PRC-25/77 amplified LS-454 speakers

[papakb]

I'm thinking of building up some amplified LS-454 speakers to go with the PRC-25/77 radios that would power directly from the battery connector on the radio and wondered if there was any interest in them. Please let me know.

Kurt
KG6KMJ

 

[m38inmaine]

I would be, I use to have one built by Steve Haney but it required an external power source which also provided power for the radio.

 

[papakb]

Over the years I've built speakers that were only amplified speakers like this one powered either by the radio or an external power source. Powering from the radio itself simplifies the wiring to a single plug. I've also built amplified speakers that had a handset connector for remote operation and some were you ran power to the speaker and that in tern powered the radio. Their advantage was that you could tuck the radio into a convenient space and turn it on and off from the speaker..

 

[ThirdGear]

Here's a video showing how to rewire the LS-454 so its pinout works with the PRC-25/77 audio connector. The LS-454/U connector pinout is normally configured for use with the PRC-68 radio family, and the instructions in this video show how to rewire it for use with the PRC-77.

https://www.youtube.com/watch?v=DIUoBEEtSrc

Basically, disassemble the connector to get access to the connector wiring. Unsolder the wire connected to the "E" pin, and re-solder it to the unused "B" pin. This is the hot speaker wire, and the audio output of the PRC-77 uses pin "B" instead of pin "E".

 

[papakb]

ThirdGear, The PRC-68 was never designed to work with a speaker and it's output audio level is even lower than that of the 25/77s. The 68s have an internal speaker for normal use but can be used with the H-189 or H-250 handsets or the Whisper Mikes that came out later on.

The PRC-68 normally has +Vcc battery voltage on pin E so there's no reason they would have wired a speaker to that pin.

Kurt
KG6KMJ

 

[mrcub63]

PRC-25 speaker

I'm thinking of building up some amplified LS-454 speakers to go with the PRC-25/77 radios that would power directly from the battery connector on the radio and wondered if there was any interest in them. Please let me know.

Kurt
KG6KMJ

Hi, I have a working PRC-25 and a 454 speaker that isn’t broadcasting thru the speaker, I’ve seen where a wiring change is needed which I don’t know how to do. Are you selling any modified 454’s that will just plug into the audio plug? With your idea above what would that look like? Would it connect where the battery is located?...thanks for any help.

Vince

 

[papakb]

The problem with connecting to the audio connectors on these radios is that you either have to have internal batteries or a second power cord for the amplifier power. The picture posted above is of one of the speakers I built and have for sale. I have 6 speakers ready to go that connect to the 14 pin battery connector so there is only a single cable between the radio and the speaker. This also has the advantage of leaving both audio connectors free for either mics, handsets, or headphones.

There were some LS-454s where the wiring was changed to match another radio set. Switching the wires is not difficult to do but it does mean opening up the UG-229 connector. No soldering is involved as the cable wires are terminated in sleeves that slip in and out of the contact plate. The wires should be on pins A and B.

 

[papakb]

I'm in the process of building up amplified speakers now and wondered how much onterest there would be in them? Please send me a PM if this is of interest to you.