On 6/19/2021 10:30 AM, Ralph Mowery wrote:> In article <gblzI.233931$lyv9.103203@fx35.iad>, user@example.net says... >> >>> How are you able to broadcast legally? Is this a low enough power that it is allowed by the FCC? Or are you on a different frequency band than commercial FM radio? >> >> As I understand it FM "broadcasting" at any power level requires a >> license in the US, the field strength limits are for devices with >> intended receivers like car stereo transmitters, wireless mic systems, etc. >> >>> When I was a kid we had low power AM transmitters that were legal, but didn't go very far at all, barely outside the house. >>> >> >> > > You can find the rules here for the FCC Part 15 low power transmitters. > > Mainly for the AM and FM band you are limiated to about 200 feet of > range for devices with out license. > > https://www.fcc.gov/media/radio/low-power-radio-general-information > > > While I would never advise breaking the law, the FCC has more to do than > worry about transmitters that go less than a mile or two unless someone > complaines about them. Just like the CB radio situation of 40 or so > years ago. You needed a license and had lots of rules to follow. > Almost no one did and finally the government threw in the towel and said > do what you want , just do not bother any licensed service. >Reception at 200 feet with say a regular portable FM radio is pretty optimistic for a maximum ERP of 0.01 microwatts.
Solar power percentage of charge control ??????
Started by ●June 19, 2021
Reply by ●June 19, 20212021-06-19
Reply by ●June 19, 20212021-06-19
On Saturday, June 19, 2021 at 10:55:20 AM UTC-7, bitrex wrote:> On 6/19/2021 10:30 AM, Ralph Mowery wrote: > > In article <gblzI.233931$lyv9....@fx35.iad>, us...@example.net says... > >> > >>> How are you able to broadcast legally? Is this a low enough power that it is allowed by the FCC? Or are you on a different frequency band than commercial FM radio? > >> > >> As I understand it FM "broadcasting" at any power level requires a > >> license in the US, the field strength limits are for devices with > >> intended receivers like car stereo transmitters, wireless mic systems, etc. > >> > >>> When I was a kid we had low power AM transmitters that were legal, but didn't go very far at all, barely outside the house. > >>> > >> > >> > > > > You can find the rules here for the FCC Part 15 low power transmitters. > > > > Mainly for the AM and FM band you are limiated to about 200 feet of > > range for devices with out license. > > > > https://www.fcc.gov/media/radio/low-power-radio-general-information > > > > > > While I would never advise breaking the law, the FCC has more to do than > > worry about transmitters that go less than a mile or two unless someone > > complaines about them. Just like the CB radio situation of 40 or so > > years ago. You needed a license and had lots of rules to follow. > > Almost no one did and finally the government threw in the towel and said > > do what you want , just do not bother any licensed service. > > > Reception at 200 feet with say a regular portable FM radio is pretty > optimistic for a maximum ERP of 0.01 microwatts.But why would you need to monitor the Sun (or shade condition) within 200 feet?
Reply by ●June 19, 20212021-06-19
On Saturday, June 19, 2021 at 12:59:46 PM UTC-4, jeff.li...@gmail.com wrote:> On Sat, 19 Jun 2021 09:36:31 -0700 (PDT), Rick C > <gnuarm.del...@gmail.com> wrote: > > (chomp) > >When they say 'drop to 2G" I assume that is just the data rate, not the protocol. I have a 3 year old phone that ATT won't let me transfer because it's 4G is LTE and ATT is only supporting something else that is actually inferior. The phone supports 3G which it seems is being phased out as of next year, with ATT anyway. If they are doing that, I would think 2G would not be available either. > Wrong. AT&T and everyone else is slowly switching to LTE. > "AT&T 3G is going away in 2022" > <https://www.att.com/support/article/wireless/KM1324171/> > If you go with LTE, you'll also need a phone that supports "HD Voice". > Some older LTE phones do not.Ok, so it's not that my phone is LTE, it's that the phone does not have HD Voice which only works between phones on the same carrier. Ok.> I can't tell what you're actually doing, but if it does NOT involve a > conventional voice cell phone handset, see detail on AT&T "Business > Connect" data only plans: > <https://www.business.att.com/categories/vehicle-solutions.html> > <https://www.business.att.com/content/dam/businesscenter/pdf/legal/att-business-connect-plans.pdf>Not sure who you are talking to. I'm using a cell phone as a phone oddly enough. I will say the Waze app is invaluable in Puerto Rico. They have very few road signs here so it is impossible to find your way otherwise.> Note: I prefer Verizon for data only: > <https://www.verizon.com/business/products/plans/machine-to-machine/> > > Bottom line: 3G is being replaced with 4G by attrition. 3G might > have another year to live, but more. Buy something that does LTE and > don't look back.I've done that, but it's not enough! -- Rick C. +- Get 1,000 miles of free Supercharging +- Tesla referral code - https://ts.la/richard11209
Reply by ●June 19, 20212021-06-19
On 6/19/2021 1:58 PM, Ed Lee wrote:> On Saturday, June 19, 2021 at 10:55:20 AM UTC-7, bitrex wrote: >> On 6/19/2021 10:30 AM, Ralph Mowery wrote: >>> In article <gblzI.233931$lyv9....@fx35.iad>, us...@example.net says... >>>> >>>>> How are you able to broadcast legally? Is this a low enough power that it is allowed by the FCC? Or are you on a different frequency band than commercial FM radio? >>>> >>>> As I understand it FM "broadcasting" at any power level requires a >>>> license in the US, the field strength limits are for devices with >>>> intended receivers like car stereo transmitters, wireless mic systems, etc. >>>> >>>>> When I was a kid we had low power AM transmitters that were legal, but didn't go very far at all, barely outside the house. >>>>> >>>> >>>> >>> >>> You can find the rules here for the FCC Part 15 low power transmitters. >>> >>> Mainly for the AM and FM band you are limiated to about 200 feet of >>> range for devices with out license. >>> >>> https://www.fcc.gov/media/radio/low-power-radio-general-information >>> >>> >>> While I would never advise breaking the law, the FCC has more to do than >>> worry about transmitters that go less than a mile or two unless someone >>> complaines about them. Just like the CB radio situation of 40 or so >>> years ago. You needed a license and had lots of rules to follow. >>> Almost no one did and finally the government threw in the towel and said >>> do what you want , just do not bother any licensed service. >>> >> Reception at 200 feet with say a regular portable FM radio is pretty >> optimistic for a maximum ERP of 0.01 microwatts. > > But why would you need to monitor the Sun (or shade condition) within 200 feet? >Monitor the Sun? Not sure what you mean. Sounds like the OP is setting up a station that's going to be broadcasting over the FCC limit for unlicensed operation but we have no idea the power level of their intent. We can assume they're properly licensed I guess, this is only an intellectual exercise at the moment and that stuff is their problem. 100 watts is the minimum for a licensed LPFM station that's good for several miles with an ordinary portable FM radio or car stereo.
Reply by ●June 19, 20212021-06-19
On Sat, 19 Jun 2021 13:37:52 -0400, bitrex <user@example.net> wrote:>On 6/19/2021 12:36 PM, Jeff Liebermann wrote: >> On Sat, 19 Jun 2021 01:25:47 -0500, Unlisted <unlisted@nomail.com> >> wrote: >> >>> However, one problem. When the sun comes back and the batteries begin >>> recharging, I dont want the equipment to turn on until the batteries are >>> up to at least 20% charge, or the equipment will begin cycling on and >>> off. (Bad for the equipment). >>> >>> What can I use to sense percent of charge and delay turning on the >>> equipment until that (pre set) % of charge is achieved? Im sure it can >>> be done, but I have no clue how..... >> >> Without hysteresis, that could make an interesting oscillator. Power >> goes down to below the threshold at night. Sun comes up in the >> morning and starts charging the battery. Circuit detects that's it's >> over your threshold and applies power to the transmitter. That >> immediately draws enough current to run the battery down below the >> threshold, which turns off the transmitter. The transmitter remains >> off the air until the sun charges the battery above the threshold. >> Transmitter goes on and off all day because the solar panel would need >> to charge the battery *AND* power the transmitter when the sun is up.>I have a cheap LED nightlight that works just like thatNot quite. The FM transmitter needs to operate during the day and turn off at night. The night light (or garden light) needs to operate during the night, and turn off during the day. The night light has the advantage of charging while there's no load. The solar panels in the FM transmitter need to both charge the battery AND power the transmitter during the day. Incidentally, most such small lights use a single NiMH cell. <https://www.electronicsforu.com/electronics-projects/garden-solar-light> <https://watergreat.com/reference/CL0116.pdf> The cell lasts about 1.5 years or 500 charge cycles. That's what I would expect from a commodity NiMH cell (although better cells might live to 2000 charge cycles). In 2006, our local radio club was looking into a solar powered repeater. So, I threw together a spreadsheet to help with the calculations. The main question was how many panels are necessary to insure 24 hr functionality. <http://www.learnbydestroying.com/jeffl/rf-calc/solar-repeater-207.xls> There are a few mistakes and bad guesses in the spreadsheet, so please be careful when using it. What it demonstrated was that the solar panels had to provide sufficient power to replace what was consumed by the repeater on a daily basis. If the panels produced less each day, the stored charge level of the battery will decrease each day, until the battery is depleted. Winter sun is the worst. Spreadsheed for doing the same with a WRT54G wireless router: <http://www.learnbydestroying.com/jeffl/rf-calc/solar-wrt54g-v101.xls> I built this and found the predicted charge cycles to be too optimistic because I didn't include multiple sources of battery and solar panel deterioration with age, weather and data sheet creativity. I also screwed up and assumed that the charge/discharge characteristics of a gell cell beattery were similar to a wet cell. -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●June 19, 20212021-06-19
On Saturday, June 19, 2021 at 11:03:26 AM UTC-7, bitrex wrote:> On 6/19/2021 1:58 PM, Ed Lee wrote: > > On Saturday, June 19, 2021 at 10:55:20 AM UTC-7, bitrex wrote: > >> On 6/19/2021 10:30 AM, Ralph Mowery wrote: > >>> In article <gblzI.233931$lyv9....@fx35.iad>, us...@example.net says... > >>>> > >>>>> How are you able to broadcast legally? Is this a low enough power that it is allowed by the FCC? Or are you on a different frequency band than commercial FM radio? > >>>> > >>>> As I understand it FM "broadcasting" at any power level requires a > >>>> license in the US, the field strength limits are for devices with > >>>> intended receivers like car stereo transmitters, wireless mic systems, etc. > >>>> > >>>>> When I was a kid we had low power AM transmitters that were legal, but didn't go very far at all, barely outside the house. > >>>>> > >>>> > >>>> > >>> > >>> You can find the rules here for the FCC Part 15 low power transmitters. > >>> > >>> Mainly for the AM and FM band you are limiated to about 200 feet of > >>> range for devices with out license. > >>> > >>> https://www.fcc.gov/media/radio/low-power-radio-general-information > >>> > >>> > >>> While I would never advise breaking the law, the FCC has more to do than > >>> worry about transmitters that go less than a mile or two unless someone > >>> complaines about them. Just like the CB radio situation of 40 or so > >>> years ago. You needed a license and had lots of rules to follow. > >>> Almost no one did and finally the government threw in the towel and said > >>> do what you want , just do not bother any licensed service. > >>> > >> Reception at 200 feet with say a regular portable FM radio is pretty > >> optimistic for a maximum ERP of 0.01 microwatts. > > > > But why would you need to monitor the Sun (or shade condition) within 200 feet? > > > Monitor the Sun? Not sure what you mean. Sounds like the OP is setting > up a station that's going to be broadcasting over the FCC limit for > unlicensed operation but we have no idea the power level of their intent. > > We can assume they're properly licensed I guess, this is only an > intellectual exercise at the moment and that stuff is their problem. > 100 watts is the minimum for a licensed LPFM station that's good for > several miles with an ordinary portable FM radio or car stereo.OK, not for this OP. Anyway, my clients are using 2G GSM to monitor batteries remotely, and partial shutdown if power is weak. For example, they can slow down the video cameras and other non-essential equipments.
Reply by ●June 19, 20212021-06-19
On Sat, 19 Jun 2021 10:38:53 -0700 (PDT), Ed Lee <edward.ming.lee@gmail.com> wrote:>On Saturday, June 19, 2021 at 10:08:44 AM UTC-7, Ed Lee wrote: >> On Saturday, June 19, 2021 at 9:59:46 AM UTC-7, jeff.li...@gmail.com wrote: >> > On Sat, 19 Jun 2021 09:36:31 -0700 (PDT), Rick C >> > <gnuarm.del...@gmail.com> wrote: >> > >> > (chomp) >> > >When they say 'drop to 2G" I assume that is just the data rate, not the protocol. I have a 3 year old phone that ATT won't let me transfer because it's 4G is LTE and ATT is only supporting something else that is actually inferior. The phone supports 3G which it seems is being phased out as of next year, with ATT anyway. If they are doing that, I would think 2G would not be available either. >> > Wrong. AT&T and everyone else is slowly switching to LTE. >> > "AT&T 3G is going away in 2022" >> > <https://www.att.com/support/article/wireless/KM1324171/> >> > If you go with LTE, you'll also need a phone that supports "HD Voice". >> > Some older LTE phones do not. >> > >> > I can't tell what you're actually doing, but if it does NOT involve a >> > conventional voice cell phone handset, see detail on AT&T "Business >> > Connect" data only plans: >> > <https://www.business.att.com/categories/vehicle-solutions.html> >> > <https://www.business.att.com/content/dam/businesscenter/pdf/legal/att-business-connect-plans.pdf> >> > >> > Note: I prefer Verizon for data only: >> > <https://www.verizon.com/business/products/plans/machine-to-machine/> >> > >> > Bottom line: 3G is being replaced with 4G by attrition. 3G might >> > have another year to live, but more. Buy something that does LTE and >> > don't look back.>> As i said before, T-mobile is still keeping 2G for now. I did switch my Verizon voice phone from 3G to 4G, but all my T-mobile data devices are still working as of today. I prefer T-mobile for data.I prefer anything over AT&T. Note that we're talking about data only plans, not smartphone plans.>Here is the link to their 2G sunset plan (or lack of): >https://www.lightreading.com/5g/t-mobile-to-leave-2g-intact-amid-3g-cdma-shutdown/d/d-id/769453Thanks. Note that T-Mobile avoided answering the senators question about how many T-Mobile customers still use 2G. "T-Mobile also disclosed that "active 2G/3G devices accounted for less than 1% of traffic on the T-Mobile network as of the week of April 11, 2021." However, the company did not directly answer Sen. Schatz's question of how many T-Mobile customers currently rely on its 2G and 3G services. I don't know how many or how much, but I suspect it's a substantial number of customers and modems which generate quite a bit of revenue for T-Mobile. Also, the cost of conversion to LTE can be quite expensive, especially if it involves a service call or truck roll and a GPRS modem to LTE modem "adapter": <https://www.t-mobile.com/news/press/att-2g-iot-lifeline> (Sept 2016) "T-Mobile Throws a Lifeline to AT&T�s Stranded 2G IoT Customers with Free SIMs and Service">If they decide to drop it, i will offer 100 million shares of SPAC for their 2G network.Good deal.>But, i am still waiting ...Me too, because I'm greedy. The carriers have been trying to kill the old 2G GPRS technologies for many years. The problem is churn. Users who are forced to migrate to the latest geatest LTE modems are also like to switch vendors and carriers. Churn is considered a bad thing in mobile data and phone. IoT = It's Obsolete Tomorrow -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●June 19, 20212021-06-19
On Sat, 19 Jun 2021 10:59:02 -0700 (PDT), Rick C <gnuarm.deletethisbit@gmail.com> wrote:>On Saturday, June 19, 2021 at 12:59:46 PM UTC-4, jeff.li...@gmail.com wrote: >> I can't tell what you're actually doing, but if it does NOT involve a >> conventional voice cell phone handset, see detail on AT&T "Business >> Connect" data only plans: >> <https://www.business.att.com/categories/vehicle-solutions.html> >> <https://www.business.att.com/content/dam/businesscenter/pdf/legal/att-business-connect-plans.pdf>>Not sure who you are talking to. I'm using a cell phone as a phone oddly enough. I will say the Waze app is invaluable in Puerto Rico. They have very few road signs here so it is impossible to find your way otherwise.You wrote: "When they say 'drop to 2G" I assume that is just the data rate, not the protocol." I wrongly assumed that you were actually using it for data. Sorry, but the industry is not very good at distinguishing between smartphone data and data only (M-to-M, IoT, data modems, telemetry, etc).>> Bottom line: 3G is being replaced with 4G by attrition. 3G might >> have another year to live, but more. Buy something that does LTE and >> don't look back. > >I've done that, but it's not enough!What? You mean you can't predict next years technical requirements before buying a phone? Send your crystal ball back to the manufacturer for repair. Ok, I'm being a bit harsh. I should probably mention that I also ended up with a few phones lacking an important feature; Wi-Fi Calling. That's where you can make and receive phone calls via wi-fi instead of cellular. Very handy if I'm in an area with chronically bad signals and it eliminates the need for an expensive nano-cellular hotspot at home. Besides the technical layer, there's also a problem with the political layer. I'm on Page Plus Cellular, now owned by TracFone, which uses the Verizon system. To provide a suitable reason for having the highest prices in the industry, Verizon chose to disable Wi-Fi calling on their MVNO (mobile virtual network operator) partners, such as PagePlus. Wi-Fi calling doesn't even appear in the installed handset firmware. If you need to use your phone in a rotten area where there's wi-fi, check out the wi-fi calling situation before leaping. Incidentally, Xfinity (Comcast) Mobile, which also uses the Verizon system, does have Wi-Fi calling enabled. -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●June 19, 20212021-06-19
On Sat, 19 Jun 2021 14:03:20 -0400, bitrex <user@example.net> wrote:>We can assume they're properly licensed I guess, this is only an >intellectual exercise at the moment and that stuff is their problem. >100 watts is the minimum for a licensed LPFM station that's good for >several miles with an ordinary portable FM radio or car stereo.<https://www.fcc.gov/media/radio/lpfm-frequently-asked-questions> Q: How far will the signal go? A: LPFM stations are limited to 100 watts and a service range of 5.6 kilometers (3.5 mile radius). This does not mean that the station cannot be heard beyond a 3.5 miles radius. It�s an approximation of the expected average coverage. -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●June 19, 20212021-06-19
On 6/19/2021 5:05 AM, bitrex wrote: [You know, it wouldn't kill you to trim posts -- including your own -- in stead of just appending to something that has already been seen!]> You can get inverters with adjustable low-voltage disconnect/hysteresis > threshold on the primary side, off the shelf.You can also directly power kit from batteries without the need for an inverter.> Dunno why the OP wants to use a laptop, mixer, audio compressor and all that. > If the station is just to play pre-recorded audio files you can batch > compress/limit them all ahead of time, put 'em on an SD card, and low-power SBC > can just spit them out to the transmitter setting the levels appropriately, > never gonna change.Or a cell phone running a tiny app -- with or without "service".> Anyway the FCC limit without a LPFM license is 250 microvolts/meter at 3 > meters; with appropriate choice of SBC and micro-power transmitter you probably > charge up and lug one battery up there a year and it run for a year, > particularly if you just run off the low voltage directly. > > Need a LPFM license for broadcasting with more power than that in the US, but > can't get 'em no mo...huh? Local makerspace set up a 50W LPFM station just a year or two ago. Scraping together the money for the antenna and tower was their last hurdle. As it is located "in town", they figure ~300K pairs of ears in its listening area. A more remote station (OP's?) might have a greater geographical coverage area -- with fewer ears.
