How to Cross
Band on DStar and DVAP using an Icom
Handheld ... and
now on Yaesu System Fusion using C4FM
C4FM Cross Band
It's been almost 6 years since
we started cross banding on DSTAR. Now that Yaesu Fusion
System is out can we cross band C4FM. The answer is
YES. A little complicated in the beginning, it
turns out to be quite simple, more so than DStar.
On my mobile, in this case the
same radio I use for DStar cross band (Icom 5100) I use the same
simplex frequency and FM mode I use for my connection to my
handheld on UHF. On the VHF side just use the repeater
frequency including offset, do not enter or use any PL.
Put your mobile radio into cross-band mode. (Be sure to
set power levels and maybe turn down your volume on both sides
and set squelch levels to Max if possible to prevent unwanted
signals from getting into the radio since there is no PL)
Now the only extra thing I did on
the portable (FT-1DR) compared to DStar is to save my remote
frequency into memory including the PL tone of the repeater you
want to operate.
When using the portable you can
use all modes including Digital, Data and FM. The radio
knows not to send PL when in digital mode so all modes will work
through your mobile radio using your handheld. All
information from the handheld is sent through your mobile and
off to the repeater including GPS location and modulation
mode. Even receiving the GPS data and different digital
modes from the repeater through your mobile will make your
handheld switch to that mode if set to auto.
Basically the C4FM works the same as if you were working your
C4FM repeater direct. If your repeater is on UHF just do
the opposite of what I have describe.
I have been using the Icom 2820
for many years cross banding on DStar and now using the newer
5100. I recently tried it using my FT-1DR portable and it
works just fine. So I would suspect any FM dual band cross
banding radio should work. I do have the FTM-400 mobile
version but I find it awkward putting it into cross band mode so
I just use my Icom 5100.
A word on the FTM-400, it does
work for C4FM with your FT-1DR just make sure auto mode on the
mobile is off and as I have describe above should work.
However if you try DStar using the FTM-400 I have found
issues, Right now I would have to say that DStar will not
work using this radio. Further testing may change that.
If you have any comments or
other ideas I would like to hear from you. Just email me
Cross Band Last July 4/2010
I have found that the DVAP unit will work cross banding through my
2820 but there are some minor issues:
- on the
DVAP be sure to run the latest firmware (1.05). Latest
version has solve many issues from earlier versions.
cross banding through your 2820 your portable must be simplex,
having an offset will not work (remember before we needed an
offset on our portable to make it work - see below).
- also I
have found that there is some inconsistencies usually when you
change parameters like linking or unlinking, even doing an echo
test. Once connected it usually works OK. If your trying to
unlink after a QSO with someone I find that it may take 3 or 4 key
downs to make the connection unlink. In the meantime your
still connected and that transmission your making trying to unlink
will keep keying up whatever you were linked to. This could be due
to the 2820 not keying up quick enough however your mobile may be
different than mine. You will have to try and experiment
thing to maybe note is that I have found that to much power from
the mobile radio to the DVAP sometimes will not allow the DVAP to
send data to the internet. I think that the DVAP not being
shielded gets overloaded from to much RF close by. I have
occasional noted this even from my handheld when sitting to close
to the DVAP beside the computer. Moving away a few feet
usually solves this problem. Same with the mobile, be sure
to be a few feet away and make sure your TX to the DVAP is on low
power. The UHF side from the mobile to you can be whatever
power you want to run.
It does work but patience may be
needed when changing parameters. I would appreciated any
email (address at bottom of page) from DVAP users that have
tried cross banding and tell me how it works for you.
When using this method the
range is well extended using your Icom 2820.
Jul.4.10 I finally got around to trying the cross band with the
newer version 1.05 of DVAP and I have to say for me it is
working a lot better. Very seldom do I have a transmission
that does not go through. This certainly gives me a lot
more range than what the DVAP is capable of. Just follow
the steps above for settings and you should enjoy much more
DStar Cross Band - updated
recently discovered how to crossband on DSTAR using a
simplex frequency rather than a duplex frequency as
described earlier, however your portable radio still
needs to have an offset setting either + or - then
zero out that offset. This has to be done only
on your digital handheld, the 2820 can just be
simplex. To make the DStar repeater work the
portable radio must look like there is an offset to
the repeater but zero-ing out that offset will make it
work as a simplex channel.
- see below
for more details
sure that Digital Monitor is set to Auto. Any
other setting will not work properly. On the left side dial in
the VHF repeater frequency and leave it in FM mode. On the
right side dial up a UHF frequency (**NOTE this frequency can be simplex, no
offset required - see below for portable settings) and
also leave this in FM mode. Set other settings like power
and squelch to what you need then put the radio into cross band
mode. (Squelch settings I would set to Max, see below for
How to put the radio
into ctross band mode:
Hold in the two main band knobs and then push and hold the
function key until the radio beeps. You should then see
the lock symbol flashing, this indicates you are in cross
band. To get out of cross band simply push and hold the
function key for a second or until the radio beeps.
your hand held program in the UHF frequency that you selected on
the 2820 and put your portable into DV mode (Just remember that this frequency must have a
programmed offset for working the DStar repeater but you can
zero out that offset to make it work as a simplex frequency).You can also use low power setting in
most cases from your hand held to the car giving you a lot more
talk time if required. Program all other parameters just
like you would normally do for DSTAR including RPT1, RPT2 and
UrCall. You can certainly store the info in a memory
channel for quicker access.
Before walking away from your vehicle you can do an ECHO test to
make sure that you have a good signal to the repeater and have no R2-D2 and also
to make sure your setup is working. Being that DSTAR has
no hang time as do most FM repeaters you can access the DSTAR
repeater just as quick as the next person. I have found
the transistion to be very quick.
Here is a image of my 2820 and
91AD when in cross band node. Click on image to make it
On the portable even though I am using a simplex frequency
note the + offset symbol on the display (just above the DV
setting). If that + or - symbol is not there you will
most likely not key the DStar repeater.
I had another
ham do the same, we had 2 hand helds, 2-2820's and the repeater
with no compromise at all. You really cannot tell that
there is any repeating going on besides the repeater
in one of your messages you might want to indicate that you
are cross banding. I recently noticed on one of the nets
a message indicating "Crossband /2820"/where after his
callsign was /91AD.
I have found one issue so far
and that is to make sure your squelch levels are set
accordingly. If local noise were to key your radio
(2820) an FM transmission would be made on the repeater
input. This will not key a DStar repeater but having a
signal on the input may prevent other users from working the
repeater. Some more experimenting may be required to
solve this issue. So far for me I have had no issues, I
usually make sure my squelch settings are set at max on both
sides. Volume level does not matter where it is set at.
have just tested the 2820 with just a simplex frequency to
talk to the portable, no offset is required. You just
need to set the offset on the portable only and zero out that
offset. This is required in order to key up your DStar
repeater via the 2820. You can certainly use a duplex
channel if required but this is best if your the only one
working the crossband.
advantages to using a simplex frequency rather than a
duplex, say your at a coffee shop using the DStar
repeater, everyone is on simplex and can hear all other
users and can also hear and work the repeater.
have heard others wondering if a plain FM dual band radio
would work. I had thought of that and actually gave it a
try using a Kenwood 700 and a TS-2000. The
answer...NO. I believe that the Icom 2820 is actually
relaying in DVmode where the other FM radios are only relaying
in FM mode and FM will not key a DStar repeater. Also
there is a band width issue.
I spent some time recently trying different methods of codes
(PL/DCS) on the RX side of the 2820. When doing so I
could not get the radio to key the repeater and in some cases
could not get the 2820 to cross band when in DV mode on the
portable. I have the feeling this will not work
so...make sure your squelches are where you need them to
prevent accidental keyup of your 2820.
you have issues with noise keying up your radio when in cross
band mode try this, activate the attenuator built into the
radio. You can vary this to some degree and this may
help reduce unwanted noise and keyup of your radio. I
have not tried this as it has not been a issue for me but
another ham here in Calgary has, VE6BGZ and it seems to work
I have not tested this but I heard
that another ham tried the above procedure in reverse from VHF
to a UHF repeater and the same procedures apparently do
work. It is critical
that you have programmed in a offset on the portable otherwise
you may not key up the repeater. If you are just
extending your DStar simplex range then the offset is not
I'll add further notes here as I find them, also if you have
any please let me know.
If you have any questions or if you have some other uses or
ideas of cross banding I would really like to hear from you even
if it's just to let me know how the cross banding is working for
you. Please email me and let me know at:
Dale / VE6CPK
Admin / VE6WRN
What others have
had to say...
Has anyone been successful with crossbanding the DVAP with a non
dstar radio, like the d700 or d710?
Yes... I have done it with an Alinco DR-635T.
The Alinco simply passes the digital voice without any decode or
encoding, so the audio is straight through. Works a treat.