Steve Hagar wrote:
> I talked to the Microair guy at Sun and Fun about the 4 watt issue. He
> related
> that they are planning on introducing a new unit at Oshkosh. I believe he
> said that the new unit will have a variable output I understand it will put
> out 5 watts or 10 watts at the flick of a switch.
That's an odd design feature. If it's capable of 10W, why a switched
5W option? 10W is pushing the limit of, if not exceeding, what you
can cleanly pump into a 50-ohm load with 13.75V. Unless the design is
fancy, the trade-off in so doing can be RF distortion, which among
other problems garbles the audio. That's why Jim Weir says in his
article that 10W costs the mfr $500 in components just for the
transmitter stage (but 1W is $50). If the idea is to switch to 10W
when needed, like when they say you're weak, twice the power --- but
distorted audio -- won't be twice the readability. Alternatively, the
thing may draw low current only 5W mode as it does now, but 10W mode
fires up a voltage upverter (like a strobe pwr supply) that's a drain
on the charging system and noise source for other avionics.
For my money, I like to first hear how she sounds on the receive end,
5W and 10W, and know quiescent current draws both ways.
Regards,
Fred F., A063
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