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Gotta remember the difference between a passive mixer like the Mini Circuits ADE and an active mixer like the push-pull J310s.

The LO drive level for the ADE is shown as +17dbm, or around 60 (I think) milliwatts. Lots more than the Galaxy's local oscillator circuit can pump out. And since it's passive it will lose roughly 5 or 6 db of your signal level passing through it.

The factory P-P FET mixer has some signal, or as they call it "conversion" gain, so changing to a passive mixer would involve making up the gain deficit. Might reduce the receiver's internal noise level, though. And the ADE mixer would stand up to larger off-channel signals before it overloads and creates its own bleedover.

The best tool for zeroing in on the best compromise between noise, sensitivity, overload resistance and selectivity is called a noise-figure meter. Never have properly learned to use one, but who knows, maybe some day?

73

<blockquote data-quote="nomadradio" data-source="post: 812031" data-attributes="member: 22">Gotta remember the difference between a passive mixer like the Mini Circuits ADE and an active mixer like the push-pull J310s. The LO drive level for the ADE is shown as +17dbm, or around 60 (I think) milliwatts. Lots more than the Galaxy&#039;s local oscillator circuit can pump out. And since it&#039;s passive it will lose roughly 5 or 6 db of your signal level passing through it. The factory P-P FET mixer has some signal, or as they call it &quot;conversion&quot; gain, so changing to a passive mixer would involve making up the gain deficit. Might reduce the receiver&#039;s internal noise level, though. And the ADE mixer would stand up to larger off-channel signals before it overloads and creates its own bleedover. The best tool for zeroing in on the best compromise between noise, sensitivity, overload resistance and selectivity is called a noise-figure meter. Never have properly learned to use one, but who knows, maybe some day? 73</blockquote>

[QUOTE="nomadradio, post: 812031, member: 22"] Gotta remember the difference between a passive mixer like the Mini Circuits ADE and an active mixer like the push-pull J310s. The LO drive level for the ADE is shown as +17dbm, or around 60 (I think) milliwatts. Lots more than the Galaxy's local oscillator circuit can pump out. And since it's passive it will lose roughly 5 or 6 db of your signal level passing through it. The factory P-P FET mixer has some signal, or as they call it "conversion" gain, so changing to a passive mixer would involve making up the gain deficit. Might reduce the receiver's internal noise level, though. And the ADE mixer would stand up to larger off-channel signals before it overloads and creates its own bleedover. The best tool for zeroing in on the best compromise between noise, sensitivity, overload resistance and selectivity is called a noise-figure meter. Never have properly learned to use one, but who knows, maybe some day? 73 [/QUOTE]

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