you can add 3 diodes in series with the + line
>to the radio. The diodes must have a current rating greater
>than the maximum current the VHF radio will draw
Can I buy something like this already set up?
Re: DC over voltage protection
Aug 02, 2003
2 Replies
If your radio's output power is between 10 to 50 watts, you might be better off with a true DC to DC converter. Astrodyne's model SVB12SC12 can use 9.2 to 16VDC input & produces solid 12VDC (upto 3.3 amps continuous). It is $115.00 each (to order, go to:
formatting link
but it should work better than other zener diode solutions (zener diodes that can handle 3.3 amps & drop 4 volts, will need a huge heatsink, anyway).
Normaly radios are rated 13.4 volts and chargeing system should produce this. You would need to regulate the whole charging system. One way with std battery chargers is a 2n3055 transistor and 36 watt bulb across output to use up extra with a opamp to drive transistor and a voltage reg driving opamp this is OK to protect battery but does not remove ripple so for a radio may not be good enough and you may get hum on transmit. Some radios will take more than others i.e. a Yaseu FT290R will take 9 to 16 volt but a Icom 290 will need 13 to 13.8 volts but 2 meter sets. So you need to read radio spec. If your getting the charging voltage from mains then use a CB power supply they are regulated and cheap.
All best Eric
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required