Ah ! The "legendary" (as in Urban Legend) SP Astro Saber with Fascinator & EDACS !
That rumor is at least 20-25 years old now... (beaten dead horse is beaten...and dead)
Speaking of Hydra radios, I do have one (I'm also a collector, so having "less than useful" radios is not a problem
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)
Mine is a M-PA & served aboard USS Enterprise [CVN65] (was used by catapult officers; we call them "chien jaune = yellow dog" here
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) . Still have the original box and manual...
As Military systems tend to have a long "lifetime", Hydra architecture was first used with M-PA, then transitioned to M-RK, and the last time I checked they were using P7100...
IIRC, several modifications were made between a "below-deck" Hydra handheld and a "flight-deck" Hydra handheld.... (noise limiting circuitry & special EMC shielding in the UDC connector for the flight-deck one IIRC...)
And of course all the over modifications between an Hydra & Non-Hydra radio...
As a short summary : 100mW, EDACS, AEGIS and encryption capable (DES), FM (IS) for the one I have...
The box state "NAVY EDACS 403 SEL" for 403-423 MHz, but in reality the 100mW modded board is a special 403-440 MHz board, not just 403-423 like the standard UHF RF board...
IIRC the radio can switch between 20 & 100mW...
Theses Hydra systems were 406-420, then they added the 380-400 MHz band...
Ericsson sold several of theses systems where I live, locally we call them SyRTE, and it is still used today (with M-RK II) aboard modern frigates...
I do have more infos, but I remember that you disliked speaking with foreigners last time we had a conversation, so I’ll leave it at that...
I do respect KevinC a lot, and I'm curious to see His/KE4ZNR firmware, but IMHO that story was Bull****.
iDEN (MiRS) is (M)16-QAM IIRC, with 6:1 TDMA (there's no way a AS can handle that)
Also, there's a lot of different VSELP vocoder "versions" (as there's also a lot of IMBE vocoder "versions", like the 7200 vs 7100 bps of P25 vs ProVoice, for exemple...)
I'm pretty sure the 30ms frame at 126 bit per frame version (among others) of iDEN was not compatible with "ASTRO VSELP" as used in the Astro Saber...
Feel free to correct me though (with proof please) as I will be delighted to see this possible, I do like a well done PoC in radio ;-)