IEEE and ARRL Letter-Band Designators, Kent Britain (WA5VJB)

In this article, Kent notes the IEEE standards-based nomenclature for the microwave bands.   He also pulls together a list of frequence and wavelength for the VHF through microwave bands, and gives the generally accepted calling frequencies for each band.


In dicussions of microwave bands, the term "band" is somewhat context dependent, as are the letters used to designate them. The generally-accepted commercial and military letter designators for microwave bands is given in the below IEEE Standard 521-1984 table.

For amateur radio work, it happens that there may be more than one allocated amateur band within the same IEEE-designated band letter. The ARRL has therefore defined its own band designators for VHF through microwave. These are given in the second table.

IEEE Standard 521-1984

Below is the IEEE's standard radar frequency letter-band nomenclature:

Band Frequency (GHz)
L 1.0 - 2.0
S 2.0 - 4.0
C 4.0 - 8.0
X 8 - 12
Ku 12 - 18
K 18 - 27
Ka 27 - 40
V 40 - 75
W 75 - 110

For more on letter-band designators, read Alphabet Soup.

The ARRL Ham Band Letter Designators

Below are the ARRL ham ban designators, used for contests and throughout this site. Data without question marks is believed correct. If you know better or can replace the question marks, send us the corrections and we will update this. Contact us here.

Band Frequency Wave-
Terrestrial Calling Frequencies (MHz)
Horizontal Polarization
Wideband/FM (Polarization)
A 50-54 MHZ 6m 50.125 52.525 (V)
B 144-148 MHZ 2m 144.2 146.52 (V)
C 222-225 MHZ 135cm 222.1 223.5 (V)
D 420-450 MHZ 70cm 432.1 446.0 (V)
9 902-928 MHZ 33cm 902.1 (Note#1, below)
E. Coast & NW:  903.1
927.5 (North CA) (V)
906.5 elsewhere? (V)
E 1240-1300 MHZ 23cm 1296.1 1294.5 (V)
F 2300-2310 &
2390-2450 MHZ
13cm 2304.1
2304.2 (Canada)
2304.5 & 2394.5 (?)
2305.2 (Canada & ARRL) (?)
US EME 2304.1, EU EME 2320.1, JA EME 2424.1
G 3300-3500 MHZ 9cm 3456.1 ?? (?)
H 5650-5925 MHZ 5cm 5760.1 ?? (?)
I 10-10.5 GHZ 3cm 10,368.1 10,250 & 10,280 (H)
10,450 (Canada) (?)
10,364.0 (ARRL) (?)
J 24-24.25 GHZ 12mm 24,192.1
24,000.1 (Canada)
24,125.0 & 24,155.0 (H)
K 47-47.2 GHZ 6mm 47,088.1 (UK & US)
47,000.1 (Canada)
47,040.1 elswhere
?? (?)
M 75.5-81 GHZ 4mm by prearrangement
N 122.25-123 GHZ 2.5mm by prearrangement
P 134-141 GHZ 2mm by prearrangement
R 241-250 GHZ 1.2mm by prearrangement
S Above 300 GHZ <1mm by prearrangement
L Light -- by prearrangement

#1 - 903 was initially chosen over 902 because it allowed more commonly available xtals to be used in the transverter. FCC part 15 devices must put out about 70 dB less energy on 901.999 as they as they are allowed on 902.001.

Since these inexpensive devices hardly have multipole interdigital filters, they meet spec by staying away from the edges of the band. In many metropolitical areas there is as much as 10 dB difference between the noise floor at 902.1 vs 903.1

As as we get more wireless phones, VCR Rabbits, and wireless can openers, it's only going to get worse. For serious work on 33cm we really should be looking at 902.010 MHz! Just remember, most IF rigs are a lot easier to tune up to 145 MHz so you are on 903, that to tune the IF rig down to 143 MHz for 902.  -  WA5VJB

The following are links to various band plans we have identified around the world. More will be added as they are discovered.

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