Yeah, I built the post mixer filter a couple of nights ago from some
brass platting. I think I am going to send away for a Level 17 mixer
with the correct frequency ranges so I can run closer to +0dBm from
the modulator.
On Thu, 10 Feb 2005 16:30:02 -0800, Bob Dengler
<[EMAIL PROTECTED]> wrote:
>
> At 2/9/2005 09:35 PM, you wrote:
>
> >I have a Circa 1982 Mini Circuits mixer, ZXM-2 but it seems it is not
> >made anymore as MCL denies all knowledge of its existince. I was
> >wondering if anyone had the spec sheet for it? It has three BNC
> >connectors on in, "R" "I" "L" and is about 2" X 3/4".
> > I was hoping I could run a 1GHz LO into it to hetrodyne a cable
> > modulator to 1277.25 for my up and coming ATV repeater project.
>
> My '91/'92 Mini Circuits catalog doesn't list it either. However, looking
> at their numbering scheme for their other mixers suggests that it's a
> 5-1000 or 10-1000 MHz unit.
>
> Yes you can use them as up-converters. However, your conversion loss will
> be higher since your output signal will be above the upper limit of the mixer.
>
> Start driving the LO port with 0 dBm @ 1 GHz & slowly increase the LO drive
> until you see diminishing increases in desired output. It's probably wants
> +7, +10 or +13 dBm of LO. And of course make sure you filter out the
> 722.75 MHz that will also be coming out of the RF port of the mixer (1 GHz
> into LO port, 277.25 MHz into IF port), as you'll be getting more power
> there than at 1277.25. Also make sure that your 277.25 signal is at least
> 20 dB down from your LO drive level, otherwise your video signal will
> intermodulate with itself within the mixer, generating all kinds of crap
> throughout the 1.2 GHz band. This means you won't get more than around -20
> dBm of 1.2 GHz signal out of the mixer, assuming it works OK at 1.2 GHz.
>
> Bob NO6B
>
>
> Yahoo! Groups Links
>
>
>
>
>
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