To help find where the interference is coming from load the RC frequencies into a scanner. Then scan for the channels that are in use (or where you hear something on them) scan for a while (at least a few hours) as some transmitters may come on for a few seconds then be off for minutes or more in between. A good way to do this is let it scan and ever time you hear something remove that channel in the end what you have left over ar the ones that should be clear.

I would then pick one that is clear and away from the busy channels.

ie if you hear something on ch 17 and 32 pick ch 24 or 25 to use.

This still may not cure you 100% due to inter-mod as mixing happens in your RX from two different sources:

Examples:

CBer running on 27 MHz and the Fire Dept on 45 MHz
FM radio station on 99 MHz and your CBer on 27 MHz (I think this is my source of interference here)
Radio station on 90 MHZ and the Weather station on 162 MHz.


The TX crystal should come from your TX manufacturer (If you have a Futaba TX use a Futaba crystal), on the RX you should use do the same (E-Flite RX us and E-Flite Crystal) all the crystal does is to tune set the frequency.


I wound up going with the Spektrum DX6 to getaway from the interference (The Spektrum runs on 2.4 GHz).
If you decide to go the Spektrum route you may want to hold off as they have a New DX7 coming out that looks pretty good.


72 MHz Radio Frequency Chart

Ch Freq
11 72.010
12 72.030
13 72.050
14 72.070
15 72.090
16 72.110
17 72.130
18 72.150
19 72.170
20 72.190
21 72.210
22 72.230
23 72.250
24 72.270
25 72.290
26 72.310
27 72.330
28 72.350
29 72.370
30 72.390
31 72.410
32 72.430
33 72.450
34 72.470
35 72.490
36 72.510
37 72.530
38 72.550
39 72.570
40 72.590
41 72.610
42 72.630
43 72.650
44 72.670
45 72.690
46 72.710
47 72.730
48 72.750
49 72.770
50 72.790
51 72.810
52 72.830
53 72.850
54 72.870
55 72.890
56 72.910
57 72.930
58 72.950
59 72.970
60 72.990


Have Fun!