Wavelengths

VHF Low
Civil Airband
Marine Band
VHF Mid
VHF High
UHF 1
UHF 2
PMR 446
UK General

VHF Low:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
68	4.412	2.206	1.103
69	4.348	2.174	1.087
70	4.286	2.143	1.071
71	4.225	2.113	1.056
72	4.167	2.083	1.042
73	4.110	2.055	1.027
74	4.054	2.027	1.014
75	4.000	2.000	1.000
76	3.947	1.974	0.987
77	3.896	1.948	0.974
78	3.846	1.923	0.962
79	3.797	1.899	0.949
80	3.750	1.875	0.938
81	3.704	1.852	0.926
82	3.659	1.829	0.915
83	3.614	1.807	0.904
84	3.571	1.786	0.893
85	3.529	1.765	0.882
86	3.488	1.744	0.872
87	3.448	1.724	0.862
88	3.409	1.705	0.852

Civil Airband:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
108	2.778	1.389	0.694
109	2.752	1.376	0.688
110	2.727	1.364	0.682
111	2.703	1.351	0.676
112	2.679	1.339	0.670
113	2.655	1.327	0.664
114	2.632	1.316	0.658
115	2.609	1.304	0.652
116	2.586	1.293	0.647
117	2.564	1.282	0.641
118	2.542	1.271	0.636
119	2.521	1.261	0.630
120	2.500	1.250	0.625
121	2.479	1.240	0.620
122	2.459	1.230	0.615
123	2.439	1.220	0.610
124	2.419	1.210	0.605
125	2.400	1.200	0.600
126	2.381	1.190	0.595
127	2.362	1.181	0.591
128	2.344	1.172	0.586
129	2.326	1.163	0.581
130	2.308	1.154	0.577
131	2.290	1.145	0.573
132	2.273	1.136	0.568
133	2.256	1.128	0.564
134	2.239	1.119	0.560
135	2.222	1.111	0.556
136	2.206	1.103	0.551
137	2.190	1.095	0.547

Marine Band:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
156	1.923	0.962	0.481
157	1.911	0.955	0.478
158	1.899	0.949	0.475
159	1.887	0.943	0.472
160	1.875	0.938	0.469
161	1.863	0.932	0.466
162	1.852	0.926	0.463
163	1.840	0.920	0.460

VHF Mid:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
139	2.158	1.079	0.540
140	2.143	1.071	0.536
141	2.128	1.064	0.532
142	2.113	1.056	0.528
143	2.098	1.049	0.524
144	2.083	1.042	0.521
145	2.069	1.034	0.517
146	2.055	1.027	0.514
147	2.041	1.020	0.510
148	2.027	1.014	0.507
149	2.013	1.007	0.503
150	2.000	1.000	0.500
151	1.987	0.993	0.497
152	1.974	0.987	0.493
153	1.961	0.980	0.490
154	1.948	0.974	0.487
155	1.935	0.968	0.484
156	1.923	0.962	0.481
157	1.911	0.955	0.478
158	1.899	0.949	0.475
159	1.887	0.943	0.472
160	1.875	0.938	0.469
161	1.863	0.932	0.466
162	1.852	0.926	0.463
163	1.840	0.920	0.460
164	1.829	0.915	0.457

VHF High:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
165	1.818	0.909	0.455
166	1.807	0.904	0.452
167	1.796	0.898	0.449
168	1.786	0.893	0.446
169	1.775	0.888	0.444
170	1.765	0.882	0.441
171	1.754	0.877	0.439
172	1.744	0.872	0.436
173	1.734	0.867	0.434
174	1.724	0.862	0.431

UHF 1:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
425	0.706	0.353	0.176
426	0.704	0.352	0.176
427	0.703	0.351	0.176
428	0.701	0.350	0.175
429	0.699	0.350	0.175
430	0.698	0.349	0.174
431	0.696	0.348	0.174
432	0.694	0.347	0.174
433	0.693	0.346	0.173
434	0.691	0.346	0.173
435	0.690	0.345	0.172
436	0.688	0.344	0.172
437	0.686	0.343	0.172
438	0.685	0.342	0.171
439	0.683	0.342	0.171
440	0.682	0.341	0.170
441	0.680	0.340	0.170
442	0.679	0.339	0.170
443	0.677	0.339	0.169
444	0.676	0.338	0.169
445	0.674	0.337	0.169
446	0.673	0.336	0.168
447	0.671	0.336	0.168
448	0.670	0.335	0.167
449	0.668	0.334	0.167
450	0.667	0.333	0.167

UHF 2:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
453	0.662	0.331	0.166
454	0.661	0.330	0.165
455	0.659	0.330	0.165
456	0.658	0.329	0.164
457	0.656	0.328	0.164
458	0.655	0.328	0.164
459	0.654	0.327	0.163
460	0.652	0.326	0.163
461	0.651	0.325	0.163
462	0.649	0.325	0.162
463	0.648	0.324	0.162

PMR 446:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
446.00625	0.673	0.336	0.168
446.01875	0.673	0.336	0.168
446.03125	0.673	0.336	0.168
446.04375	0.673	0.336	0.168
446.05625	0.673	0.336	0.168
446.06875	0.673	0.336	0.168
446.08125	0.673	0.336	0.168
446.09375	0.673	0.336	0.168

UK General:

Frequency (MHz):	Wavelength (m):	Half (m):	Quarter (m):
77.6875	3.862	1.931	0.965
86.3375	3.475	1.737	0.869
86.3500	3.474	1.737	0.869
86.3625	3.474	1.737	0.868
86.3750	3.473	1.737	0.868
164.0500	1.829	0.914	0.457
164.0625	1.829	0.914	0.457
169.0875	1.774	0.887	0.444
169.0125	1.775	0.888	0.444
169.0625	1.774	0.887	0.444
169.3125	1.772	0.886	0.443
173.0500	1.734	0.867	0.433
173.0625	1.733	0.867	0.433
173.0875	1.733	0.867	0.433
449.3125	0.668	0.334	0.167
449.4000	0.668	0.334	0.167
449.4750	0.667	0.334	0.167
461.2875	0.650	0.325	0.163
461.3750	0.650	0.325	0.163
461.4500	0.650	0.325	0.163
462.1000	0.649	0.325	0.162

Note that the quarter wave antenna is normally the closest impedance match (about 50 ohm) to the input of your scanner.