It took some digging but I found the frequencies those Eartec radios are preprogrammed to use. They are not reprogrammable.
I read the reply from my friend jwilkers, and also thought it was strange that they would openly advertise them as “no licence required” when Eartec is well known in the theatre industry for both good quality simplex (two way radios) and duplex (wireless intercom) systems. I now have the answer.
They are an FRS radio, and use the 14 FRS channels. The reason they do not need a licence is because they are FRS and not GMRS, and the output power is under 1/2 watt. (Their actual output power is .38 watts.) The photos give the impression that the antenna is removable but it is not. (To comply with FCC regulations on FRS radios.)
Basically, it is a business-class FRS radio, designed for licence-free short range two-way communications.
So, to answer your question - they are locked-in to FRS frequencies and are not reprogrammable. If you are interested, here is a list of the frequencies they are programmed to. (Note that the channel numbers here are NOT necessarily the same channel numbers that Eartec is using.)
1 462.5625 Shared with GMRS
2 462.5875 Shared with GMRS
3 462.6125 Shared with GMRS
4 462.6375 Shared with GMRS
5 462.6625 Shared with GMRS
6 462.6875 Shared with GMRS
7 462.7125 Shared with GMRS
8 467.5625 FRS use only
9 467.5875 FRS use only
10 467.6125 FRS use only
11 467.6375 FRS use only
12 467.6625 FRS use only
13 467.6875 FRS use only
14 467.7125 FRS use only
The seem to be good radios and users seem to like them, as long as you know the limitations. Range will be a bit shorter than GMRS because they output less than .4 watts of power, plus frequencies are shared with any other users in your area. CTCSS and DCS codes only block out transmissions from users not using the same codes; they don’t make transmissions private. All users within range all share the same 14 frequencies. But if your needs are for a simple, clear, licence-free short-range radio, they seem an okay solution, especially if there are not a lot of other FRS and GMRS radios in your geographical area.
As for the “digitally scrambled” comments, my friend above is correct. This must be some kind of marketing-speak, and not technically correct. I suspect that they use preprogrammed DCS codes and are perhaps exaggerating them as “encrypted” radios.
Personally, if they meet your needs, I would hang on to them. But if you are finding interference on all your channels, there is not much you can do except go licence-free digital or apply for a business licence for your own dedicated frequency and buy business-class radios.
The new radios you purchased that are programmable can NOT be legally used on the same FRS frequencies. (I suspect you picked up some Chinese-made amateur radios such as the UV-5R.) These amateur radios are not type-rated for FRS and cannot legally be used on those channels, even if the power can be adjusted to below 1/2 watt. FRS radios cannot legally be reprogrammable nor can come with removable antennas.
If my suspicions are correct and they use preprogrammed frequencies and built-in DCS codes, you will need to scan those codes before you can get another radio to work with them anyway. The company is not going to tell you what these preprogrammed tone codes are. If you turn off all DCS and CTCSS codes on any other FRS radio, you will be able to RECEIVE on your new radios, but will not be able to TRANSMIT from the new radio to the Eartec. To decode the DCS or CTCSS built-in codes, you will need a scanner, two-way radio or frequency counter that can scan DCS and CTCSS codes.
To be legal, your choices are to buy more Eartec radios; scan for the built-in codes and frequencies and buy any other brand of FRS radio; sell the Eartecs and buy digital 900 Mhz radios; or sell the Eartecs and apply for a business licence for your own dedicated frequency.
Be aware that if they preprogrammed FRS frequencies and likely DCS codes into their own channel numbers, the channel number marked on the Eartec radios is NOT likely going to be the same as the channel number of any other brand of radio. This is why you will need to scan for both the frequency and tone code if you decide to add any other brand of radio to your fleet.
The nice thing is that there are inexpensive frequency counters on the market that can effectively scan for the frequency and CTCSS or DCS code when held within a few inches of the transmitting radio.