Re: Advise / Help with FCC Part 15 AM/FM installation

Kirt White / K7KDW

Sorry,  as longs as that was, there was one thing I forgot to touch on.

Dan brought up the Christmas light transmitters which I agree may be a quick way to get up and running, especially if there is someone locally that would loan it out. 

I researched setting this up at one time and a lot of people were using the same (higher power) ones you can find on Ebay. That said, EDM Electronics makes one they market toward Christmas displays. It is highly regarded for that and, even though theirs is low power, people report getting great coverage. Technically speaking I'm sure it would serve this purpose well. 

I just checked their website ( and they are selling a "drive-in" package for churches. Maybe those are pre-assembled, I don't know. Either way, they have availability. 

Again, I'll just re-iterate that even though there are lots of churches and individuals using these options, none of these are part 15 certified so take from that what you will.


From: <> on behalf of Kirt / K7KDW <kirtwhite@...>
Sent: Thursday, May 7, 2020 11:25 AM
To: <>
Subject: Re: [SnoVARC] Advise / Help with FCC Part 15 AM/FM installation
I used to have a part 15 FM transmitter but I got rid of it a while ago. Hopefully some of my experience with using them can help

Some brands may give a discount for a church if you order direct. I'm pretty sure Decade used to. Their transmitters are expensive but are rock solid. This may vary and, depending on your budget, some of these may be out of the question. I also assume most of these companies have back orders now.

Some churches are using non certified transmitters. I assume mostly because it's cheaper and they aren't aware of the regulations. Some will get away with using 1/2 watt or one that has adjustable power levels but some of these transmitters can be 5-25 watts. I think I still have a higher power one laying around and I would definitely not recommend using something like that, even aside from the legailty. 

Some transmitters have built in antennas and some have external connectors. I haven't used one with a built in antenna but I doubt it would matter much for a parking lot. Having an external antenna gives you the added benefit of moving the antenna closer and higher up but is an added cost as well as an additional piece of equipment to deal with. A simple telescoping antenna gives you the ability to tune it (somewhat) and has worked well for me in the past. 

Depending on the size of your parking area (and how noisy the band is in that area), a decent bluetooth FM transmitter may give you enough coverage. I wouldn't expect these to get much past 50 feet but it may be worth a try since I'm sure these are still readily available. Whichever one you choose, you would want one that could be frequency tuned. One like this ( that doesn't have the cigarette lighter attachment built in would help in powering it without resorting to a creative solution. You would also need a bluetooth transmitter that could be paired with it to transmit out of your mixer.   As a side note, you wouldn't want the pastor or whoever is speaking to be able to hear the output audio as the delay would be distracting. This is a few moving parts and I don't know how successful it would be but the parts are fairly inexpensive.

Our broadcast FM spectrum around here is pretty congested. Finding a good "open" frequency takes some trial and error. Distant FM signals (that still sound like white noise on your radio) still raise the noise floor so not only finding where there is an open frequency but finding the quietest can take some time. If you have an SDR that you can use to see the spectrum this can be beneficial. You may find some of the quietest spots to be on the edge of the digital sidebands of FM stations that come in pretty clear to that area.

Don't use a portable radio to test with. The sensitivity differences between car and portable receivers vary too much.

If your transmitter has the ability to transmit in mono, doing so may give you better results.

I hope some of these tips help and hopefully you can find the right solution.


From: <> on behalf of Lou Giliberto (KD7HCW) via <louis.giliberto@...>
Sent: Thursday, May 7, 2020 1:13 AM
To: <>
Subject: Re: [SnoVARC] Advise / Help with FCC Part 15 AM/FM installation
Sorry for the multiple responses. I was digging through some notes of mine.

For wifi the easiest solution is Zello. A broadcast room can be made. People would also be able to listen from home that way. If the service provides free wifi no cell data needs to be used.

Sent from ProtonMail mobile

-------- Original Message --------
On May 7, 2020, 1:09 AM, Lou Giliberto (KD7HCW) via < louis.giliberto@...> wrote:

Asking here might be useful as well.

Sent from ProtonMail mobile

-------- Original Message --------
On May 7, 2020, 1:06 AM, Lou Giliberto (KD7HCW) via < louis.giliberto@...> wrote:

See if they have inventory direct.

You can also find them on eBay a lot.


Sent from ProtonMail mobile

-------- Original Message --------
On May 6, 2020, 9:41 PM, Dan Pflugrath < dpflugrath@...> wrote:

If you can't find inventory for a FM or AM Low power transmitter you might inquire of someone who had one of those huge Christmas light displays that broadcast music with their light show.  Seems like they would not be using it at this time so one may be able to borrow one until you can find inventory.  They might even assist in setup


There are suppliers for Christmas Light display components that may be an uncommon source with inventory.


Just a suggestion to get up and running







From: [] On Behalf Of Robin Amundson
Sent: Wednesday, May 6, 2020 8:06 PM
Subject: [SnoVARC] Advise / Help with FCC Part 15 AM/FM installation


I’m thinking someone from SnoVarc can make suggestions on this request?



Robin, WA7CPA 

Begin forwarded message:

From: "George Jones" <georgejones@...>
Date: May 6, 2020 at 7:18:54 PM PDT
To: "'Radio Club of Redmond N7KE'" <rcrr@...>
Subject: Advise / Help with FCC Part 15 AM/FM installation



I would like to solicit suggestions/ideas from RCR members on my need to install a AM or FM low-power transmitter at my church in Renton to support “drive-in” service.   I have examined a number of suppliers of low-power Part 15 gear and am finding very little inventory due to recent demand resulting from the Corvid-19 lockdowns.


Has anyone had any experience with such devices and using and/or sourcing same.  Any suggestions on alternates to communicating using AM/FM transmission with cars in a parking lot? – using wifi and smartphones has been suggested but I don’t have clear understanding of how to proceed.


I recall a project article in Popular Electronics in the 1960’s about building your own unlicensed low-power AM station so the obvious question to all the hams out there – does anyone have any AM/FM low-power transmitter sitting on the shelf that could be borrowed or purchased?


Anyway – any thoughts would be appreciated.


George Jones



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