How
to
Cross
Band
on
DStar
and
DVAP
using
an
Icom
2820 (2)
and
a
Digital
Handheld ...
Jul
4/10
DVAP Cross Band
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)
as
this version has solved many issues from previous versions.
- when
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 inconsistancies 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 keydowns to make
the
connection unlink. In the meantime your still conncected and
that
transmission your making trying to unlnk 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 with this.
- another
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 range.
DStar Cross Band - updated
Dec 31/09
I just
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
First
in
the
Digital
Setting
Menu
make
sure that
Digital Monitor is set to Auto.
Any
other
setting
will
not
workproperly.
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 comment)
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.
Now with
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 larger. 
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
itself.
Maybe
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.
Squelch
Settings:
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.
Notes:
I
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.
There are
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.
I
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.
If
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
for him.
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 required.
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:
ve6cpk@shaw.ca
Enjoy!!! 73...
Dale / VE6CPK
Admin / VE6WRN
110109e
What others have
had to say...
Has anyone been successful with crossbanding the DVAP with a non
dstar radio, like the d700 or d710?
Rich W0RWC
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.
Mark ZL2UFI