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Title: Portable FM receivers
Post by: Bradford "BJ" James on May 24, 2021, 06:55:05 PM
Doing a couple of beach events this summer (covid dependant) where the local radio station will be broadcasting. Organizers are hoping for some speakers to be set up in some fairly remote locations. Plan is to use a few FM receivers plugged into rechargeable powered speakers.
Any suggestions on half decent battery powered portable FM receivers? Earphone out should be sufficient.
Cheers.
Title: Re: Portable FM receivers
Post by: Tim Weaver on May 24, 2021, 08:12:40 PM
Doing a couple of beach events this summer (covid dependant) where the local radio station will be broadcasting. Organizers are hoping for some speakers to be set up in some fairly remote locations. Plan is to use a few FM receivers plugged into rechargeable powered speakers.
Any suggestions on half decent battery powered portable FM receivers? Earphone out should be sufficient.
Cheers.

Baofeng UV-5R has FM. Probably only mono, but that shouldn't matter. Bonus is that you can use them as crew Comms afterwards. Also weather radio, etc. They can operate in the HAM range, but if you don't broadcast there you'll be fine. It will do FRS/GMRS freqs too. All in all a very impressive little hand unit.
Title: Re: Portable FM receivers
Post by: Mike Caldwell on May 24, 2021, 08:36:55 PM
Buried in a sealed box at the bottom of my parts, pieces and adapters case is a vintage Sony
AM - FM Cassette Walkman.
I've had to dig out a couple times each for the radio and the cassette.

https://www.radiomuseum.org/r/sony_walkman_fmam_stereo_cassette_player_wm_f2015.html (https://www.radiomuseum.org/r/sony_walkman_fmam_stereo_cassette_player_wm_f2015.html)
Title: Re: Portable FM receivers
Post by: MattLeonard on May 25, 2021, 12:25:13 AM
Doing a couple of beach events this summer (covid dependant) where the local radio station will be broadcasting. Organizers are hoping for some speakers to be set up in some fairly remote locations. Plan is to use a few FM receivers plugged into rechargeable powered speakers.
Any suggestions on half decent battery powered portable FM receivers? Earphone out should be sufficient.
Cheers.

Please share if you find something. I do a fair amount of FM broadcast for events - and have not had much luck finding small portable units with any degree of quality, much less a line output (at best, a crappy headphone amp/out).

Car receivers/antennas seem to have the best reception/sensitivity/selectivity - and we've wired up a few of our crew's cars to have loose RCA cable outputs that could feed into remote mixer/PA. I built a little rack for my Subaru that can do (4) SRX812 boxes  for ~360 degree coverage.
Title: Re: Portable FM receivers
Post by: Russell Ault on May 25, 2021, 01:22:34 AM
Baofeng UV-5R has FM. Probably only mono, but that shouldn't matter. Bonus is that you can use them as crew Comms afterwards. Also weather radio, etc. They can operate in the HAM range, but if you don't broadcast there you'll be fine. It will do FRS/GMRS freqs too. All in all a very impressive little hand unit.

As a licensed ham, I really wish people wouldn't recommend this approach. There's a reason (a few, actually) that the UV-5R (and its knockoffs) doesn't have FCC certification (heck, there are debates within the ham community about whether we should be using them, and we're licensed to build our own radios from scratch).

Using them on FRS frequencies in the US would require that they be FCC certified; to use them on GMRS frequencies you'd additionally need an individual GMRS license. Using them on other frequencies (which is how they're typically used, since they're a royal pain to reprogram from the keypanel and the factory default simplex frequency is VHF) is even worse.

I'm sure Henry Cohen will be along shortly to say a few words of his own, but please don't use uncertified radios.

-Russ
Title: Re: Portable FM receivers
Post by: Kevin Graf on May 25, 2021, 08:00:48 AM
Isn't this thread about radio receivers, rather than transmitters?
The local radio station has its licensed transmitter, but i don't know what the latency might be.
Anyway, a while back I bought some:
JVC KT-HDPK1 'HD', 12 Volt tuners. The price was low and they work great.
Title: Re: Portable FM receivers
Post by: Jason Glass on May 25, 2021, 11:12:08 AM
Doing a couple of beach events this summer (covid dependant) where the local radio station will be broadcasting. Organizers are hoping for some speakers to be set up in some fairly remote locations. Plan is to use a few FM receivers plugged into rechargeable powered speakers.
Any suggestions on half decent battery powered portable FM receivers? Earphone out should be sufficient.
Cheers.

If you want a total pro-level FM receiver with XLR balanced line outputs:

https://www.inovonicsbroadcast.com/product/679 (https://www.inovonicsbroadcast.com/product/679)

Which can be powered with any large ruggedized 12 volt power bank such as:

https://www.amazon.com/dp/B0791WDZTW/ref=cm_sw_r_cp_apa_glt_fabc_FJGHJBBT2CE9N62E90BJ

Did someone mention latency?  In the USA, FM stations typically employ a 7-second "profanity delay" that gives their operators a chance to beep or mute anything that could get the station fined.  Digital HD stations have an additional approximately 8 seconds of processing time, which is duplicated on their analog channel for audio alignment.
Title: Re: Portable FM receivers
Post by: Tim Weaver on May 25, 2021, 02:22:34 PM
As a licensed ham, I really wish people wouldn't recommend this approach. There's a reason (a few, actually) that the UV-5R (and its knockoffs) doesn't have FCC certification (heck, there are debates within the ham community about whether we should be using them, and we're licensed to build our own radios from scratch).

Using them on FRS frequencies in the US would require that they be FCC certified; to use them on GMRS frequencies you'd additionally need an individual GMRS license. Using them on other frequencies (which is how they're typically used, since they're a royal pain to reprogram from the keypanel and the factory default simplex frequency is VHF) is even worse.

I'm sure Henry Cohen will be along shortly to say a few words of his own, but please don't use uncertified radios.

-Russ


They are not illegal to own. They are illegal to sell, but even that, the FCC has failed to enforce.

It's exactly like the chinese made LED lights here that everyone is using. They do not have a UL listing and as such you would be liable if you start a fire, for example, even if the light wasn't the cause of the fire.


Besides BJ is looking for a receiver and as far as I'm aware any receiver of any kind is legal to own and use.
Title: Re: Portable FM receivers
Post by: Daniel Levi on May 25, 2021, 03:04:11 PM
Wouldn't any battery powered radio reciever of somewhat decent quality do the job, i.e. one from the likes of Sony or Roberts, plenty of them with decent battery life and a usable headphone output.
I have a Roberts Solar DAB 2 and a modern Sony FM/DAB unit and both seem to output acceptable quality audio.
Title: Re: Portable FM receivers
Post by: Henry Cohen on May 25, 2021, 03:30:19 PM
They are not illegal to own. They are illegal to sell, but even that, the FCC has failed to enforce.
Lack of enforcement does not convey a right to use in contradiction of law or statute.

Quote
It's exactly like the chinese [sic] made LED lights here that everyone is using. They do not have a UL listing and as such you would be liable if you start a fire, for example, even if the light wasn't the cause of the fire.
Actually it's not exactly the same. One is a question of conducting oneself lawfully, the other is a civil liability matter.


Quote
Besides BJ is looking for a receiver and as far as I'm aware any receiver of any kind is legal to own and use.
All radio frequency receivers must obtain a Part 15 certification from a TCB (Telecommunications Certification Body, essentially a recognized testing lab) to ensure any spurious emissions to not exceed published limits.
Title: Re: Portable FM receivers
Post by: Henry Cohen on May 25, 2021, 03:31:48 PM
Did someone mention latency?  In the USA, FM stations typically employ a 7-second "profanity delay" that gives their operators a chance to beep or mute anything that could get the station fined.  Digital HD stations have an additional approximately 8 seconds of processing time, which is duplicated on their analog channel for audio alignment.

Just means that first delay tower needs to be about 700' or 1500' from the main PA  ;D
Title: Re: Portable FM receivers
Post by: brian maddox on May 25, 2021, 04:32:09 PM
Just means that first delay tower needs to be about 700' or 1500' from the main PA  ;D

I like how you think.

"The delay tower has to go RIGHT HERE"

"But we were gonna put the taco stand there. Can't it go 100 feet that way?"

"NOPE!"

"Why?"

"ummmm....  reasons?...."
Title: Re: Portable FM receivers
Post by: Russell Ault on May 25, 2021, 05:39:20 PM
They are not illegal to own.{...}

Sure, but—outside of some very specific situations—in the US they are illegal to use (hence my "please don't use uncertified radios" plea).

Encouraging the OP to break the law ("you can use them as crew Comms afterwards", etc.) isn't consistent with my impression of how this forum typically operates.

-Russ
Title: Re: Portable FM receivers
Post by: Henry Cohen on May 25, 2021, 06:32:54 PM
Encouraging the OP to break the law ("you can use them as crew Comms afterwards", etc.) isn't consistent with my impression of how this forum typically operates.

Correct; it's not (or at least try not to).
Title: Re: Portable FM receivers
Post by: Jason Glass on May 25, 2021, 07:04:26 PM
Just means that first delay tower needs to be about 700' or 1500' from the main PA  ;D

Haha, umm, that'd be 7,000 or 15,000 feet away!

Edit:  Doh!  Correcting my correction!  It's 7,700 and 16,500 feet.  That last 100 of 1,100 ft per second gets more significant as time marches on.
Title: Re: Portable FM receivers
Post by: Dave Garoutte on May 25, 2021, 07:09:21 PM
Haha, umm, that'd be 7,000 or 15,000 feet away!
Oh, those pesky zeros!
Title: Re: Portable FM receivers
Post by: Bradford "BJ" James on May 25, 2021, 10:51:46 PM
Thanks for the replies, guys.  Gives me a start.
Title: Re: Portable FM receivers
Post by: Henry Cohen on May 26, 2021, 11:12:45 AM
Haha, umm, that'd be 7,000 or 15,000 feet away!

Edit:  Doh!  Correcting my correction!  It's 7,700 and 16,500 feet.  That last 100 of 1,100 ft per second gets more significant as time marches on.

Damn decimal place . . .
Title: Re: Portable FM receivers
Post by: Patrick Tracy on May 26, 2021, 12:05:58 PM
I don't know if it qualifies as decent by your standard, but Rolls makes an FM tuner with XLR output that runs on 12-15 VDC.

https://www.bhphotovideo.com/c/product/1272859-REG/rolls_hrs84_fm_digital_tuner.html/specs
Title: Re: Portable FM receivers
Post by: Pete Erskine on May 27, 2021, 05:26:43 PM
Doing a couple of beach events this summer (covid dependant) where the local radio station will be broadcasting. Organizers are hoping for some speakers to be set up in some fairly remote locations. Plan is to use a few FM receivers plugged into rechargeable powered speakers.
Any suggestions on half decent battery powered portable FM receivers? Earphone out should be sufficient.
Cheers.

Very successful in using Unity Intercom to distribute audio.  Best results with cellulsr cell phones, locally powered not using wifi.

Audio is full bandwidth and very low latency.
Title: Re: Portable FM receivers
Post by: Andrew Broughton on May 28, 2021, 04:23:55 PM
Very successful in using Unity Intercom to distribute audio.  Best results with cellulsr cell phones, locally powered not using wifi.

Audio is full bandwidth and very low latency.
Different application, but I'm wondering if the audio can be stereo at the receiving end?