Icom R20 birdies

Good.....for this class and price, No scanners without birdies !

Some birdies disappear when changing the gain,some disappear with
the antenna connected or when squelch-level is set to 1

The importance of(no)birdies is relative,they can be very annoying
when searching a frequency-range for unknown signals...when they are
very strong they may even "mask" weaker signals on the same frequency
Birdies can be locked out,it all depends on how you use the scanner

At first sight most birdies are not in the usual communication-bands.
Lots of birdies in the the 2,4 ghz band however...a little
disappointing,Icom has never been a star above 2 Ghz..the R20 is still
useable for "detecting" wireless video-signals...you may lockout these
birdies since video-signals are a few Mhz wide you will still detect
them,a search step of 100 Khz is small enough...even better would be to
prepare a memory-bank with 200 channels at 1 mhz spacing (2.3~2.5 Ghz)

2359.3500(10Khz),2366.2000(10Khz),2366.8000(12Khz),2383.2650(6Khz)
2405.2000(5Khz),2430.0925(2khz*),2456.7000(18Khz),2470.5000(16Khz*)
2491,5350(7Khz),2647.4000(4Khz),2682.9600(2Khz),2902.5500(8Khz)
3003.000(20Khz),3136.3500(7khz),3180.8000(4Khz),3216.3600(2khz)

To give you any idea of how many birdies there are in other
scanners, look at the list of birdies found in a Bearcat 3000 XLT
Don't forget that this Bearcat only does the frequency range of
25~512 and 760~1300 Mhz (measuring conditions same as above)

30.0000(10Khz),37.1000(10khz),40.0000(5khz),50.0000(15Khz),
132.2750(15Khz)198.3950(3khz),312.4650(35Khz),428.5950(5Khz),
455.3200(5Khz),835.5550(12Khz),842.0450(2 Khz),930.7350(5Khz),
967.8000(12Khz),967.8350(15Khz),967.8700(5Khz)996.8850(2Khz),
1083.9900(8Khz),1114.1200(5Khz),1141.9500(7Khz),1142.0000(12Khz)
1142.0300(18Khz),1158.1550(5Khz),1216.2650(7kHZ),1221.6050(7Khz),
1290.4000(5Khz)1291.3650(5Khz),1291.3300(5Khz)

This bearcat 3000 XLT has been my favorite scanner for many years
...lucky enough it's birdies have never been a problem for me.