14 Jul
2004
14 Jul
'04
7:16 a.m.
I finally got the receiver out today and played with it. It seems to
work well for the most part and the sensativity is great! We picked up WWV
from Colorado at 15MHz with only a key stuck into the
RF Signal In port.
The only real problem that we found was that you can't select
any BandWidth
of 20KHz or below. This thing is FULL of filters and attenuators. I suspect
one the relays or drivers in it is bad and isn't selecting the right filter
below 20Mhz. BTW it has a wirewrap control card in it. I haven't pulled it
out yet but it looks like it might be a Multibus card!
Stan Barr found this and send it to me:
Wide Range Receiver Model R-1250
The Model R-1250 wide range receiver is tunable from 100Hz* to 1GHz using
external control, front panel keyboard or a single tuning knob. It has
continuous frequency coverage and automatic preselection filtering.
The unit has selectable IF bandwidths and AM/FM envelope detectors as
well as a built-in IEE-488 bus to allow interfacing to a computer for
automated sytem operation. It has an 8 digit LED display and the frequency
resolution ranges from 0.1Hz below 250Khz to 100Hz above 20Mhz. The R-1250
requires a power supply of 115/230 volts ac, 50/60Hz single phase, measures
222 x 431 x 533mm and weighs 38Kg. It has a logged MTBF in the field of
greater than 2500 hours.
Manufacturer: Dynamic Sciences, Chatsworth, California.
* That's what it says - 100 Hertz...
I also found that it's supposed to be sensitive enough to pick up a
signal at only 10db above the Johnson noise level! AND I found that the
intermediate-frequency (IF) filters have adjustable bandwidths ranging from
50 Hz to 200 MHz!!!
Does anybody have any idea what the AM Pulse strencher control, AM
Slideback control and Log/Lin control are supposed to do? Or what the
Calibrate In posts are for or what the difference is betweeen the regular
Signal In port and the Low Freq Signal In port is?
I posted posted some pictures at <http://www.classiccmp.org/hp/dyn_sci/>.
Joe