The company Argent Data Systems produces ADS-SR1 , which is basically a simplex repeater, voice beacon or voice mailbox. For example, in simplex repeater mode, after connecting to a radio station, it records up to a 218-second session, which it then broadcasts. The recording is performed at 19.2kHz sampling, which guarantees high quality recording.
In the voice beacon mode, it is possible to preprogram ten messages that will be broadcast at set times.
In voicemail mode, the session is stored in the memory, which is broadcast only after receiving the required DTMF code.
One cable is enough to connect the ADS-SR1 to the transceiver. Control is realized through DTMF instructions. ADS-SR1 has many interesting functions, e.g. CW ID. Manufacturer in manuals also provides a diagram. Retail price is . More on https://www.argentdata.com/catalog/product_info.php?products_id=98