I have owned a VR-500 for a few years. Its performance directly relates to how you intend to use it and which features are most important. I wanted ss/cw detection, extreme portability, large memory capacity and wide band reception. The VR-500 fits into my shirt pocket and I take it with me in my travels. The fact that it runs from 2 AA batteries is a definite plus. A fresh set of AA batteries lasts about 15-20 hours. I use both rechargeable NiMH's and alkalines.
In my case for HF, I mostly listen to fixed frequency stations - milcom, transoceanic aircraft and number stations where transmissions are channelized. In those applications, it works good enough for casual listening. I did have to slightly realign the BFO so that SSB signals sound correct (it was off by about -600 HZ as received from the factory). The IF bandwidth is about 8 KHz for LSB/USB/CW modes so don't expect razorsharp selctivity. But for casual listening it's just fine.
There are a few quirks in the LSB/USB modes. First, the BFO frequency is injected into the center of the bandpass. As a result, the VR-500 is not capable of single frequency reception. As a result the VR-500 does not tune LSB, USB or CW signals like a communications receiver. As a matter of fact, because of how the BFO works, you can use the USB mode to receive LSB and vice versa. Second, the tuning rate always defaults to the 100 Hz steps regardless of the autoband settings. This is more of an annoyance than a problem. The quick get around is to select the manual step rate mode.
As far as amateur radio monitoring, it is definitely not up to par with a real ham type receiver, especially if you intend to tune around. But then again, since it covers all bands and all modes from 160 Meters through 1296 MHz and it fits in your shirt pocket it's pretty hard to beat. I use it to monitor several 75 meter SSB nets, W1AW CW practice, RTTY bulletins, propagation beacons and qrp calling frequencies. I've used it to copy SSTV, PSK-31 and RTTY with decoder software.
The normal AM mode bandpass is very wide - approx 16 KHz. This results in mediocre SWBC reception. There is a software mod (NAM) to reduce the IF bandwidth from 16 KHz to about 8 KHz. This makes a significant improvement in performance for SWBC. The IF response is somewhat nonsymmetrical - one side of the response is very steep and the other has less of a slope, much like a Cohn filter. It is definitely not a communications receiver. It does work just fine for casual SWBC listening and I use the VFO presets for the SWBC bands between 49 - 13 meters.
AM BCB reception with the NAM mod is fairly good. With the 26 inch whip, I can hear most of the stations that I can hear on my car radio. Performance below the AM broadcast band is ok, once you get out of the urban environment otherwise there is a lot of crud from the AM BCB. I use it to listen to NDB's and can easily hear some stations as far as 150 miles in the daytime using a short, 26 inch whip. Most other owners use a short length of wire rather than a full sized antenna because the front end overloads easily for most HF and below frequencies. (On VHF/UHF I use full size antennas with no problems.)
Its main drawbacks for HF performance:
1. Does not have single signal reception for SSB/CW
2. The IF bandwidth is too wide. The NAM mod helps alot on AM but the filter response is somewhat nonsymmetrical.
3. The front end overloads very easily and the attenuator is not much help
4. The receive is not good for general tuning.
As far as VHF/UHF performance is concerned, I mainly listen to milcom aircraft, some public service and amateur radio repeaters. The ability to cover the UHF military aircraft segments is a definite plus in my book.
There is a quirk in the VFO scan mode. I noticed that some frequencies like 145.010 could not be scanned in VFO scan mode using 20 KHz steps. My VR-500 always defaulted to scanning 145.000, 145.020 etc regardless of how I initialized the scanning. I devised a simple test to determine if a frequency can be scanned in VFO mode. If you divide the desired frequency by the VFO step rate and your answer is a whole number answer such as 7250.0 or 7251.0 then you can scan the frequency. Since 145.010 MHz / 20 KHz = 7250.5 you can not scan this freq in VFO mode using that step rate. If you use a 10 KHz scan rate the answer is 14501, an integer. So to get around this problem, I set my VFO scan rate to 10 KHz steps for this range. One drawback to this solution is that I scan twice as many channels as needed.
Note that there are some frequencies where this trick will not work. As example the VHF fire band between 154.1300 and 154.4450 is in 15 KHz steps. Since the VR-500 also doesn't have 7.5 Khz steps, you are out of luck. Interestingly,the police band assignment between 154.6500 and 154.9650, which is also in 15 KHz steps scans just fine since 154.6500 MHz / 15 KHz = 10310.0, a whole number whereas 154.1300 MHz / 15 Khz = 10275.333.
Its main drawbacks for VHF/UHF performance:
1. scan rate is too slow - about 10-15 channels/sec
2. it is somewhat prone to front end overload - and cell images in the 900 - 908 MHz range are strong. Ditto in the 536-556 MHz range, not quite as strong but the entire cell band is there.
3. There is a quirk in the VFO scan
4. The stock stubby antenna is resonant in the 130 MHz range and has a distinct null around 160 MHz. Many owners stop using the stock antenna.
5. Besides being blocked for cellular in the US version, there are several other freq's blocked - approximately 620-629, 784-797, and 1055-1068 MHz. So some UHF TV aural channels are blocked.
6. If you are going to use it mobile, you need an amplified speaker. Its' audio is a little weak.
As far as sensitivity is concerned, the VR-500 is pretty good. Most frequencies, signals less than 1 microvolt are easily detected. But keep in mind that this receiver is not going to be up to par with your dedicated HF rig or even your 2 meter HT. Both will most likely receive better but they probably aren't as versatle as this little jewel.
Dan
Apple Valley, MN
