I came across a General Inst. 450I sat reciever . Is there any value in having one of these.
There is one handy use for analog receivers, provided that the receiver has a convenient way for specifying the frequency it's tuned to. Basically you can use it to determing the SR of DVB-S, DVB-S2 and some DCII signals, in the event that you don't have a blind search receiver (and so far there aren't many available for DVB-S2).
Basically, to determine the SR, I tune the analog receiver to the frequency of the digital signal, and connect a SW communications receiver to the baseband output of the analog receiver, in FM mode. You then scan through the SW band, and you'll find strong carrier signals associated with the SR of the digital signal. For example an SR of 4444 would show up at 4.444 MHz, an SR of 30000 would show up at 30.000 MHz, etc.
I find the frequency so the signal using a slow scan program that goes with a Broadlogic PC card receiver I use. Along with a VB program I wrote, it gives me nice spectrums of the sat band.
Anyway, the combination of freqs via the Broadlogic card and SR via the baseband output of an analog sat receiver gives the capability of identifying new transponders without the need for a blind scan receiver. Right now, it's the only way I can find DVB-S2 signals.
BTW, the SR determination is VERY accurate. I can generally be right on the proper SR value, and almost never more than one unit off. The freq via the Broadlogic is dependent on the LNB stability, but is usually within about 1 or 2 MHz.
There are still occasional things to view in analog though, so there are also other uses.
EDIT: I forgot to comment on the "provided that the receiver has a convenient way for specifying the frequency it's tuned to" issue. Some receivers don't have a conveneint way of doing this. Some very old analog receivers tune to preset channel freqs, and you can't tune change those freqs. Most more recent receivers have some way of tuning the freq, but it's not always easy to determine. Ie my old Echostar-7000/HT8 receivers tuned to the center freqs, then allowed you to tune off center by a number of MHz, but figuring out exactly where you were in the band was very confusing, particularly on Ku, where the center freqs were not standard. On my Drake 1824, there is a hidden screen that pops up a bunch of hex numbers, and there is a chart to convert the hex numbers into the freq being tuned to. My Monterey 55, however gives you a nice on screen readout of the freq, which is very convenient. I'm not familiar with the 450, so I don't know if it's convenient or not with that receiver.