Neighborhood low power FM radio

[Blast]

I live in a typical Houston suburb of about 800 house covering approximately 1 square mile. It's always seemed that setting up a local, low-power radio station to broadcast neighborhood news and useful knowledge would be useful during an emergency. With that in mine, I finally pulled the trigger on a C.Crane Digital FM Transmitter. 

This transmitter can be powered by 3 AAA batteries or the included AC transformer, but any 5V DC power source can run it. The audio in-cable is about 20" long with a standard miniplug. The built-in antenna is 10". Broadcast frequencies cover the entire commercial FM range of 87.7 to 108 MHz. C.Crane says this transmitter has a range of 45-75 feet, depending on what's in the way.

When I placed this unit in the 2nd-story window I could pick up it's signal clearly in my 4Runner's radio 600 feet away, with multiple houses and trees between me and it. Adding extra wire to the built-in antenna, making it approximately 30" long will improve the signal reach even more. Using an alligator clip to attach the extra wire makes it a non-permanent change, which should retain its FCC legality at the time of writing this post.

Of course, another way to increase range is to place it higher up. Putting it on my roof would or perhaps run it up a streetlight. Since the type of audio input doesn't matter, this could be wired to a walkie-talkie or other radio receiver to deliver the audio instead of a long audio cable. In this manner it's kind of like a ham radio repeater. C.Crane actually suggests this Radio-->Transmitter-->Radio technique on their website as a way to increase coverage.

I doubt one of these transmitters could cover the entire neighborhood, but a network of them could. I'm thinking if I could convince five other people to purchase one of these, everyone would be within range of a transmitter. I'm going to bring it up on our neighborhood FB page and see what sort of response I get.

Meanwhile, what thoughts do y'all have?
-Blast

[MacWa77ace]

My first thought as soon as you mentioned you could hit it with a walkie talkie I thought 'network'.

Second thought was, "if you're listening to this broadcast, you are the resistance."

Third was that in addition to the 5 neighbors buying the transmitter, they'd need to have emergency power.

[NT2C]

My first thought is, GMRS and just legally adopt all your neighbors so y'all just need the one license.



my thought may be somewhat colored by having taken a pain pill for my back an hour ago

[TACAIR]

Plus 1 on the GMRS

You can legally run 50 watts into a high gain antenna on the roof.   More than enough cover the neighborhood.

[MacWa77ace]

The idea of an FM info channel in an emergency is valid. Everyone in the neighborhood has an FM receiver. Less than 1% I'd guess have a GMRS receiver.

Even with 800 houses you could post a flyer at every house in one day notifying of info updates and news broadcast at such and such a time on such and such an FM channel.

Example
Daily @ 12 noon on 88.8 FM.

I was also thinking, over the weekend, that the repeater stations could be powered by 12v inverters connected to cars or cars with built in power converters and then you don't have to have the repeater stations have backup power per se. One less thing to buy. Of course that has its limitations too.

[TACAIR]

Amazon.com: BaseWish 7W 1W Long Range FM Transmitter with LCD & 3.5mm Audio Cable - Ideal for Drive-in Church, School & Supermarket Events, Light Shows & Fireworks Display - Black : Electronics
Amazon.com: BaseWish 7W 1W Long Range FM Transmitter with LCD & 3.5mm Audio Cable - Ideal for Drive-in Church, School & Supermarket Events, Light Shows & Fireworks Display - Black : Electronics

$80.  7 watts, FFC certified!

A lot of radio, Amazon also sells 15 watt versions Amazon.com: 15W FM Radio Broadcast Transmitter, 15 Watt Stereo Long Range Radio Station FM Broadcast Transmitter for Church, Radio Station, Home : Electronics for about $170 w/antenna. 
****

7 watts should give you about 3 to 4 miles, more than enough for your neighborhood- yes?

[Blast]

Amazon.com: BaseWish 7W 1W Long Range FM Transmitter with LCD & 3.5mm Audio Cable - Ideal for Drive-in Church, School & Supermarket Events, Light Shows & Fireworks Display - Black : Electronics
Amazon.com: BaseWish 7W 1W Long Range FM Transmitter with LCD & 3.5mm Audio Cable - Ideal for Drive-in Church, School & Supermarket Events, Light Shows & Fireworks Display - Black : Electronics

<SNIP>

7 watts should give you about 3 to 4 miles, more than enough for your neighborhood- yes?

Interesting! Yes, mounted in the right spot, this should be able to cover the entire neighborhood. That wouldn't need anyone else to buy equipment. 
I can't tell from the product picture but it looks like the antenna on the BaseWish transmitter might be removable, but that's probably wishful thinking on my part. And even if it is, I'd probably get a visit from the FCC if I mated it to this antenna: https://amzn.to/3VBrTC1

[Blast]

Even with 800 houses you could post a flyer at every house in one day notifying of info updates and news broadcast at such and such a time on such and such an FM channel.

Example
Daily @ 12 noon on 88.8 FM.

I was also thinking, over the weekend, that the repeater stations could be powered by 12v inverters connected to cars or cars with built in power converters and then you don't have to have the repeater stations have backup power per se. One less thing to buy. Of course that has its limitations too.

Yes, it'd be easy to get the word out via flyers, word of mouth, and assorted yard signs. And yes, "top of the hour" broadcasts or some similar schedule makes sense, and have a prerecorded list of tips playing on repeat the rest of the time. It's scary to see how many people don't know they can flush their toilet by pouring water in the bowl.

My neighborhood has a lot of hunters and many of them probably have FRS walkie-talkies. Part of the repeated tips could be telling people with those HTs that the "emergency DJ" is listening to a set channel and can broadcast notes he/she receives on that channel.

Between hurricanes and ice storms, our neighborhood has been through a lot and one of the outcomes of that is the very large number of generators and solar panels owned by people. Emergency power to recharge phones and other electronic devices hasn't been much of an issue here. 
-Blast

[MacWa77ace]

It's scary to see how many people don't know they can flush their toilet by pouring water in the bowl.

In my neighborhood we'd be telling them not to do that as we use lift stations that require power, the county supplies generators post prolonged outage [hurricanes] but those have limited fuel and may run out if the outage is to long and supply chains are interupted. Florida is flat.

Without the lift stations operating the sewers would back up into the houses if water sources are added while the stations are down. Toilets, kitchen sinks, baths/showers all go to the same place.

Depending on the neighborhood, there may be a newsletter or other media that you can periodically post reminders of these contact and info sources. Pre Event.

If you have unlimited power, then you can run your station 24/7, but if power is limited maybe only twice a day for as short a span as possible to get the message out.

[Blast]

It's scary to see how many people don't know they can flush their toilet by pouring water in the bowl.

In my neighborhood we'd be telling them not to do that as we use lift stations that require power, the county supplies generators post prolonged outage [hurricanes] but those have limited fuel and may run out if the outage is to long and supply chains are interupted. Florida is flat.

Dang, that sucks about your toilets. Houston is flat but not THAT flat.

As far as power for the transmitter goes, Crane claims 110 hours of broadcast time from a single set of AAA batteries. I have an excessive amount of solar panels and 12V LiFePO4 batteries due to one of my businesses, so even in a TEOTWAWKI situation, I can keep broadcasting pretty much until the Golden Horde overruns me. 
-Blast

[NT2C]

It's scary to see how many people don't know they can flush their toilet by pouring water in the bowl.

In my neighborhood we'd be telling them not to do that as we use lift stations that require power, the county supplies generators post prolonged outage [hurricanes] but those have limited fuel and may run out if the outage is to long and supply chains are interupted. Florida is flat.

Dang, that sucks about your toilets. Houston is flat but not THAT flat.

As far as power for the transmitter goes, Crane claims 110 hours of broadcast time from a single set of AAA batteries. I have an excessive amount of solar panels and 12V LiFePO4 batteries due to one of my businesses, so even in a TEOTWAWKI situation, I can keep broadcasting pretty much until the Golden Horde overruns me. 
-Blast

If one of your businesses blesses you with such things and you would like to advertise said business on here, we should discuss it in the staff areas. 

[MacWa77ace]

Dang, that sucks about your toilets. Houston is flat but not THAT flat.

You might have the same deal as me there, depending on your neighborhood.

I found a Houston sewer design manual and there is a section on lift stations.
https://www.houstonpermittingcenter.org/media/3066/download?inline
REF: https://www.houstonpermittingcenter.org/office-city-engineer/design-and-construction-standards#agency-links-1471

I'd look into it.

[Blast]

Dang, that sucks about your toilets. Houston is flat but not THAT flat.

You might have the same deal as me there, depending on your neighborhood.

I found a Houston sewer design manual and there is a section on lift stations.
https://www.houstonpermittingcenter.org/media/3066/download?inline
REF: https://www.houstonpermittingcenter.org/office-city-engineer/design-and-construction-standards#agency-links-1471

I'd look into it.

Thanks, this is definitely something that requires more study.
Hmmm, the nearest lift station to our neighborhood appears to be over 8 miles away. I'm in an unincorporated section of Harris county. There is a wastewater treatment plant 1.3 miles away.
-Blast

[Blast]

Some really good information on the whole line of C. Crane FM transmitters: https://radiojayallen.com/c-crane-fm-transmitter-3/
The owner of this website is extremely helpful in suggesting ways to increase the range of these transmitters.
-Blast

[Braums]

Thanks for sharing this.  Our housing development has about 240 houses and surrounding farms in rural NC. This has potential.

[Lambykins]

Wow.
I never knew this was a possible thing!
Excuse what is presumably a stupid couple of questions....
1 Do you have to have call letters?
2 If yes, are they assigned or do you choose them yourself?
3 How do you choose (or assigned) your spot on the dial?

[TACAIR]

Dang, that sucks about your toilets. Houston is flat but not THAT flat.

You might have the same deal as me there, depending on your neighborhood.

I found a Houston sewer design manual and there is a section on lift stations.
https://www.houstonpermittingcenter.org/media/3066/download?inline
REF: https://www.houstonpermittingcenter.org/office-city-engineer/design-and-construction-standards#agency-links-1471

I'd look into it.

Thanks, this is definitely something that requires more study.
Hmmm, the nearest lift station to our neighborhood appears to be over 8 miles away. I'm in an unincorporated section of Harris county. There is a wastewater treatment plant 1.3 miles away.
-Blast

LOL

I called the wastewater folks and got referred to an Engineer.  Guy said I was the first person to call about lift stations and backups.

I'm good, a sewer access shaft (manhole) will erupt some 2 miles from my house before a backup becomes an issue.
Not counting grease-bergs.

[Blast]

Wow.
I never knew this was a possible thing!
Excuse what is presumably a stupid couple of questions....
1 Do you have to have call letters?
2 If yes, are they assigned or do you choose them yourself?
3 How do you choose (or assigned) your spot on the dial?

These low power transmitters are sold for use in private homes and business, so no licenses are required to use them. No specific frequency is assigned, you just have to find a frequency no licensed radio station is using on the FM dial so that you don't interfere with their signal.
The fact that sticking them high up in the air increases their range (line of sight) is just a law of physics, not against the laws of government. 
-Blast

[NT2C]

Wow.
I never knew this was a possible thing!
Excuse what is presumably a stupid couple of questions....
1 Do you have to have call letters?
2 If yes, are they assigned or do you choose them yourself?
3 How do you choose (or assigned) your spot on the dial?

These low power transmitters are sold for use in private homes and business, so no licenses are required to use them. No specific frequency is assigned, you just have to find a frequency no licensed radio station is using on the FM dial so that you don't interfere with their signal.
The fact that sticking them high up in the air increases their range (line of sight) is just a law of physics, not against the laws of government. 
-Blast

Like any good government agency ever let that stop them. 

Witness the Part 95 rules for CB and how far you're allowed to communicate, regardless of what physics might be doing to band conditions.

[Z.O.R.G.]

I was doing some research over the weekend and found this...

Low Power FM Radio | Federal Communications Commission (fcc.gov)

Does this serve your needs Blast?

It needs to operate a minimum of 8 hours a day, but a 5 minute PSA every 15 minutes does that.  I'm thinking a cleaver computer operator could put out a weather announcement (from NOAA), some community announcements, etc. on a loop.  Log into a web app and upload/update what you want said.  Add the national anthem at the end if you need extra time.  In the event of a disaster, update the messages or go online in person.