Exact Frequency?

[jcherepy]

Monitoring the Atlanta RCAG site at Carson Spring, TN (more in another thread) I hear the controller give frequencies such as 124.12 or 126.92. Is this the exact frequency or is it really 124.125? I ask this because I'm using an ICOM IC-A6 and I can not enter a zero as the final digit.

 

[doctordialtone]

is it really 124.125?

See here:

Atlanta (ZTL) Air Route Traffic Control Center Scanner Frequencies and Radio Frequency Reference

Scanner Frequencies and Radio Frequency Reference for Atlanta (ZTL) Air Route Traffic Control Center

www.radioreference.com

Atlanta Center

GEORGIA 10/17/2014 ATLANTA ATLANTA ARTCC IDENT ZTL RCAG SITE NEWPORT, TN LATITUDE - 35-54-20.34 N LONGITUDE - 083-17-44.57 W FREQUENCY 236.5 DELETED FREQ USE DISCRETE DELETED ALTITUDE ULTRA-HIGH DELETED FREQUENCY 282.225 ADDED FREQ USE DISCRETE ADDED ALTITUDE ULTRA-HIGH ADDED Can anyone verify...

forums.radioreference.com

 

[jcherepy]

Thanks for the reply, but that's a lot to digest and really does not answer my question. Perhpas I should be a bit more clear. I hear the controller tell an aircraft to contact Memphis on 124.12. Is 124.120 or just shorthand for 124.125?

 

[wtp]

shorthand.

 

[AM909]

Because the channel spacing is 25 kHz, the last digit is unnecessary. If the second to last digit is 0 or 5, the last digit must be 0; if it's 2 or 7, the last digit must be 5. There are only four channels that start with 124.1: 124.100, 124.125, 124.150, 124.175; they are spoken over the air as 124.1 (zeros omitted), 124.12, 124.15, and 124.17. Sometimes, the leading 1 is omitted, especially on readback.

[Add: So yes, [1]24.12 is just shorthand for 124.125 MHz.

I think the '.' is supposed to be spoken as "decimal", but is usually just "point" (at least in the U.S.)]

This got more complicated with 8.33 kHz channel spacing, which is a different subject. [Add: discussed at Another 8.33 kHz Scanner table anybody? Here you are! ]

 

[jcherepy]

Thanks for the replies. I give a listen tomorrow.