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February 27th 04, 10:14 AM

On Thu, 26 Feb 2004 20:58:19 -0800, Frank Gilliland
wrote:

In , wrote:

One other oddity. Before I power up the radio, the amp is drawing
zero current. As soon as I power up the radio (on RX), the amp starts
drawing 180 ma, whether it is switched on or off.

Impossible. The amp has no input for the powered condition of the
radio (receive).

Wrong -- it's very possible. That is a MOSFET amp with no power switch. A bad
combination to be sure, because as long as there is source-drain voltage, any
kind of signal can drive it to some extent. It's possible that C1 could be
shorted (after all, it's only rated for 50 volts) and the output of the radio
have a DC component. Or if D2 is blown (a 1N4148 passing 3 watts -- yikes!) D1
will hold a nice, steady DC bias on the MOSFET. There are a lot of possible
scenarios for what he is describing. What -is- impossible is for you to think
before you demonstrate your ignorance. Haven't we been through this before,
Tnom? Didn't you learn anything the first dozen times?

But hey, it's a cheap and crappy amp, and you get what you pay for.

Do you have the coax in-out connected backwards?

You have your brain connected backwards. Quit trying to act like you know what
you are talking about.

I stand by my post. There is no voltage on the radios coax on receive
that will activate the amps increase in current draw. You should pay
more attention. Even if there was a DC voltage C1 on the amp would
block it.

"You have your brain connected backwards. Quit trying to act like you
know what you are talking about." I just couldn't resist.

http://www.rmitaly.com/download/inst...nstruction.pdf

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