the right side of the 2nd photo. I am sure being in the valley helped "tunnel" the signal through and/or we got some refraction over the top edges.

 

As an update we have been heavily overcast here for about 2 weeks. So much so it appears the panels are making little power.  I have connected into myGMRS nets on Sundays, a Wed Tech Net and the Sat Family Fun Net with Santa. Each was about 2 to 4 hours of TX time each. On Sunday, 12-19-21, at the start of the net the repeater went off-line. I assume the battery protection circuit kicked in. This is the first time the repeater went down this year.
Yesterday, 12-20-21, it was heavily snowing all day, so little to no charge. Today, 12-21-21 (Winter Solstice) we have direct sun. The sun isn't reaching the panels until around 11:00AM and it will be gone by 4:00PM. The sun is also at a very low angle. This week it seems like I have a chance for 2 mostly sunny days and a few partly cloudy ones. Guess we will see if that is enough to bring the battery back up to 12.6 volts from 11.2 and turn the repeater back on.

On the plus side we are going to be gaining daylight at a rate of about 4 minutes a day from here on. By February we will be back to around 8 hours of sunlight. 

I attached a photo I took around 11:15AM today of the repeater site. The ridge line you see runs east/west so the face of the ridge is nearly due south. The shadow you see is caused by the opposing mountain blocking the sun. The sun is able to get the site around 11:00AM due to a valley that runs north/south on the east side of the mountain. As the sun continues to rise it is able to stay over the top of the mountain. It kind of follows the contour the mountain if you will. I attached a time-lapse image I stole illustrating the suns arc during winter for reference.

For those asking why I didn't put it up higher, it is b/c it's too hard to get to (the grade is steeper than it looks) and the summit has no good place for it. No poles to place it on to keep the panels above the snow line and it would be too easy for hikers to tamper with it.  This spring I am going to relocate it further west down the ridge line several miles. This will increase it's RF footprint into populated area and pull it further from hikers.

Anyway, this has been a fun project for me.

It depends on your climate and how much use it will see. 

The RT97 draws about 2 amps on high power and .09 amps when in stand-by.

I am running an RT97 on solar power here in Alaska. During the summer when we have lots of sun a 9 amp hour battery and 30 watt panel do just fine. Everytime I checked on it the battery was at 100% capacity. During the winter we have a few issues that make it more difficult. During winter solstice there is only around 4 hours of sunlight.  We also have cold weather to deal with. Drop a lead acid battery to around 0 degrees F and you are down to around 80% of its capacity. Last winter I had it running on a 30 watt panel and a 14 amp hour battery. It wasn't enough. By November the battery was already being run down to the cut off voltage of 11.2 volts. 75% of last November the repeater was down. We didn't have enough snow to prevent me from getting to the site so I was able to get to it and swap it battery out for a 9 amp hour one I had. Yes it is smaller but I wanted to save the larger, more expensive, battery from damage. It lasted for about a week before going down again. I would come back up after a week or two for a few days and then go down again. From there it only got worse. The solar controller shut down the repeater for the majority of winter. Low voltage and cold temperatures resulted in a frozen battery sometime between December and February. Once frozen the voltage dropped to near zero and the solar controller shut down completely. My repeater site is inaccessible once winter sets in due to snow level and steep grades.

This spring I changed a few things. Keep in mind all my components need to be hiked up to about 2400 feet by hand. The components had to fit in or attach to a backpack or two.

POWER GENERATION:
This spring I added a 50 watt panel. This brought up the solar power to 80 watts total. The 80 watts of panels should generate enough solar energy on a 4 hour cloudy day to replace the 2.2-ish amps that the RT97 uses while in stand-by for 24 hours. I based this on monitoring the output of the panels on an overcast day this summer. I waited until the sun's elevation (as informed by a smartphone app) matched that it in the winter and saw the battery being charged at a rate of about 800 milliamps.  4 hours at 800 is 3.2 amps.  That is 1 extra amp...in theory. 
POWER STORAGE:
I upgraded to a 35 amp hour battery and put it underground by over a foot. Just being a foot underground shields the battery from the extreme highs and lows. At that depth theory says it should be at the avg daily temperature. If this setup works through the winter I am relocating the repeater to an even more remote location and will try to get the battery further down. Being underground also has the benefit of keeping the battery cool in the summer, which in theory, should prolong it's life. This 35 amp hour battery chould, in theory, keep the repeater running in stand-by mode for about 13 days or it could support about 14 hours of non-stop transmission in the winter with ZERO solar input. This factors in a 20% reduction in capacity due to cold temperatures.

With these two upgrades the battery should really never be run low unless we have significant activity on the repeater without any days of decent solar generation. The larger battery helps store "extra" power from the sunny days and/or the additional hours of overcast days before/after winter solstice. This keeps the battery at a higher level of charge. Being kept at high charger levels and buried underground protect it through the colds snaps. 

Since I implemented the changes the repeater has been running 24/7. The past several weeks have been COLD here. The avg daily temperature as been between -5 and 5 degrees fahrenheit. Lows have been down below -20 degrees. For the past two weeks I have connected into the myGMRS national net for about 4 hours on Sundays. This has resulted in about 3 to 4 hours worth of transmission time each Sunday on the repeater as people talk across the nation. So far the battery appears to be doing fine as the repeater has not gone down. Hours of sunlight will continue to decrease through December at which point it will start picking up again. The skies will also start to be clear of clouds more often as we push past mid winter. 

So for me, it looks like 80 watts of solar power and a 35 amp hour battery are needed but again that is due to cold winter conditions with low sun levels. I don't know where you are but if you are in the lower 48 I would say the system could be more like my first attempt, 30 watts solar and a 9 amp hour battery and I would bet a 50 watt solar and 14 amp hour battery would give some extra head room.

I have a few other posts up detailing my experiences with the RT97. If you register you can browse them.

Solar Panel:  
https://www.amazon.com/Renogy-Monocrystalline-Efficiency-Charging-Applications/dp/B07GTH79JP/ref=sr_1_4?crid=2OBPM6JH5RIF2&keywords=50%2Bwatt%2Bsolar%2Bpanel%2Brenogy&qid=1637621917&sprefix=50%2Bwatts%2Bsolar%2Bpanel%2Breno%2Caps%2C318&sr=8-4&th=1

Solar Controller:
https://www.amazon.com/dp/B07Q79TC2L?ref=nb_sb_ss_w_as-ypp-ro-model_ypp_ro_model_k0_1_10&crid=LSOHLRTW8QW2&sprefix=10+amp+sol
 
Battery:
https://www.batteriesplus.com/productdetails/slaa12=35c


Battery-S-12330.pdf

As an update we have been heavily overcast here for about 2 weeks. So much so it appears the panels are making little power.  I have connected into myGMRS nets on Sundays, a Wed Tech Net and the Sat Family Fun Net with Santa. Each was about 2 to 4 hours of TX time each. On Sunday, 12-19-21, at the start of the net the repeater went off-line. I assume the battery protection circuit kicked in. This is the first time the repeater went down this year.
Yesterday, 12-20-21, it was heavily snowing all day, so little to no charge. Today, 12-21-21 (Winter Solstice) we have direct sun. The sun isn't reaching the panels until around 11:00AM and it will be gone by 4:00PM. The sun is also at a very low angle. This week it seems like I have a chance for 2 mostly sunny days and a few partly cloudy ones. Guess we will see if that is enough to bring the battery back up to 12.6 volts from 11.2 and turn the repeater back on.

On the plus side we are going to be gaining daylight at a rate of about 4 minutes a day from here on. By February we will be back to around 8 hours of sunlight. 

I attached a photo I took around 11:15AM today of the repeater site. The ridge line you see runs east/west so the face of the ridge is nearly due south. The shadow you see is caused by the opposing mountain blocking the sun. The sun is able to get the site around 11:00AM due to a valley that runs north/south on the east side of the mountain. As the sun continues to rise it is able to stay over the top of the mountain. It kind of follows the contour the mountain if you will. I attached a time-lapse image I stole illustrating the suns arc during winter for reference.

For those asking why I didn't put it up higher, it is b/c it's too hard to get to (the grade is steeper than it looks) and the summit has no good place for it. No poles to place it on to keep the panels above the snow line and it would be too easy for hikers to tamper with it.  This spring I am going to relocate it further west down the ridge line several miles. This will increase it's RF footprint into populated area and pull it further from hikers.

Anyway, this has been a fun project for me.

I have the two panels running in parallel...hopefully that helps some with partial shading when it happens. So far the manufacturer says at -10 degrees C I should be around 80% capacity at a .05C discharge. Look a few posts above for more info on that.
 
We shall see if it powers back up this week.
 
If I wasn't in Alaska and was further south I am confident this system would be running flawlessly with just the 50 watt panel.

Sounds like a solar recharged RT97 w/ a simple N9TAX rollup antenna might work for you. Simple, small, portable, and little to no environment impact.

If you want a complete setup that can be carried in a large backpack:

A 30 watt solar panel can fit in a large backpack. A 30 watt panel and a 14 amp hour SLA battery seems to work well here in Alaska during the Spring/Summer/Fall Season but can't keep up during the cold winters with little sun. If you are not in an area that suffered from greatly reduced solar in the winter it would be a solid place to start.

Use some alum angle riveted to the back to mount the RT97 and a small solar controller directly to the back of the panel. You can attach the panel directly to a tree, place the SLA battery at the base, and hang the N9TAX in the tree itself.   I have posts in this forum about my setup and it might stir some ideas for you.

Is this some 100% Duty Cycle Commercial Grade Setup? Nope. But I get 20-30 miles out of mine to 5 watt handhelds and it works for us.
 

 

Yes. I use the 450-512 splits as I don't have use for HAM but it sounds like the OP wants to cross over the HAM...which ideally would also be 2 meters but I personally don't know any radios that can do that besides CCRs. 
 
I 'solved' that issue for me by just buying a VHF VX-231 for the few 2 meter channels I wanted to listen to....as well as MURS.

Another option is Vertex. Used VX-231 radios can be found for 30-40 dollars on eBay and they have excellent performance for GMRS use. The programming software can be found pretty easy and the USB cables on eBay work.
 
If you decide to go this route I can help you select the right radio, cable and software. PM me if needed.