Thursday, 18 May 2017

Lithium conversion for PRC-350

The PRC-350 is a 2W VHF FM manpack transceiver in the Clansman range. Its probably the most famous military radio that no one has ever heard of - because its the radio whose antenna has the flag attached in this photo -

The one in my collection has the common 'battery cassette' intended to take 10x NiCd 'C' cells. I have 8x Alkaline cells in mine at present, but that is an incredibly expensive way to run the set! Original, or NOS, NiCd battery packs for this radio seem to be unobtainable now.

A full set of modern 'C' size NiMH cells could be used, but this is rather expensive, and heavy. So for around the same cost, and having an empty, decelled alloy battery pack available, Ive decided also on this radio to go the Lithium Polymer route.

Its the shipping that makes your eyes water buying these things! But, give them credit at Hobbyking, i ordered yesterday afternoon and it was here first thing this morning!

I was aiming for a pack of around 1800mAh, which I thought more than adequate for the PRC-350, but then I saw this one on special offer - 2200mAh for just 30p more, but without a main output connector. Well, I would have had to cut the connector off anyway! So a good bit of extra capacity for a few pennies extra!

This is a 4S pack, giving an output of 14.8v. The PRC-350 has a 'nominal' supply voltage of 15v, but an operational voltage range of 12 to 21v, so this pack will be spot on. I will add a low voltage monitor and alarm of course, using D sub connectors as I did on the 24v 4000mAh pack for the PRC-320/PRC-351, the connector doubling as the balance charge port. I will also add a DC output connector to allow it to be used to supply other kit, perhaps also a USB charge output?

All being well, this and the PRC-350 could be going up for a SOTA on Snowdon in a couple of weeks!

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