SXA portophone is a 6 channel VHF handy available in junk for approximately Rs.300. I bought 2 nos recently. It needs 2 crystals. I have been looking for information on crystals and tuning information of SXA.
\nRecently Allen Antony, SWL, provided with me all the necessary information.<\/p>\n
Crystals
\nTx crystal frequency= f\/8
\nwhere f is the desired transmission frequency
\nRx crystal frequency = (f – 10.7) \/3<\/p>\n
It seems there are 2 versions of SXA available one with 2 watt and the other with 5 watt power output. Update: 27 April 2008<\/p>\n The original design of SXA portaphone is by design. There is an article on SXA in the Elektor magazine December 2007 issue. The handies that I have , are manufactured by West Bengal electronics corporation.<\/p>\n My friend Allen (VU3AUZ) has successfully converted the SXA to cover the entire 144-146 band with a DDS VFO.<\/p>\n I have seen service manual of SXA during once of the hamfests. I would love to get hold of a copy.<\/p>\n","protected":false},"excerpt":{"rendered":" SXA portophone is a 6 channel VHF handy available in junk for approximately Rs.300. I bought 2 nos recently. It needs 2 crystals. I have been looking for information on crystals and tuning information of SXA. Recently Allen Antony, SWL, provided with me all the necessary information. Crystals Tx crystal frequency= f\/8 where f is… Continue reading SXA Portophone VHF handy<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"_links":{"self":[{"href":"https:\/\/brainstorms.in\/index.php?rest_route=\/wp\/v2\/posts\/15"}],"collection":[{"href":"https:\/\/brainstorms.in\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/brainstorms.in\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/brainstorms.in\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/brainstorms.in\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=15"}],"version-history":[{"count":0,"href":"https:\/\/brainstorms.in\/index.php?rest_route=\/wp\/v2\/posts\/15\/revisions"}],"wp:attachment":[{"href":"https:\/\/brainstorms.in\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/brainstorms.in\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/brainstorms.in\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nThese set were used by Kerala police ( probably some 10 years back). I am yet to trace the manufacturer.
\nI have scanned and made a jpeg from the sheets Allen has provided. He has also given me detailed handwritten notes on tuning the set for Amateur band. I am yet to try it. I will post details as soon as I do it.
\nA big thanks to Allen for the help.
\nThe transmitter layout is here<\/a> and the receiver here<\/a><\/p>\n