No RF receiving when mmdvm_hs_dual used with RT80
Posted: Fri Feb 22, 2019 2:26 am
Hi,
I'm using Pistar running on a raspi-3B having a mmdvm_hs_dual_hat board V1.3 mounted.
Its running in gateway mode but there came up problems
as I got two new cute Retevis RT80 (brand new model).
Hopefully the community can help to solve them, thank you:
1.)
The mmdvm gateway works fine on RF if I use my RT3 or RT90.
But using the new Retevis RT80 I mostly cannot get into the gateway by RF. The MMDVM ignores 99% of
calls to the Gateway which have been tried using both RT80.
I made frequency calibrations using the mmdvmcal function and also BER optimisation.
It came out that the MMDVM RX was about 120Hz too high.
I adjusted the offset by setting it into "RX-offset"
in MMDVMHost menu. Anyway, no effect but BER tested
in mmdvmcal with ~0.17% !
As a last desperate test I tried the RT80s to get in touch with a local DMR repeater (20km from home)
Both worked fine on the parrot.
After all: Strange, isnt it?
Anybody out there telling me how to solve that?
It seems to be pretty clear that this must be a problem at the mmdvm's
(I tried a V1.0 and a V1.3 board, same behaviour).
One of my ideas is that the RT80s does a little too much deviation but
unlike at the RT3 and RT90 deviation index cannot be adjusted at the RT80.
Desperately looking for any idea...
Thank you!
73 de DG4EK,
Peter
-------------------------------------------------
Friday, 02/22/19
Additional information:
In the last hours I practized a little bit more with the RT80 and
the MMDVM. It came out that the MMDVM does not recognize RT80s TXed DMR signal.
Therefore MMDVM does not send an answer to the RT80 and no connection can take place.
I'm pretty sure about this cause if some signal from the net is put to RF
then RT80 takes this as an recognition of its own RF signal (of cause the
RT80 has to TX at the same time when MMDVM sends it signal from the net).
If that happens, then MMDVM accepts further RT80 transmissions and put them into
the internet.
Thats the reason why I got some random connects during daytime.
If all TGs are quiet (as they are mostly during night time)
then no connect is possible.
Any idea what I can do ?
Thanks a lot
73 de DG4EK, Peter
I'm using Pistar running on a raspi-3B having a mmdvm_hs_dual_hat board V1.3 mounted.
Its running in gateway mode but there came up problems
as I got two new cute Retevis RT80 (brand new model).
Hopefully the community can help to solve them, thank you:
1.)
The mmdvm gateway works fine on RF if I use my RT3 or RT90.
But using the new Retevis RT80 I mostly cannot get into the gateway by RF. The MMDVM ignores 99% of
calls to the Gateway which have been tried using both RT80.
I made frequency calibrations using the mmdvmcal function and also BER optimisation.
It came out that the MMDVM RX was about 120Hz too high.
I adjusted the offset by setting it into "RX-offset"
in MMDVMHost menu. Anyway, no effect but BER tested
in mmdvmcal with ~0.17% !
As a last desperate test I tried the RT80s to get in touch with a local DMR repeater (20km from home)
Both worked fine on the parrot.
After all: Strange, isnt it?
Anybody out there telling me how to solve that?
It seems to be pretty clear that this must be a problem at the mmdvm's
(I tried a V1.0 and a V1.3 board, same behaviour).
One of my ideas is that the RT80s does a little too much deviation but
unlike at the RT3 and RT90 deviation index cannot be adjusted at the RT80.
Desperately looking for any idea...
Thank you!
73 de DG4EK,
Peter
-------------------------------------------------
Friday, 02/22/19
Additional information:
In the last hours I practized a little bit more with the RT80 and
the MMDVM. It came out that the MMDVM does not recognize RT80s TXed DMR signal.
Therefore MMDVM does not send an answer to the RT80 and no connection can take place.
I'm pretty sure about this cause if some signal from the net is put to RF
then RT80 takes this as an recognition of its own RF signal (of cause the
RT80 has to TX at the same time when MMDVM sends it signal from the net).
If that happens, then MMDVM accepts further RT80 transmissions and put them into
the internet.
Thats the reason why I got some random connects during daytime.
If all TGs are quiet (as they are mostly during night time)
then no connect is possible.
Any idea what I can do ?
Thanks a lot
73 de DG4EK, Peter