domenica 5 febbraio 2012

SEM 52-S military handheld

Months ago, I've bought a german military handheld: a SEM 52-S. Specifications: see
Is an FM handheld with frequency coverage that includes 6 meters, 1 watt circa power out, very big and weighty, but so cool! 6 fixed channels programmable with internal contraves.

The radio is a SEM 52-S/FZ/46 and is not born as an handheld: is user on tanks with a mount, see, but is useable as handheld using a SEM 52-S battery pack (delivered with the transceiver).
I've also the antenna, a long (93 cm!!!) SEM 52A antenna, with fits perfectly in SEM 52S

  • First Job: rebuid battery pack
The battery pack comes with a broken, unusable NiCd battery pack. The box is also very dirty and in bad conditions. I build a new battery pack using two docks for 4 AAA battery, and fit in 8x900 mAh NiMH AAA. The result is shown below:

  • Second Job: arrange an alternative antenna
I have an original antenna, but is very long (93cm) and I want a smaller one for short-range contacts. I choose to modify a commercial item. I buoght an old 43 MHz whip antenna: 43 MHz is almost a dead band, and dealers are happy to sell one for a very discounted price. The antenna is a CTE model HP-FLEX/B.

The antenna is 54 cm long. Using the FT-817 as a tunig tool, I cut the antenna until a dip in SWR happens (I stop at 1.5:1). The antenna is now 36cm tall (from bottom of BNC connector to top of the whip. See the shorted antenna mounted on SEM 52-S

Next job: building a speaker-microphone (to do)

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