> Yes , I've tried to feed the signal from my external reference
> oscillator into the 1200, but it takes literately volts of
> signal to get
> it to switch to the external osc. input.
I forget what the spec was, but it seems to me it was less than +10 dBm. I
think there was a warning on it that said not to exceed 1/4 watt (+24 dBm).
I remember my 1500 was a little more fussy about external ref input level
than most of my other test equipment. Currently I have a Rubidium on my
bench that feeds an 8-port passive power divider. The output of the
Ribudium is 5Vp-p sine wave, drops down to about 4Vp-p with a 50 ohm load on
it. I think originally I had a two-way power divider, one leg fed the IFR,
the other leg fed a 4-way splitter to feed other equipment. As a rough
guess I was giving the IFR about +13 dBm and it was happy with that.
You can probably find a video distribution amp that has a bandwidth in
excess of 10 MHz to do the job if you need more output than your reference
can provide. Most will do at least 2Vp-p into 75 ohms, maybe a little less
into 50 ohms, should still give you close to +10 dBm. Or look for a
high-output video amp that will do 5Vp-p to be sure you've got enough
headroom. Lots of analog video DA's should be available for next to nothing
thanks to the DTV transition...
--- Jeff WN3A
