
This article is written about the difference between Xianglong's A25 military and H-250 handset according to some investigation of the internal structure of the H-250 handset from Internet.
1. Required functions that written on specifications of the H-250.
The H-250 has been produced by various manufacturers, and delivered to the US military, so the products must be produced according to required specifications and pass a functional inspection.

Part of a document published online that shows the H-250 handset specifications required by the US Department of Defense (published in 1977)
2. Required performance specifications of the H-250/ A25
Item | H-250 | A25 |
Weight: | Approximately 350g | Matched |
Speaker impedance: | 1000Ω (@1kHz) | 1000Ω (@1kHz) |
Microphone impedance: | 150Ω (@1kHz) | 150Ω (@1kHz) |
Microphone output level: | More than -56dB(@1kHz) | -59dB(@1kHz) |
Distortion: | Less than 5%(300Hz~3500Hz) | Less than 5%(200Hz~4000Hz) |
Operating temperature range | -20℃~65℃ | -45℃~55℃ |
Water resistance: | Remains fully function after submerged in 3 feet (91cm) of water for 2 hours | Remains fully function after submerged in 1 meter of water for 2 hours |
PTT switch durability: | More than 2 million actuations | More than 2 million actuations |

Calculated microphone frequency characteristic
Vibration and drop test to confirm performance quality specifications, including electric characteristics, are mandatory.
If you need this kind of military handset, welcome to contact us by email sales01@yyxlong.com or direct call 008613858299721.