supply of suppling and commissioning digital signasuppling and commissioning digital signa,supply and commissioning digital signal receiver rakshak to receive signal transmitted from digital signal modulator dsm25s-udm-1as per rdso specification no. rdso/spn/tc/105-2015, ver.-2. 1 dtd: 18.05.2022including maintenance for two years specifications working on vhf frequency 160.450m hz.. inbuilt battery. housing in small pocket model (mobile phone type) with built in antenna and rechargea ble battery. facility to connect external battery charger. battery charging status is indicated by led belt-h anging arrangement. dimension of rakshak shall be less than 20x50x150 (wxdxh), (h=100 unit + 50 art enna =150). net weight rakshak shall be less than 150 gms, 5mm led indication- up signal received bl ued led, dn signal received yellow led bi directional received green led. [ warranty period: 30 months after the date of delivery ] ] , supplying, installation and commissioning digital signal modulator portable up. dn & ud tran smitter dsm25s-udm-1 as per rdso specification issued vide rdso/spn/tc/105-2015 ver 2.1 dated 18.0 5.2022 for transmitting the train approaching up,dn & ud signals to the corresponding digital signal receiv er (rakshak) including maintenance for two years. specifications : working on vhf frequency 160.45 mhz with antenna and cable. built in battery 12v/7ah , battery charger working on 220 v ac, incorporated with 12v dc battery with charger. charger should have a 13.8v/2amp , cvcc mode for charging battery portabl e up/dn transmitter should have following facility mode switch to start & stop transmitter mains socket to connect 230v ac through mains cord for charging battery, manual trigger switch up & dn for transmitting signal manually. external terminal block screw connector (4way) for connecting : up trigger contact from relay room, dn trigger contact from relay room , dimension of portable up/dn transmitter shall be less th an 200x275x200mm (wxd