For this review, I used a Radio Shack Pro-404, although the GRE PSR100 is nearly identical.
These are analog-only, conventional channel units, and their upper frequency coverage tops out at 512 mhz. Pc-programmability is a plus, (no alpha tags) along with spectrum-sweeper, and weather alerting using FIPS codes. The simplified interface is a welcome to newcomers to the hobby, although the smart ones will do their homework in the forums and databases to make sure that there are conventional systems left in their area. For the time being, generic airband, marine, railroad etc should be no problem.
The 404 I tested had amazingly loud audio - louder than any other handheld I've encountered lately. The high-end was a bit harsh for my tastes, although in a very noisy environment, this might lead to enhanced intelligibility. You can push it into distortion, but you'll know immediately as the difference between loud and distorted is a knife-edge difference on the volume pot. Some typical GRE hiss was heard from the audio amp.
The major issue for those in metropolitan areas like myself, is that the scanner uses only a dual-conversion setup with a first IF of 10.7 mhz. I really thought that went away in the 90's, as other manufacturers in this price range have been using triple-conversion. Typically, the dual-conversion means that image frequencies 21.4 mhz away from your intended station can be mixed in.
In my case, a local college security team on a 460 business band freq landed right on top of my 483 mhz Sheriff's system. At first, I was amazed at the lack of professionalism on the Sheriff's channel - something I'm definitely not used to so I tuned down 21.4 mhz away and sure enough, the college team was on their assigned frequency. Airband was the same, as I was able to hear the data bursts from an amateur radio packet system invading my local airport tower. Surely, a ham should know not to interfere with an aircraft tower! Nope - the dual-image 21.4 mhz away was the culprit.
One would think that you might be able to smother this effect with an attenuator, (also NOT my preference - it is like using a sledgehammer to pound in a finishing nail), but the 404 does not have an attenuator.
I also noted that the sensitivity in airband (118-136) was a bit down from my other units - and the specs revealed that it is least sensitive in this band.
Amateurs wanting to use it for 440 UHF monitoring may find themselves off frequency if their area has switched to 20khz spacing - with the standard 12.5 khz spacing of most scanners, you might zoom right past an active system while searching. If your area has made a switch to 20khz spacing, just put the system into a memory, knowing that the scanner will be a bit off frequency.
Overall, I really like the loudness of the audio when not cranked into distortion (although I wish manufacturers would pay attention to the high-end and amplifier hiss), and would have kept it, even with the lower sensitivity on the airbands, but the dual-conversion IF circuitry let me down, so away it went.
These are analog-only, conventional channel units, and their upper frequency coverage tops out at 512 mhz. Pc-programmability is a plus, (no alpha tags) along with spectrum-sweeper, and weather alerting using FIPS codes. The simplified interface is a welcome to newcomers to the hobby, although the smart ones will do their homework in the forums and databases to make sure that there are conventional systems left in their area. For the time being, generic airband, marine, railroad etc should be no problem.
The 404 I tested had amazingly loud audio - louder than any other handheld I've encountered lately. The high-end was a bit harsh for my tastes, although in a very noisy environment, this might lead to enhanced intelligibility. You can push it into distortion, but you'll know immediately as the difference between loud and distorted is a knife-edge difference on the volume pot. Some typical GRE hiss was heard from the audio amp.
The major issue for those in metropolitan areas like myself, is that the scanner uses only a dual-conversion setup with a first IF of 10.7 mhz. I really thought that went away in the 90's, as other manufacturers in this price range have been using triple-conversion. Typically, the dual-conversion means that image frequencies 21.4 mhz away from your intended station can be mixed in.
In my case, a local college security team on a 460 business band freq landed right on top of my 483 mhz Sheriff's system. At first, I was amazed at the lack of professionalism on the Sheriff's channel - something I'm definitely not used to so I tuned down 21.4 mhz away and sure enough, the college team was on their assigned frequency. Airband was the same, as I was able to hear the data bursts from an amateur radio packet system invading my local airport tower. Surely, a ham should know not to interfere with an aircraft tower! Nope - the dual-image 21.4 mhz away was the culprit.
One would think that you might be able to smother this effect with an attenuator, (also NOT my preference - it is like using a sledgehammer to pound in a finishing nail), but the 404 does not have an attenuator.
I also noted that the sensitivity in airband (118-136) was a bit down from my other units - and the specs revealed that it is least sensitive in this band.
Amateurs wanting to use it for 440 UHF monitoring may find themselves off frequency if their area has switched to 20khz spacing - with the standard 12.5 khz spacing of most scanners, you might zoom right past an active system while searching. If your area has made a switch to 20khz spacing, just put the system into a memory, knowing that the scanner will be a bit off frequency.
Overall, I really like the loudness of the audio when not cranked into distortion (although I wish manufacturers would pay attention to the high-end and amplifier hiss), and would have kept it, even with the lower sensitivity on the airbands, but the dual-conversion IF circuitry let me down, so away it went.
