I have been thinking about the possibility of assembling a general coverage, that is, not like a scanner, receiver using assorted modules, including the front end sections of obsolete cable tuners, The 46 Mhz IF strips from Older VCRs, and possibly various TV tuners. The idea is to avoid the need for a synthesizer with a PLL that tunes in steps . It seems like it should be possible to have AM, FM, and product detectors, as well as some kinds of digital ones.
The big motivation has been the re-assigning of many of the UHF TV frequencies to various other services, and the thought that this might provide some interesting listening.But none of the various strips were designed to work with each other. So it is not a simple project. Has anybody experimented with any such concepts with any success?

 

Even if it worked you won't be able to listen in to much. Almost all the new services in those bands use complex digital modes that require a DSP stage to demodulate and are most likely encrypted.

 

One can quickly and easily monitor all UHF frequencies with a SDR dongle.

 

One can quickly and easily monitor all UHF frequencies with a SDR dongle.

The RTL-SDR R820T2 RTL2832U with assorted antennas tunes from 500 kHz to 1.7 GHz with 2.4MHz bandwidth for under $30.

 

Thanks for pointing out some alternatives, those are interesting concepts.
Certainly a number of those dongles. coupled with a computer, can monitor any frequency, at least in theory. And only a few pieces of software are required to make them work. But without the computer those dongles are merely a pretty key-fob. I have read some of the articles and seen two presentations about those dongle receivers and while they work fairly adequately, getting them is mostly an exercise in Pay Pal or check writing, and if one of them quits and it is the hardware, the service is replacement. I have seen pictures of those setups and they consist of a dongle hanging out the side of a notebook computer, with a heavy antenna cable connected to the dongle. That is not even a slightly rugged setup. A home-brew receiver can be far more durable than that.