ARRL

Secure Site Login

KC6N

Joined: Sun, Jan 18th 2015, 21:14 Roles: N/A Moderates: N/A

Latest Posts

Topic Author Posted On
HTs with direct frequency entry KD2ADL on 21/1/15
The Yaesu FT1DR will work this way. You would need to have set the proper PL tone though.
Yaesu's new digital hand held 0001567416H80 on 20/1/15
Yea those Yaesu $500 repeaters haven't proven too reliable around here anyway.

As for the compatibility with P25, The FSK tones for the three of the C4FM variants are (di-bit/CarrierOffset):

DMR: 01/+1944 kHz, 00/+648 kHz, 10/-648 kHz, 11/-1944 kHz
P25: 01/+1800 kHz, 00/+600 kHz, 10/-600 kHz, 11/-1800 kHz
Fusion: 01/+2700 kHz, 00/+900 kHz, 10/-900 kHz, 11/-2700 kHz

You can see that the DMR and P25 are pretty narrow by comparison to Fusion. From a modulation perspective, DMR and Fusion are probably compatible, although the packet structure is completely different so they can't talk. Fusion has the same problem with packet structure but also the deviation is quite a bit higher. Although these are all essentially C4FM, the "FM" part is different for all of them (and dramatically different in the case of Yaesu Fusion). A P25 receiver confronted with a Fusion signal would probably consider it over-deviated, although depending on how the baseband processor is designed, it might be able to AGC it down -- but the packet structure is still different.

One thing that Yaesu got right is that they decided to use the call sign as the radio ID. Sadly, DMR didn't allow an alphanumeric field for the radio ID so we are stuck with those "phone numbers" and a contact list. It works fine but could have been nicer. Oh well, it wasn't designed with hams in mind.

I don't know much about DSTAR, never used it but I think it addresses some of these things as well.
Yaesu's new digital hand held 0001567416H80 on 19/1/15
Start following Connect Systems then. They are threatening to make exactly what you describe. Supposedly the initial incarnation will be DSTAR + ETSI compliment DMR. Nobody is doing CDMA that I am aware of.

You probably know that Fusion is not P25 comparable -- It is interesting that when I was at an event at HRO a few weeks back and I asked the Yaesu rep why they did their own thing and didn't release something that followed one of the established standards, he said they decided to follow P25, but Fusion radios are not compatible with that standard. Too bad really, I think that they could have been money ahead by doing that. Another interesting thing is that the repeaters that they are selling for $500 aren’t holding up well. There are at least 5 of them in the San Diego area (lots of clubs have pulled out old Micor/Mitrek based machines and dropped these things in only to have them go kaput in a couple months. The TX PA’s seem prone to failure. Moral is just set the old repeater aside, you may need it again.
Yaesu's new digital hand held 0001567416H80 on 19/1/15
Yaesu Fusion does have one nice advantage in that the repeaters act like FM repeaters (in fact ARE FM repeaters) for FM users so they are dual purpose. They repeat FM when someone comes in on FM and they repeat C4FM when someone comes in "Yeasu Fusion". I think they see it as a better route for migration to digital for hams than DSTAR. FWIW, I have the FT1-DR Yaesu walkie and a Vertex Standard VXD-720 DMR radio And like DMR better. Not a lot of folks on Fusion yet.

DMR has a huge network and radios can be had for $180 (Connect Systems CS-700) and even cheaper ($150 if you don't mind ordering a Hytera radio from China via e-bay). Google DMR-MARC. Search for DMR in your state.

Fusion may be quite nice once it takes off. Yaesu is trying really hard. They are giving the repeaters away to clubs for $500. There are a couple of guys out here (San Diego, CA) who are fiddling with the WIRES thing and Fusion who have it working sort of like DSTAR and DMR but they have a lot of catching up to do.

Dave
KC6N

Back to Top